NOVELTY - Manufacturing of 5-methylfurfural comprises: (i) forming reactant mixture comprising (a) carbohydrate including hexoses, pentoses and/or polysaccharides, (b) water, (c) aromatic solvent, (d) a catalyst comprising trichloro rhodium compound (I), palladium/ carbon, ruthenium/ carbon, trichloro ruthenium, rhodium/ carbon, triiodonickel, triiodopalladium, triiodorhodium and/or trichloroiridium compound (II), and (e) acid including hydrogen iodide, hydrochloric acid, hydrogen bromide and/or sulfuric acid; and (ii) reacting reactant mixture under hydrogen pressure to form 5-methylfurfural product.    USE - The method is useful in manufacture of 5-methylfurfural (claimed), which is used as liquid fuel.    DETAILED DESCRIPTION - Manufacturing of 5-methylfurfural comprises: (i) forming a reactant mixture comprising: (a) a carbohydrate including hexoses, pentoses and/or polysaccharides, (b) water, (c) an aromatic solvent,(d) a catalyst comprising trichloro rhodium of formula (RhCl3.xH2O) (I) (where rhodium is present at 38.5-45.5%), palladium/ carbon, ruthenium/ carbon, trichloro ruthenium, rhodium/ carbon, triiodonickel, triiodopalladium, triiodorhodium and/or trichloroiridium compound of formula (IrCl3.xH2O) (II), and (e) an acid is hydrogen iodide, hydrochloric acid, hydrogen bromide and/or sulfuric acid; and (ii) reacting the reactant mixture under hydrogen pressure of 30-1000 PSI at 25-200 degrees C for 0.5-44 hour to form 5-methylfurfural product. INDEPENDENT CLAIMS are also included for:    (1) manufacturing of 5-methylfurfural comprising either: forming a reaction mixture of fructose, hydrogen iodide, catalyst, water and benzene; and reacting the mixture under hydrogen pressure of 300 PSI 75-90 degrees C for about 2 hours to produce 5-methylfurfural; or forming a reaction mixture of a carbohydrate comprising inulin, sucrose, glucose, cellulose or their mixtures, hydrogen iodide, ruthenium(III) chloride, water and benzene; and reacting the mixture under hydrogen pressure of 300 PSI at 75 degrees C for 2 hours to produce 5-methylfurfural; and    (2) continuous manufacture of 5-methylfurfural comprising: steps (M1) and (M2) as above per se; and (M3) separating the 5-methylfurfural from the reaction product to form an aqueous portion having catalyst and acid, then combining the aqueous portion with additional carbohydrate and aromatic solvent, and repeating steps (M2) and (M3).