Fuel equivalent condensate

It Is possible, of conrse, that the solvatu might be less volatile than the raffinate and more volatile than the extract, or vice versa. In any event, the total fuel equivalent is determined by ndding the appropriate subeel of Eqs, (22.2-9)-(22.2-12), These equations assume thet ihe overhead condensers in the recoveiy distillations accrue neither penalty (refrigamtion) nor credit (hent recovery), If this is not the case, the appropriate adjustments may be made in the manner described in the paragraphs on distillation. 

In most cases, Qf ei is calculated based on the lower heating value of fuel. G,- is quantified in different units according to specifications in the marketplace, namely, Btu/h for fuel, Ib/h for steam, and kWh for power. Thus, specific FE factors can be developed as follows based on this general definition of fuel equivalent. Energy are required for making boiler feed water (BFW), condensate and cooling water. The FE factors for these utilities will be discussed in Chapter 3. 

Other criteria can be used to establish the extinction condition and that are partially equivalent to the critical Damkohler number. Such criteria are a critical mass transfer numbers (BCI) [21,32], critical mass flux of fuel [2,6,28] or critical temperatures (Ta) [2,5,29-31], The critical mass transfer number has a direct influence over the flame temperature, and thus, represents the link between the condensed phase (i.e., production of fuel) and the chemical time. The critical mass flux operates under the same principle, but assumes a consistent heat input. Combustion reactions generally have high activation energy, therefore, the reaction can be assumed to abruptly cease when the temperature reaches a critical value (Tcr). 

Figures 4 and 5 present model calculations for a Montana Rosebud coal-fired, potassium carbonate seeded combustor operated under slightly fuel-rich conditions (equivalence ratio = 1.09). Note that KPO2 and KPO3 are the dominant neutral phosphorus species at all temperatures. Negative ion chemistry is dominated by PO2 and PO3 below 2000 K, phosphorus species negative ions outnumber free electrons. The only negative ion which Is comparable in concentration to PO2 is Fe02 and then only at the upper temperature range. The sharp temperature falloff of Fe02 Is caused by the stability of condensed Iron containing species.

By mixing the stack gas with air, and by convective mixing above the stack, the mole fraction water vapor is reduced, and hence the condensation temperature is reduced. However, for equivalent dilution, the coal-burning plant will always have a lower condensation temperature. Thus, on cold winter days, the condensation of water vapor will occur more often and to a greater extent from power plants firing natural gas than from those using other fuels. 

The biosynthetic reactions involve a series of condensation processes and are distributed between cytosol and microsomes. All of the carbons of cholesterol are derived from acetyl-CoA, 15 from the methyl and 12 from the carboxyl carbon atoms. Acetyl-CoA is derived from mitochondrial oxidation of metabolic fuels (e.g., fatty acids) and transported to cytosol as citrate (Chapter 18) or by activation of acetate (e.g., derived from ethanol oxidation) by cytosolic acetyl-CoA synthase (Chapter 18). All of the reducing equivalents are provided by NADPH. 

Table 4.12 Estimated total reserves of fossil fuels (after World Energy Council 2002). Approximate conversion to tonnes of oil equivalent based on energy equivalence factors of 1.07 for natural gas liquids (condensate), 0.9 for heavy oils, 0.7 for hard coals, 0.47 for brown coals, 0.23 for peat and 0.861 per 103m3 for gas (1 tonne crude oil = c.7.3 barrels = c.l.lbm3)...

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