The focus of the work presented in this thesis is recycling of commercial enzymes in a continuous process for production of bioethanol from biomass. To get a deeper understanding of the factors affecting the potential for enzyme recycling, the interactions between enzymes and biomass, the adsorption and desorption as well as stability and recovery of activity was investigated. More knowledge on these factors have enabled a process adapted for enzyme recycling. The driver being that enzyme consumption remains a major cost when producing bioethanol from lignocellulosic biomass. Unlike previous studies, this PhD project investigates enzyme recycling at industrial relevant conditions in the Inbicon process, e.g. high dry matter conditions and process configurations that could be implemented in large scale.

The results point towards potential processes for industrial recycling of enzymes, but they also point towards generic challenges with the stability of the enzyme proteins. Quite unique for the first time results from large scale testing of enzyme recycling in a lignocellulosic biomass to ethanol process are reported.