US Patent 7504545 Process for the preparation of alkylene glycols

A process for the conversion of an alkylene oxide to the corresponding alkylene glycol in the presence of carbon dioxide, water and a catalytic composition comprising a mixture of an organic base present in an amount in the range of from 10 to 90 mol % (based on the mixture) and a salt of the organic base and a hydrogen halide the salt being present in an amount in the range of from 10 to 90 mol % (based on the mixture), wherein the organic base comprises a carbon-based compound comprising one or more nitrogen atoms with at least one free electron pair and/or one or more phosphorous atoms with at least one free electron pair, and has a pKa high enough that it is capable of binding carbon dioxide under the reaction conditions.