PRODUCTION OF SUGARS FROM BIOMASS USING SOLID CATALYSTS

摘要

The invention provides a process for producing sugars from lignocellulosic biomass, comprising: drying lignocellulosic biomass; hydrolyzing the dried feedstock with a hydrolysis catalyst to reach high conversion of cellulose and hemicellulose to sugars; washing and/or separating the sugars from the residual solids (containing lignin and catalyst); combusting the residual solids to burn the lignin and produce an ash stream comprising the hydrolysis catalyst; recycling the ash stream comprising the hydrolysis catalyst to the hydrolysis reactor; and recovering the sugars. Some variations envision drying a feedstock (e.g., sugarcane straw) with flue gas, then mixing with catalysts, rotating until hydrolysis is completed, separating sugars, washing out catalyst and lignin, burning catalyst and lignin and collecting catalyst from the bottom of a fluidized bed to recycle the catalyst to the front (with fresh biomass). Alternatively, the catalyst may be first separated from lignin and only the lignin is burned.

主权项

1. A process for producing sugars from lignocellulosic biomass, said process comprising:
(a) drying a feedstock comprising lignocellulosic biomass to produce a dried feedstock with a moisture content of about 5 wt % or less; (b) introducing said dried feedstock and a solid hydrolysis catalyst into a hydrolysis reactor; (c) in said hydrolysis reactor, hydrolyzing said dried feedstock in the presence of said hydrolysis catalyst and under effective hydrolysis reactor conditions, to reach at least 50% conversion of cellulose and hemicellulose to sugars, wherein said sugars are in combination with residual solids comprising lignin and said hydrolysis catalyst; (d) washing and/or separating said sugars from said residual solids; (e) combusting said residual solids to burn said lignin and produce an ash stream comprising said hydrolysis catalyst; (f) recycling at least a portion of said ash stream comprising said hydrolysis catalyst to said hydrolysis reactor; and (g) recovering or further processing said sugars.