Production of cyclic acetals or ketals using liquid-phase acid catalysts

Abstract

A liquid composition containing at least 2 mole % of water, at least 50 mole % of polyhydroxyl compounds, at least 3 mole % of cyclic compounds, and at least 0.01 mole % of a homogeneous acid catalyst. The mole percentages are based on the moles of all liquids in the composition. The liquid composition optionally contains up to 20 mole % of carbonyl compounds, based on the number of moles of the cyclic compounds. The cumulative amount of any other liquid ingredient in the liquid composition does not exceed 10 mole %. The cyclic compounds include cyclic acetals, cyclic ketals, or a combination thereof. The liquid composition is derived from a process for making cyclic compounds by feeding aldehyde or ketone compounds and polyhydroxyl compounds to a reaction vessel at a molar ratio of polyhydroxyl compounds to aldehyde or ketone compounds of at least 3:1, reacting these compounds in the presence of a homogeneous acid catalyst to generate a liquid phase homogeneous reaction mixture containing the acid catalyst without separating water from the reaction mixture as it is being formed in the reaction mixture, withdrawing the liquid phase homogeneous reaction mixture from the reaction vessel as a liquid product stream, and feeding the liquid reaction product stream to a distillation column to separate cyclic acetal or ketal compounds from unreacted polyhydroxyl compounds.