Analysis of internal and external energy flows associated with projected process improvements in biomass ethanol production
- Cite this article as:
- Stone, K. & Lynd, L.R. Appl Biochem Biotechnol (1995) 51: 569. doi:10.1007/BF02933459
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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.