Energy input costs

Raw material costs Energy input costs Royalty and licence payments... 

The U.S. chemical industry achieved an annual reduction of 4.2% in energy input per unit of output for the period 1975—1985 (2). This higher reduction resulted from cost optimization, the tradeoff of increased capital for reduced energy use, that was driven by energy prices (4). In contrast, from 1985 to 1990, the energy input per unit of output has been almost flat (2) as a consequence of falling prices. The average price the U.S. chemical industry paid for natural gas fell by one-third between 1985 and 1988 (1,5). 

Equation (9-245) also shows that the fixed-capital cost per unit of energy input must not exceed 40,000 (GJh ) h or 144 per... 

The dryers make use of warm air, flue gases, and direct radiant heat to the liquid-particle mixture. This method allows complete extraction of the solid through removal of the liquid by vaporization. Due to the energy input required with this method, it is the most costly. 

Andraos, J. (2005) On Using Tree Analysis to Quantify the Material, Input Energy, and Cost Throughput Efficiencies of Simple and Complex Synthesis Plans and Networks Towards a Blueprint for Quantitative Total Synthesis and Green Chemistry. Organic Process Research and Development, 10, 212-240. 

The catalytic esterification of ethanol and acetic acid to ethyl acetate and water has been taken as a representative example to emphasize the potential advantages of the application of membrane technology compared with conventional distillation [48], see Fig. 13.6. From the McCabe-Thiele diagram for the separation of ethanol-water mixtures it follows that pervaporation can reach high water selectivities at the azeotropic point in contrast to the distillation process. Considering the economic evaluation of membrane-assisted esterifications compared with the conventional distillation technique, a decrease of 75% in energy input and 50% lower investment and operation costs can be calculated. The characteristics of the membrane and the module design mainly determine the investment costs of membrane processes, whereas the operational costs are influenced by the hfetime of the membranes. 

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