Case Study : Underground Gasification (UCG) – Majuba Update

Mark van der Riet Corporate Consultant Eskom Holdings Ltd South Africa

Introduction

• Eskom presently generates 88% of its electricity from coal. • This predominance will decrease, with the introduction of alternative energy carriers. • Sustainable options are required to mitigate the continued usage of coal. • Eskom has run a comprehensive Clean Coal Technology research and development program for several decades, to explore, identify and demonstrate solutions. Coal Roadmapping

• Technology demonstrations are essential • Technology transfer is required • No single technical solution fits all needs • South Africa needs to reduce dependency on coal for primary energy • Eskom’s own Clean Coal Roadmap is closely aligned with international best practice • South Africa is also embarking on a national coal roadmap (SANERI/FFF) IEA CCC Clean Coal Roadmap for India and RSA to 2030

Source : IEA-CCC 152, C Henderson, SJ Mills, Sept 2009

IEA-CCC suggested targets : 90% CO 2 removal, 45% efficiency, near-zero NO x, SO x, particulates Eskom’s Clean Coal Programme • Improved efficiencies on existing Sub Critical Pulverised Coal • Supercritical Pulverised Coal – Medupi & Kusile • Ultra-Supercritical Pulverised Coal - scanning • Fluidised Bed Combustion - pilot • Conventional and advanced emissions control - FGD • Surface gasifier - IGCC • Carbon Capture and Storage • Underground coal gasification – IGCC IGCC = Integrated Gasification Combined Cycle UCG-IGCC Basic Principles

Surface Plant (incl. IGCC) commercially proven with other gases

Gas out

Air in UCG is a process where air is injected into the cavity, water enters from surrounding strata, and partial combustion and gasification take place at the coal seam face after ignition. The UCG commercially proven resulting high-pressure gas in Former Soviet Union stream is returned to the (FSU) – Eskom is surface, where the gas is demonstrating in RSA dried and then combusted in Graphic Reference : Science & Technology a high-efficiency power Review, Lawrence Livermore National Lab, USA, station to generate April 2007 electricity. UCG – Current World Trends

• FSU – Uzbekistan : Angren commercial plant refurbishing • New Zealand : Solid Energy NZ starting site characterisation R&D. Eventual UCG-CCGT • USA : • Laurus Energy investigating a 2.3 bt resource in Wyoming • CIRI developing a 100MW UCG-CCGT in Alaska

• LLNL investigating the potential of UCG + H 2 production + CO 2 sequestration • : • Linc Energy Pilot plant recommissioned. Relocating to S. Australia • Carbon Energy 100d pilot trial successful. 20MWe pilot with CCS announced • Cougar Energy site characterisation successful, and 10,000 Nm3/h pilot under construction UCG – Current World Trends cont.

• UK : • Being investigated for coal under the Firth of Forth • Clean Coal investigating 5 North Sea coal resource sites • VP Power drilling in the Kish Basin, Dublin Bay • India : • GAIL approved a feasibility study • Abhijeet Group investigating UCG-CCGT • Pakistan : approved a feasibility study for UCG-CCGT • : study underway with JV : Marubeni, Linc Energy and Vinacomin • China : • Historically 16 sites, typically small scale • New initiatives underway for SNG and methanol, following a successful 1 month trial • Southern Africa : Eskom & Sasol, with several other entrants emerging Eskom Strategic Drivers for UCG-IGCC 1.Security of supply Baseload option

Lower C0 2 Emissions (25 % lower than super critical PF 2.Clean energy coal)

3.Flexibility Modularity, lead time

Potentially 350GWe

4.Utilize Unminable Coal Better utilisation than conventional mining

5.Lower cost option Competitive R/MWh LCA Comparative Emissions

1000 4.0

900 3.5 800 3.0 700 600 2.5 500 2.0

400 1.5 300 CO2 kg/MWh net kg/MWh CO2 1.0 200 100 0.5

0 0.0 net kg/MWh NOx/SOx/Particulates Conv PF Super PF Conv IGCC UCG-IGCC Nat Gas CC (Without FGD) (With S removal to suit GT) CO2 NOx SOx Particulates

Data Reference : Australian ACARP Life Cycle Assessment (LCA) study, Case Study B20, June 2002 The only cleaner coal-based technology is the developing ultra-supercritical PF Environmental Precautions

Outer Water Sampling Zone Water : • Surrounding aquifers monitored monthly – concentric perimeters. No Inner Water Sampling Zone UCG contamination evident Production Area Air : • Baseline air quality tests. Continuous ambient emission monitoring Land :

• Baseline flora & fauna survey & soil UCG Water Monitoring Network tests • Comprehensive EMP & regular audits • Majuba site shows natural vegetation re-establishes rapidly after drilling Ambient Monitoring Station disruption • Subsidence is being monitored at Majuba using devices for conventional underground monitoring. The potential strata collapse has also been modelled. Minimal subsidence observed Sungazer Lizard Preservation UCG Aquifer Philosophy

• The UCG cavity pressure always maintained < hydrostatic pressure • flow is always inwards • Production wells steel-lined & cemented down to coal seam • protects the surrounding aquifers • Ash left underground Diagram not in proportion In Majuba, coal seam is 3-5m thick, and 280m underground • UCG temperature = + 1200 oC • leaching tests underway • Majuba seam capped by 180m of

dolorite sills & segmented by dykes Seam • Lateral water flow is nil/low • Australian pilot (1999-2003) had 3 rd party audit, approved by Austr. EPA Resource Utilisation Efficiency 20% of coal resource utilised

Thermal Efficiency Beneficiation Mining

20 50 66 0% Super-critical Power Station with Longwall Mine & Beneficiation 100%

36% of coal resource utilised

Thermal Efficiency Chemical Efficiency Mining Efficiency

36 71 95 0% UCG-IGCC 100%

Thermal 0.5% of resource utilised Efficiency 1% Extraction Efficiency

50 0% CCGT with CBM 100% UCG Coal Value Chain Reduction = Less Cost

The shorter value chain translates to lower cost, confirmed with Eskom concept-level and international costing Eskom’s UCG Progress

• Scanning study - April 2001, Eskom noted UCG technology potential. • Scoping study - Nov 2002, highlighted potential at Majuba colliery • Pre-feasibility study - Dec 2003, confirmed Majuba potential • Detailed site characterisation study - July 2005, confirmed the potential • 20 th January 2007 – Eskom 3 commissioned a 3-5000 Nm /h pilot plant Gas Pipeline Horseshoe construction on Majuba coalfield • 31 st May 2007 – first electricity generated from UCG gas at Majuba • 7km x 600mm NB steel pipeline built to link UCG with Majuba U4  Mar 2010 – cofiring UCG gas into Majuba  Design underway for a 100 - 140 MW OCGT demo plant  Engineering and EIA will commence thereafter for a new 2100 MW power station, based on UCG and Combined Cycle Gas Turbine-Steam Turbine 108 MWe Alstom GT11N2 Eskom’s UCG Progress

UCG Site Eskom’s UCG Progress

Average Gas Quality (ex. Pilot plant, May 2009) : Min (% vol) Max •Hydrogen H2 14.0 18.0 •Oxygen O2 0.2 0.2 • Water Vapour H2O 5.0 5.0 • Atm. Nitrogen N2 44.3 52.0 • Carbon Monoxide CO 7.0 11.0 • Carbon Dioxide CO2 16.5 18.5 •Methane CH4 2.8 4.5 Eskom UCG Indicative Development

2005 20th January 2007 2003 2002 Site Commissioned Pre-feasibility Characterisation 5000 Nm3/h pilot plant Done Scoping Study Study on Majuba coalfield

Apr 2009 Mar 2011Jan Jun 2014 2014 Mar 2018 Sep 2020

6MW Cofire

DRA = Decision Release Approval = Design, Engineering & Costing 40MW Demonstration Plant ERA = Execution Release Approval = Procure, Construct and Commission To do Ph2 DRA ERA COD

2100MW Commercial Plant U1 U2 U3 U4 U5 U6 DRA ERA COD COD COD COD COD COD UCG CCS Potential

+ UCG creates a cavity that could

potentially sequester CO 2 + The remnant coal, char and ash would

have a higher surface area for CO 2 sorption + Infrastructure and wells already in place – Requires depth > 800m

– Interaction of CO 2 with remnant coal, char and ash must be proven There is much research to be done ! – UCG leaves behind a heat effect cavity, with unknown behaviour UCG Conclusions

• UCG is a promising clean coal option which allows the effective extraction and use of RSA coal resources • UCG has a role to play in the reduction of greenhouse gases and has possible potential for carbon capture and storage • UCG is gaining momentum worldwide • The Eskom UCG pilot has been operating reliably for 33+ months • No environmental impacts have been noted to date • Based on work to date, UCG appears to be a very promising, stable and viable primary energy (baseload) option with potential on multiple sites • Eskom is embarking on commercialisation of the technology, with the first milestone being successful operation of a 40 MW demonstration plant Thank You

Eskom’s Ankerlig OCGT Majuba UCG E Class GT