Performance Evaluation of Pilot Scale Anaerobic Membrane Bioreactor (AnMBR) Treating Ethanol Thin Stillage

This paper describes the ongoing operations of a 12 m3 pilot-scale AnMBR treating thin stillage from a corn-to-ethanol wet mill facility. The main objective was to evaluate the performance of the anaerobic CSTR system coupled with an ultrafiltration (0.08 μm) flat-sheet membrane unit. Following an initial start-up stage the system ran steadily at a flux in the 4-6 LMH range, with MLSS concentrations of 22-26 g/L. The observed trans-membrane pressure (TMP) rarely exceeded 20 kPa when pushed to the higher end flux and always recovered after an overnight relaxation. A simple mass balance revealed excellent COD removal (over 98%), at the loading rate of 6-8 kg TCOD/m3/day. This study is ongoing and the data will be analyzed as it is collected.