Prospect of underground coal gasification in Bangladesh
Main source of energy fuel in Bangladesh is natural gas and day by day it is trimming the proven reserves. There are provisions of potential renewable energy resources like the solar, wind, tidal etc.; but the initiatives are very slow. Coal reserves and their prospects could not assure the nation as there are proven coal reserves of about 4,750 Mt (equivalent to 975 GM3 of gas, which is around 3 times greater than the present gas reserve in Bangladesh). Those coal reserves are discovered in the North-Western part of Bangladesh at the depth ranging 200-1100 m. The special feature of the coal seams are found in the same geological formation and thickness is high (on average 38-64m).One of the major issues, is the minable amount of the resources in conventional mining method. Barapukuria coal mine is under operation since 2005 and running a 250 MW coal fired power plant. But the mining method is not yet proven as suitable one, due to jointed layer thick coal seam (51 m) with faulty overburden and wider aquifer zone. The underground mining environment is hazardous including high temperature, suffocative humidity and releasing of unpredictable carboneus gases from the coal faces which make the life expectancy of this mine questionable. The geographical position and climatic conditions of Bangladesh, especially the monsoon rain extends several weeks to months which are major setback for economic viability of the open striping mining. The policy makers still could not finalize the national coal policy. In this stage the government is stepping up for construction of coal fired power stations run by imported coal. A group of skilled and dedicated entrepreneur is seeking the pathways for exploiting unminable coals within a safe engineering framework and bringing the global Underground Coal Gasification (UCG) projects under the same umbrella. India, Pakistan, Indonesia, Japan even the Vietnam has already joined the cohort. But why not Bangladesh, though they have huge amount of coal reserves which are not minable in conventional methods. This paper presents a review on development of this technology, investigates the geology and formation of the deposits and seeks suitability of the gasification methods as a sustainable engineering model considering social, environmental & economic issues, which may be helpful for fore stepping towards unconventional coal extraction activity for combating energy crisis.
