Coal and Petroleum

Natural gas is very important fossil fuel as it is very easy to transport through pipes, apart from this also it can be stored under high pressure as compressed natural gas (CNG) which is being used now a day as a fuel for transport vehicle.

CNG stands for Compressed Natural gas. In CNG compressed gas (which is mainly methane gas) is stored under high pressure as compressed natural Gas. Advantages of CNG:

• CNG is a very important fossil fuel because it is easy to transport through pipes.
• CNG is also used for power generation and now used as fuel for transport vehicles because it is less polluting.
• It is a cleaner fuel.
• Due to the absence of any lead or benzene content in CNG, the lead fouling of spark plugs is eliminated.
• CNG-powered vehicles have lower maintenance costs when compared with other fossil fuel-powered vehicles.
• CNG fuel systems are sealed, which prevents any spill or evaporation losses.
• CNG mixes easily and evenly in air being a gaseous fuel.
• CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 �C) and a narrow range (5%-15%) of flammability. That is it is less polluting and more efficient.

Also natural gas is used as starting material for the manufacture of a number of chemicals and fertilisers.

Some exhaustible natural resources like coal, petroleum and natural gas are called fossil fuels as they are formed from the dead remains of living organisms (fossils). Fossil fuels are non-renewable resources because they take millions of years to form, and reserves are being depleted much faster than new ones are being made. The production and use of fossil fuels raise environmental concerns.

Coal: About 300 years ago the earth had dense forests in low lying wetland areas. Due to natural processes, like flooding these forests got buried under the soil. They get sank deeper and deeper and temperature gets increasing day by day, under high pressure and high temperature dead plants slowly got converted to coal. Coal's primary use is for the generation of electricity. It is also used in the industrial and retail sector as fuel for heating and powering foundries, cement plants and other industrial and manufacturing facilities.

Petroleum: Petroleum was formed from organisms living in the sea. As these organisms died, their bodies settled at the bottom of the sea and got covered with layers of sand and clay. Over millions of years in absence of air and under high temperature and high pressure the dead organisms get transformed into Petroleum and natural Gas. Petroleum is a dark oily liquid. It has an unpleasant odour. It is a mixture of various constituents such as Petrol, Diesel, etc. and the process of separating these constituents from crude oil is called Refining.

Coal is a hard and black coloured non-metal which is used to cook food, in the past it was also used to run railway engines, apart from this it is also used to produce electricity in thermal power plant; it is also used as fuel in various industries. Following are the products of coal:

Coke: Coke is a product of coal; it is tough, porous, and black in colour and almost pure formof carbon. It is used in making steels and in extraction of many metals

Coal tar: coal tar is the product of coal which is the mixture of various substances. Products obtained from coal tar is used for manufacturing a variety of products like dyes, drugs, perfumes, explosives, paints, photographic materials, roofing materials etc.

Coal gas: Coal gas is obtained during the processing of Coal to get coke. It is used as a fuel in many industries situated near the coal processing plants.

Petroleum is a dark oily liquid. It has an unpleasant odour. It is a mixture of various constituents such as Petrol, Diesel, etc. and the process of separating these constituents from crude oil is called Refining. The refining of petroleum is done in a petroleum refinery for petroleum products.

Exhaustible resources like coal, petroleum are formed from the dead organisms, it takes millions of years for formation of these fuels, and On the other hand the known reserves of these will last almost a few hundred years. A part from this since these products are not environmental friendly as burning of these fuels is a major cause of air pollution and their use is also linked to global warming therefore we should use these resources only when it is actually required. Wise use of natural resource will result in better environment, smaller risk of global warming and their availability for a longer period of time.