TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal component of metal salt and metal oxide is aluminum, chromium, tin, titanium, zirconium, or element from Groups I, IIa, IIIa, VIIa, VIIIa, Ib or IIb. The solid hydrogenation catalyst supported on greater than or equal to 1 catalyst support comprises a metal from nickel, copper, chromium, ruthenium, iridium, palladium, cobalt, rhodium, rhenium, osmium, platinum, and/or platinum black or its compound, preferably ruthenium on carbon, ruthenium on alumina, and iridium on carbon.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The reactant is 2,3-butanediol-having fermentation broth. The inert solvent is greater than or equal to 1 liquid hydrocarbon, aromatic compound, or ether; and/or 2-butanol. The inert solvent is greater than or equal to 1 5-20C straight-chain, branched, or cyclic liquid hydrocarbon; 6-20C liquid aromatic compound; or liquid 4-16C dialkyl ether. The individual 2-5C alkyl of the 4-16C dialkyl ether is straight-chain or branched. The heterogeneous catalyst system is a dual function catalyst; has (wt.%) greater than or equal to 1 solid acid catalyst (0.1-20) and greater than or equal to 1 solid hydrogenation catalyst (0.1-20); or has greater than or equal to 1 unsupported or supported solid acid catalyst, and greater than or equal to 1 unsupported or supported hydrogenation catalyst. The solid acid catalyst supported on greater than or equal to 1 catalyst support is heterogeneous heteropolyacids or their salts, metal oxides, mixed metal oxides, and/or metal salts, preferably natural clay minerals, and/or cation exchange resins. The catalyst support is oxides of silica, alumina, and/or titania; barium sulfate; calcium carbonate; zirconia; and/or carbons. EXAMPLE - ESCAT 440(RTM: ruthenium-supported-on-carbon powder catalyst) (0.05 g) as hydrogenation catalyst and Amberlyst 15(RTM: macroreticular, sulfonated, cross-linked copolymer of styrene and divinyl benzene) (wet) (0.1 g) as acid catalyst were added to 2,3-butanediol (BDO) (1 g) at a pressure of 5.52 MPa for 2 hours at 150 degrees C. The reaction yielded a BDO conversion of 82.4%.