Impacts of microchannel parameters on CLEAs immobilization

Cross-linked enzyme aggregates (CLEAs) are suitable to use in microchemical technology, but CLEAs shortcomings limit their application. The combination of CLEAs and microchannel can overcome CLEAs shortcomings. However, it is unclear how CLEAs immobilization is affected by microchannel parameters. The effects of microchannel (geometry, diameter, length) and its groove (shape, depth, size, density) on urease-CLEAs immobilization were investigated. Moreover, CFD simulation was conducted to reveal the effects of CLEAs particle size on fluid dynamic in microchannel. Results showed that microchannel reactor with immobilized urease-CLEAs (MRIC) had the highest activity under the following optimal conditions: Wave-type microchannel, 50.0 cm in microchannel length, 2.0 mm in microchannel diameter, and triangular groove that was 1.0 mm in depth, 1.2 mm² in size, and 2.0 individuals/cm² in density. MRIC activity was up to 1.450 U/cm², which was 4.63 times higher than that of the microchannel reactor with free urease (MRFU). Moreover, MRIC showed better reusability than MRFU. CFD simulation confirmed that the presence of CLEAs disturbed local flow velocity in microchannel. This study indicates that the combination of CLEAs and microchannel is a promising strategy to prepare enzymatic microchannel reactor.