GB299373A - - Google Patents

Abstract

299,373. I. G. Farbenindustrie Akt.- Ges. Oct. 24, 1927, [Convention date]. Alcohols; ethers.-Polylydroxy compounds are hydrogenated by treatment in solution or suspension in water with hydrogen in presence of a hydrogenating catalyst under raised pressure and at, a temperature not exceeding 300‹ C. The process is particularly applicable to sugars, starch, cellulose, glycerine, hexites, glucosans and polyhydroxy acids such as gluconic acid; glycerine and its further restriction product, 1 : 2-dihydroxypropane, comprise the main products. Pressures of 70-100 atmospheres are usually employed, and the temperature is preferably above 200‹ C. The hydrogenating catalysts used are those of the iron and platinum groups, alone or in combination. Examples are given of the production of a mixture of dihydroxypropane and glycerine by treatment of sorbite, dextrose, cane sugar, starch and cellulose using nickel as catalyst. The hydrogenation of glucose to produce first the hexite and then glycerine is mentioned. Specification 309,200 is referred to. The Specification as open to inspection under Sect. 91 (3) (a) is not confined to the presence of water or to a temperature limit of 300‹ C. It refers to the use of pressures of 10-60 atmospheres, 200 atmospheres and even 1,000 atmospheres. The following catalysts are also specified :-copper, silver, gold, tungstic acid, or mixtures thereof, mounted if desired on a carrier such as pumice, silicic acid and asbestos; also nickel oxide, a mixture of nickel, cobalt and copper, or a mixture of cobalt and copper. It states that the reaction may be effected in the presence of a solvent and that in some cases another gas such as carbon dioxide may be present. It describes the treatment of straw, peat and sawdust to produce dihydroxypropane and glycerine; in the case of sawdust, there may also be obtained mannite and isopropyl alcohol. It includes additional examples of the production of dihydroxypropane from glycerine in the absence of water or other solvent, dimethoxy- (or diethoxy) -trihydroxyhexane from dimethyl- (or diethyl)- cellulose in presence of water, and dihydroxypropane, glycerine and isosorbide from cellulose in presence of water. This subject-matter does not appear in the Specification as accepted.