RECYCLING OF COMMERCIAL ENZYMES IN THE PRODUCTION OF SECOND GENERATION ETHANOL

Abstract

The present work proposes a procedure to evaluate the economic impact of recycling cellulolytic enzymes in ethanolproduction from sugarcane bagasse process. Three scenarios of ethanol-producing plants of different capacities are set to make the theoretical calculations. The proposed procedure starts from the experimental results reported on the yield changes obtained at the laboratory level when the original enzyme is used and when it is recycled on one or two occasions. From the technological demands of enzymatic quality, some necessary mixtures are established so the levels of addition of original enzyme are evaluated for different levels of recycling of enzymes. The procedure then includes possible scenarios for recycling the enzymes one or several times and it establishes the economic impacts regarding reduction of raw materials. Since the process of recycling enzymes is planned for an industrial installation, economic estimates of the investment are made for a given capacity with and without recycling of enzymes. For the three capacities, the investment and production costs are estimated, as well as the investments required to be able to recycle the enzymes in the enzymatic hydrolysis stage. Recovery of investments is also considered and projected. The economic benefits of recycling enzymes increase as installed production capacity increases.