Abstract: It is disclosed a process to produce a bio-product starting from a ligno-cellulosic feedstock, comprising a pre-hydrolysis step of the ligno-cellulosic feedstock in one or more pre-hydrolysis vessels to produce a liquid pre-hydrolyzate comprising water and water soluble hemicellulose, followed by a multi-step hydrolysis of the water soluble hemicellulose. The hydrolysis steps are conducted in separated vessel. The liquid pre-hydrolyzate is subjected to a partial hydrolysis step in a first hydrolysis vessel, to produce a first hydrolyzate. A portion of the first hydrolyzate, comprising remnant water soluble hemicellulose, is recirculated in at least one pre-hydrolysis vessel and subjected to a second hydrolysis step. Another portion of the first hydrolyzate comprising monomeric sugars is removed and converted to the bio-product, preferably after a refining hydrolysis step. The process also produces a hemicellulose-depleted feedstock which is preferably treated to produce a cellulosic pulp.

Abstract: It is disclosed a process to produce a bio-product starting from a ligno-cellulosic feedstock, comprising a pre-hydrolysis step of the ligno-cellulosic feedstock in one or more pre-hydrolysis vessels to produce a liquid pre-hydrolyzate comprising water and water soluble hemicellulose, followed by a multi-step hydrolysis of the water soluble hemicellulose. The hydrolysis steps are conducted in separated vessel. The liquid pre-hydrolyzate is subjected to a partial hydrolysis step in a first hydrolysis vessel, to produce a first hydrolyzate. A portion of the first hydrolyzate, comprising remnant water soluble hemicellulose, is recirculated in at least one pre-hydrolysis vessel and subjected to a second hydrolysis step. Another portion of the first hydrolyzate comprising monomeric sugars is removed and converted to the bio-product, preferably after a refining hydrolysis step. The process also produces a hemicellulose-depleted feedstock which is preferably treated to produce a cellulosic pulp.

Abstract: It is disclosed an integrated process for producing at least a cellulosic pulp comprising cellulose in the form of fibers and a polyols stream from a ligno-cellulosic feedstock comprising cellulose, hemicellulose and lignin. The process comprises the steps of: a) Treating the ligno-cellulosic feedstock to produce the cellulosic pulp and at least a liquid sugar stream comprising water and monomeric sugars derived from the hemicellulose of the ligno-cellulosic feedstock; b) Catalytically converting the monomeric sugars of the liquid sugar stream to a polyols mixture, comprising primary polyols and secondary polyols; c) Separating at least a portion of the polyols mixture into at least the polyols stream and a residual stream, wherein the polyols stream comprises the majority by weight of the primary polyols and the residual stream comprises the majority by weight of the secondary polyols; d) Recovering a first thermal energy from the residual stream in a first recovery unit.