into the third side stream 10 while the relatively larger substrate particles unreacted cellulosic material and some residual smaller molecules are retained and ultimately returned to the agitated hydrolyzer 2 for further processing the third side stream 10 is then introduced into an ultrafilter 11 ultrafilters utilize porous membranes with pore diameters in the range of 20 1000 angstroms that are usually used to filter dissolved macromolecules such as proteins and enzymes many such filter materials are available from various manufacturers and typical of these is the uf 38 membrane from filmtech corporation minneapolis minn to form a fourth side stream 12 the fourth side stream 12 should only contain water glucose and cellobiose the ultrafilter 11 is in fluid communication with the attritor 6 and the agitated hydrolyzer 2 the ultrafilter 11 will allow a large portion of the relatively smaller water glucose and cellobiose molecules of the third side stream 10 to pass through while the relatively larger enzyme molecules cellulase and a small portion of the smaller molecules are retained and ultimately returned to the agitated hydrolyzer 2 to allow for further processing ultrafiltration is utilized to return the enzymes cellulase and a small portion of the glucose and cellobiose to the agitated hydrolyzer 2 while a separated large portion of the third side stream 10 is further processed to remove a large portion of the cellobiose and glucose this step increases reaction efficiency in that it allows for continuous removal of a large portion of the inhibition products glucose and cellobiose from the agitated hydrolyzer 2 the sole purpose of the cellobiase reactor 13 is to convert the cellobiose to glucose cellobiose is converted to the glucose product by utilizing a cellobiase reactor 13 the cellobiase reactor.