Development of effective biofuel production from paper sludge by novel fermenting-fungus

Paper sludge (PS) is discharged form paper-making mill and the incineration of it is one of major CO2 emission resource. For reduction of CO2 emission and efficient use of PS, the ethanol production from PS was investigated. First, the components ratio of various PSs was analyzed in detail. Next, three cellulases for hydrolysis were selected among several commercial cellulase reagents and then the optimal mixture ratio of them was decided by using DOE method. An optimal fermenting-fungus was selected from our Mucor sp. library based on growth and fermentation ability in PS. Furthermore, soaking PS in NaOH and HCl solution in series could reduce pulping regents and inorganic materials so that they cannot inhibit hydrolysis and fermentation. Finally, the simultaneous saccharification and fermentation with an optimal cellulase cocktail and a fermenting-fungus from NaOH-HCl treated PS was performed. As a result, 21.3 g/L ethanol could be produced and the fermenting-efficiency was 67.2 %.