Increasing reaction rate and conversion in the spinning cloth disc reactor: Investigating the effect of using multiple enzyme immobilized cloths

The spinning cloth disc reactor (SCDR) is a novel mesh supported enzyme rotating reactor system for process intensification. In this study, to increase the enzyme loading in the SCDR, a new reactor operational mode was designed by increasing the number of cloths used in the SCDR to form a multi-cloth stack on the spinning disc. To test its effectiveness, the influence of the number of cloths in the SCDR on reaction conversion and rate was investigated. The flow within the multi-cloth stack was characterized by residence time distribution (RTD) analysis and an imaging of the flow and dye penetration in the SCDR.For different tributyrin substrate concentrations (10-40gL^-1), the reaction rate and conversion increased when the number of cloths was increased from one to two, indicating that the enzyme loading in the SCDR can be easily tailored to the desired reaction system by simply changing the number of immobilized enzyme cloths. The mean residence time increased with an increase in the number of cloths at different spinning speeds and flow rates, due to flow existing inside the volume of the multi-cloth stack. The number of tanks-in-series (N) decreased as the increase of cloth number on the spinning disc, indicating that more cloths caused larger deviation from plug flow. The visual study showed that the multi-cloth stack would not essentially change the flow types in the SCDR, and the fluid could penetrate through the three layers of multi-cloth at both low (100rpm) and high (400rpm) spinning speeds.