Construction of heterogeneous thermal biocatalytic system for high-performance cellulosic ethanol production.

As a renewable energy source, cellulosic ethanol has excellent prospects that can help break our dependence on fossil fuels. Simultaneous saccharification and fermentation (SSF)is the most appealing strategy for producing cellulosic ethanol. However, for the SSF process, the disparity between the optimal temperatures for cellulases (50 °C) and yeasts (30 °C) hinders the efficacy of SSF. Herein, the composite material of 2D titanium carbon nanosheets (Ti3C2Tx) and graphene oxide (GO), having excellent photothermal conversion efficiency, was used as the carrier for cellulase immobilization. This composite material served as the central component of the heterogeneous thermal SSF system. With precise photothermal control, this composite maintains the immobilized enzyme SSF system with maximum catalytic efficiency. Under the conditions of this experiment, the ethanol yield of the conventional SSF system was 387 μg/mL, which was enhanced to 480 μg/mL with the photothermal immobilized enzyme technology, an enhancement of 18.5 %. Thus, this strategy is extremely beneficial for promoting the industrial use of cellulosic ethanol and reducing carbon emissions throughout the life cycle.