In the Vision Statement Bangladesh, the government has declared that ‘Electricity for All’ will be ensured by 2020, writes Shaidur Rahman Khan
The energy demand of Bangladesh is increasing day by day and people need more and more energy to pass their life comfortably and conveniently. The need for electrification of entire Bangladesh remains just as vital today. At the present time, the United States has the World’s largest economy. Since all industrial and other economic activities rely on electricity or other means of power, the primary energy production can be considered as an indicator of a country’s economic strength. The USA has about 6% of world’s population, but consumes more than 30% of the world’s energy. On the contrary, India has 15% of the world’s population and consumes only 1% of the world’s energy. Bangladesh has about half of the USA population and about 1/8 of the India’s population. However, the energy production in Bangladesh is not a match to either of these countries. The Power generation of Bangladesh is mainly depends on gas but the gas reserve of Bangladesh is depleting very rapidly. According to experts in the hydrocarbon industry, the demand and supply gap will continuously be widening as the government failed to make a move in proper time considering the situation. At present, the country produces about 1,700 million cubic feet (mmcf) of gas per day against a demand for 1,800 mmcf. The shortage is about 100 mmcf a day. The demand is growing at 8-10 percent per year while the gas production is not rising proportionately for constraints on the exploration and transmission side. The government has moved for holding 3rd round gas-block biding. But it takes at least 7- 9 years to get gas from any block to be allocated through the latest bidding. Despite such a situation in view, the country does not have any dependable option to rapidly increase production to cope with the demand side. If this situation remains unchanged, within few years the gas based power plant and fertilizer factories would be seriously sufferings. Then agriculture and other industries would be in threaten condition. So Bangladesh urgently needs alternative energy source and coal is the only source to meet the long term energy demand of the country.
In the Vision Statement Bangladesh, the government has declared that ‘Electricity for All’ will be ensured by 2020. As, it would be difficult to supply gas in any new power plant with the present reserve, then coal is the only option left for power generation. For generation of 20,000 MW power about 60 million tones of coal per annum (Barapukuria quality) is required. Bangladesh coal reserve is around 2500 million tones. Underground method can extract maximum 20% of the resource, In Bangladesh experience it is likely to be less than 10%; so by underground method of mining only 250 million tones can be extracted. Whereas it can be mined more than 90% by open pit method. Considering the demand of Bangladesh, open pit mine is the only viable option.
Now the geological and other considerations: The coal deposits of Bangladesh are mainly concentrated in three districts (Dinajpur, Rangpur and Joypurhat). The generalized stratigraphy of the coal basins of that region is Madhupur Clay at the top which is between 3m to 15 m thick and beneath this layer high water bearing Upper Dupi Tila Formation having thickness of more than 100m followed by Lower Dupi Tila Clay comprising of mainly impermeable clay layer.
Permian Gondwana sediments underlying by the Dupi Tila Formation are hosted the coal basins such as the Barapukuria and Phulbari. The Permian Gondwana sediments are underlain by Basement rocks.
Coal seams of northwestern part of Bangladesh is believed to be connected with the overlying Dupi Tila aquifer through fractures and fissures and in some cases there is no confining layer between coal and Dupi Tila aquifer. Also the immediate roof rock is not strong enough to support the overburden. So considering the geological, hydrogeological conditions and position of the resources of the northwestern part of Bangladesh, it is assumed that open pit mine would be suitable for that region except Jamalganj Coal Field (1053 m depth).
Coal seams in the northwestern part of Bangladesh are very thick. Underground mining is not appropriate method of mining for very thick coal seams as it leads to unsafe and poor recovery of resources, inevitable surface subsidence. Specially in the conditions of northern Bangladesh where coal fields are located, difficult geological, geotechnical and hydrogeological conditions will inevitably lead to flooding and water inrush, roof collapse, spontaneous combustion of coal with lethal Carbon monoxide emissions, methane gas concentrations in mine environment threatening explosions and permanent loss of land over the mining areas. Barapukuria mine for example mined so far only approximately 400,000 tonnes of coal where subsidence is already reported. More mining will invite permanent loss of land, displacement of people and leading the subsided area to be a waterbody.
Barapukuria mine also demonstrates how much dangerous and unsafe working conditions are prevailing there ; already 6 people are killed in the mine so far including expatriates; Very high temperature (42°c & 52°c above and below the coal seam VI ) and 100% humidity offers low productivity, rapid loss of equipment, non functional electronic devices due to humidity, problem of retaining workforce, high waterflow (Barapukuria mine pumps 280 litres per seconds of water to prevent mine flooding), problem of uninterrupted power supply; shortages of timber supply (underground mine development needs timber supply for roof support ) and very difficult pillar less mining in the inclined and thick seam conditions.
By developing open-cut mine in the northwestern part of Bangladesh, the country would get high quality coal resource which would ensure long term energy security at affordable price. The open-pit mine development in that region would be one of the largest developments in Bangladesh and has the potential to bring significant benefits to the country. Local and regional benefits directly attribute to the mine development including public revenue; employment opportunities, infrastructure development (rail, road, international port facilities), security of energy resources, reduce demand on declining gas reserves; improve access to sanitation, health and educational facilities. Coal mining would provide opportunities for increase economic growth through both private investment and direct employment.
But we can not ignore social and environmental impact by the open-cut mining activities. There are technologies best practices for the environmental impact mitigation. Also proper compensation, rehabilitation and resettlement framework are needed for the affected people by the mining activities. Before implementation of the open-cut mine, it would be an urgent need for ensuring the implementation of appropriate technological measures for environmental impact management and proper rehabilitation of the project affected people. The writer is a geologist
Source: The News Today
Date: 27/04/2008
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