Analysis of internal and external energy flows associated with projected process improvements in biomass ethanol production
- General Electric Company, Schenectady, NY (United States)
- Dartmouth College, Hanover, NH (United States)
Possible improvements in biomass ethanol production are described involving heat-pumped distillation, steam-cycle heat integration, elimination of seed fermenters, pretreatment heat integration, advanced pretreatment, thermophilic DMC, and increased carbohydrate yield to 90% of theoretical. Relative to the current state-of-the-art National Renewable Energy Laboratory process design, the futuristic process has 101% higher electricity revenue, 31% higher ethanol revenue, and 35-39% higher overall revenue depending on the assumed ethanol value. The overall first-law thermodynamic efficiency is 43% for the current NREL design and 59% for the futuristic process. A general consideration of the costs associated with the process improvements examined indicates that: (1) 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; (2) Steam cycle improvements and pretreatment heat integration are expected to have modest cost benefits that are dependent on increased electricity revenues; and (3) 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.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- OSTI ID:
- 150442
- Report Number(s):
- CONF-940526-; CNN: Contract RD-1-11068; Contract XAE-3-13005-01-104386; Grant BCS-9058392; TRN: 95:007973-0055
- Resource Relation:
- Conference: 16. symposium on biotechnology for fuels and chemicals, Gatlinburg, TN (United States), 9-13 May 1994; Other Information: PBD: 1995; Related Information: Is Part Of Sixteenth symposium on biotechnology for fuels and chemicals; Davison, B.H. [ed.] [Oak Ridge National Lab., TN (United States)]; Wyman, C.E. [ed.] [National Renewable Energy Lab., Golden, CO (United States)]; PB: 823 p.
- Country of Publication:
- United States
- Language:
- English
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