Category: Fuel and Combustion

For any hydrocarbon fuel, we have xCnH2n + 2 + yO2 → aCO2 + bH2O where x, y, a, and b are constants to be evaluated. Equating the weights of C, H, and O on both sides of the equation, we have xn = a or a = xn x(2n + 2) = 2b or b = [x/2] (2n + 2) = x(n + 1)   2y = 2a + b or y = a + [b/2] = xn + [x/2] (n + 1) = [x/2] (3n + 1) Substituting there…

The following chemical equations are used to calculate the amount of oxygen required and the amount of gases produced by the combustion of fuel, by using the molecular weight of the elements in kg:

The cooling of flue gases to room temperature is not possible in most combustion processes. Therefore, the amount of latent heat of water vapour goes waste. Accordingly, for the calculation of the lower calorific value, we assume that the water vapour formed during combustion leaves as vapour.   LCV = HCV − heat carried away…

All fuels containing hydrogen produce water vapour during combustion. If these products of combustion are cooled to the room temperature, the water vapour will condense evolving its latent heat of vapourisation, producing the maximum amount of heat per kg of fuel. This heat is known as higher calorific value (HCV).

The calorific value of a solid or liquid fuel is defined as the heat evolved by the complete combustion of unit mass of fuel. The calorific value of a gaseous fuel is expressed as the heat evolved by the complete combustion of one cubic metre of gas at standard temperature and pressure. There are two…

The ultimate analysis gives the percentage of each chemical element in coal, along with ash and moisture. This analysis gives the following components on mass basis: Carbon (C), hydrogen (H2), oxygen (O2), nitrogen (N2), sulphur (S), moisture (M), and ash (A). Thus, C + H2 + O2 + N2 + S + M + A = 100 %…

The proximate analysis of coal is carried out to determine its behaviour when heated. It gives the percentage of fixed carbon, volatile matter, moisture content, and ash content. This analysis is sufficient for commercial purposes. The following procedures are adopted to estimate the various contents of coal:

The analysis of solid fuels may be carried out in two ways: proximate analysis and ultimate analysis.

The organic material produced by plants and their derivatives is called biomass. It includes forest crops and residues, energy crops, and animal manure. It reacts with oxygen in combustion and natural metabolic process to release heat. The material may be transformed by chemical and biological processes to produce intermediate biofuels such as methane gas, ethanol,…

LNG comes from dry natural reservoirs, mainly constituting about 85–90% of methane (CH4) with very small percentages of ethane and propane. Its critical temperature is about 73°C. It is found in coal reserves in tight sands and is trapped in geo-pressurised zones within the earth. LNG is obtained when natural gas (NG) is placed under…