Monday, May 5, 2008
9-34

Continuous Enzymatic Saccharification of Paper

Yaping Chao1, Hideaki Yukawa2, and Jun Sugiura1. (1) Research & Development Division, Oji Paper Co., Ltd., 10-6, Shinonome, 1-Chome, Koto-ku, Tokyo, Japan, (2) Research Institute of Innovative Technology for the Earth, Kyoto, Japan

The cost of enzyme such as cellulase is still a barrier to practical bioconversion of cellulosic biomass today. To minimize the enzyme consumption in a long term, we constructed a continuous enzyme-recycling saccharification process using copy paper as the substrate. This process was composed of a ceramic filter to keep residue paper remaining in the reactor and an ultrafilter to recycle enzyme back to the reactor; as a result it could be operated for a long interval without new enzyme addition and at the same time the product sugar could be carried outside from the process continuously.
In order to achieve a high enzyme recovery rate and a high sugar yield, enzyme(Multifect CX10L) concentration in the reactor, paper supply flow rate and retention time were optimized. We found that enzyme could be recovered efficiently and show a high reducing sugar yield of 90% stably for over 40 days by increasing enzyme concentration to have a ratio of substrate  to enzyme in the reactor to be 2 under the condition of retention time as 12 hrs.