Improvement of pretreatments and technologies for enzymatic hydrolysis of cellulose from industrial and agricultural refuse and comparison with acidic hydrolysis.

Chemical and enzymatic hydrolysis of cellulose are compared. Basic research on paper mill celluloses shows that it is mainly the endo- and exocellulase activities which are absorbed on the substrate. In the case of the Trichoderma reesei complex with Aspergillus niger beta-glucosidase, the exocellulase activity has proved to be the limiting factor in the design of a reactor which recycles the enzyme complex. Tests were carried out on various pretreatments for substrates of more complex chemical composition, such as straw, maize stalks, beet pulp. The rate and overall degree of hydrolysis, especially for straw, were improved by chemical treatments in combination with mechanical processes. A first pilot plant for straw hydrolysis was set up with the aim of attaining high sugar concn in the fermenter.