Lower calorific value

The rotary kiln design allows for accepting a mix of high-chlorinated wastes (solvents, chlorinated tars, plastics). Such kilns are usually designed in relation to a specific optimal calorific value in the input. The input mix should be set in such a way that this optimal composition is approached (e.g., PVC waste and other waste streams with a lower calorific value). It is likely that a 100% input of PVC would lead to all kind of problems of temperature control due to its relatively high calorific value. Chlorine contents of over 50% can easily be accepted. A final demand is that the particle size should be 10 x 10 x 10 cm at maximum. This implies that sometimes waste has to be shredded before it can be put into the kiln. Other acceptance criteria have not been published in literature. 

LHV Lower heating value (= lower calorific value)... 

Comparison of the organosulfur compounds produced by pyrolysis of eastern Oklahoma coals from within one seam shows that lower rank (lower calorific value) coals consistently yield high concentrations of thiophenes relative to benzo- and dibenzothiophenes. Pyrolysates of higher rank coals contain lower concentrations of organosulfur compounds than coals of lower rank and are dominated by dibenzothiophenes. Coals of similar rank (e.g. 517 and 512) from different seams yield markedly different distributions of organosulfur compounds upon pyrolysis, suggesting that the distribution is controlled by source material as well as maturity. 

AHc is different from the lower calorific value measured in an oxygen bomb calorimeter... 

Treblinka would have required 430 million pounds, or 195,000 metric tons, of air-dried (seasoned) wood. Due to the short notice and brief time that Himmler allegedly allotted for this process, such a large quantity of air-dried wood would certainly have been impossible to get, which is why only fresh ( green ) wood of lower calorific value would have been available. The calorific value of seasoned wood is 3,600 kcal/kg, whereas that of green wood is only 2,000 kcal/kg.113 Therefore the total required quantity of wood would have increased to 351,000 metric tons, and the daily requirement of green wood was thus approximately 1,900 metric tons. Assuming medium-sized trees of 1 cord volume and 1,500 lbs., the total number of trees needed comes to roughly 515,000. 

Fuel analysis results presented in Table 1 provide a comparison between the biofuels and coal. On an as-fired basis, the four bio els had significantly lower calorific values (8- 3 MJ/kg) compared to coal (21 MJ/kg), partly attributable to the higher moisture content of the biofuels. Also, biofuels had lower ash and fixed carbon contents but relatively higher volatile matter contents than both coal and bark/coal blend. 

Basis for Plant Design. The composition of municipal refuse is assumed as shown in Table III. The municipal refuse has the lower calorific value of ca. 1,500 Kcal/Kg. Plant size of 600 T/D is assumed. The capital investment costs, utilities, etc. were calculated using contacts with equipment vendors. Cost for repairs are assumed to be two percent of the plant construction cost per year. Unit costs of utilities and unit prices of recovered energy and material are assumed, based on the actual prices in 1979. Ash and other residues disposal cost is assumed to be 2,450 Yen/T, taking note of the representative cost data of large cities in Japan, The grant available to a municipality is assumed to pay up to fifty percent of the capital investment. The remaining investment cost must be amortized in fifteen years with the interest rate of six percent. 

Although both are graded solid fuels of broadly similar bulk densities there are significant differences in respect of other properties. The densified refuse derived fuel has a lower calorific value, higher ash content and lower ash fusion temperature. The major differences are the much higher proportion of volatile matter in the dRDF coupled with a very much lower value for the fixed carbon. These differences are likely to be sufficient to render not only the combustion properties different, but also the deposition from the respective flue gases. 

A common cause of confusion arises between the use of the gross (or upper) and the net (or lower) calorific value. 

Producer gas is made by the partial combustion/gasification of coal in a gas producer. It has a lower calorific value than natural gas or liquid petroleum gas. 

As with conventional S I-engines, running on hydrocarbon liquid fuels, the means of fuel mixture, either internal or external, is important. As mentioned above, naturally aspirated hydrogen engines utilizing external mixture formation have a lower power output than comparable gasoline engines of the same cylinder capacity. This is mainly due to the lower calorific value of the mixture per cylinder volume. 

Water gas had a lower calorific value than coal gas, so the calorific value was often boosted by passing the gas through a heated retort into which oil was sprayed. The resulting mixed gas was called carburetted water gas. 

A minimum temperature of 1100°C, combined with a residence time of 4 s, is needed in the high-temperature zone to ensure satisfactory destruction of organics. To achieve the minimum temperature a lower calorific value of about 5000 kcal/kg (9000BTU/lb) is needed for the feed. This is easily reached for hydrocarbons and other solvents containing little water. However, if much water is present, additional support fuel may be necessary. 

In all cases the heat of combustion of the solvent to be destroyed needs to be known. In almost every case the water generated in the destruction will be discharged as water vapour and so the lower or net calorific value is the appropriate one to use and it is the one quoted here. The only common solvent which has no hydrogen to convert to water and therefore has identical higher and lower calorific value is carbon disulphide. 

Starch industry Amylases, amylogluco-sidases and glucoamylases Glucose isomerase Converts starch into glucose and various syrups. Converts glucose into fructose in production of high-fructose syrups from starchy materials, with enhanced sweetening properties and lower calorific values than sucrose. 

Kotas, T.J. The Exergy Method of Thermal Plant Analysis. Malabar, Fla. Krieger Publications, 1995. Proves that the fuel chemical exergy and the lower calorific value of the fuel, with different units, are numerically equal. 

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)... 

The comparison of physical properties of biogases with various origins and natural gas are depicted in Table 2.6. Biogases have lower calorific value, flame speed and flammability limits compared with natural gas, mainly because of COj presence (Porpatham et al. 2008). 

Duarte and Maugeri (2014) studied lipid production by Candida sp. LEB-M3 cultivated in pure and raw glycerol. The feasibility of biodiesel production by the yeast Candida sp. LEB-M3 was indicated by predicting FAME properties for pure and raw glycerol respectively, including cetane number (56—53), heat of combustion (37—39 kJ/g), oxidative stability (8.58 h), kinematic viscosity (3.82—3.79 mm /s), density (807—872 kg/m ), and iodine index (74—115.5 gE/lOOg). Leiva-Candia et al. (2015) estimated biodiesel properties produced from SCO derived from Rhodosporidium toruloides, Lipomyces starkey, and Cryptococcus curvatus cultivated on biodiesel by-product streams. More specifically, cetane number (62.39—69.74), lower calorific value (37,393.49—37,561.68 kJ/kg), cold-filter plugging point (4.29—9.58°C), flash point (158.73—170.34°C), and kinematic viscosity (4.6—34.87 mm /sat 40°C) were determined. 

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