Assessment of the optimal operating conditions for pale lager clarification using novel ceramic hollow-fiber membranes

Abstract

In this work, the lager beer clarification and stabilization process previously developed was further tested by replacing the 0.8-μm ceramic single-tube membrane module with a novel ceramic hollow-fiber membrane module having the same pore size to offset the known ineffectiveness of back-flushing cleaning techniques in ceramic multi-channel monolithic modules.In total recycle crossflow microfiltration (CFMF) trials, the quasi-steady state permeation flux (Jss) tended to a limiting flux (J*), that was found to increased with the crossflow velocity (vS) in the range of 0.5–6.0 m s−1. The ideal hydraulic pump energy consumption per unit liter of permeate recovered was practically independent of the aforementioned operating variables and of the order of (66.5 ± 0.5) W h L−1. Nevertheless, to obtain a quasi-state state permeation flux greater than the target permeation flux (i.e., 100 L m−2 h−1) for rough beer clarification via membrane processing in the absence of CO2 backpulsing, TMP had to be greater than 2 bar and vS to vary from 4 to 6 m s−1. Not only was the performance of the ceramic hollow-fiber membrane module at 10 °C, vS = 2.5 m s−1, and TMP = 2.4 bar with 2-min periods of CO2 back-flushing applied every 50–60 min superior to that of the polymeric hollow-fiber membrane process patented by Heineken and Norit Membrane Technology, but also the use of ceramic hollow-fiber membrane systems would extend the membrane life span up to ten years, this reducing the contribution of the annual membrane replacement to the overall operating costs of beer clarification.