Patent ID: 8809569

Claim:
A method of preparing a dialkyl carbonate and diol products in an integrated process comprising: reacting an alkylene oxide with carbon dioxide in the presence of a non-halide-containing homogeneous carbonation catalyst in a first reaction zone to form a crude cyclic carbonate product; and introducing the crude cyclic carbonate product from the first reaction zone along with an aliphatic monohydric alcohol to a second reaction zone containing a transesterification catalyst comprised of a strongly basic Type I ion exchange resin in gel form of polystyrene crosslinked with divinyl benzene having from about 4% to about 8% crosslinking, and from about 40% to about 60% water retention, the ion exchange resin including at least one of quaternary ammonium groups or quaternary phosphonium groups, the transesterification catalyst being configured as substantially spherical beads having a particle size of from about 0.2 mm to about 1.5 mm and allowing the cyclic carbonate product and monohydric alcohol to react under reaction conditions to form the dialkyl carbonate and diol products wherein the non-halide-containing homogeneous carbonation catalyst comprises inorganic compounds selected from the group consisting of hydroxides, carbonates, and bicarbonates of alkali metals, or organic compounds selected from the group consisting of alkali methoxides and alkali ethoxides.