Coal bed methane and underground coal gasification


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A brief introduction to coal bed methane (CBM) and underground coal gasification. It includes yields and possible environmental impacts. A group presentation as part of my MSc at Keele University.

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  • Use in pulverized and fluidized technologies 1. install a membrane in the flue gas stream which diverts the CO2 flow while allowing others to flow Bind with the solvent then heated release stream of co2 recycle back some co2 escapes also call CO2 scrubbing technique. Run the capture process decrease the efficiency 9% amine solvent and chilled ammonia
  • H2 rich fuel gas need not to be pure hydrogen as it goes trough a combined cycle. But this is ten to twenty times expensive than conventional. By gasification technologies N2 can be converted to fertilizer. 10% of the mercury still remains
  • Since one molecule of methane is replaced by two molecules of CO2, and assuming a cost of CAN$28.50 per tonne of CO2, the CO2 for injection would account for CAN$57.00 of the gas price per tonne of methane produced. If some of the CO2 in the injection gas can be replaced by nitrogen (ie in flue gas), the economics improve
  • freeze-thaw/evaporation. This technology reduces the volume of water to be disposed through injection by evaporation during summer months and by factional freezing during the winter. It has been implemented successfully as a pilot in the San Juan
  • Coal bed methane and underground coal gasification

    1. 1. Can Coal Really Be Green? ESC: 40032 Clean & Green Technology II: Power From Beneath The Earth By: Daniel Wilson Udeshika Weerakkody
    2. 2. <ul><li>“ Green technology or clean technology is the application of the environmental science to conserve the natural environment and resources, and to curb the negative impacts of humans ( )” </li></ul><ul><li>To be Green: </li></ul><ul><ul><li>Should not entail pollutant emissions or other hazardous to the environment on substantial scale </li></ul></ul><ul><ul><li>Should not involve the perpetuation of substantial human hazards or social injustices </li></ul></ul><ul><ul><li>Should not be substantially depleted by continuous use </li></ul></ul>
    3. 3. Coal <ul><li>Pollutants: Carbon monoxide, Methane, </li></ul><ul><li>Carbon dioxide, Particulate matter, Nitrogen </li></ul><ul><li>oxides, Sulphur dioxides, Trace elements </li></ul><ul><li>(Arsenic, Lead, Flourine, Mercury), </li></ul><ul><li>H 2 O (gas) </li></ul><ul><li>Globally, coal mines emit approximately 400 million metric tons or 28 billion cubic meters of Carbon dioxide equivalent annually . </li></ul><ul><li>About 8% of total anthropogenic methane emissions come from coal mines (Lee, 2008) </li></ul><ul><li>17 billion tons of coal remain in UK </li></ul>
    4. 4. Clean Coal Technology (CCT) <ul><li>“ Technologies designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation and use” (Department of Trade and Industry, 1994) </li></ul><ul><li>“ Clean coal” is the industries green washing buzzword to “clean up” its dirty image –(Greenpeace, 2009) </li></ul>
    5. 5. Cleaner Coal Technology <ul><li>Coal washing-Lowers the level of sulphur and minerals in the coal. </li></ul><ul><li>Pollution Control in Existing Power Plants </li></ul><ul><ul><li>Selective catalytic reduction (SCR) and Low Nitrogen Burners - NO X </li></ul></ul><ul><ul><li>Flue Gas Desulphurisation (FGS)- SO 2 </li></ul></ul><ul><ul><li>Electro Static Precipitators and fabric filters </li></ul></ul><ul><ul><li>(ESP) – Particulate matter </li></ul></ul><ul><ul><li>Activated Carbon Injection – Mercury </li></ul></ul><ul><li>Supercritical Pulverised Coal Combustion (PCC) - uses high pressures and temperatures </li></ul><ul><li>Fluidised Bed Coal Combustion (FBC)- Use lower temperatures </li></ul>
    6. 6. Post Combustion Capture Flue gas Boiler Steam Turbine Standard emission controls (SCR, FGD, ESP) CO 2 Capture Steam Electricity & Water Coal Air Captured CO 2 Flu Gas (N 2 , O 2 , H 2 O) Flue gas
    7. 7. Carbon Sequestration <ul><li>Growing additional forests </li></ul><ul><li>in large scale </li></ul><ul><li>Depleted oil or gas wells </li></ul><ul><li>Deep coal seams </li></ul><ul><li>Saline aquifers </li></ul><ul><li>Ocean sequestration </li></ul><ul><ul><li>Capture and inject deep into the ocean </li></ul></ul><ul><ul><li>Enhance the natural absorption </li></ul></ul>
    8. 8. Technologies and Processes for total emission prevention <ul><li>Coal-fired Integrated Gasification Combined cycle (IGCC) – Producing electricity with Carbon capture </li></ul><ul><li>Coal Bed Methane (CBM) </li></ul><ul><li>Underground Coal Gasification (UCG) </li></ul><ul><li>Integrated Gasification Fuel Cells (IGFC) </li></ul>
    9. 9. Integrated Gasification Combined Cycle (IGCC) Water gas shift reaction Gasifire CO 2 capture Gas cleaning Gas turbine Steam turbine Coal Oxygen H 2 O Slag CO-rich syngas H 2 O steam H 2 rich syngas (CO 2 and H 2 Captured CO 2 Exhaust gas Capture emissions Electricity Flue gas (N 2 , O 2 , H 2 O) H 2 rich fluegas Electricity
    10. 10. Enhanced Coal Bed Methane (ECBM) Coal CH 4 CO 2 injection Microbial Conversion Displace
    11. 11. CO2 Injection CO2 Tank & Pump Trucks CO2 Compressor Drilling New Well Coring Bit
    12. 12. Environmental Impacts of ECBM <ul><li>Groundwater depletion </li></ul><ul><li>Disposal of large volumes of produced water; Cause goiters, patterns of multiple sclerosis, cancer and high mortality rates </li></ul><ul><li>Methane contamination of shallow groundwater </li></ul><ul><li>Noise pollution </li></ul><ul><li>Air pollution </li></ul><ul><li>Surface disturbances </li></ul><ul><li>Ground water acidification </li></ul>
    13. 13. UCG UCG successfully being used in Australia, Uzbekistan, China and India. Potential of 17 Billion tons of coal remains in the UK (Hestor 2010). Can be successfully paired with intermittent renewables (Davison 2009). H2 can be 17% more efficient than UCG (Gnanapragasam et al 2010). Source:
    14. 14. Environmental risks of UCG with Carbon Capture <ul><li>Groundwater pollution, toluene and benzene. (Shu-qin et al 2007). </li></ul><ul><li>CO 2 changes pH of groundwater, increasing mobility of metals. </li></ul><ul><li>Risk of subsidence and underground explosions. </li></ul><ul><li>Lack of scientific knowledge of deep UCG and CCS. </li></ul><ul><li>Supercritical CO 2 may be deeper than 800m, due to impurities in the waste stream. </li></ul>
    15. 15. Conclusion: Can Coal Really Be Green? <ul><li>- If conventional coal power stations are shutdown. 45% efficient drops to 35% when CCS is used. Oxyfuel adds 5% to the efficiency. </li></ul><ul><li>- Shallow coal is used for CBM with CCS. Minimal emissions. </li></ul><ul><li>- Deep coal is used for H 2 production with CCS. 98.5% capture rate. </li></ul><ul><li>- All underground coal workings need thorough surveying. </li></ul>
    16. 16. <ul><li>Fossil fuel subsidy world wide is $312bn a year (IEA World Energy Outlook 2010). Need to subsidise UCG and CBM, not conventional fossil fuel extraction and combustion. </li></ul>
    17. 17. References <ul><li>Boyle,G. Everett, B . (2003). Energy and sustainablity power for a sustainable future . oxford university press </li></ul><ul><li>Davison, J. 2009. Electricity Systems With Near-Zero Emissions Of CO 2 Based On Wind Energy And Coal Gasification With CCS and Hydrogen Storage. International Journal Of Greenhouse Gas Control . 3, pp.683-692. </li></ul><ul><li>Gnanapragasam, N. Reddy, B. Rosen, M. 2010. Hydrogen Production From Coal Gasification For Effective Downstream CO 2 Capture. International Journal Of Hydrogen Energy . 35, pp.4933-4943. </li></ul><ul><li>Hestor, R. Harrison, R. eds. 2010. Carbon Capture Sequestration & Storage. Royal Society of Chemistry </li></ul><ul><li>Jaccard. Kenneth, M. (2007). sustainable fossil fuel:The unusual suspect in the quest for clean and enduring energy , Cambridge university press </li></ul><ul><li>McGovern,M. (2007). CO2-Enhanced Coalbed Methane Recovery in the Allison Unit, San Juan Basin. Burlington Resources Inc. </li></ul><ul><li>Shu-qin, L. Jing-Gang, L. Mei, M. Dong-lin, D. 2007. Ground Water pollution From Underground Coal Gasification. Journal Of China University Of Mining & Technology . 17 (4) pp.0467-0472. </li></ul><ul><li>Wong,S. Gunter,W.D. Law, D. Economics of Flue Gas Injection and CO2 Sequestration in Coalbed Methane Reservoirs , Alberta Research Council </li></ul><ul><li> </li></ul><ul><li> </li></ul><ul><li> </li></ul><ul><li> </li></ul>
    18. 18. Questions ?