Patent ID: 7439353

Claim:
A process of manufacturing cellulose acetate, the process comprising: steaming a material selected from one or more of bagasse, kenaf, reeds and rice straw in a pressure vessel in a sub-critical state at a temperature of about 150 to 350° C. and a pressure of about 15 to 29 MPa for about 10 to 30 minutes to obtain a mixture of a solid product and a solution product, wherein the solid product comprises cellulose, wherein the solution product comprises soluble hemicelluloses and polyphenol converted from lignin separated from lignocelluloses, and wherein the sub-critical state is such that the solid product and the solution product are obtained from the material solely due to the temperature and pressure conditions of the state; filtering the mixture to separate the solid product; and dehydrating and acetylating the solid product in the presence of acetic anhydride and sulfuric acid to obtain cellulose acetate from the solid product.