Gross energy content

Source 1O ODt/annum Gross Energy Content /EJ Cost /GJ... 

Table 19.8 Gross energy contents (MJ/kg DM) of silages and the grasses from which they were made...

The results" (of three different methods) "indicate that the gross energy content of feed and faeces can be determined mo.st accurately by combustion." 1124j. 

Specific Heat and Combustion Heat The specific heat of sunflower oil at constant pressure is 2.197 J/kg °C (29). The energy content or combustion heat of an oil is a major parameter when used as an energy source. The gross heat contents of all vegetable oils are fairly close to each other. Ali and Hanna (30) report a gross heat content of regular sunflower oil of 39,575 kJ/kg, and Bhattacharyya and Reddy (31) a value of 39,486 kJ/kg. 

The H2 energy content adopted was the gross combustion enthalpy of H2 at 0°C and 1 atm, which is 3.05 kcal/1, as shown in Table 3. The absorbed light is assumed to be the same as the measured irradiation energy of the light source, at the level of the culture medium. 

Carbohydrate contents in seeds of M. oleifera ranges between 16.5-17.8%. The cmde fibre contents ranges between 3.5-4.8% (15). The gross energy by bomb calorimetry approximates 18.7 MJ kg" while the metabolizable energy is 9.5 MJkg" m.Moringa leaves (6). 

For all feed materials with high fat content (oils and fats), the EEd, Ed and OMd were assumed to be 85%, both in the growing pig and the adult sow. This value is the same as the average of the literature values and does not take into account the potential (but unlikely) differences in digestibility associated with the degree of fatty acid unsaturation. However, it cannot be used for products rich in free fatty acids (e.g.acid oils) for which the EEd (and the Ed) are much lower. Finally, the Ed of synthetic amino acids was fixed at 100% and the DE value was therefore considered to be the same as the gross energy concentration of the pure amino acid. 

Feedstock energy represents the energy of the fuel bearing materials that are taken into the system but used as materials rather than fuels. The quantities of hydrocarbon feedstocks that are taken into the system are represented in terms of their gross calorific value because, frequently, in the course of processing, some, if not all, of this feedstock may be converted to a fuel. It is a simple matter to convert from feedstock energy to mass if the calorific value is known since the energy content of a feedstock is simply the product (calorific value x mass). 

The gross energy (GE) content of foods is measured as the heat of combustion in a bomb calorimeter. Typical values are 17.5 MJ/kg,... 

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