Technical Assistance Consultant’s Report
Project Number: 46052 March 2015
People’s Republic of China: Roadmap for Carbon Capture and Storage Demonstration and Deployment (Financed by the Carbon Capture and Storage Fund)
Component B–Oxy-Fuel Combustion Technology Assessment
Prepared by
Andrew Minchener, Team Leader (International CCS Expert) Zheng Chuguang, Deputy Team Leader (National CCS Expert) Liu Zhaohui, International Carbon Storage Expert Jiao Zunsheng, International Carbon Storage Expert Pei Xiaodong, International Economic and Financial Analyst Li Xiaochun, National Carbon Storage Expert Zhao Haibo, National Energy Economist Chen Ji, National Policy Analyst Gao Lin, National Road Mapping Expert Xi Liang, National Financial and Risk Analyst
For: Department of Climate Change, National Development and Reform Commission (Executing Agency) Dongfang Boiler Group Co. Ltd (Implementing Agency)
This consultant’s report does not necessarily reflect the views of ADB or the Government concerned, and ADB and the Government cannot be held liable for its contents. (For project preparatory technical assistance: All the views expressed herein may not be incorporated into the proposed project’s design.
Road Map for Carbon Capture and Storage
Demonstration and Deployment
Component B: Oxy-fuel Combustion
Technology Assessment
FINAL REPORT
Andrew Minchener, Team Leader (International CCS Expert)
Zheng Chuguang, Deputy Team Leader (National CCS Expert)
Liu Zhaohui, International Carbon Storage Expert
Jiao Zunsheng, International Carbon Storage Expert
Pei Xiaodong, International Economic and Financial Analyst
Li Xiaochun, National Carbon Storage Expert
Zhao Haibo, National Energy Economist
Chen Ji, National Policy Analyst
Gao Lin, National Road Mapping Expert
Xi Liang ,National Financial and Risk Analyst
March 2015
ADB TA‐8133 (PRC) People’s Republic of China: Road Map for Carbon Capture and Storage Demonstration and Deployment
Component B: Oxy-fuel Combustion Technology Assessment
Final Report
November 2014
Summary
The ADB TA project TA8133-PRC People’s Republic of China: Road Map for Carbon Capture and Storage Demonstration and Deployment Component B has focused on oxy-fuel combustion as a promising CO2 capture technology, which offers significant CCS potential within the Chinese context. This technical assistance project has been designed to promote the implementation of a full chain 200MWe oxy-fuel demonstration, while also providing in- depth technical-economic-environmental-social assessment of Chinese oxy-fuel demonstration and deployment. The aim is to identify the current gaps, challenges, synergies and priority topics for the oxy-fuel CCS demonstration in China. It has been implemented under the overall supervision of the Executing Agency, the National Development and Reform Commission, and there is close cooperation with the Implementing Agency, the Dongfang Boilers Co. Ltd., in order to address the issues for the technological transformation to oxy-fuel combustion carbon capture, transport and utilization/storage at the 200MWe Shenhua Guohua Shenmu power plant, which has been designated as the site for a subsequent demonstration project.
The key findings are as follows:
WP1 Oxyfuel technical consideration and assessment Oxy-fuel combustion is the process of burning fossil fuel using pure oxygen instead of air as the primary oxidant. The concentration of CO2 in dry flue gas can reach more than 80%, and after a simple purification process this can be increased to more than 95% so as to meet the needs of large-scale pipeline transportation and utilization/storage.
The oxycombustion technology has been the subject of considerable research and development work both in China and worldwide, covering system design, calculation method for boiler performance and combustion, pollution control, operational flexibility, monitoring and optimization. This has progressed from fundamental studies, laboratory rig trials, through to industrial pilot scale projects. The work indicates that the technology shows considerable energy and environmental promise for coal firing power plants with CCS, offering a synergetic removal of conventional pollutants such as SOx and NOx as well as CO2, which provides a near zero emissions clean coal utilization technology. It appears well suited to both new build and retrofit applications since it maintains the original power plant structure by combining a conventional combustion process with a cryogenic air separation process. These major components are mature technologies that have been extensively deployed.
Oxycombustion appears to be relatively economically attractive compared to other coal based carbon capture processes, namely post-combustion capture and IGCC. That said, it is a new technology, and, as yet, there are no large-scale oxycombustion full CCS chain demonstration power plants established worldwide, although the USA and UK governments are now taking forward such projects. Consequently, the economic assessments are still subject to a high level of uncertainty.
It is also important to put such comparisons in perspective. At present all three major technology options would appear to have opportunities to reach the stage of market deployment due to their specific strengths. In this regard, oxyfuel combustion appears more suited to deployment as a base load unit because of a relatively weak load adjusting capability compared to the other options, of which in particular post combustion capture has reasonable CO2 capture capability at part load. Oxyfuel is also readily suitable both for new
and retrofitted coal-fired plant, with the potential to reduce the overall CCS chain cost for deep aquifer storage where relatively low CO2 purity, say less than 95%, can be used. In contrast, for EOR usage, in which over 99% CO2 purity is generally needed, an increased energy penalty for oxy-combustion would be expected that will take away some of its perceived cost advantages.
With regard to establishing a near to medium term roadmap for oxycombustion technology deployment in China, the need is to take into account the date when CCS commercial implementation is likely to be taken forward, the drivers for such implementation, together with the scope to improve upon what CCS technology is available at present. Thus at some point in 2020-2030, China could establish large scale CCS technology deployment, which means that with the wish to exploit its own IPR, such technologies will need to be identified with the first large scale demonstrations to be taken forward in the near future.
Taking 2030 as that point, the projections are that the number of new coal fired plants beyond that date to, say, 2050 will be relatively small. Consequently, if China then wants to achieve major CO2 reductions from the coal power sector, that reduction will mainly have to come from existing coal power plants. Those plants built since 2015 will almost all be large, high efficiency, ultra-supercritical units with capacities of at least 660MWe and mostly 1000MWe. From 2025, the expectation is that there will be a new generation of advanced ultra-supercritical coal fired power plants being installed with ever higher cycle efficiencies in the range of 50% and capacities of perhaps 1300MWe. Such High Efficiency Low (non- GHG) Emissions (HELE) power plants will be best suited for retrofit CCS applications. This means that to ensure that the plants built from, say, 2015 can have CCS retrofitted then a significant number will need to be made CCS-ready, such that CCS retrofit can readily be accommodated in due course. In contrast, pre-combustion capture technology via IGCC will only be suitable for new applications and then only if the technology can be shown to perform in line with required power station operational practices.
This scenario means that the retrofit choice will be between oxycombustion and post combustion capture. When this is considered, the choice is likely to be regional. Thus oxyfuel combustion will be an attractive proposition, with better prospects than post combustion capture, in regions that have stressed water resources. Based on current water resources and the future distribution of newly built coal-fired power station in China, about 30 to 40 percent of CCS-ready power stations should be designed to be able to subsequently incorporate oxy- fuel technology. The exact capacity level depends on the extent of CCS to be deployed by 2030 but levels close to 100GWe have been suggested.
As well as defining the schedule for a near term technology demonstration, there is a need for supporting R&D activities will need to address the scope for scale up of oxy-fuel equipment and system integration technology with better energy performance and lower costs of critical components. These will include future technology innovation to achieve lower cost air separation units (ASUs), and the development of a CO2 compression and purification unit (CPU) with simultaneous impurity gas separation, as both possibilities can be expected to reduce the overall oxyfuel technology costs significantly.
WP2 Prefeasibility assessment support for the 200MW oxy-fuel coal-fired demonstration power plant A pre-feasibility assessment of the application of oxy-fuel combustion CO2 capture technology to a 200MWe coal-fired power plant has been undertaken to support the
implementation of the intended oxy-fuel demonstration project of the Shenhua Group. The more promising design for such a demonstration plant has been identified as one where it can be air combustion/oxy-fuel combustion compatible, as this gives flexibility for operational variations that are likely to be needed during a large scale demonstration of oxy-fuel combustion in China.
For the retrofit of a 200MW coal-fired power plant with oxy-combustion, including a LIFAC de-sulphurization device, the results indicate that the electricity cost would be 686RMB/MWh, which is 1.7 times that of the corresponding conventional plant that would have been equipped with the limestone-gypsum desulfurization system and a SCR denitrification system. The static investment cost is 1.2 times that of the corresponding conventional plant, while its net power output is 0.6 times that of the corresponding conventional plant. The increase in the static investment cost is mainly because of the high commercial price of the ASU, and the significant decrease of the net power output, mainly because of the high power consumption of the ASU and CPU systems.
Sensitivity analysis shows that coal price, ASU power consumption and CO2 capture efficiency are the three parameters that most influence the economic performance of the oxy- combustion technology. Most importantly, with the increase of the plant capacity, the economic characteristics improve significantly because of the decrease in the unit investment cost and the increase in the system thermal efficiency. This suggests that the deployment of oxycombustion technology at a scale in line with NDRC requirements of at least 600MWe capacity would appear to have considerable promise.
For subsequent commercial scale units, the associated techno-economic analysis has indicated that oxy-combustion technology would currently result in an 11~12% net efficiency loss for a simple integrated system; however, this could be limited to 7~9% for an advanced integrated system.
There remain some technical issues to be resolved, in terms of fuel flexibility and the potential impact on CO2 quality for subsequent use/storage. Thus it has been suggested that if there are increasing restrictions on CO2 pipeline purity, this will have a relatively great effect on CO2 avoidance costs for oxyfuel plant, as further processing becomes required in the CPU. This is an area where parametric plant based studies are needed to determine a viable operating window for the technology alongside the impacts of coal sulphur content and gas quality. However, these are not technology showstoppers. Consequently, oxyfuel combustion is ready for large scale demonstration in order to address the remaining uncertainties and to establish a likely market niche for the time when deployment of CCS is seen as a commercial reality.
WP3 Feasibility study of geological CO2 storage in the Ordos Basin for the proposed Shenhua Guohua oxy-fuel combustion plant demonstration project For any full chain CCS demonstration, the need to ensure adequate and effective CO2 storage is fundamental to the success of the project. Accordingly, a pre-selection phase site characterization manual appropriate for Chinese application has been developed, including procedures, techniques, and tools for geological CO2 storage site characterization, monitoring, and verification, together with a cost assessment of the site characterization for a potential full-scale CO2 storage project, as will be required for the proposed Shenhua Guohua Shanmu oxy-fuel combustion CCS demonstration project. This approach has been applied in the Ordos Basin and a promising storage site has been identified some 70 km from the power
plant. A strategic approach has been proposed and costed, whereby 10% of the expected 1Mt/year of CO2 captured is sold for EOR and the remaining 90% is stored in a saline aquifer close to the oil field. At the same time, the brine that is extracted from the aquifer is sold for desalination in this water stressed region, thereby generating an additional revenue scheme alongside that for EOR.
Although this WP focuses on a possible demonstration project in the Ordos Basin, the storage manual that has been developed provides a basic foundation for the preparation of all geological CO2 saline aquifer storage projects in order to accelerate the deployment of geological CO2 storage activities in China.
WP4 Assessment of institutional capacity opportunities for Dongfang Boilers Company and other stakeholders It is recognsied that the Shenhua Group already has expertise and experience in pre- combustion CO2 capture and subsequent storage at the industrial pilot scale (< 100,000 tonnes CO2 per year) at its coal to liquids demonstration unit near Ordos. However, this proposed oxycombustion demonstration project would represent an order of magnitude scale up in terms of the annual quantities of CO2 to be captured plus would use a different CO2 transport regime as well as a different CO2 capture technique. Consequently, it would be of benefit to Dongfang Boilers and Shenhua Guohua Power if they can engage with other experts from outside China, in particular to gain an appreciation of how large demonstration projects have been established elsewhere. The most promising options would be the project developers taking forward the USA and UK oxyfuel demonstration projects, and, in the latter case, Chinese government officials could also gain an appreciation of a very interesting approach to ensuring demonstration projects can be established within the utility market on a sound financial basis and to also hear about some innovative policies designed to establish CCS on a viable basis alongside other low carbon options.
Recommendations for the way forward In overall terms, this technical assistance project has promoted the implementation of a full chain 200MWe oxy-fuel demonstration and, when the provisional outcomes of the technology roadmap are considered, it is suggested that there is a need to establish such a large scale demonstration project while also taking forward technology innovative R&D to develop lower cost, lower energy components to improve technology competitiveness.
With regard to a specific project, the 200MW oxyfuel combustion project that has been initiated by the Shenhua Group at the Shenhua Guohua coal power plant in Shenmu is a promising contender, offering the prospect of capturing about 1Mt CO2/year for subsequent saline aquifer storage and EOR application. The Shenhua Group has expressed very strong interests in oxycombustion and has established close technology cooperation with Dongfang Boilers, Huazhong University of Science and Technology and the Southwest Electric Design Institute.
The pre-feasability study is in progress and is expected to be finished within this year, with the work of this ADB TA project providing input and assistance via Dongfang Boilers. According to Shenhua's schedule, the FEED study could be prepared from next year onwards.
Alongside this, HUST is also working on a 35MW oxyfuel project. Construction of the plant will be finished this year and, if everything goes well, commissioning should begin by the
start of 2015. This 35MW project is the base and reference for the much bigger 200MW oxycombustion project. A key requirement is to address the remaining potential technical issues, thereby providing greater confidence for the successful completion of the 200MW FEED study
As such, this ongoing oxycombustion development and the intended subsequent demonstration project could offer China an important means to establish itself as a technology leader, thereby building successfully on its earlier industrial pilot activities. At the same time, it is important to establish a clear, overall development schedule, including the work to be done on the 35MW unit and how that will be used within the subsequent FEED study. If this overall programme can be successfully established, it will provide China with a further near term CCS prospect, including establishing IPR opportunities.
Finally, it must also be stressed that for large scale demonstration, the need for positive policies and regulations to support commercial prototype demonstrations, plus ensuring a viable financial approach to that demonstration, are absolutely critical. At the same time, public acceptance concerns relating to CO2 transport and CO2 storage/utilization must be addressed as part of any project preparatory phase, which would be common for all CCS technologies.
Table of Contents 1 Introduction
1.1 Background 1.2 Objectives 1.3 Project organization
2 WP1: Oxyfuel technical consideration and assessment
2.1 Current status of oxy-fuel combustion development 2.1.1 Technology description 2.1.2 Global development of oxyfuel combustion technology 2.1.3 Development of oxyfuel combustion technology in China 2.1.4 Foreign technology providers 2.1.5 Domestic stakeholders 2.1.6 Potential advantages of oxyfuel combustion technology 2.1.7 Challenges for oxyfuel combustion technology deployment 2.2 Strategic analysis 2.2.1 Necessity of CCS for China 2.2.2 SWOC analysis on oxy-fuel combustion CO2 capture technology 2.2.3 Possible ways forward 2.2.4 Concluding remarks 2.3 Commercial deployment learning curves for oxyfuel technology 2.3.1 Introduction 2.3.2 Methodology 2.3.3 Learning rates for fossil fuel energy systems with CO2 capture 2.3.4 Case study 2.3.5 Results and discussion 2.3.6 Cost reduction potential of the oxyfuel power plants in China 2.3.7 Conclusions 2.4 Technical guidelines to support system design of a 200 MWe oxy-fuel combustion demonstration power plant 2.4.1 Technical choice 2.4.2 Composition of an oxy-combustion system 2.4.3 Analysis of the construction conditions for the demonstration project 2.4.4 Definition of main operating parameters 2.4.5 Overall process specification 2.4.6 Subsystem processes and instructions 2.5 Roadmap for oxy-fuel combustion deployment in China 2.5.1 Aims and objectives 2.5.2 Background 2.5.3 Methodology for comprehensive evaluation of CO2 capture technologies 2.5.4 Overall considerations 2.5.5 Recommended roadmap of oxy-fuel combustion technologies suitable for China
Annex A Comprehensive evaluation of oxy-fuel capture technologies
3 WP2: Prefeasibility assessment support for the 200MW oxy-fuel coal- fired demonstration power plant
3.1 Techno-economic evaluation of the 200 MWe oxyfuel demonstration plant 3.1.1 Background 3.1.2 Input data 3.1.3 Cost calculations 3.1.4 Cost calculation about conventional power plants 3.1.5 Cost calculation about oxy-combustion power plants 3.1.6 Comparative assessment 3.1.7 CO2 avoidance cost 3.18 Sensitivity analysis 3.1.9 Conclusions 3.2 Financing prospects and managing risks. 3.2.1 Critical technical issues linked with financial and operational decisions 3.2.2 Financing options 3.2.3 Private financing mechanisms 3.2.4 Public financing mechanisms 3.2.5 Other CCS financing options 3.2.6 Assessing the option value of retrofitting a 200MW power plant for oxyfuel CO2 capture 3.2.7 Risk management for oxyfuel CCUS project Annex B Summary of risk register for Guohua Shenmu 200MW oxyfuel CCS project 3.3 Policy analysis 3.3.1 Analytical framework 3.3.2 Policies and measures 3.3.3 Relevant laws and regulations 3.3.4 Supporting policy analysis 3.3.5 Conclusions
4. WP3: Feasibility study of geological CO2 storage in the Ordos Basin for the proposed Shenhua Guohua oxy-fuel combustion plant demonstration project
4.1 Introduction 4.2 Brief review of existing best practice manuals for site characterization 4.3 Shenhua Guohua Shenmu CO2 storage demonstration project 4.3.1 Geographic and geological background 4.3.2 Project management plan 4.4 Site selection for CO2 storage projects 4.4.1 Preliminary selection for further site characterization and selection 4.4.2 Site selection for CO2-EOR 4.4.3 Site selection for CO2 saline aquifer storage 4.4.4 Numerical simulation
4.5 Economic evaluation methodology of CCS project 4.5.1 Cost of CO2 transport 4.5.2 Cost of saline aquifer CO2 storage 4.5.3 The cost of brine treatment 4.5.4 Integrated economic evaluation of CO2 transport and storage 4.5.5 Cost evaluation of site characterization tools in the implementation phase 4.6 Risk assessment of selected sites 4.7 Schedule of the storage site development 4.8 Site characterization manual 4.8.1 List of site characterization technologies including monitoring tools 4.8.2 Cost range of necessary monitoring technologies 4.8.3 Need for further work
5 WP4: Assessment of institutional capacity for Dongfang Boilers Company and identification of measures to strengthen that capacity together with improved public outreach
5.1 Introduction 5.2 Capacity assessment for Dongfang Boilers Co. Ltd. 5.2.1 Overview 5.2.2 Future prospects for Dongfang Boilers 5.2.3 Overview of the project structure 5.2.4 Assessment of institutional capacity of Dongfang Boilers to implement the oxyfuel based CO2 capture demonstration project 5.3 Capacity assessment and strengthening measures in analysis, planning, and implementation of oxy-fuel combustion CO2 capture technology 5.3.1 Assessment of the capacity of Dongfang Boilers personnel to implement a CCS retrofit on a 200MWe coal fired power plant 5.3.2 Capacity assessment of other stakeholders 5.4 Recommendations for improvement in institutional capacity 5.4.1 Dongfang Boilers 5.4.2 Other stakeholders 5.4.3 Outreach activities
6 Conclusions
7 References
List of tables
Table 1 Overview of activities as defined in the project terms of reference Table 2 Oxyfuel combustion industrial scale pilot projects outside of China Table 3 Proposed large scale oxyfuel demonstration projects Table 4 China oxyfuel combustion research program Table 5 Listing of Chinese oxyfuel combustion experimental systems>10KWt Table 6 Possible large-scale oxy-fuel combustion demonstration projects in China Table 7 Major power generation equipment suppliers’ profile Table 8 Main gas separation equipment suppliers’ profile Table 9 Main stakeholders of Chinese oxyfuel combustion research and demonstration Table 10 Estimates for PC plants without CO2 capture and retrofitted oxyfuel power plants with CO2 capture Table 11 Learning rates of capital and O&M cost for each technology option Table 12 Estimated COE and learning rates of COE for three types of CO2 capture plants in China Table 13 200MW Air separation unit parameter requirements Table 14 Boiler coal consumption Table 15 The main parameters of milling system Table 16 Compression gas purification system input conditions Table 17 Different types of large-scale CO2 transport conditions Table 18 Evaluation criteria relating to the four principles for assessing CO2 capture technology Table 19 Main technical indicators of 200MW power plant Table 20 The cost calculation method Table 21 Ultimate analysis and lower heating value of the Shenhua coal Table 22 Techno-economic analysis results for all different plants under three loads Table 23 Cost of 200 MW unit list Table 24 The influence of WASU Table 25 The influence of cF Table 26 The influence ofcASU Table 27 The influence ofcCPU Table 28 The influence of WCPU Table 29 The influence of I Table 30 The influence ofploan Table 31 The influence of rCO2 Table 32 The influence ofYlife Table 33 The influence of H Table 34 Ultimate analysis results and lower heating values of other three coal samples Table 35 cCOE, cCAC and cCCC results corresponding to the four coal samples Table 36 The influence of plant capacity Table 37 The influence of financial resources Table 38 Survey of previous cost estimates for 500MW oxyfuel combustion CO2 capture power plant Table 39 Contribution of technology vendors in financing existing CCS pilot projects Table 40 Perceived incremental risk exposures specific to oxyfuel technology Table 41 Risk response strategies applied in project risk analysis Table 42 Top 20 risks specific to Shenhua Guohua 200MW oxyfuel CCS project Table 43 Risks likely transferrable through existing insurance policies Table 44 Emissions performance standards in the USA and Canada
Table 45 Best practice manuals and guidelines reviewed Table 46 Criteria for screening reservoirs for CO2-EOR suitability Table 47 Selected oil field parameters in the Ordos Basin Table 48 Major evaluation criteria for site selection of saline aquifers Table 49 Selection criteria of saline aquifer formations for CO2 storage Table 50 Major formations in Yulin of Ordos Basin modified from well Yu 82 Table 51 Parameters of the simulation model of Liujiagou Formation. Table 52 Reservoir properties of representative saline aquifer Table 53 Reservoir properties of representative oil field Table 54 The brine salinity of different formations in Ordos Basin Table 55 Basic parameter settings for CCUS cost analysis Table 56 Technical design of Shenhua Guohua CCUS project Table 57 The cost of CO2 storage and transport. Table 58 The cost of Guohua CCUS project Table 59 Basic influencing factors settings for sensitivity analysis Table 60 The results of the sensitivity analysis with carbon tax Table 61 The results of the sensitivity analysis without carbon tax Table 62 The cost components of well drilling and completion Table 63 The cost components of well log and logging Table 64 The cost components of well completion cost Table 65 Site characterization and monitoring tools for CO2 storage in saline aquifer Table 66 The monitoring tools selected in pre-injection phase for CO2 storage in saline aquifer Table 67 Unit cost of monitoring technologies
List of figures
Figure 1 Project framework Figure 2 Typical oxy-combustion process Figure 3 International oxyfuel combustion research projects Figure 4 History of development of oxyfuel combustion including China Figure 5 The proposed 35MW oxyfuel combustion industrial pilot scale project
Figure 6 Projected reduction in CO2 emissions intensity in China Figure 7 Projected growth in CO2 emissions in China Figure 8 Projected CO2 emission reduction contribution of CCS in China Figure 9 Projected relative contributions for various carbon mitigation technologies in China in 2050
Figure 10 Net costs of CO2 emission reductions Figure 11 Techno-economic analyses of PCC and oxy-fuel technologies
Figure 12 Indicative learning curves for three CO2 capture technology options Figure 13 Typical coal-fired power plant’s air combustion system Figure 14 High-temperature cycle combustion system Figure 15 Wet cycle combustion system Figure 16 Dry cycle combustion system Figure 17 Adiabatic flame temperature chart of air combustion and oxyfuel combustion under different circulation ratio
Figure 18 Recycle ratio versus SA pressure fraction O2 and mean pressure fraction O2 for dry cycle system
Figure 19 Recycle ratio versus SA pressure fraction O2 and mean pressure fraction O2 for wet cycle system Figure 20 Air combustion Figure 21 Oxyfuel combustion dry cycle compatible solution Figure 22 Oxyfuel combustion wet cycle new solutions Figure 23 Schematic diagram for water system Figure 24 Constitution of LCOE Figure 25 The relationship of LCOE and CO2 price Figure 26 The relationship of LCOE and CO2 tax Figure 27 Results of the sensitivity analysis Figure 28 Estimated effect of oxidant purity on avoidance cost Figure 29 Estimated payoff distribution of retrofit option Figure 30 Simulated probability distribution of retrofit decision in the 200MW oxyfuel project’s lifetime Figure 31 Simulated cumulative retrofit probability in in the 200MW oxyfuel project’s lifetime Figure 32 Major risks categories in integrated CCS projects Figure 33 Policy considerations for a demonstration project
Figure 34 Graphical representation of “Project Site Maturation” through the exploration plan Figure 35 Topographic map of the Ordos Basin Figure 36a Source-sink matching of Guohua oxy-fuel combustion Figure 36b Source-sink matching of Guohua oxy-fuel combustion Figure 37 Geological map and cross section of the Ordos Basin Figure 38 Priority aquifer sites identification Figure 39 Layout of the CO2 injecion wells and production wells Figure 40 Geological model used for CO2 injection simulation Figure 41 TOUGH CO2 injection simulation results for the Liujiagou Formation Figure 42 Total CO2 injection and total water production for the Liujiagou Formation Figure 43 An incline view of the injected CO2 plume for the Liujiagou sandstone Figure 44 The CO2 plume resulting from 20 year injection for the Liujiagou Formation Figure 45 TOUGH CO2 injection simulation results for the Majiagou Formation Figure 46 Total CO2 injection and total water production for the Majiagou Formation Figure 47 An incline view of the injected CO2 plume for the Majiagou Limestone Figure 48 CO2 plume resulting from a 20 year injection for the Majiagou Formation. Figure 49 Relation of pipeline investment unit length with CO2 storage capacity and pipeline length Figure 50 Relation of the levelized cost of CO2 transport with CO2 mass flow and pipeline length Figure 51 Wellsite arrangement of CO2 saline aquifer storage Figure 52 Relation between levelized storage cost and injection capacity Figure 53 The cost of treating water in four desalination processes Figure 54 The results of the sensitivity analysis with carbon tax Figure 55 The results of the sensitivity analysis without carbon tax Figure 56 Phases and process typically related to CO2 storage projects Figure 57 Chinese government institutions involved in energy policy and administration
Abbreviations
ASU – air separation unit CCS – carbon capture and storage CCUS – carbon capture, utilization, and storage CFB – circulating fluidized bed CO2 – carbon dioxide CO2-EOR – carbon dioxide-enhanced oil recovery CPU – carbon dioxide purification unit DBC – Dongfang Boilers FEED – front-end engineering design GIS – geographic information system Gt – gigatonne HUST – Huazhong University of Science and Technology IEA – International Energy Agency IGCC – integrated gasification combined cycle IPR – intellectual property rights km – kilometer LCOE – levelized cost of electricity m – meter Mt – million tonne MWe – megawatt electrical MWth – megawatt thermal NETL – National Energy Technology Laboratory (US Department of Energy) NOx – nitrogen oxides PRC – People’s Republic of China R&D – research and development TA – technical assistance UK – United Kingdom US – United States WP – work package
1 Introduction
The ADB TA Project‐8133 People’s Republic of China (PRC) Road Map for Carbon Capture and Storage Demonstration and Deployment comprises two parts. For Component A, the aim is to develop a CCS Roadmap for the PRC, which is intended to provide an input to the development of policies that will support the achievement of climate change objectives appropriate to the PRC’s political and economic circumstances. Component B focuses on building capacity among key stakeholders for oxy-fuel combustion, which offers significant potential for carbon capture and storage/utilization (CCUS) within the Chinese context.
The overall TA project is financed on a grant basis by the CCS Fund under the clean energy financing partnership facility. It is included in the People’s Republic of China’s country operations business plan, 2012-2014, and is being implemented under the overall supervision of the National Development and Reform Commission (NDRC). With regard to component B, the day-to-day coordination, guidance, and support are provided by counterpart staff of the Implementing Agent, the Dongfang Boiler Co. Ltd. As a wholly owned subsidiary of Dongfang Electric Corporation (DEC), the Dongfang Boiler Co. Ltd. (DBC) is one of the three major utility manufacturers in China, with some 30% of the utility boilers domestic market. It has an annual production capability of 35GW power plant boilers, 9,000 tonnes auxiliaries, 5,000 tonnes various types of pressure vessels, and 4-6 sets of 1GW nuclear island and conventional island. It is also a first-class service provider of power plant and general contractor of environmental protection equipment (flue gas desulfurization and denitrification) in China. With the national demand for reduction of carbon emissions, the company attaches great importance to the development of CCUS technology.
1.1 Background
China is one of the largest contributors to global CO2 emissions. In 2010, 76.8% of China's total power generation (4228TWh) and 67.6% of the installed capacity (962.2GW) were based on coal. Although China is by far the world leader in the deployment of high efficiency low emissions coal power plants, in particular supercritical and ultra-supercritical units, the sheer number of coal power plants in operation leads to extensive CO2 emissions. For example, in 2010, China’s CO2 emissions exceeded 7 billion tonnes, of which those from coal-fired power plants accounted for nearly 40% of the total. Although the proportion of coal in the energy mix is projected to decline, even by the end of 2050, coal will still be the primary energy resource.
The current measures for reducing the greenhouse gas emissions of the PRC are focused on improving energy efficiency, energy conservation and increasing the share of non-fossil fuel energy sources. At the same time, as reflected in the PRC government’s 2011 Action Plan on Climate Change, there is a growing recognition that while these options are very important, they will only go so far and that CCUS will also need to play a key role in China’s climate change abatement strategies, It is an important climate mitigation technology that offers
medium to long term opportunities to make very deep cuts in CO2 emissions while continuing to utilize coal for major applications.
There are currently three first generation technical options for CO2 capture, namely post- combustion, pre-combustion and oxy-fuel, and each has its own characteristics. The post- combustion capture techniques are established at industrial pilot scale and can be retrofitted to both existing and new supercritical and ultra-supercritical power plants, which increasingly will comprise the Chinese coal power fleet. However, the energy penalty and both capital and operating costs of using this technology are relatively high. For the pre-combustion capture technique, while it has potential to offer a lower overall cost of CO2 capture, it is only applicable to IGCC, which has not established a market niche in the coal power sector due to technological complexity and very high capital investment costs. The third approach is oxy- fuel combustion technology, which is a relatively new approach that has the potential to avoid the disadvantages of the other options. It has been extensively investigated and developed in recent years, although it has yet to be trialled at significant scale.
Thus, oxyfuel is a technology that shows promise within the Chinese context. There has been strong technical involvement by various research groups and industrial stakeholders, such as Dongfang Boiler Co. Ltd, Huazhong University of Science and Technology (HUST) and the Shenhua Guohua Electric Power Co. Ltd., who together have established an industrial innovation strategic alliance, in order to take forward the development of critical technologies. That said, oxy-fuel combustion is a relatively new carbon capture technology and any first large scale full chain demonstration in China will face many challenges and risks, especially for determining the way forward for subsequent commercial applications.
Up to now, no large scale oxy-fuel demonstration plant has been implemented worldwide, and consequently there is no international experience to draw upon in detail. There remain several technical challenges to address, such as assessment and characterization of geological storage as well as determining the prospects and risks associated with the utilization of the CO2 captured for EOR. For the longer term, there is a need to analyze and evaluate the application prospect, motivational policy, financing environment, and macroeconomic impact of the oxy- fuel combustion technology and other carbon capture technologies within the Chinese electric power industry. Public awareness and acceptance are important too.
Besides these technical analyses and engineering practices, another major concern of NDRC is the need for a comprehensive roadmap for the development of oxy-fuel combustion technology that is applicable to the Chinese situation. The absence of a clear and feasible oxy- fuel combustion technology roadmap means uncertainty regarding the technical future, insufficient coordination between key stakeholders, and a lack of supporting regulation and policy.
Accordingly, this project has focused on the technological transformation of oxy-fuel combustion for the 200MWe Guohua Shenmu power plant as a means to address the challenges noted above. This has included strategic analysis and capacity strengthening, and
building the technology R&D roadmap for oxy-fuel combustion in the PRC. Thus TA8133 Component B will complement both Component A and various other ADB CCS related capacity building projects within the PRC.
1.2 Objectives The project comprises four work packages, as shown in Figure 1.
Figure 1 Project framework
In overall terms, this technical assistance project is designed to promote the implementation of a full chain 200MWe oxy-fuel demonstration, while also providing in-depth technical- economic-environmental-social assessment of Chinese oxy-fuel deployment, demonstration and application. The outputs arising include: Technical guideline for oxy-fuel combustion, including the identification of the critical technological gaps and barriers, together with possible solutions and pathways that lead to a technology R&D roadmap for oxy-fuel combustion in the PRC; Prefeasibility study for a 200MWe oxy-fuel demonstration project in China, including techno-economic evaluation, cost analysis, financial analysis, risk assessment, policy analysis and carbon storage prefeasibility assessment;
CO2 storage characterization manual, which will incorporate the identification of priority storage sites for the demonstration project; and Capacity assessment and strengthening measures in analysis, planning, and implementation of oxy-fuel combustion CO2 capture technology, together with possible public outreach initiatives.
1.3 Project organization In terms of detailed activities, as set out in the ADB Terms of Reference, these are summarized in Table 1 and presented in the subsequent sections of the report.
Table 1 Overview of activities as defined in the project terms of reference WP1 Oxyfuel technical consideration and assessment Review the current state of oxy-fuel combustion development, determine the key obstacles and technical bottlenecks and propose a feasible solution.
Develop strategic choice and potential pathways for oxy-fuel combustion CO2 capture in CCS demonstration and deployment.
Consider project learning curves for the commercialization of the oxy-fuel combustion CO2 capture technology. Formulate and recommend technical guidelines performance parameters rules, taking international best practices into consideration.
Elaborate the technology roadmap for oxy-fuel combustion CO2 capture technology and CCS demonstration. WP2 Prefeasibility assessment support for the 200MW oxy-fuel coal-fired power plant Support the feasibility study for an identified demonstration project in China and develop a project implementation guide for retrofitting of existing power plants. Carry out techno-economic evaluation of oxy-combustion power plants in China and analyze financially an identified oxy-combustion power plant including risk analysis; Carry out policy analysis of developing oxy-fuel technology in China. Carry out carbon storage prefeasibility assessment of the 200MW oxy-fuel project.
WP3 Establish CO2 storage manual
Carry out a pre-feasibility study of CO2 geological storage.
Formula a manual and cost assessment on site characterization of CO2 storage. Support the preparation of the capacity strengthening module and feasibility study for an identified demonstration project WP4 Propose capacity evaluation and public outreach Detailed assessment of the institutional capacity gaps Development and implementation of a capacity strengthening programme
2. WP1: Oxyfuel technical consideration and assessment
Oxyfuel combustion is a new technology under development and, as yet, there are no large- scale oxy-fuel demonstration power plant established worldwide. Accordingly, the assessment
of critical technological gaps/bottlenecks for the technology and the identification of possible solutions or pathways has had to be undertaken through reviews of the national and international industrial pilot-scale projects and associated design studies, for which capacities are in the range 3-35 MWth.
2.1 Current status of oxy-fuel combustion development Oxy-fuel combustion is the process of burning fossil fuel using pure oxygen instead of air as the primary oxidant. The concentration of CO2 in dry flue gas can reach more than 80%, and after a simple purification process this can be increased to more than 95% so as to meet the needs of large-scale pipeline transportation and storage. This technology can also greatly reduce the SO2 and NOx emissions to achieve a synergetic removal of pollutants, which provides a near zero emissions of clean coal utilization technology.
2.1.1 Technology description Figure 2 presents the typical oxy-combustion system process.
Figure 2 Typical oxy-combustion process (Alstom 2014)
The high purity oxygen from the Air Separation Unit (ASU) is mixed with the Recirculated Flue Gas (RFG). Part of this mixture provides the pulverized coal transport medium delivered into the furnace with the fuel, while the remainder enters into the furnace as the oxidant to complete a process similar to traditional air combustion. RFG is used to maintain a high furnace temperature, reasonable boiler radiation and convection heating surface heat transfer. The flue gas that exits the boiler, which has a high concentration of CO2, has non-GHG pollutants removed and then passes into the gas purification unit to ensure a high purity of CO2, for transport and subsequent utilization or storage.
2.1.2 Global development of oxyfuel combustion technology Figure 3 summarises the oxyfuel combustion history from laboratory scale through to proposed demonstration applications within the USA, Japan, Canada, Australia, UK, Spain, France, and the Netherlands. The major research institutions and companies include: EERC, ANL, B&W, Air Products and the U.S. Subsidiary of Alstom in America; IHI and HITACHI in Japan; CANMET in Canada; IFRF and BHP in the Netherlands; the University of Newcastle and CS Energy in Australia;, CIUDEN in Spain; Alstom and Doosan Babcock in the UK; and Vattenfall in Germany. Figure 4 provides a broader representation by including the work within China to indicate the relative progress.
1000
Pilot scale Whiterose 426 ENEL 320 Commercial scale( without CCS) Endosa 300 Shenmu 200 Demonstration scale( with CCS) FutureGen 168 100 Youngdong 100
Renfrew 30 Callide A 30 Pearl Plant 22 International Comb 11.7 Vattenfall 10 MWe Oxy-coal 13.3 B&W 10 HUST 12 10 CIUDEN 10 Jupiter 6.7 TOTAL CIUDEN 6.7 JSIM/NEDO(Oil) 4.0 OHIO 10 (NG) 10
Capacity / ANL/EERC 1.0 IFRF 1.0 ENEL 1.0 1 HUST 1 Alastom 1.0 IHI 0.4 B&W/AL 0.4 PowerGen 0.3 ANL/BHP 0.2 IVD-Stuttgart 0.2 RWE-NPOWER 0.2 CANMET 0.1 HUST 0.1 0.1 1980 1990 2000 2010 2020 The year it put into operation
Figure 3 International oxyfuel combustion research projects
Figure 4 History of development of oxyfuel combustion including China
In the last ten years, there has been some significant progress with industrial pilot units being established, Table 2. In particular, Vattenfall built the world’s first 30MWth oxyfuel combustion device at Schwarze Pumpe, Germany in 2008. The Australian CS Energy Company built the world’s first and so far largest 30MWe oxyfuel combustion power generation demonstration plant in Callide in 2011. In Spain, the CIUDEN technology research center built a 20MWth pulverized oxy-coal boiler and the world's first 30MWth fluidized bed test device. In China, construction of its first 35MWth oxyfuel power plant should be completed before the end of 2014.
Table 2 Oxyfuel combustion industrial scale pilot projects outside of China Project Scale Start Power CO Name Type Main fuel 2 (MWe) date Generation % (country)
Vattenfall 10 New 2008 Coal N 99.9 (Germany) Callide 30 Retro 2010 Coal Y (Australia) TOTAL 10 Retro 2009 Gas Y 99.9 (France) CIUDEN 10 New 2010 Coal N (Spain)
CIUDEN 7 New 2010 Coal N (Spain)
Jamestown 50 New 2013 Coal N /Praxair(USA)
Jupiter Pearl plant 22 Retro 2009 Coal N (USA)
Babcock& Wilcox 70% 10 Retro 2008 Coal N (USA) dry
Doosan Babcock 13 New 2008 Coal N (UK)
Jiuda Yingcheng 12 Retro 2011 Coal N 80% (China)
In August 2010, the U.S. Department of Energy announced the launch of an oxyfuel demonstration project under a restructured FutureGen 2.0 programme, as a public-private partnership with a total budget of US$1.65 billion. This will comprise the retrofit of a 200MWe coal-fired power plant in Meredosia, Illinois with full CCS chain oxy-combustion technology. The aim is to capture more than 1 Mt of CO2 each year, which accounts for more than 90% of the plant’s CO2 emissions, and to reduce other emissions to minimal levels. The CO2 is to be transported and stored underground in nearby deep saline aquifers (Bellona 2013).
In the UK, Capture Power Limited (a consortium of Alstom Power, Drax Power and the British Oxygen Company) and the National Grid established the White Rose Project. The aim
is to build a new state-of-the-art 426MWe (gross) clean coal power plant with full CCS, capturing approximately 2 Mt of CO2 per year. This will link into the planned development of a CO2 transportation and storage infrastructure to an offshore saline aquifer in the North Sea, which would have capacity for storing CO2 arising in the future from possible additional CCS projects in the area. The UK Government has provided funding for a FEED study, after which in early 2015 a final investment decision will be taken by the Government and the consortium on the construction of the plant. On that timescale, the plant would be expected to become operational by 2020. In the meantime, the European Commission has confirmed that the project is in line to receive about £250m from its stimulus programme.
Table 3 Proposed large scale oxyfuel demonstration projects
Scale and Technology Progress and launch Country Project parameters source time
250MWe Vattenfall Cancelled due to Germany Supercritical ALSTOM Jänschwalde licensing problems
Capture Power 426MWe ALSTOM Second stage, UK White Rose Supercritical AP FEED study Prefeasibility study; CIUDEN 300MWe Spain FWAL Compostilla Fluidized bed Delayed due to funding problems. FutureGen2.0 168MWe BW Second stage, U.S. Subcritical AL NETL FEED study Doosan Korea Yong Dong 100MWe Cancelled Babcock
South Korea had planned to build a 100MWe oxyfuel demonstration power plant at Yongdong, with the detailed design to be undertaken between 2012 and 2015. Although support had been pledged by KEPCO, KOSEP Power Company, Korea Institute of Machinery and Materials, and the Korea Institute of Industrial Technology, this proposed project has been suspended due to overall funding problems.
In Spain, the Compostilla Project OXY-CFB300 aimed to demonstrate the technological feasibility of capture, transport and CO2 storage for fossil thermal plants, using oxyfuel with circulating fluidised bed technology at the 300 MWe scale. The intention was to construct a new plant close to Endesa’s Compostilla power plant, together with the infrastructure for CO2 transport and storage. However, this project has been cancelled due to funding problems.
2.1.3 Development of oxyfuel combustion technology in China The fundamental research of oxyfuel combustion in China began in the mid-1990s, involving Huazhong University of Science and Technology, Southeast University and North China Electric Power University. Table 4 lists some main research programs of oxyfuel combustion supported by the Chinese government and industrial companies. Table 5 provides a list of oxyfuel combustion experimental systems (>10kWth) either completed or planned in China.
Table 4 China oxyfuel combustion research program Project Type Project name Timescale National Key Basic Research Greenhouse gas CO2 enhanced oil recovery resource 2006~2010 Program of China utilization and underground sequestration National Key Basic Research Development of a new type of combustion and separation 2011~2015 Program of China technology for low cost CO2 enrichment The National High Technology Coal combustion’s CO2 emission reduction technology and 2005~2008 Research and Development pollutants removal Program of China The National High Technology O2/CO2 recycle combustion device and system optimization 2009~2011 Research and Development Program of China National Key Technology Research 35MW oxyfuel combustion and equipment research & 2012~2014 and Development Program of the engineering pilot scale project Ministry of Science and Technology of China The State Key Program of National New ideas and methods of realizing oxygen combustion 2010~2013 Natural Science of China CO2 enrichment International S&T Cooperation New generation of coal transformation and power 2012~2014 Program of China generation technology for Sino-US advanced coal technology cooperation International S&T Cooperation Key technology research for large scale carbon capturing 2011~2013 Program of China and storage based on oxygen combustion Shenhua Group of Major Scientific Oxyfuel combustion carbon capture coal-fired power plant 2012~2014 and Technological Projects technology research and system integration
Following extensive fundamental and laboratory trials, in 2011, Huazhong University of Science and Technology built the first 3 MW integrated oxyfuel combustion test platform in
China, which can capture up to 7000 tonnes of CO2 per year. The system was designed according to the industry standard, so that it can provide a straightforward means for scale-up. In the process of system design, construction and commissioning, it realized the following key technology breakthroughs: For the oxyfuel combustion system, a new type of oxyfuel burner, oxygen injector and air and flue gas system were designed. Both the oxyfuel combustions and air combustion conditions achieved high efficient stable combustion, and the combustion efficiency was greater than 95% for different kinds of bituminous, anthracite and mixed coal. Oxyfuel–air switch operation can be readily and safely achieved within half an hour, having mastered the controlling point and established the control instruments for system operational stability.
Under the oxyfuel combustion conditions, the CO2 enrichment can be optimized through careful operating procedures and minimising air leakage. A dry flue gas CO2 concentration of more than 80% can be stably achieved, with subsequent purification and
compression producing liquid CO2 at gretaer than 95% purity. Adjustment of the circulation ratio can effectively change the distribution of the heat transfer in the furnace, such that the heat transfer characteristics under the oxyfuel combustion condition of dry circulation with 26% oxygen concentration are similar to that in air combustion condition. Oxyfuel combustion characteristics and pollutants emission control have been investigated in detail, such that a NOx emission reduction of 50 ~ 70% can be achieved, due to the process large circulation ratio and low local oxygen concentration. It is also
possible to achieve greater than 95% desulfurization efficiency with a simplified dual alkali desulfurization system.
Table 5 Listing of Chinese oxyfuel combustion experimental system>10KWt Unit Thermal rating Completion Furnace type & fuel (MW) time Huazhong University of 0.3 Vertical pulverized coal 2006 Science and Technology Huazhong University of 3 Front wall pulverized coal 2011 Science and Technology The vertical one- Tsinghua University 0.025 dimensional pulverized coal 2008 furnace Fluidized bed, no gas Zhejiang University 0.020 2004 circulation Zhejiang University 2 pulverized coal,kiln 2010 North China Electric Coal pressurization 0.025 2011 Power University bubbling bed Southeast University 0.050 Fluidized bed 2011 Under Southeast University 2.5 Fluidized bed construction Institute of Engineering 0.1 Fluidized bed,Coal 2013 Thermophysics Institute of Engineering Under 1 Fluidized bed,Coal Thermophysics construction
Combined with the advantages and characteristics of a circulating fluidized bed, Southeast University has undertaken a systematic research programme of CFB oxyfuel combustion. This included the construction of a CFB oxyfuel combustion test device (50KW) which is the first one realizing gas circulation in China and the first one realizing wet flue gas circulation in the world. They also improved the measurement and data acquisition system, and based on the mass balance in the oxy-fuel process, wrote a program for real-time computing systems online analysis. Using this test platform Southeast University has successfully conducted a 300 hour gas cycling test. At present, a 2.5MW oxyfuel combustion CFB experimental system has been established by Southeast University in cooperation with B&W USA. This included a parallel bed heat exchanger that overcame the heat carrier limitations oft the traditional external circulating fluidized bed with only circulating ash. Some unburned carbon is introduced to burn and release heat. When running in the bubbling bed mode, the heat transfer coefficient is increased. It is easy to adjust the circulation by controlling the amount of air supply such that heat transfer could be more than 15% of the boiler heat load. This solves the problem that the heating surface arrangement is limited under conditions of high oxygen concentration by arranging the heating surface in the parallel bed, which greatly reduces the size of the boiler and further matures the circulating fluidized bed oxyfuel combustion technology. These results allow oxy-fuel technology to make a large step in the commercial applications for future power plant.
Following this useful R&D, large industrial pilot scale projects are being established. In May 2011, Huazhong University of Science launched a 35MW oxyfuel combustion industrial demonstration project, which is a joint venture supported by the Ministry of Science and
Technology and involving Dongfang Boiler (Group) Co., Ltd., Sichuan Air Separation Plant (Group) Co., Ltd. and JiuDa (Yingcheng) Salt Co., Ltd.. The aim is to build a 35MW oxyfuel unit at the Salt Company's captive power plant, Figure 5.
Figure 5 The proposed 35MW oxyfuel combustion industrial pilot scale project
The system uses a front wall swirl combustion system, equipped with a cryogenic air separation system, and the boiler and system adopt compatible designs to enable both air combustion and oxyfuel combustion. It can carry out air combustion / dry cycle / wet cycle oxyfuel combustion assessment tests. The aim is to achieve CO2 concentration in the flue gas in excess of 80%, a CO2 capture rate greater than 90%, and an annual CO2 capture capability of one hundred thousand tonnes. This CO2 can be stored in disused salt mines, while some can also be used in the salt production process for removal of calcium and magnesium components. Construction of the plant began in December 2012, and it is expected to be completed by the end of 2014.
Table 6 Possible large-scale oxy-fuel combustion demonstration projects in China Size and Sources of Progress and the planned start Project Owner / plant parameters technology time Shenhua Group 200MWe Pre-feasibility study completed Shenmu plant HUST, DBC, Subcritical FEED study underway
Pre-feasibility study completed. 350MWe Datang Daqing plant ALSTOM Project schedule yet to be Supercritical determined. Shanxi Intl Electricity Pre-feasibility study completed. Taiyuan Sunshine 350MWe B & W, USA Project schedule yet to be project Supercritical determined.
Xinjiang Guanghui 170MWe Energy JOC Pre-feasibility study underway Subcritical
Chinese enterprises are also actively preparing some large-scale oxyfuel combustion technology-related demonstrations. Table 6 lists the possible projects.
In March 2012, the Shenhua Group launched a systems integration and design technology
research project to establish an oxyfuel combustion coal-fired power plant capable of capturing at least 1 Mt CO2 per year. Huazhong University of Science and Technology and Dongfang Boiler Group Co., Ltd. together with Southwest Electric Power Design Institute and other units are involved in this joint research project. The project was officially launched in November 2012, and the first phase is expected to be completed late in 2014.The content includes a technical & economic evaluation for new construction and transformation program, together with some pre-research of boilers, burners, smoke coolers and other key equipment.
Shanxi International Energy Group Limited (SIEG) announced that it has signed a cooperation agreement with Air Products in connection with a 350MWe oxyfuel combustion power generation demonstration project to use Air Products unique oxyfuel combustion CO2 purification technology. This will include feasibility studies and demonstration plant conceptual design. The demonstration project is to be located in Taiyuan, and will include the purification of the captured CO2 both for use and storage.
Datang Group signed a memorandum of understanding with Alstom on September 21, 2011 to form a long-term strategic partnership for the development of carbon capture and storage demonstration projects. Alstom and Datang will cooperate to develop two coal-fired power plant CCS demonstration projects, with one to be located in Daqing, which will comprise a 350MWe coal-fired power plant to use the Alstom oxyfuel combustion technology.
The Xinjiang Guanghui New Energy Company also signed a strategic cooperation agreement with the U.S. Jupiter oxygen company on carbon capture and emission reduction projects. The Jupiter Oxygen Company plans to invest US$200 million in cooperation with Guanghui New
Energy Construction in developing CO2 capture and other related boiler renovation projects.
2.1.4 Foreign technology providers For the aforementioned industrial demonstration projects, various vendors’ oxyfuel devices have been verified.
Table 7 Major power generation equipment suppliers’ profile Large Pilot Combustion Compression/ Other scale Company Fuel scale system purification system Demo MW MWe Concurrent ALSTOM Coal/Gas 1 tonne/hour Yes 15,30 426 /Rotational flow Babcock& Coal Rotational flow None Yes 30 168 Wilcox Doosan Babcock Coal Rotational flow None None 40 100 IHI Coal Rotational flow None None 30 None Foster Wheeler Coal CFB None None 30 300
Alstom, IHI, Doosan Babcock, HITACHI, Babcock & Wilcox and other major power equipment manufacturers all passed an assessment test for single oxygen swirl 30MW burners, which can be used to complete a large-scale demonstration. Alstom completed a 15MW scale enriched tangential firing system validation testswhile Foster Wheeler completed
30MW enriched semi-industrial validation for CFB applications. Air Products, Linde, Air Liquide and other gas separation equipment suppliers completed 10~30MW compression purification system assessment tests. The success of these tests forms the foundation for the large-scale demonstration projects. Tables 7 and 8 summarize the major international oxyfuel technology vendor profiles.
Table 8 Main gas separation equipment suppliers’ profile Pilot scale Company ASU CPU Large scale demonstration performance Air Cryogenic 1MW CPU at Schwartz Shanxi Yangguang CPU with PRISM membrane Product separation Pumpe Pyroelectricity 350MWe Air Pure oxygen CO CPU Lacq 30MW Future plant 168MWe Liquide 2 Linde, Cryogenic Meet the requirements of food Black pump 40 White Rose 426MWe BOC separation grade Cryogenic Praxair Near Zero Emissions CPU No No separation Cryogenic High Recovery Near Zero 15MWt Hammond, Xinjiang Guanghui Energy Jupiter separation Emissions CPU Indiana 170MWe
2.1.5 Domestic stakeholders
Table 9 Main stakeholders of Chinese oxyfuel combustion research and demonstration Universities/ Scientific Governmental Agencies Enterprises Research Institution Climate Change Division of National Huazhong University of Shenhua Group Development and Reform Commission Science and Technology Social Development Division of National Southeast University Datang Corporation Science and Technology Department Hi-tech Development & Industrialization Shanxi International Division of National Science and Tsinghua University Energy Group Technology Department Technology & Equipment Division of Xinjiang Guanghui Zhejiang University National Energy Administration New Energy Sources Policy & Law Division of Environmental Harbin Institute of Dongfang Electric Protection Department Technology Group North China Electric Southwest Electric Land and Resources Department Power University Power Design Institute Wuhan Institute of Rock The Administrative Center for China’s and Soil Mechanics , Sichuan Air Separation Agenda 21 Chinese Academy of Group Sciences Institute of Policy and Management, Chinese Academy of Sciences
The National Development and Reform Commission, Ministry of Science and Technology, National Energy Administration, Environmental Protection Department, Land and Resources Department are promoting the various stages of CCS development and demonstration, including technology research and development, demonstration, environmental monitoring,
storage utilization, policies and regulations, and international cooperation. Table 9 lists the main stakeholders of Chinese oxyfuel combustion research and demonstration.
2.1.6 Potential advantages of oxyfuel combustion technology Oxyfuel technology is based on the existing coal-fired boiler system, such that the radiation and heat convection in the furnace can be close to the original air combustion condition by choosing the appropriate proportion of circulating gas. Consequently, subject to quite small modifications in the air preheating and the flue gas system, together with need to include both air separation and flue gas compression purification systems, the technique is suitable for the retrofit of existing coal based power plants. Analysis by U.S. National Energy Technology Laboratory analysis also suggests that it should be possible to achieve a lower retrofit cost than by using alternative technologies. For new plants, where there would be no need for air blown operation, it should also be possible to reduce system investment and operating costs by reducing the size of the boiler, as well as including the thermal coupling of air separation - boiler - flue gas purification and compression systems, together with the use of acid gas compression technology.
The use of gas recycling technology has a positive impact on flue gas heat loss. This is the major part of the heat loss in a modern boiler, and the very high flue gas recycling rates should reduce this considerably.
The oxyfuel system also results in a synergetic removal of pollutants. Besides over 90% removal of CO2, due to the flue gas condenser and acid gas purification/compression technology, NOx, SOx, particulate matter and other emissions can be controlled at 10ppm or less, resulting in a near "zero" emissions coal-fired power generation technology.
2.1.7 Challenges for oxyfuel combustion technology deployment Based on both Chinese and international experience, there are several barriers for oxyfuel technology demonstration and deployment, although these are not all technology specific but rather reflect the more generic issues associated with CCS. These are covered in detail in the TA8133 Component A final report, and include the need to limit additional capital investment costs and operating efficiency penalties, lack of strongly defined supporting policies and regulations plus potential public acceptance issues, particularly with CO2 transport and storage.
2.2 Strategic analysis This task comprises:
An examination of the strategic importance of CCS and the oxy-fuel combustion CO2 capture technology for power generation for the PRC; Building on medium to long-term cost and emission reduction potential projections, to assess competitiveness of the technology compared to alternative technologies to mitigate greenhouse gas emissions; and An analysis of the strengths, weaknesses, opportunities, and constraints (SWOC) of the oxy-fuel combustion CO2 capture technology for CCS demonstration and deployment in
power plants in the context of the PRC energy sector.
2.2.1 Necessity of CCS for China As the world largest developing country with a population of over 1.3 billion, China has achieved a spectacular economic growth since the Opening Reform in 1978. Most of this economic growth has been fuelled through the use of coal, both as a fuel and a chemical feedstock. Since 2006, China has overtaken the USA to be the largest CO2 emitter worldwide. In 2009, coal accounted for more than 69.4% of total energy consumption in China, of which over 80% of that coal consumption was used for power generation. In 2009, the Chinese
Government pledged to reduce the 2020 CO2 emissions intensity (CO2 per unit of GDP) by 40%-45% compared to 2005 levels (State Grid Corporation of China 2010). To date, the focus has been on the introduction of energy efficiency initiatives across many industrial sectors, renewable power opportunities plus an increase in the introduction of nuclear power and increases in hydropower generation. There has also been the closure of significant numbers of small, obsolete coal power plants plus the introduction of large high efficiency coal fired power plants.
0.40
0.30
0.20 CO2 emission per GDP(Mt/GRMB) 0.10
0.00 2005 2010 2015 2020 2050
Figure 6 Projected reduction in CO2 emissions intensity in China (NBS 2012; CAIT 2012)
60,000
38,357 40,000
17,383 CO2 Emission(Mt) 20,000 13,573
0 2015 2020 2050
Figure 7 Projected growth in CO2 emissions in China (NBS 2012; CAIT 2012)
At the same time, the government recognized that CCS, which captures and transports CO2 from major point sources to a storage site where the CO2 is injected in to geological
formations (Almendra and others 2011), has emerged as a very promising technology with great capacity for CO2 reductions in coal-fired power plants (Metz and others 2005; Meadowcroft and Langhelle 2009; Markusson and others 2012). This is particularly important for China with its extensive use of coal for a wide range of applications.
20% 18% 16% 14% 12% 10% CCS contribution ratio in 8% emission reduction 6% 4% 2% 0% 2020 2030 2040 2050
Figure 8 Projected CO2 emission reduction contribution of CCS in China (IEA 2010)
CCS 18% End‐use fuel and electricity efficiency 38% Renewables 15%
End‐use fuel Power switching generation Nuclear 9% effciency 10% 10%
Figure 9 Projected relative contributions for various carbon mitigation technologies in China in 2050 IEA (2010)
This point has also been considered by the International Energy Agency (IEA), which has identified a need for CCS as a critical factor in reducing greenhouse-gas emissions in countries with extensive fossil fuel use. IEA projections indicate that CCS will be an integral
part of any lowest-cost mitigation scenario where the long-term average increase in global temperatures is limited to less than 4°C, and will need to be deployed widely in both power generation and industry. It has suggested that to limit the rise in global temperatures to acceptable levels, about 120 gigatonnes (Gt) of CO2 would need to be captured and stored across all regions between 2015 and 2050. At that time, in broad international terms, the IEA suggested that one-third of that total might come from the PRC as shown in Figure 8 (IEA 2010). This type of projection is considered in greater detail in the Component A report, where a possible PRC roadmap for demonstrating and deploying CCUS is presented, based on more recent and more comprehensive national data.
According to the IEA's report, as shown in Figure 9, CCS could contribute at least 18% of the required global CO2 emission reductions by 2050. This represents a higher proportion of CO2 emission reductions than from making a transition to renewable energy and more than triple the contribution from nuclear energy.
($/t CO2e) 200
150
100
50
0 biodiesel nuclear CCS‐coal solar Power biothanol wind plant
Figure 10 Net costs of CO2 emission reductions (ico2n 2011)
With regard to cost, CCS is in the same range as other CO2 reduction options such as wind, solar and bioethanol, Figure 10. In addition, a study by the Delphi Group, released in 2009, concluded that CCS has the largest potential for annual cost reductions, closely followed by nuclear, wind power and vehicle fuel efficiency improvements. The study notes that CCS is cost-competitive with other GHG reduction options such as solar and wind, since it may get potential net cost reduction from revenue arising from CO2 use in EOR applications (ico2n 2009).
2.2.2 SWOC analysis on oxy-fuel combustion CO2 capture technology This study provides an analysis of the strengths, weaknesses, opportunities and constraints
(SWOC) on oxy-fuel combustion CO2 capture technology for CCS demonstration and deployment in power plants in the context of the PRC energy sector, including comparison with alternative options.
Strengths Well researched technology within China China has established an extensive R&D programme for oxyfuel, ranging from fundamental studies, work at labscale, through various rig based units, culminating in the construction of a 35MW oxy-fuel combustion industrial pilot test unit (Liu 2012). Thus the fundamental work has included mechanisms of coal combustion, emission control and pollution treatment during combustion, mathematical modeling of combustion, combustion diagnostics and optimization, research and development of combustion technology and advanced power generation technology. This has provided a solid foundation for subsequently achieving oxy-fuel combustion demonstration progress.
Timing is right for commercial prototype demonstration activities This extensive R&D suggests that the developers can progress to a commercial prototype demonstration unit, of which the intended Shenhua Guohua 200MW coal-fired power plant would provide a good example, offering the prospect of capturing about 1Mt CO2/year for subsequent storage/EOR application (Liu 2012).
Scope to readily interface with existing thermal plant At present, over 60% of the total energy is supplied from coal combustion power plants, which remain as the largest CO2 emission source by coal combustion in China. Most of these plants have been in operation for several years. If it is necessary to control CO2 emissions of these existing power plants, the best approach for retrofit of such plants would be oxy-fuel combustion. It maintains the original power plant structure by combining a conventional combustion process with a cryogenic air separation process. The major components, namely, coal combustion and air separation, are mature technologies that have been extensively employed, so that the retraining requirements for personnel are reduced. In principle, it could be readily fitted to 600-1000 MWe units and 300MWe units although the latter would probably be too old to justify the investment.
In contrast, for post-combustion capture, the need to add an end of pipe chemical process to capture CO2 could be complex as the original design would not have allowed for the introduction of an additional scrubber system, necessitating redirection of some low pressure steam away from the turbine to the capture unit. It should also be noted that the introduction of IGCC with pre-combustion capture could only be applied to new power plants since this technology option is not suitable for retrofit.
Reduce equipment investment for environmental control
One of the most noticeable advantages of oxy-fuel combustion is the low NOX emission, due to the use of oxygen for combustion, which eliminates nitrogen from air. Pilot-scale oxy-fuel demonstrations have so far confirmed that air infiltration can be effectively limited, a highly enriched CO2 flue gas can be produced, which results in significant NOX emissions reduction compared to air combustion operation. This suggests that a downstream and expensive deNOx system would not be required. With regard to SOx emissions, oxy-combustion generally produces similar amounts of SOX compared to an air combustion process (Damen and others
2006; Kanniche and others 2010). However, the continually-recycled flue gas results in higher-concentration SOx than a conventional air combustion technique. It has been shown that the CO2 purification unit (CPU) can remove almost all of the standard pollutants such as SOX, NOX and Hg from the flue gas stream. Thus the CPU can be used not only as a CO2 removal device but also as an emissions control unit. As a result, an oxy-fuel power plant could omit equipment such as flue gas desulfurization (FGD), selective catalytic reduction (SCR), and Hg control devices like activated carbon injection. This would lead to significant savings on capital investment and improved efficiency of the plant, although this may limit the breadth of operation, as given in the weakness list.
Other cost advantages Data for comparing the capital costs of different CCS technologies are by definition uncertain as such plants have yet to be built at commercial scale. That said, there does appear to be a general acceptance that oxyfuel may have a small advantage over post combustion capture (PCC), particularly for retrofit applications (Singh 2013). However, most cost studies have stressed that little difference in costs has yet to be discerned for either oxyfuel or PCC, and that both technologies should therefore be pursued to maturity. A recent paper (Rubin 2012) carried out an extensive review of literature on this topic, the results of which are summarized in Figure 11, where PCC and oxy-fuel combustion are compared, and which show a small advantage for oxyfuel.
45 40 Supercritical PC, PCC 35 30 Supercritical PC, oxy‐coal 25 20 15 10 5 0 Net plant efficiency(%)Net plant efficiency(%) Additional energy Reduction in net kWh without CCS with CCS input(%) per net kWh output(%) for a fixed output energy input
Figure 11 Techno-economic analyses of PCC and oxy-fuel technologies (Rubin 2012)
A less favourable assessment of oxyfuel was presented in a recent study which investigated the effect of parameters such as CO2 and oxygen purity, CPU and ASU performance and cost, and coal composition on the competitivity of a 550 MW net oxyfuel plant with an equivalent post-combustion capture plant (Borgert and Rubin, 2013). A principal conclusion is that increasing restrictions on CO2 pipeline purity will have a relatively great effect on CO2 avoidance costs for oxyfuel plant, as further processing becomes required in the CPU.
Avoidance costs were shown to increase by up to 20% as CO2 exit purity varied from 88.3% to 99.9%, with high sulphur coals adding roughly another 20% for all CO2 purities. Because of this effect, comparison with a modelled post-combustion system found that oyfuel struggled to compete on avoidance cost with anything other than low sulphur coals and cosequestration of flue gas contaminants.
Weakness Cost comparison with alternative low carbon technologies High capital and operational costs provide significant uncertainty for companies interested in developing CCS technology (Rubin 2012). In China, based on the possible demonstration projects, the cost of generating electricity at power plants with CCS is expected to increase to 0.63-1.08 RMB/kWh, compared to coal based electricity generation without CCS of 0.2-0.25 RMB/kWh. For oxyfuel plants, the major cost is the air separation unit (ASU) that significantly raises the overall costs, and at present there is no viable alternative. As the most energy intensive plant process the cryogenic ASU is particularly in need of further development and adaptations specific to oxyfuel plant such as larger, more efficient, and more flexible units. Ceramic membranes are a potentially higher efficiency alternative means of oxygen production, in which the absence of cryogenic cooling means that the energy of the hot, compressed air feed can be recovered after the oxygen is extracted. This technology has reached the pilot-scale but is not yet a commercial reality.
Technical concerns Although the technology is ready for large scale demonstration, there remain some technical issues to be resolved, many of which relate to the altered behaviour of coal combustion in an atmosphere of oxygen and recycled flue gases (Lockwood 2014). While the destabilising effect of the increased heat capacity can in large part be countered by raising oxygen levels to 27-30%, new burner designs have been introduced by several manufacturers to optimise combustion and increase the possible range of operating parameters. These are usually based on swirl burners, which promote a high degree of recirculation of hot exhaust, sometimes in conjunction with injection of pure oxygen via oxygen lances; both of which act to accelerate ignition close to the burner. Improved understanding of the combustion behaviour at the level of the coal particle is also important for developing accurate CFD simulations to ensure that the performance of pilot-scale combustion can be reliably translated to design for operation of a full-scale plant.
Recycle of flue gases before FGD or drying steps is an attractive option for raising plant efficiency, but may carry considerable added risk of both low- and high-temperature corrosion. Increased levels of water vapour and SO3 found in hot recycle schemes are known to raise the acid dew point and therefore require stringent control of flue gas ductwork above this temperature in order to avoid severe corrosion.
The influence of oxyfuel conditions on high-temperature corrosion of superheaters and waterwalls is harder to elucidate, and pilot and lab results have produced a wide range of frequently contradictory data. However, there is significant evidence to suggest that several high-temperature mechanisms are exacerbated in oxyfuel atmospheres, such as sulphidation, water vapour oxidation, and severe hot corrosion in the presence of alkali metals. On the other hand, carburisation of alloys appears to be effectively restricted under oxidative conditions. While oxyfuel corrosion seems to adhere to familiar air corrosion chemistry, more research is required to identify appropriate boundaries for materials in the new environment. It is possible
that corrosion risk will limit future oxyfuel plant to either less problematic fuels or more conservative recycle and FGD implementation.
Although oxyfuel combustion can produce dried flue gases with over 90% CO2, the remaining fraction is largely made up of the light gases N2, O2, and Ar, which would significantly raise the energy required to compress the product gas to pipeline pressures, as well as potentially exceeding the limits set by existing pipeline and EOR specifications. The partial condensation of the flue gases required to remove these species also imposes its own strict limits on flue gas contaminants in order to avoid damage to the sensitive compressors and cryogenic equipment. Temperature swing adsorption is used for deep flue gas dehydration, while a variety of means for polishing of SOx, NOx and mercury to trace levels have been trialled at the lab-scale or in CPUs operating at large oxyfuel pilots. These include conventional alkaline scrubs, pressure swing adsoprtion, distillation of NO2, and a novel sour compression process in the chemistry of SOx and NOx at high pressure is exploited to promote their removal as condensates.
Lack of financial support While China has an extensive R&D budget for CCS research, it has yet to determine how best to take forward the possible demonstration projects. This issue is covered in the section on policy issues, which suggest several means whereby China can positively support CCS demonstration activities.
Lack of standards Currently, specific technical standards for CCS power plants are lacking, including the emission performance standards (EPS) and the standards for monitoring and verifying the safety of CO2 storage.
Opportunities Introduction of policies to support CCS demonstration The development of CCS is still at the early stage in China, and the introduction of sound supporting policies and economic incentives by the government of China could play a key role for its future development. Currently, there is no mandate to share CCS technology standards or provide guidance for CCS activities among energy companies, research institutes, and universities. There is an opportunity to provide effective guidance for new technology introduction, and improve the market creation. Moreover, the Chinese government could make a clear CCS industry development strategy in cooperation with industry, which could speed up CCS technology and project development.
Improvement of emissions trading scheme China currently possesses no national mandatory ETS in service, although the NDRC has plans to establish a nationwide carbon trading scheme by 2015, while a voluntary pilot scheme through ten emissions exchanges has been established to promote voluntary emissions reduction in China. This pilot program offers a flexible mechanism for the regional governments to plan, organize and implement the carbon trading approach, which is beneficial for trading of carbon emission allowances among the different industries within the region and helps retain the trading benefits in the region. The first industries incorporated into
the trading scheme will come from those intensive emissions sources including the cement sector, steel sector, and power generation sector. Under the scheme, the gross carbon emission allowances are initially identified and will be then allocated to firms covered by the scheme. When the firms emit more than allocated, they will need to pay for the extra emissions. Thermal power plants, as the largest carbon intensive emitter, are therefore driven to make some technological improvement, to cut down CO2 emissions.
International cooperation At the research level, there have been some very significant CCS collaborative agreements between China and the other countries. There should be scope to take such cooperation further to the demonstration phase although it might prove difficult to engage international technology suppliers on CO2 capture technology development since the issue of IPR is likely to prove a sticking point. That said, there should certainly be scope to assist China on large scale CO2 transport and storage/EOR characterisation, which could be covered by, for example, cooperation on clean energy technology between China and the USA.
Inclusion of CCS in the CDM regime At the 2011 Climate Change Conference (COP/MOP) in Durban, agreements on the modalities and procedures for inclusion of CCS in CDM were reached, which set up strict rules to govern CCS. The acceptance of CCS as an offsetting activity under the CDM is an important step forward and marks a significant recognition of the role that the technology can play in reducing the world’s greenhouse gas emissions (GCCSI 2011). However, China does not yet possess regulations to accommodate the procedures to incorporate CCS technology in CDM. If this can be addressed successfully, in order to determine modalities and procedures, it could pave the way for the verification of Carbon Emissions Reduction and project management, thereby providing a means to gain some revenue for a large scale CCS project.
Constraints
CO2 storage security China does not yet have a comprehensive CO2 storage atlas prepared and, although work is underway, progress is quite slow. Although there are some existing geological data, most of these are controlled by the few state-owned oil and coal companies, which are not willing to share the information. Hence the existing data is not complete and detailed enough to accurately determine the potential qualified zones for CO2 storage. In parallel, China has yet to establish the detailed level of monitoring and verification to enable regulators to satisfy themselves on the safety of CO2 storage.
Public acceptance It is evident from certain attitudes in Europe and the USA that it is essential to engage the public and environmental groups when new large scale coal based projects are introduced and, if this engagement is not wholehearted then there can be problems in ensuring local and provincial government support, especially with regard to CO2 transport and storage.
In China, the top down command economy approach could ensure that a project proceeds;
however, increasingly ensuring that the public and other stakeholders understand the issues will be beneficial for the long-term CCS development.
2.2.3 Possible ways forward From a strategic perspective, there appear to be several routes that should be considered.
Use of internal strengths to take advantage of external opportunities
The Chinese government has applied various policies to reduce emissions of SO2, NOx and particulates from coal power plant and alongside this has supported the development of the appropriate emission reduction technology within China. This offers an opportunity to build on the public demand for emissions reduction to push forward with CCS demonstration and deployment. For oxy-fuel combustion, there is considerable expertise built up in China on most aspects of the technology, which would provide a sound basis to establish further IPR opportunities.
In particular, oxy-fuel combustion technology is very suitable for the retrofitting of existing plants and this provides opportunities to establish commercial scale retrofit projects, which can also benefit from possible EOR revenue and CDM credits, together with possible international financing such as from the ADB.
Thirdly, as the national ETS scheme is established, this will offer opportunities to lower the operating cost of power plants that introduce new technology to reduce emissions such as oxyfuel.
Use of external opportunities to compensate for internal disadvantages Firstly, the government should consider accelerating the development of the national ETS to reduce the burden on the oxy-fuel power plant owners, and at the same time, the owner of an oxy-fuel plant should attract international capital for the operation of plant and attract investment funds from multi channels, such as CDM regime, to compensate the high operating costs. Alongside this, the government could consider providing some incentives to establish international cooperation projects.
The government should also define the key regulatory policy such as standards for monitoring and verifying and safety of CO2 storage, take the opportunity of international cooperation, and positively introduce and absorb international advanced experience, combining with China’s policy situation, to establish a complete set of industry regulations and standards.
Use of internal strengths to avoid or reduce the external constraints First, the government should strengthen the investment for the construction of the demonstration projects. In particular, the government should ensure a successful oxy-fuel combustion demonstration project, both to improve the stakeholder’s confidence and to be able to gain international prestige and publicity alongside probable major oxyfuel projects in the USA and the UK. This can then be fed back to other Chinese stakeholders to establish early opportunity retrofit projects. In all cases, there will be a need for CO2 storage/EOR
characterization, which could be appropriately supported by the Chinese government and preferably with international cooperation. The government should also strengthen the environmental impact assessment of oxy-fuel technology development, as a means to further publicise the technological and environmental benefits.
Means to circumvent external constraints to make up for internal disadvantage.
The government should define a set of comprehensive standards for CO2 emissions, CO2 storage and set up corresponding regulatory standards for monitoring and verifying procedures. A set of comprehensive standards are very important in the early stage of oxy-fuel combustion industrialization.
Second, the government should inform the public that these demonstration and early deployment projects are an integral part of China’s programme for environmental protection. Through a variety of promotions, the government should make the public aware of the importance of emission reduction so as to promote policies which pave the way for emissions reduction technology, such as carbon tax.
2.2.4 Concluding remarks
CCS is one of the essential technologies to reduce CO2 emissions in the global context, especially in China, which is highly dependent on coal. CCS offers a large potential for deployment, of which oxy-fuel combustion CO2 capture technology is an attractive option. There are several demonstration opportunities with retrofit applications being a promising way forward. There should be scope to establish a major demonstration project linked to other complementary initiatives such as the forthcoming national ETS and the CDM scheme. This can all be linked to international CCS programmes through the demonstration of China’s commitment to reductions in carbon intensity while also building national and international awareness of Chinese major leading role in the drive to establish commercial CCS projects.
2.3 Commercial deployment learning curves for oxyfuel technology
2.3.1 Introduction Learning curves provide a means to make projections on future cost reductions as technologies become increasingly deployed on a commercial basis, with the expectation that future technological improvements will drive down costs. It is a well-established methodology in many industries ranging from manufacturing to defense production, and has been used in advanced energy-economic models to describe cost reductions as a function of cumulative production or deployment of a technology.
The applications for energy technologies mainly cover photovoltaic modules and wind turbines, and as yet only a few have been applied to fossil fuel energy systems. That said, with the interest in CCS, some attention has been directed to cost predictions of energy technologies equipped with CO2 capture. However, the findings must be viewed as tentative since the baseline data were drawn from studies prior to 2007 since when more
comprehensive estimates have been made (Rubin and others 2007). There has been work to create a Power Technology Futures Model (PTFM) based on learning curves as a means to forecast the possible performance improvement and cost reductions (Ordowich and others 2012), as well as attempts to extend an existing model with learning curves to project future development of power plants with CO2 capture (van den Broek 2009). In China, there has been an initial estimate on the learning curves, leading to a prediction of the future cost tendency for IGCC power plants with CO2 capture (Li and others 2012).
Within this TA project, a set of learning curves has been developed to make an initial projection of the cost trends for oxyfuel combustion carbon capture technology in power plants in China and to compare it with post-combustion (PCC) and pre-combustion carbon capture technology options so as to gain some indications of future technology deployment opportunities.
2.3.2 Methodology The single-factor-experience curve is used to characterize the trends, which relates cost or efficiency to cumulative output. The formula is expressed as Y a , where Y is the specific cost or efficiency of the xth unit, is the cumulative production (installed capacity in this study) through a period, while a is the cost of the first unit, and b is a constant estimated from historical data. Four parameters remain crucial for the each learning curve: the learning rate; the baseline installed capacity; the installed capacity learning minimum ( ) and the installed capacity learning maximum ( ). The learning rate is defined as the percentage change in the variable of interest (efficiency or cost caused by a doubling of installed capacity), which is generally in the range 0 to 30% and could be estimated from historical data. Based on the definition, the learning rate could be generated as 1 2 . With regard to the baseline installed capacity, it is defined as the initial installed capacity. The learning minimum and maximum formulate the installed capacity where learning begins and ends. In this study based on the limited data and qualitative judgements about the relative maturity of current CCS power systems in China, the nominal values of for post-combustion system, IGCC system and oxyfuel system are respectively assumed to be 3GW, 5GW, 7GW and the nominal value of for these three systems are assumed to be 100GW for unprejudiced comparison (Rubin and others 2007; Li and others 2012).
2.3.3 Learning rates for fossil fuel energy systems with CO2 capture Parameters like capital cost, O&M costs and cost of electricity (COE) are often employed to assess the technical-economic performance of a power plant. For each parameter, the factors that impact on its learning may be different. In this situation, it is necessary to estimate the learning curve of each cost variable. Learning rate of the unit capital cost The total capital cost of a plant divided by the net power output is the unit investment, as presented by is the unit capital cost, ¥/kW; is the total plant capital cost, ¥; is the capital cost of
plant submit, ¥; and is the total power output, kW. According to the definition of learning rate, the expression for unit capital cost can be written in the form: , , , 1 1 1 , , ∗ ∗