Analysis of internal and external energy flows associated with projected process improvements in biomass ethanol production
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
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