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. |