Eskom UCG Strategic Intent

Transcription

1 Eskom UCG Strategic Intent Chris Gross Dr Mark Van der Riet EPPEI, Technology Division Eskom Holdings SOC Ltd South Africa Presented at : FFF & IEA-CCC Conference, Underground Coal Gasification - going forward, 13th to 14th July 2011, Johannesburg, South Africa.

2 Content 1. Context 2. Eskom s UCG Strategic Drivers 3. Majuba Coalfield, South Africa 4. Eskom UCG Program 5. Environmental Impacts 6. Risk Status 7. UCG Performance 8. Conclusions 2012/02/28 2

3 Context

4 Context Coal is one of South Africa s largest primary energy resources. Eskom presently generates 88% of its electricity from coal. This predominance will decrease, with the introduction of alternative energy carriers to mitigate the impact of the continued usage of coal (refer to IRP 2010). Coal will however remain a dominant, albeit reducing primary energy carrier for the foreseeable future in RSA. Eskom has therefore run a comprehensive Clean Coal Technology research and development program for several decades, to explore, identify and demonstrate solutions for continued coal usage. Underground Coal Gasification (UCG) is one of the advanced clean coal technology options being demonstrated by Eskom 2012/02/28 4

5 Context - Eskom Primary Energy 2009/10 : 246,566 GWh Net 2012/02/28 5

6 Context - Policy Adjusted IRP 2010 There is a clear intent to start moving South Africa away from coal in the next two decades Policy Adjusted IRP Capacity 2010 to 2030 Total capacity Capacity added (including committed) from 2010 to New (uncommitted) capacity options from 2010 to MW % MW % MW % Coal OCGT CCGT Pumped Storage Nuclear Hydro Wind CSP PV Other Total IRP Section 7.4 Research into Underground Coal Gasification (UCG) should have a priority in the research agenda as there is a potential for this option to be used in place of natural gas. Existing 2010 capacity = 43,895 MW (including non-eskom generators) Less decommissioning capacity (-10,902 MW up to 2030) = 32,993 MW by /02/28 6

7 Eskom s UCG Strategic Drivers

8 Eskom s UCG Strategic Drivers 1. Security of supply 2. Clean energy 3. Flexibility Baseload option Lower C0 2 Emissions Modularity, lead time 4. Utilize Unminable Coal 5. Lower cost option Potentially 350GWe Better utilisation than conventional mining Competitive R/MWh 2012/02/28 8

9 RSA Unminable Coal Resources UCG enables the effective extraction and use of previously unminable RSA coal resources Map Source : S Walker, Major Coalfields of the World, IEA CCC/32, June 2000 Three quarters of South Africa s coal resources are currently regarded as unminable. UCG is ideally suited to extracting such coals. UCG is therefore a strategic energy option for the country s future. 2012/02/28 9

10 Majuba Coalfield, South Africa

11 Majuba Colliery at closure : /02/28 11

12 Why choose Majuba for UCG? Majuba coal field was found to be unminable by conventional means due to dolorite intrusions, heat affected coal and seam displacements Coal seam metres deep Eskom owned the Mineral Rights Land used for cattle farming, and Eskom owns the farm land Study showed that gas could be cofired with coal at Majuba power station giving a direct use for the gas. Study also showed that gas could be used as a fuel for a modern, high efficiency IGCC power station. Dolorite intrusions Majuba 4100MW power station 2012/02/28 12

13 Eskom UCG Program

14 Majuba UCG 2012/02/28 14

15 Eskom UCG Development Plan 20th January th October 2010 Done 2002 Scoping Study 2003 Pre-feasibility Study 2005 Site Characterisation Commissioned 5000 Nm3/h pilot plant on Majuba coalfield Commissioned Nm3/h cofiring into Majuba power station Provisional Future Dates Apr 2009 Dec 2011 Mar 2015 Sep 2015 Mar 2020 Sep 2022 Demonstration Plant Current Design Construction Commission 2100MW 1 st Proof-of-Concept Plant To do Design Construction U1 Comm U2 Comm U3 Comm U4 Comm U5 Comm U6 Comm 2012/02/28 15

16 UCG Project Progress UCG technology scan - April 2001 Scoping study highlighted potential at Majuba colliery - Nov 2002 Pre-feasibility study confirmed Majuba potential - Dec 2003 Site characterisation study confirmed the potential - July 2005 Eskom flarestack 20 Jan 2007 Commissioned a Nm 3 /h pilot plant - 20 Jan 2007 First electricity generated from UCG gas at Majuba - 31 May 2007 Eskom has licenced UCG technology from Ergo Exergy Technologies Inc. (Canada) 100 kw converted diesel genset 2012/02/28 16

17 UCG Project Progress Eskom Co-firing : Commissioned new co-firing gas treatment plant Jun 2010 Commissioned new 7km x 600mm NB pipeline to Majuba power station Jun 2010 Gas co-fired into Majuba U4-28 Oct 2010 UCG-OCGT demo plant : Design study underway for a demonstration plant comprising 250,000 Nm 3 /h gas production and a MW gas turbine plant Gas Pipeline to Majuba power station 15,000 Nm3/h gas treatment plant 2012/02/28 17

18 UCG Phased Development Pilot Demo 1 st Proof-of-Concept Plant 5-15,000 Nm3/h 250,000 Nm3/h 3,800,000 Nm3/h MW OCGT Approx MW CCGT per unit X multiple units = approx MW This figure explains UCG modularity, and the technology roll-out 2012/02/28 18

19 Environmental Impacts

20 Environmental Impacts : Water Baseline water sampling performed of aquifers, including coal seam Water from surrounding aquifers monitored from shallow and deep boreholes, in concentric rings surrounding the process UCG is monitored extensively with piezometers (for measuring pressure & temperature) No UCG contamination evident 2012/02/28 20

21 Environmental Impacts : Air Baseline air quality tests done prior to UCG Permanent meteorological station on the UCG site monitors wind speed/direction, ambient temperature, barometric pressure Eskom s continuous ambient emission monitoring stations monitor meteorological parameters, SO 2, NO 2, O 3, PM 10 etc. Additional comprehensive audit completed for : meteorological parameters, CO, CO 2, SO 2, H 2 S, NO, NO 2, BTX, NH 3, PM 10, PM 2.5 etc. Permanent monitoring site to be established UCG-IGCC promises a reduction in greenhouse gas emissions, compared to conventional power stations 2012/02/28 21

22 Environmental Impacts : Land Comprehensive plan in place with management and rehabilitation procedures. Regular audits done. Baseline flora & fauna survey and soil tests done prior to UCG starting up Majuba site shows natural vegetation re-establishes rapidly after drilling disruption Surface impact minimal postgasification Subsidence is being monitored at Majuba using devices for conventional underground monitoring. The potential strata collapse has also been modelled. No subsidence observed yet. 2012/02/28 22

23 Risk Status

24 Risk Status Feb 2011 Risk Rank Mitigation Environmental High Monitoring, engagement design, Permitting Licences & High Engagement Cost Creep & Financial Medium Project management Resources Skills & Medium Recruitment & training Schedule Creep Medium Project management 2012/02/28 24

25 UCG Performance

26 Majuba Seam Detail Details in another Eskom presentation Coal Seams 2012/02/28 26

27 Eskom s UCG Production Data Operating Data - 20 Jan 2007 to 20 Jan 2011 : Total coal consumed/gasified = tons Total gas produced = m 3 A representative CV of the gas was 4.2 MJ/Nm 3 The average efficiency is 72 % 20 GJ/ton) Current gas production rate = m 3 /hr (6768 cfm) Average well exit temperature = 168 ºC (344 ºF) Maximum well exit temp (normally temporary) = 430 ºC (806ºF) Average water consumption = 0.58 litre per kg of coal. 2012/02/28 27

28 UCG Gas Composition Range Gas composition varies with the lifetime of the production well, and between production wells. Gas composition depends on the operating parameters such as P and flow, and also on the design of the underground gasifier. Incorrect gasifier design or operation can result in the gasifier running in combustion mode. The final volume of gas is a blended average from several production wells. UCG Gas - major components only Composition (% by vol) Hydrogen H Oxygen O Water Vapour H 2 O 5 Atm. Nitrogen N Carbon Monoxide CO 7-12 Carbon Dioxide CO Methane CH Calorific Value LHV MJ/Nm /02/28 28

29 Conclusions

30 Conclusions UCG is a promising clean coal option which allows the effective extraction and use of previously unminable RSA coal resources UCG has a role to play in the reduction of greenhouse gases and has possible potential for carbon capture and storage The Eskom UCG pilot has been operating reliably since Jan months and counting!! No environmental concerns have been noted to date Eskom has embarked on the phased research, development and demonstration of the technology, culminating in the 1 st Proof-of-Concept Plant comprising approximately 2100 MW 2012/02/28 30

31 THANK YOU Eskom UCG website URL : /02/28 31