Tag: chemistry

Otto cycle is the typical cycle for most of the cars internal combustion engines that work using gasoline as a fuel. To reduce pollution LPG is used as a source of clean fuel. Blast furnace gas may be combined with natural gas or coke oven gas before combustion. Hence all of the above are used for internal combustion of engines.

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.

Compressed Natural gas is the cleanest of all the fossil fuels, composed primarily of methane. The main products of the combustion of natural gas are carbon dioxide & water vapor, which are the same compounds we exhale when we breathe.  Coal & oil are composed of much more complex molecules, with a higher carbon ratio & higher nitrogen & sulfur contents. This means that when combusted, coal & oil release higher levels of harmful emissions, including a higher ratio of carbon emissions, nitrogen oxides & sulfur dioxide. Coal & fuel oil also release ash particles into the environment, substances that do not burn but instead are carried into the atmosphere & contribute to pollution.

The combustion of natural gas, on the other hand, releases very small amounts of sulfur dioxide & nitrogen oxides, virtually no ash or particulate matter & lower levels of carbon dioxide, carbon monoxide & other reactive hydrocarbons

Compressed Natural Gas happens to be a very viable alternative to traditional fuels particularly for use in the automobile industry. Being low in pollutants, high in calorific value and heat yield, economical and available in abundance globally, CNG is the perfect alternative for most.

Secondly, CNG is environment friendly as it reduces vehicular exhaust emissions significantly. Carbon Monoxide emissions are reduced to a maximum of 90 per cent and Hydrocarbon emissions by 60 per cent as compared to vehicles that use Petrol. Carbon Dioxide emissions, a cause for global warming, are also reduced significantly by 10 per cent.

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.

Liquefied Petroleum Gas is considered as cleanest fuel because of the following reasons:

1. LPG has a high calorific value. The calorific value of LPG is about 50 KJ/g.
2. It is very neat and clean domestic fuel. LPG burns with a blue smokeless flame and leaves no ash behind. So, it does not cause any pollution. Therefore, LPG is a clean fuel.
3. It does not produce any poisonous gases on combustion.
4. LPG is easy to handle and convenient to store.
5. LPG is easy to handle and can be ignited almost instantaneously.

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. 

Energy can neither be created nor destroyed, but it does change its form. And not all forms of energy are usable and it gets dissipated as heat energy and sound energy. The energy that is wasted cannot be recovered. Moreover, the current sources or energy such as fuels are non-renewable in nature and are rapidly consumed. That is why we are facing energy crisis.

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.

CNG is made by compressing natural gas which is mainly composed of methane, to less than 1 percent of the volume it occupies at standard atmospheric pressure. It is stored and distributed in hard containers at a pressure of 20–25 MPa, usually in cylindrical or spherical shapes.