Comprises of a softening stage and a curing stage to prepare cellulosic fibrous aggregate (hemicellulose) for anaerobic purification

摘要

A process for the preparation of a cellulosic fibrous aggregate, comprising a softening (hydrothermolysis) stage and a curing stage, whereby in the softening stage a section of cellulosic fibrous material is exposed to the action of a liquid aqueous softening agent at an elevated temperature and at a pressure of at least the equilibrium vapour pressure of the softening agent at the operating temperature, in which at least part of an aqueous stream, contaminated with organic material, obtained as effluent stream from the zone wherein the softening has been effected, is subjected to an anaerobic purification treatment and at least part of the resulting purified aqueous stream is recycled to the hydrothermolysis stage.