Higher calorific value

The waste products from any process (gases, liquids and solids) which contain significant quantities of combustible material can be used as low-grade fuels for raising steam or direct process heating. Their use will only be economic if the intrinsic value of the fuel justifies the cost of special burners and other equipment needed to bum the waste. If the combustible content of the waste is too low to support combustion, the waste will have to be supplemented with higher calorific value primary fuels. 

A high-density fuel is preferred because it normally has the greatest heating value per unit volume of fuel. Jet fuels derived from paraffinic crudes have a slightly lower density but higher calorific value per equivalent mass than those refined from naphthenic crudes. 

Higher calorific value compared to HTPB and therefore better ballistic performance. 

In another method the poisonous carbon monoxide is oxidized by ferric oxide to innocuous carbon dioxide, the product containing 85 per cent, of hydrogen, and having a lower density and higher calorific value than ordinary water-gas ... 

Feedstock Characteristics. Feedstock characteristics are presented in Table I. Results of the metal analysis will be considered in Phase II of the project. Calorific values were approximated using Dulong s formula and not actually measured. The oat straw had a lower ash content than the stover and a correspondingly higher calorific value. Calorific values, calculated on a dry basis and including the latent heat of water vapour in the products of combustion (high heat value), were 17.9 MJ/kg for the straw and 16.0 MJ/kg for the stover. 

These gases are often of higher calorific value than the low BTU gas obtained with gas generators, but include higher hydrocarbons. These products must be separated by condensation, in order that the engine burn only the incondensable part. 

A multiple-hearth reactor has been successfully tested for the production of high yields of liquid fuels and chemicals. The reactor enabled the separation and recovery of water on the one hand and oil fractions or the other hand. Biooil yields reached about 50% by weight of the air-dry feedstock. Both the oil and charcoal have a higher calorific value than the raw wood feedstock. 

Lower equilibrium moisture contents resulted in the solid products having higher calorific values. In addition, the effective calorific value of peat fuel decreased as the level of moisture increased. The gross calorific value (CV) determined by the bomb calorimetric method and the effective calorific value (ECV) of the samples are shown in Table 1. The ECV was calculated using the equation as described on (flS M 8814 ) ... 

Waste with higher calorific values yield higher energy in incineration. The calorific value of waste varies with the country In China, Korea, or Brazil, the values are -4,000-6,000kJ/kg, and in the United States... 

Polymers, composed of long molecules based on carbon-carbon links, are inherently combustible. Many, such as the polyolefins, have a much higher calorific value than coal. It is not surprising that the materials suppliers have invested enormous resources into improving the flammability resistance of plastics. There are many ways of assessing burning performance, e.g. ... 

Why do some coals have a higher calorific value than pure carbon ... 

Higher calorific value (MJ/kg) Lower calorific value (MJ/kg) Flue-gas volume (1 bar, 0°C) (m /kg) Flue-gas loss (sensible heat) (MJ/kg) Efficiency based on higher value Efficiency based on lower value Adiabatic combustion temperature (°C)... 

Plastics have a higher calorific value than coal and superficially it would seem logical to use waste plastics instead of fossil fuels. However, in Europe (although not in Japan) public opinion is turning away from burning waste because of the perceived (although not necessarily real) dangers of toxic effluent. Incineration is not seen by the public to be a safe process and this conception may be difficult to reverse. 

Boiler efficiencies were equal to or slightly greater with the TDF blends due to its higher calorific value and low moisture content. 

In Equations (3.7) to (3.9) FC, M, and A stand for the mass percentages of fixed carbon, moisture, and ash from proximate analysis and St is the total sulfur determined in ultimate analysis, whereas HHV is the higher calorific value of the coal in MJ/kg [10]. 

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