Production of fermentable sugars and lignin from biomass using supercritical fluids

Inventors

Kilambi, Srinivas • Kadam, Kiran L.

Assignees

Renmatix Inc

Abstract

Methods are disclosed for the continuous treatment of biomass comprising a pretreatment step, wherein said biomass is contacted with a first supercritical, near-critical, or sub-critical fluid to form a solid matrix and a first liquid fraction; and a hydrolysis step, wherein said solid matrix formed in said pretreatment step is contacted with a second supercritical or near-supercritical fluid to produce a second liquid fraction and an insoluble lignin-containing fraction. Also disclosed are apparatuses for the continuous conversion of biomass comprising a pretreatment reactor and a hydrolysis reactor associated with said pretreatment reactor.

Core Innovation

The invention relates to a method of treating a fractionated biomass by providing a slurry comprising the fractionated biomass, water, cellulose, and insoluble lignin. The slurry is contacted with a second reaction fluid to form a reaction mixture comprising a second solid fraction comprising insoluble lignin and a second liquid fraction comprising saccharide selected from the group consisting of cello-oligosaccharides, glucose, and mixtures thereof.

The contacting uses a second reaction fluid comprising water and occurs at temperatures and pressures at near the critical point of water, the subcritical point of water, the critical point of water, or above the critical point of water. After forming the reaction mixture, the temperature of the reaction mixture is reduced to a temperature below near the critical point of water or below the subcritical point of water.

Additional embodiments include adding carbon dioxide to the second reaction fluid. Further embodiments include performing contacting as a hydrolysis step and performing hydrolysis of the second liquid fraction with hot compressed water or a third near-critical or sub-critical fluid in the presence of an acid with specified concentration ranges.

Claims Coverage

The independent claim coverage is based on a single independent claim. It centers on two inventive features, with dependent claims further refining hydrolysis conditions, carbon dioxide, acid concentration ranges, and separation by extrusion.

The inventive coverage centers on contacting fractionated biomass slurry with a water-containing second reaction fluid at near-critical, subcritical, critical, or above-critical water conditions to form a second solid fraction comprising insoluble lignin and a second liquid fraction comprising cello-oligosaccharides and/or glucose, followed by reducing the reaction mixture temperature below the near-critical or subcritical threshold. Dependent claims further narrow the contacting to hydrolysis conditions and add carbon dioxide, acid concentration ranges, and extrusion separation.

Stated Advantages

Documented Applications