is obtained directly from the pulp mill the alkali hydrolyzed pulp product is then directed in a line 112 to a first washing step 114 to remove excess alkali hydrolysis agent and hemicellulose any washing apparatus known to those skilled in the art may be employed in the first washing step 114 preferred is the use of a two stage drum washer and wash press the alkali hydrolysis agent can be recovered optionally with membrane filtration to separate out the pentosans and hemicellulose and sent via a line 118 and returned to the pulp mill 120 such as to the bleach plant or recovery boiler of the pulp mill to recover five carbon sugars or other inorganic chemicals by methods known to those skilled in the art additionally recovered alkali hydrolysis agent having had the pentosans and hemicellulose removed can be directly recycled to the alkali hydrolysis step 106 via a line 116 the washed alkali hydrolyzed pulp from the washing step 114 is then directed through a line 122 to an acid hydrolysis step 124 in the acid hydrolysis step 124 the pulp is hydrolyzed by addition of an acid hydrolysis agent from a source 126 via a line 128 the acid hydrolysis agent can be.