Carbon dioxide is used as a reaction solvent in the hydrogenation of organic compounds. The carbon dioxide is preferably a liquid or a supercritical fluid. The hydrogenation method can be used advantageously in methods for making tetrahydroiso-alpha-acids from alpha-acids, iso-alpha-acids, or beta-acids....http://www.google.es/patents/US6020019?utm_source=gb-gplus-sharePatente US6020019 - Hydrogenation of hop soft resins using CO.sub.2
