Methane is released as a direct result of the physical process of coal extraction. Coal is extracted through mining which in turn releases methane previously trapped within the coal seam into the air supply of the mine as layers of the coal face are removed, thus creating a potential safety hazard.
Why are there explosions in coal mines?
Coal mine explosions are generally caused by either methane or coal dust. Methane gas is a byproduct of coal. It can build up over time in coal mines when there are not enough other types of gases to dilute it to prevent an explosion. … Explosions happen when the methane comes in contact with a heat source.
What is coal bed methane and why is it controversial?
The controversy surrounding coal bed methane extraction has to do with the use of water during the process and its impact on global climate change. Coal bed methane exploration involves pumping large volumes of water out of coal seams to reduce the hydrostatic pressure and liberate the gas.
Is there methane in coal?
Coal mine methane (CMM) refers to methane released from the coal and surrounding rock strata due to mining activities. In underground mines, it can create an explosive hazard to coal miners, so it is removed through ventilation systems.
Why methane gas is collected prior to exploitation of coal from coal mine?
Due to coal mining activities (and subsequent pressure decrease in coal seams), methane is released from the coal and surrounding strata. This leads to the build-up of methane in mines, which potentially creates an explosive hazard.
How do you stop coal dust explosions?
Coal dust explosions in underground coal mines are prevented by generous application of rock dust (usually limestone). If an explosion should occur, the rock dust disperses, mixes with the coal dust and prevents flame propagation by acting as a thermal inhibitor or heat sink.
Which factor explains why coal dust is explosive?
Coal dust suspended in air is explosive—coal dust has far more surface area per unit weight than lumps of coal, and is more susceptible to spontaneous combustion. As a result, a nearly empty coal store is a greater explosion risk than a full one.
Where is coal bed methane found?
Why is coal seam gas so controversial?
Coal seam gas (CSG) is a polarising issue in some communities. Proponents argue that CSG is a vital energy resource, necessary for continued gas supply. Opponents claim that CSG could have serious environmental and social impacts.
Is methane a liquid or gas?
At room temperature and standard pressure, methane is a colorless, odorless gas. The familiar smell of natural gas as used in homes is achieved by the addition of an odorant, usually blends containing tert-butylthiol, as a safety measure.
Does burning coal release methane?
Methane gas leaks from the ground both naturally and from coal, oil, and gas extraction. New research shows that more of the gas in the atmosphere comes from the fossil fuel industry than previously thought.
Which product is formed when coal is heated in the absence of air?
Coal gas, gaseous mixture—mainly hydrogen, methane, and carbon monoxide—formed by the destructive distillation (i.e., heating in the absence of air) of bituminous coal and used as a fuel. Sometimes steam is added to react with the hot coke, thus increasing the yield of gas. Coal tar and coke (qq.
How is coal bed methane extracted?
Methane may be extracted by drilling wells into the coal seam. The goal is to decrease the water pressure by pumping water from the well. The decrease in pressure allows methane to desorb from the coal and flow as a gas up the well to the surface. Methane is then compressed and piped to market.
Is coal seam gas renewable?
Coal seam gas is a non-renewable energy resource that is a by-product of coal. It is a ‘pure’ and ‘non-toxic’ gas and for this reason has attracted a lot of commercial interest. During the process of coal formation, biogenic and thermogenic methane gas forms.7 мая 2012 г.
How is coal formed?
Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years.
What is coal bed methane Upsc?
Coal bed methane (CBM) refers to a reserve of natural gas stored in coal seams. It is an unconventional form of natural gas. … Coal Bed Methane could also be an important topic for the UPSC Prelims Exam.