GB926034A - Process for producing chemicals from a woody material - Google Patents

Abstract

Woody materials are converted into chemicals by reaction in an autoclave at 120 DEG to 180 DEG C. and at a pressure of 20 to 80 p.s.i. for a plurality of hours with an aqueous catalytic reaction solution of an alkali metal salt of cymenesulphonic acid, xylene-sulphonic acid, toluenesulphonic acid, benzoic acid or salicylic acid, lignin and insoluble cellulose are removed from the lower part of the autoclave and a vapour mixture including furfural, acetic acid, carbon dioxide and water is removed from the top of the autoclave and condensed, acetic acid being thereafter extracted from the condensed mixture by means of furfural. The resulting extract may be subjected to a multiple distillation process whereby the furfural is recovered for use as a solvent in the extraction of the acetic acid. The concentration of the alkali metal salt is preferably in the range of 25-40% by weight, the lignin being then formed as a solution in the catalyst, or in the range of 1-4% by weight, the lignin and cellulose being then formed as an integral solid mixture. In Example 3, where Loblolly pine is used as the woody material, turpentine is amongst the products. Specification 841,229 is referred to.ALSO:Woody materials are converted into chemicals by reaction in an autoclave at 120 DEG to 180 DEG C. and at a pressure of 20 to 80 p.s.i. for a plurality of hours with an aqueous catalytic reaction solution of an alkali metal salt of cymenesulphonic acid, xylenesulphonic acid, toluenesulphonic acid, benzoic acid or salicylic acid, lignin and insoluble cellulose are removed from the lower part of the autoclave and a vapour mixture including furfural, acetic acid, carbon dioxide and water is removed from the top of the autoclave and condensed, acetic acid being thereafter extracted from the condensed mixture by means of furfural. The resulting extract may be subjected to a multiple distillation process whereby the furfural is recovered for use as a solvent in the extraction of the acetic acid. The concentration of the alkali metal salt is preferably in the range of 25-40% by weight, the lignin being then formed as a solution in the catalyst, or in the range of 1-4% by weight, the lignin and cellulose being then formed as an integral solid mixture. Specification 841,229 is referred to.ALSO:Woody materials are converted into chemicals by reaction in an autoclave at 120 to 180 DEG C. and at a pressure of 20 to 80 p.s.i. for a plurality of hours with an aqueous catalytic reaction solution of an alkali metal salt of cymenesulphonic acid, xylenesulphonic acid, toluenesulphonic acid, benzoic acid or salicylic acid, lignin and insoluble cellulose are removed from the lower part of the autoclave, and a vapour mixture including furfural, acetic acid, carbon dioxide and water is removed from the top of the autoclave and condensed, the acetic acid being thereafter extracted from the condensed mixture by means of furfural. The resulting extract may be subjected to a multiple distillation process whereby the furfural is recovered for use as a solvent in the extraction of the acetic acid. The concentration of the alkali metal salt is preferably in the range of 25-40% by weight, the lignin being then formed as a solution in the catalyst, or in the range of 1-4% by weight, the lignin and cellulose being then formed as an integral solid mixture. When the lignin is obtained as a solution, said solution is preferably diluted with water after filtering off the cellulose, the temperature of the diluted solution being from 60-70 DEG C., the precipitated lignin filtered off and the filtrate concentrated for re-use in the autoclave. Lignin prepared in this way may be used as an extender for plastics, a soil conditioner, a rubber additive or as a tanning material. Specification 841,229 is referred to.