Analysis of internal and external energy flows associated with projected process improvements in biomass ethanol production
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Elimination of seed reactors, advanced pretreatment, and thermophilic DMC all have large potential cost reductions independent of their benefits with respect to increased surplus electricity;
Steam cycle improvements and pretreatment heat integration are expected to have modest cost benefits that are dependent on increased electricity revenues; and
The relative cost of heat-pumped distillation depends on scale, capital recovery, and electricity value, but is generally similar to the already low cost of conventional distillation provided that the fermentation broth has a reasonably high ethanol concentration.
A comparison of utilizing biomass for ethanol-electricity coproduction and utilizing biomass for dedicated electricity production indicates that these two alternatives have approximately equal economic benefits. At the electricity yields associated with the futuristic process, every 1% displacement of US transportation demand is accompanied by a 0.29% displacement of electricity demand, underscoring the potential significance of electricity coproduced with ethanol in meeting energy needs.
Index EntriesBiomass ethanol electricity efficiency cogeneration
- 1.Chem Systems. Technical and Economic Evaluation, Wood to Ethanol Process. Office of Energy Demand Policy, Department of Energy, Washington, in press.Google Scholar
- 3.Lynd, L. R. and Grethlein, H. E. (1984),Chem. Eng. Prog. 81, 59.Google Scholar
- 5.South, C. R., Hogsett, D. A., and Lynd, L. R. Accepted byEnz. Microb. Technol. Google Scholar
- 7.Ladisch, M. and Schwandt, R. (1992), Report of the starch conversion work grop, inProceedings, Technology for Expanding the Biofuels Industry, Biofuels Program, Department of Energy, Washington.Google Scholar
- 10.Lynd, L. R. (1989), Fiechter, A. ed., inAdv. Biochem. Eng./Biotechnol. 38 1.Google Scholar