GB868421A - Improvements in or relating to trimethylolalkane products - Google Patents

Abstract

Trimethylolalkanes are recovered from aqueous reaction liquors resulting from the reaction of formaldehyde with an aliphatic aldehyde containing from 3 to 5 carbon atoms in the presence of an alkali, by extracting the reaction liquor with a water-immiscible solvent to form a solvent solution of the extracted material, separating the solvent solution from the reaction liquor, contacting the separated solution with water to form an aqueous solution of the extracted material and separating the solvent, contacting the aqueous solution with a cation-exchange material and an anion exchange material, and evaporating the effluent from the ion exchange treatment to recover a trimethylolalkane. Suitable solvents are, for example, alcohols having 4-7 carbon atoms, particularly amyl alcohol, and ethyl acetate. It is desirable before extracting the reaction liquor to concentrate it by evaporating some of the water. Preferably the extraction is carried out at a temperature between 60 DEG and 90 DEG C. In a preferred method of carrying out the process the separated solution is steamdistilled to form the aqueous solution of the extracted material but, alternatively, the separated solution may be contacted with water and the aqueous phase separated, for example, by decantation. The aqueous reaction liquors used as starting materials may contain, in addition to the desired trimethylolalkane and the alkali metal formate, the following compounds:- <FORM:0868421/IV (b)/1> trimethylolkane, <FORM:0868421/IV (b)/2> monocyclic formal of trimethylolalkane, <FORM:0868421/IV (b)/3> linear formal or trimethylolakkane, and <FORM:0868421/IV (b)/4> in which R is an alkyl radical having 1-3 carbon atoms.