Abstract: High quality trimethylolalkane can be easily and efficiently produced at a high yield through a reaction between n-alkanal and formaldehyde in the presence of tertiary amine and water, in which a reaction mixture obtained after the reaction is heated up to a temperature at which a salt of tertiary amine with formic acid produced as a by-product can be thermally dissociated so as to distill tertiary amine and water from the reaction mixture, and a formate of trimethylolalkane produced in the distillation of tertiary amine and contained in a residue is reacted with water, ammonia, primary amine or secondary amine; and the tertiary amine distilled from the reaction mixture is reused in producing trimethylolalkane.

Abstract: High quality trimethylolalkane can be easily and efficiently produced at a high yield through a reaction between n-alkanal and formaldehyde in the presence of tertiary amine and water, in which a reaction mixture obtained aster the reaction is heated so that a salt of tertiary amine with formic acid produced as a by-product is decomposed into hydrogen and carbon dioxide and/or water and carbon monoxide, and tertiary amine; and the tertiary amine distilled from the reaction mixture is reused in producing trimethylolalkane.