Abstract
This paper describes a conceptual process to convert wood and other lignocellulosics to butanol, isopropanol, and ethanol. The concept is based primarily on the well-known butyl solvents fermentation in which Clostridium bacteria convert carbohydrates to solvents. Two new developments are introduced: the progressing batch reactor for carbohydrate production by wood hydrolysis and a low-energy,liquid extraction process for product separation. Their impact on the traditional process is also discussed. The overall process comprises four major sections: feed handling, acid hydrolysis, fermentation, and solvents recovery. The hardwood chips and sawdust used as feedstock are the source of lignocellulose most readily available on a commercial scale throughout the United States and Canada(1). Other cellulosic feedstocks such as bagasse, straw, and corn stover could also be used without significant process modification. Preliminary production and capital costs are estimated for a base-case grassroots plant processing 200,000 dry metric ton of wood per year and producing 89 million lb of solvents. (The overall yield of the process is expected to be approximately 445 lb of solventsper dry metric ton of wood.) For the purposes of this study the plant is designed to be self-sufficient in utilities. Established large markets now exist for the products. However, there is also a potential market for n-butanol and isopropanol as cosolvents for methanol in gasoline. Butanol can also be blended directly with diesel fuel if economically warranted (2,3). A block flow diagram of theprocess is shown in Figure 1.
Original language | American English |
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Number of pages | 15 |
State | Published - 1986 |
Bibliographical note
Work performed by Solar Energy Research Institute, Golden Colorado and Badger Engineers, Inc., Cambridge, MassachusettsNREL Publication Number
- NREL/TP-231-3023
Keywords
- butanol
- butyl
- ethanol
- isopropanol
- lignocellulose