title: Kinetics of ethanol fermentations in membrane cell recycle fermentors.
abstract: Ethanol fermentation by yeast was carried out in a cell filtration recycle system with a hollow-fiber membrane filter. Maximum biomass concentrations up to 210 g dry wt/L were obtained, but in normal operation concentrations they were between 100 and 150 g/L. The ethanol productivity using 14% glucose feed was 85 g/L h, with an ethanol concentration of 65 g/L and an ethanol yield of over 90%. The ethanol productivity and yeast growth rate decreased as the cell concentration increased beyond a certain level. The cell mass in the reactor was maintained by a proper manipulation of diluticn rate and bleed ratio depending on the growth rate.
authors.affiliation: Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, P.O. Box 131 Dongdaemun, Seoul, Korea.
authors.forename: C W
authors.initials: CW
authors.lastname: Lee
authors.forename: H N
authors.initials: HN
authors.lastname: Chang