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Pakistan can use coal as substitute for gas

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By Fasahat Mohiuddin

KARACHI: There is an acute gas shortage all over the country besides power, and we have to use our indigenous coal reserves to convert into natural gas to overcome the shortage instead of importing gas at very higher rates.

The natural gas reserves in Pakistan will be exhausted in the next six years against the high demand, while the government claims that reserves are for the next 20 to 25 years, which is not a factual position.

This was stated by alternate energy expert, Manaullah Khan, consultant of an American firm ATCO based in Houston, Texas, USA. Khan these days is working in the Middle East for oil companies.

Natural gas plays an important role in Pakistan’s economy, as it contributes around 50 per cent of the total commercial energy supply in the country.

Pakistan’s total remaining gas reserves are estimated at 29.80 trillion cubic feet (2008) which are adequate for meeting the gas requirement of Pakistan for 6 years at the current rate of production.

The present constrained demand of gas for 2008-09 is 5.28 trillion cubic feet. Pakistan’s gas demand and supply projections indicate a widening gap of approximately 600 MMCFD by the year 2010-11. The gap starts to emerge in 2007-08 and builds up to 1000 MMCFD by 2010-11, as the current gas fields gradually go off plateau.

It should be noted that the present international rate of natural gas is around $6.00 per 1000 cubic feet. When the cost of import plus the cost of transportation and distribution is added, it will cost 5 times higher than the present gas price in the country.

Unless we start using coal directly as a substitute for gas consumption in the power plant and other related industries, we may not be able reduce the growing demand of our natural gas.

Coal gasification and coal-to-liquid are some proven technologies available which can be successfully employed in Pakistan to reduce dependence on imported oil and natural gas.

In addition to coal, there are many waste materials like cow dung, municipal solid waste, industrial waste, rice husk, wheat and rice straw and other composite materials which can be used to produce bio gas, which can be used a substitute of natural gas for winter heating and CNG filling stations for vehicle fuels. If this waste-to-energy technology is adopted in Pakistan on a fast track basis, then the problem of gas shortage can be overcome within a few years.

Coal gasification offers one of the most versatile and cleanest ways to convert the energy content of coal into electricity, hydrogen, and other energy forms.

Rather than burning coal directly, gasification breaks down coal, or virtually any carbon-based feedstock, into its basic chemical constituents.

In a modern gasifier, coal is typically exposed to hot steam and carefully controlled amounts of air or oxygen under high temperatures and pressures. Under these conditions, carbon molecules in coal break apart, setting into motion chemical reactions that typically produce a mixture of carbon monoxide, hydrogen and other gaseous compounds.

Gasification, in fact, may be one of the best ways to produce clean-burning hydrogen for tomorrow’s automobiles and power-generating fuel cells. Hydrogen and other coal gases can also be used to fuel power-generating turbines or as chemical “building blocks” for a wide range of commercial products.

The pioneering coal gasification electric power plants are now operating commercially in the United States and in other nations, and many experts predict that coal gasification will be at the heart of future generations of clean coal technology plants for several decades into the future.

A coal gasification power plant, however, typically gets dual duty from the gases it produces. First, the coal gases, cleaned of their impurities, are fired in a gas turbine, much like natural gas, to generate one source of electricity. The hot exhaust of the gas turbine is then used to generate steam for a more conventional steam turbine-generator. This dual source of electric power, called a “combined cycle,” converts much more of coal’s inherent energy value into useable electricity. The fuel efficiency of a coal gasification power plant can be boosted to 50 per cent or more.

As early as the 1890s, lamplighters once made their rounds down the streets of many of America’s largest cities lighting street lights’ fuel with “town gas,” the product of early and relatively crude forms of coal gasification (town gas is still used extensively in some parts of the world, such as China and other Asian countries). Once the vast fields of natural gas were discovered and pipelines were built to transport the gas to consumers in the 1940s and 50s, the use of town gas phased out.

Coal gasification-based power concepts got their biggest boost in the 1990s when the US Department of Energy’s Clean Coal Technology Programme provided federal cost-sharing for the first true commercial-scale IGCC plants in the United States. Pakistan must take a similar initiative if it wants to solve the energy shortage problem.

Coal plays a major part in the world’s energy system and hence in global economic and social development. Coal currently supplies over 38 per cent of the world’s electricity and 23 per cent of global primary energy needs. Coal-fired electricity drives the economies of the two most populous and fastest growing countries in the world today, China and India, as well as a number of key industrial economies, such as the USA and Germany. Coal consumption is expected to grow by around 1.4 per cent per year over the next thirty years.

Another important local fuel which can be used is fuel grade ethanol which is a by-product of sugar mills. Brazil, India and other countries are using 20 to 30 per cent fuel grade ethanol with petrol to reduce the dependence of important fuel.

If we reduce the cost of petrol by using fuel grade ethanol, then it will reduce the use of CNG in motor vehicles. The cost of production of fuel grade ethanol can be reduced by using bio gas as fuel in place of natural gas or fuel in their boilers. The bio gas can be produced from the process waste of fuel grade ethanol plant, thereby reducing the cost of production.