Abstract: A method for separating acid and sugars obtained from liquids resulting from the acid hydrolysis of a material containing at least one of cellulose and hemicellulose is disclosed, comprising adding the liquids to a separation unit comprising a bed of anionic exchange or exclusion chromatographic material whereby the acid is adsorbed onto the chromatographic material, thereby producing a series of first fractions comprising sugar solutions and a later series of fractions comprising acid solutions. A process for an economical, energy efficient production of ethanol from municipal solid waste and other cellulosic feedstocks is also disclosed.

Abstract: A method for separating acid and sugars obtained from liquids resulting from the acid hydrolysis of a material containing at least one of cellulose and hemicellulose is disclosed, comprising adding the liquids to a separation unit comprising a bed of anionic exchange or exclusion chromatographic material whereby the acid is adsorbed onto the chromatographic material, thereby producing a series of first fractions comprising sugar solutions and a later series of fractions comprising acid solutions. A process for an economical, energy efficient production of ethanol from municipal solid waste and other cellulosic feedstocks is also disclosed.

Abstract: A method for separating acid and sugars obtained from liquids resulting from the acid hydrolysis of a material containing at least one of cellulose and hemicellulose is disclosed, comprising adding the liquids to a separation unit comprising a bed of anionic exchange or exclusion chromatographic material whereby the acid is adsorbed onto the chromatographic material, thereby producing a series of first fractions comprising sugar solutions and a later series of fractions comprising acid solutions. A process for an economical, energy efficient production of ethanol from municipal solid waste and other cellulosic feedstocks is also disclosed.

Abstract: A substantially continuous membrane separation process has been discovered in which the known benefits of a cell-recycle fermentor are unexpectedly enhanced because pH is controlled from 4.0 to 5.5 with a nitrogen-containing base. The ammonium lactate formed is not precipitated, allowing continuous removal of lactic acid so as to maintain a concentration of lactic acid about 12% by wt in the broth. When combined with recycle of UF retentate, operating this cell-recycle fermentor allows the build-up of a cell population in the range from above 5.times.10.sup.9 CFU/ml to 5.times.10.sup.10 CFU/ml, which population is much denser than one which can be produced with the specified pH control in a batch fermentor, after self-termination of the fermentation. This super-dense population of cells, In turn, not only accelerates production of lactic acid but also minimizes contamination by foreign cells.