Ethanol conversion

Moles of H2 produced per mole of ethanol converted. b Approximate exit compositions at close to 100% ethanol conversion as the data are extracted from respective figures. c Traces of ethylene was also detected. 

The next parameter of importance is the Peclet number of the liquid and the gas phase. For the specified Reynolds number, the Peclet number for the liquid phase using the Michell-Furzer correlation (eq. (3.417)) is 0.74. The minimum value of Z/dp for ethanol conversion between 0.1 and 0.9, evaluated using the Mears criterion (eq. (3.421)), is 2.84 and 62.11 respectively, much lower than the value used in the example, which is about 2500. Thus, the operation can be assumed to follow the plug-flow model. 

Process Capital investment (Smillion) Annualized capital cost ( ) (capital charge factor, 0.17) Minimum ethanol selling price ( /gal ethanol) Conversion of hexose to EtOH ... 

Some functional clarification of these problems has been provided by recent comparative genotyping of alcoholics and non-alcoholics. Studies in Chinese (83-85) and in Japanese (86,87), supported by meta-analysis (88), indicated significantly reduced frequencies of beta2 and gammai in alcoholics, besides the usually present aldehyde dehydrogenase deficiency (see below). It means that the high rate of ethanol conversion to the toxic and unpleasant acetaldehyde tends to reduce ethanol consumption, particularly if acetaldehyde is slowly metabolized. 

Ethanol conversion facilities can readily be designed to use fuel sources other than oil or natural gas. Small-scale on farm plants can utilize corn stover as a boiler fuel, and larger plants can rely on coal as a boiler fuel to produce process steam. The ethanol production process can then be viewed as a means of converting lower grade energy forms, such as coal, distressed crops or solar energy, into premium transportation fuel. 

Ethanol Feedstock Costs (Canadian I) for Lower, Middle, and Upper Values of Tuber Yield Range, and Increasing Ethanol Conversion Factors (I t-1 tubers), Given a Land Price of 2,500 ha-1 in Quebec... 

Carbonylation activity of ethanol using ethyl iodide as a promoter has been investigated using RhNaX as a catalyst (208,211). Some carbonylation activity does occur, with formation of ethyl propionate however, ether and also olefin formation results in rather poor selectivities to the ester. The selectivity decreases with increasing ethanol conversion. Olefin formation was ascribed to a dehydrohalogenation reaction, i.e.,... 

Figure 6-3.2 Yield of acetaldehyde as a function of ethanol conversion. Data were obtained at 518 K. Data points (in order of increasing ethano conversion) were obtained at space velocities of 26,000,52,000,104,000, and 208,000 h"h The curves were calculated for a first-order series reaction in a plug-flow reactor and show yield of the intermediate species B as a function of the conversion of reactant for various ratios of rate constants and. [Reprinted with permission fiom Ind. Eng. Chan. Prod. Res. Dev., 22, 212 (1983). Copyright 1983 American Chemical Society.]...

Table 1 gives the dependence of ethanol and phenol concentration in the condensate and degree of conversion of organic substances on temperature. With a temperature rise from 550 to 700 the ethanol concentration decreased from 12,000 mg dm to trace levels. This corresponds with a change in the degree of ethanol conversion from 94 to almost 100%. These values are consistent with a chan in the degree of conversion of organic substances Xqqq, based on the COD of the liquid reagents before and after reaction. Phenol was analyzed in the condensate because it is an intermediate product of the reaction. Its concentration was small and decreased slightly with temperature increase. The effect of DPS concentration in the gas mixture on the yield of the oxidation process is presented in Table 2. The experiments were carried out at 600 C.

Algal productivity, starch content and ethanol conversion rate... 

Catalysts were prepared in three different methods impregnation, impregnation followed by treatment with NaBLL, and precipitation of NiC204 on Y203. A high ethanol conversion of about 98% and H2 selectivity of 55% were obtained at 380 °C. H2 selectivity did not increase above 500 °C. 

Approximate exit compositions close to 100% ethanol conversion as the data are extracted from respective figures. 

---