Environment Sustainable Development test - 8

The Pollutant Standards Index, or PSI, is a type of air quality index, which is a number used to indicate the level of pollutants in air. The PSI is reported as a number on a scale of 0 to 500. The index figures enable the public to determine whether the air pollution levels in a particular location are good, unhealthy, hazardous or worse.

A catalytic converter is an emissions control device that converts toxic gases and pollutants in the exhaust gas to less toxic pollutants by catalysing a redox reaction (an oxidation and a reduction reaction). Catalytic converters are used with internal combustion engines fuelled by either petrol (gasoline) or diesel—including lean-burn engines as well as kerosene heaters and stoves. These converters combined oxygen with carbon monoxide ($$CO$$) and unburned hydrocarbons ($$HC$$) to produce carbon dioxide and water.

Biogas or gobar gas refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.It is composed of 75% methane and 25% carbon dioxide.

Non-luminous flames are the ones that burn blue. These flames have access to as much oxygen as they could possibly use, so they can burn very efficiently. All of the carbon that gets used can be turned into carbon dioxide, so there's actually no soot. Complete combustion of LPG takes place. Hence, it burns with a blue flame.

The Complete Combustion of Natural Gas yields carbon dioxide and water. Complete combustion happens when the hydrocarbon burns in an excess of air. An excess of air means that there is more than enough oxygen to cause all of the carbon to turn into carbon dioxide.

The methane gas burns with a clear blue flame.

methane + oxygen  $$\rightarrow$$ carbon dioxide + water + energy

$$CH_4(g) +  2O_2(g)   \rightarrow  CO_2(g) +  2H_2O(l)$$           

The reaction is exothermic. The heat released from burning natural gas is used for central heating and to generate electricity.

Liquefied Petroleum Gas or LPG consists mainly of methane, propane, propylene, butane, and butylene in various mixtures. It is produced as a by-product of natural gas processing and petroleum refining. The components of LPG are gases at normal temperatures and pressures.

Compressed natural gas (CNG) can now be used as a fuel for gas-fueled captive power plants. Natural gas as fuel source has a significant number of benefits versus diesel including reduced emissions and reduced fuel costs.

Natural gas can be used to generate electricity in a variety of ways. The most basic natural gas-fired electric generation consists of a steam generation unit, where fossil fuels are burned in a boiler to heat water and produce steam that then turns a turbine to generate electricity. It is a non-renewable resource. Natural gas is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is another resource and fossil fuel found in close proximity to and with natural gas.

CNG is stored in pressurized vessels or spheres. They are gaseous in nature at STP. For it to be transported and used it is liquefied and kept in pressurized tanks. 

Ethyl mercaptan, is a colourless gas or clear liquid with a distinct odour. It is an organosulfur compound with formula $$C{ H }_{ 3 }C{ H }_{ 2 }SH$$.

Thioethanol also known as ethyl mercaptan, is a colourless gas or clear liquid with a distinct odour. It is an organosulfur compound with formula $$C{ H }_{ 3 }C{ H }_{ 2 }SH$$.