Date on Master's Thesis/Doctoral Dissertation

5-2009

Document Type

Master's Thesis

Degree Name

M. Eng.

Department

Chemical Engineering

Committee Chair

Berson, Robert E. (Eric)

Subject

Hydrolysis; Fermentation

Abstract

Enzymatic hydrolysis is the most common method of producing fermentable sugars from lignocellulosic biomass. Limitations to this step include the high cost of enzymes, and the time required to process the biomass. To increase the throughput and decrease catalyst cost, the preliminary development of a continuous concentrated sulfuric acid process is explored. The process requires two distinct steps. The first step involves hydrolyzing lignocellulose to fermentable sugars, glucose and xylose. The second step consists of glucose and xylose removal from the concentrated acid stream. The separation of sugars decreases the production of reaction byproducts and allows for the recycle of acid to the process. Single stage acid hydrolysis was tested at nine different reaction conditions. The optimum reaction condition occurred at 70 weight percent acid and 80°C with 58.2 percent glucose release as a percentage of available glucan and 86.5 percent xylose release as a percentage of available xylan. Detection of xylose and glucose in solution occurred at different times. These peaks are separated by enough time to warrant continuous removal of produced glucose and xylose to limit the production of reaction byproducts. In order to optimize this reaction condition, a limit of 63 percent glucose release as a percentage of available glucan was observed. A preliminary investigation of Dowex Monosphere 99 ion exchange resin to separate glucose and xylose from 70 weight percent was performed. At the column conditions tested, the sulfuric acid caused shrinkage and deactivation of the ion exchange resin leading to inefficient separation of glucose and xylose.

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