Carbon Dioxide Emission by Combustion Fuels:

Carbon Dioxide Emission by Combustion Fuels:

Environmental emission of carbon dioxide - CO2 - from fuels like coal, oil, natural gas, LPG and bio energy

To calculate the CO₂ emission from a fuel, the carbon content of the fuel are multiplied by the ratio of the molecular weight of CO₂ (44) to the molecular weight of carbon (12) -> 44/12 = 3.7.

Approximately environmental emission of Carbon Dioxide - CO₂ - from the combustion of different fuels can be approximated from the table below:

Fuel	Carbon Content (kg C/kg fuel)	Energy Content (kWh/kg)	Emission of CO2 (kg CO2/kWh)
Coal (bituminous/anthracite)	0.75	7.5	0.37
Gasoline	0.9	12.5	0.27
Diesel	0.86	11.8	0.24
Light Oil	0.7	11.7	0.26
Natural Gas, Methane	0.75	12	0.23
LPG - Liquid Petroleum Gas	0.82	12.3	0.24
Bioenergy	0	-	0

Bioenergy is produced from biomass derived from any renewable organic plant, including

· dedicated energy crops and trees

· agricultural food and feed crops

· agricultural crop wastes and residues

· wood wastes

· aquatic plants

· animal wastes

· municipal wastes and other waste materials

Emissions of CO2 can contribute to climate change. Combustion of bioenergy don't add to the total emission of carbon dioxide as long as the burned biomass don't exceed the renewed production. (Emission of CO₂ from combusting wood is in reality approximately 0.18 kg/hWh)

A variety of biofuels can be made from biomass resources, including

• ethanol

• methanol

• biodiesel

• Fischer-Tropsch diesel
  

• gaseous fuels like hydrogen or methane

Energy from Nuclear Fuel:

Energy from Nuclear Fuel:

Nuclear energy is the energy that directly releases after controlled Atomic reactions. Nuclear power is obtained from release of nuclear energy, a type of nuclear technology involving the controlled use of nuclear reactions. Out of two (fission and fusion) known technology, fission technology is used by nuclear power plant and fusion technology is under development stage.

A. In nuclear fission technology is splitting of the nucleus of an atom to produce two more or less equal fragments. In this process, a large amount of energy is produced; which is used for generation of electricity. This phenomenon of fission reaction is mostly done with nuclei of the element uranium; when bombarded by neutrons, to produce a great variety of products including large amount of heat energy.

B. Nuclear power plants generate electricity by using heat obtained from such fission reaction; usually use uranium-235 (U-235) as fuel. The nucleus of U-235 has 92 protons and 143 neutrons. When bombarded by extra neutrons on U-235, it loses atomic balance and becomes unstable to split into smaller pieces of fission products and releases more neutrons. This post splitting mass difference causes to release huge energy in the form of heat. The extra neutrons produced responsible for further chain reaction within the leftover mass of uranium. In nuclear power plant this generated heat is utilized to drive a turbine generator to produce electricity. As no physical burning of fuel is taken place, the nuclear power plants emit very low carbon dioxide (CO2) as compared to their counterpart of coal, oil or gas fired power plants. World has quite a large reserve of Uranium (more than gold); mostly located in Australia (35 per cent), Russia and CIS countries (29 per cent), Canada (13 per cent), Africa (8 per cent), and South America (8 per cent).

C. Nuclear power poses great environmental advantages:

• Emission of carbon dioxide and other greenhouse gases into atmosphere is very negligible; thereby not responsible for global warming;
• Quantum of energy obtained is very large from very less quantity of nuclear fuel (the complete fission of 1 kg of U-235 could produce 8 x 1013 joules of energy, almost one million times more than the amount of energy produced by burning 1 kg of coal);
• Neutron produced from fission reaction used for initiating self-sustaining series of reactions; i.e., chain reaction, results in a continuous release of nuclear energy.

D. Nuclear Fusion technology is to combine two light atomic nuclei to form one heavier nucleus. This process generates tremendous amount of energy - heat. As this technology generates enormous amount of energy, we are now struggling to control this quantum of energy obtained out of fusion reaction– thereby, not yet developed fully. Developed world is making every effort to make nuclear fusion technology workable. The energy released from atomic fusion can be unimaginably great - our celestial Sun and other stars shine through this fusion since their inception. If fusion energy does become practicable it would offer the advantages such as:

(1) an effectively limitless source of fuel;

(2) it would be of inherent safety , as the amount of radioactive material present would be much low;

(3) as waste products that are less radioactive and simpler it would be easer to handle them than those from fission .