Hydrochloric acid is recovered from a lignin composition in a process, comprising providing a particulate lignin composition that comprises lignin, water and hydrochloric acid; contacting the particulate lignin composition with a stream of stripping gas comprising an aprotic gas to obtain an acidified vapor stream that comprises water vapor, hydrochloric acid and aprotic gas; and recovering hydrochloric acid from the acidified vapor stream.

Hydrochloric acid is recovered from a lignin composition in a process, comprising providing a particulate lignin composition that comprises lignin, water and hydrochloric acid; contacting the particulate lignin composition with a stream of stripping gas comprising an aprotic gas to obtain an acidified vapor stream that comprises water vapor, hydrochloric acid and aprotic gas; and recovering hydrochloric acid from the acidified vapor stream.

Biomass feedstocks (e.g., plant biomass, animal biomass, and municipal waste biomass) are processed to produce useful products, such as fuels. For example, systems are described that can be useful for separating solids and high molecular weight species from liquids of bioprocessed biomass material slurries.

The present invention provides a method comprising: (i) contacting a cellulose-comprising input material with an aqueous hydrolyzing solution comprising at least 35% wt. of at least one mineral acid to farm a hydrolyzate comprising a mixture of water-soluble carbohydrates and optionally a solid fraction; (ii) contacting said hydrolyzate with an extractant comprising a first solvent S1, to form a first (preferably solid) residue (preferably comprising precipitated carbohydrates, e.g. mono-, di- and/or oligo-saccharides) and an acid-comprising extract; (iii) separating said acid-comprising extract from said first residue; (iv) modifying said acid-comprising extract to form a second (preferably liquid) residue (preferably comprising dissolved carbohydrates) and an acid-comprising modified extract; (v) fractionating said modified extract into an S1-enriched fraction and an acid-enriched fraction; (vi) reusing said SI-enriched fraction to form said extractant; and (vii) reusing said acid-enriched fraction to form said aqueous hydrolyzing solution; wherein (a) at least 10% wt. of the cellulose is hydrolyzed and said mixture of water-soluble carbohydrates comprises monosaccharides, disaccharides and/or oligosaccharides; (b) SI forms a single phase when mixed with an identical weight of 70% sulfuric acid aqueous solution at 25 C.; (c) S1 comprises at least 65% wt. of said extractant; and (d) said acid-comprising extract comprises at least 60% wt. of the acid and at least 5% wt. of the carbohydrates in said hydrolyzate.

The present invention provides a method comprising: (i) contacting a cellulose-comprising input material with an aqueous hydrolyzing solution comprising at least 35% wt. of at least one mineral acid to farm a hydrolyzate comprising a mixture of water-soluble carbohydrates and optionally a solid fraction; (ii) contacting said hydrolyzate with an extractant comprising a first solvent S1, to form a first (preferably solid) residue (preferably comprising precipitated carbohydrates, e.g. mono-, di- and/or oligo-saccharides) and an acid-comprising extract; (iii) separating said acid-comprising extract from said first residue; (iv) modifying said acid-comprising extract to form a second (preferably liquid) residue (preferably comprising dissolved carbohydrates) and an acid-comprising modified extract; (v) fractionating said modified extract into an S1-enriched fraction and an acid-enriched fraction; (vi) reusing said SI-enriched fraction to form said extractant; and (vii) reusing said acid-enriched fraction to form said aqueous hydrolyzing solution; wherein (a) at least 10% wt. of the cellulose is hydrolyzed and said mixture of water-soluble carbohydrates comprises monosaccharides, disaccharides and/or oligosaccharides; (b) SI forms a single phase when mixed with an identical weight of 70% sulfuric acid aqueous solution at 25 C.; (c) S1 comprises at least 65% wt. of said extractant; and (d) said acid-comprising extract comprises at least 60% wt. of the acid and at least 5% wt. of the carbohydrates in said hydrolyzate.

The present disclosure relates to a dewatering systems, and related methods, that are adapted to convey lignocellulosic biomass to separate at least a portion of the water from a lignocellulosic biomass slurry and accumulate the dewatered lignocellulosic biomass. The dewatering system also includes a headspace occupied by a gas that is at a pressure that facilitates transferring the accumulated biomas into a pretreatment reactor having a pressurized headspace. Such a dewatering system can prevent undue mixing and backflow of gas (e.g., steam) from the pretreatment reactor.

The present disclosure relates to a dewatering systems, and related methods, that are adapted to convey lignocellulosic biomass to separate at least a portion of the water from a lignocellulosic biomass slurry and accumulate the dewatered lignocellulosic biomass. The dewatering system also includes a headspace occupied by a gas that is at a pressure that facilitates transferring the accumulated biomas into a pretreatment reactor having a pressurized headspace. Such a dewatering system can prevent undue mixing and backflow of gas (e.g., steam) from the pretreatment reactor.

Biomass feedstocks (e.g., plant biomass, animal biomass, and municipal waste biomass) are processed to produce useful products, such as fuels. For example, systems are described that can be useful for separating solids from liquids of bioprocessed biomass material slurries. For example, filtration systems are described that include multiple centrifuges, e.g., multiple tandem centrifuges.

The present invention is directed to a novel and advantageous process for the purification of biomass hydrolysate as well as the purified hydrolysate produced after the inventive process and the use of the purified hydrolysate as a fermentation medium.

The present invention is directed to a novel and advantageous process for the purification of biomass hydrolysate as well as the purified hydrolysate produced after the inventive process and the use of the purified hydrolysate as a fermentation medium.