Reduction of Greenhouse Gas Emissions from the Oil Refining and Petrochemical Industry Reference Number: PH3/8 Date Issued: June 1999
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The reduction of greenhouse gas emission from the oil refining and petrochemical industry Report Number PH3/8 June 1999 This document has been prepared for the Executive Committee of the Programme. It is not a publication of the Operating Agent, International Energy Agency or its Secretariat. Title: The reduction of greenhouse gas emissions from the oil refining and petrochemical industry Reference number: PH3/8 Date issued: June 1999 Other remarks: Background to the Study The IEA Greenhouse Gas R&D programme (IEA GHG) is systematically evaluating the cost and potential for reducing emissions of greenhouse gases arising from anthropogenic activities, especially the use of fossil fuels. Greenhouse gases are produced from a variety of industrial activities. The main sources, not related to power generation, are those energy intensive industries, which chemically or physically transform materials from one state to another. During these processes, many greenhouse gases (carbon dioxide, methane, nitrous oxide) are released. One notable example is oil refining and petrochemicals where considerable amounts of greenhouse gases are produced. Relatively little attention has been focused on the abatement/mitigation of greenhouse gas emissions from the industrial sector. This study is the second in a series looking at greenhouse gas abatement/mitigation options for energy intensive industries. Carbon dioxide, methane and other hydrocarbons are emitted during the refining of oil, production of petrochemicals and the storage of feedstocks and products. The purpose of this study is to consider the abatement/mitigation options in the oil refining and petrochemicals industry. The study was carried out by AEA Technology of the United Kingdom. Industry overview Oil refining involves breaking down and separating the complex mixture of hydrocarbons in crude oils into standard fuel and non-fuel products. These products include; gasoline, diesel oil, heavy fuel oil, liquefied petroleum gas (LPG), bitumen and lubricants. Crude oil and natural gas are also raw materials for petrochemicals such as polymers, certain alcohols and other chemical products. Refineries, worldwide, process 10 million tonnes of crude oil per day. Large refineries produce the full range of products while smaller refineries may make only gasoline, diesel and heating fuels. Refining processes can be grouped into three classes: • separation (usually distillation) • conversion (usually thermal, catalytic or hydrocracking) • upgrading (e.g. HDS1, demetallisation, hydrocracking, catalytic cracking, coking) A refinery is a highly complex and integrated installation requiring many auxiliary facilities, including large storage facilities for feedstocks and products, extensive port and dock facilities, and on-site services such as electricity, heat and cooling. Heat is used in the many distillation, conversion, reforming and finishing (product purification) processes in the refinery, with considerable attention paid to heat integration. Motive power to turn pumps and other equipment is normally provided by 1 Hydro-desulphurisation i electricity, often generated on site. Refineries are typically fuelled by crude oil or by waste products from the conversion processes, but sometimes use coal or natural gas as well, depending on local supplies. Refining is closely related to the marketing of refined products. Both parts of the industry are closely regulated by legislation. It is essentially a commodity industry with stiff competition. The rate of return on capital is, in general, relatively low, at least in Europe. Despite this general situation, the refining industry in OECD countries has been able to adjust to stricter product quality requirements, making the necessary investments as regulations change. When addressing emissions from the refining industry it should be made clear that this is only one of the elements in the total chain from production of oil to delivery of the final service to the user, i.e. transport, work or heat. Life cycle analysis, both at the level of the overall chain and at the more detailed level of individual products, can be a revealing way of understanding the impact of different options but is outside the scope of this report. This report covers the following areas • Greenhouse gas emissions from oil refining and petrochemical processes globally. • The principal types and sizes of refining operations within (i) Europe (ii) North America (iii) South America (iv) Japan (v) Asia, identifying areas of likely expansion, outlining the main processing steps, the chemistry involved and the types of fuels used. • Current environmental legislation, pressure for ‘green’ products and how these will affect future refinery practice and the products produced. • All emissions from a typical plant as well as current recovery processes for minimising waste. • Future technological developments and any barriers to development of these technologies together with potential costs and timescales of implementation. • Future emissions to the year 2020 with consideration of future developments. Results and Discussion Many changes have occurred in the refining business, dictated largely by the demands of the market place with decreasing demand for heavy fuel oils and increasing demand for lighter transportation fuels, together with increasing environmental constraints. At the same time, there has generally been an increase in pressure to produce ‘greener’ products, such as unleaded petrol, low benzene and low sulphur fuels, and low aromatic solvents. Restrictions on sulphur content, in particular, have greenhouse gas implications for refineries. Future trends will continue towards larger and more complex refineries with the capacity for deep conversion processing of heavier crudes to lighter products. To compete with this trend, current refineries will have to expand to incorporate more processing units and increased desulphurisation capacity. Refineries and petrochemical plants are a potential source of atmospheric emissions of carbon dioxide 2 (CO2), carbon monoxide (CO), methane (CH4), Volatile Organic Compounds (VOCs ), sulphur, reduced sulphur compounds and oxides of sulphur, ammonia, oxides of nitrogen, toxic organic micropollutants (dioxins, PAHs3), heavy metals, particulates and odour. Global estimates of greenhouse gases from oil refining and petrochemicals production are shown in Table 1. 2 Volatile Organic Compounds 3 Polyaromatic Hydrocarbons ii CO2 CH4 N2O Refineries 686.9 Mt/yr in 1994 5-45 Kt/yr in 1994 1-6 Kt/yr Petrochemicals 520 Mt/yr in 1996 Not estimated 150-600 Kt/yr (adipic acid manufacture) Table 1. Global emissions from oil refining and petrochemicals The largest emission sources are associated with energy use, as shown by the breakdown of sources given in Table 2: Source Percent of refinery CO2 emissions Oil and gas fuel firing of furnaces and boilers 65% Regeneration of cat cracker catalyst 16% Flares < 3% Methane steam reforming to make hydrogen 2% Incineration and effluent processes 1% Power (55% imported) 13% Table 2 Sources of refinery CO2 emissions Typical CO2 concentrations in refinery vent gases are: 4 • From combustion plant, furnaces, boilers, flares and FCC regenerators: about 13% CO2. • From gas turbine power generators or machinery-drives: about 3% CO2. • From steam reforming process for H2 generation: up to 100% CO2. Options for reducing greenhouse gas emissions from refineries include: • refinery process optimisation; • refinery use of non-carbon-based energy sources; • reducing the carbon content of fuels; • optimising the efficiency of heat and power production and use; • reducing the amount of wastes flared; • CO2 capture and disposal. Refinery operators aim to obtain the maximum yield of valuable products for the minimum cost. These aims are consistent with minimising greenhouse gas emissions from refineries - any carbon in crude, which is not incorporated into fuels, petrochemical feedstocks or other products will mostly, sooner or later, be emitted into the atmosphere as CO2, CO or VOCs. Carbon monoxide and VOCs in their turn will be converted by atmospheric processes into CO2. An important aspect of refinery design and operation is to ensure that every process operates with maximum efficiency and minimum energy input. Low-value product or waste such as process off- gases provides much of the energy requirement. Natural gas, LNG, LPG, coal-bed methane or indeed refinery gas have lower carbon-to-hydrogen ratios than fuel oils, and will give lower greenhouse gas emissions for a given unit of energy. Gas- fired power generation is highly efficient, and future developments are expected to focus on incremental improvements to combined-cycle gas turbine technology which could allow efficiencies of up to 60% to be reached over the next decade. 4 Fluid bed catalytic cracker iii Refineries may generate their own power or purchase it from outside. Some alternative energy sources may be more suitable for internal use, some will only be usable as an external source; possible examples range through nuclear, solar, wind, geothermal, hydro. Following a series of incidents around the world, in much of Europe and North America, nuclear power has lost its mid-century image as the clean technology of the future. Elsewhere nuclear power retains importance, particularly in countries without substantial oil reserves. In Japan, for example, where nuclear power meets about 14% of the national energy needs, the nuclear share of electricity generation is likely