A method for producing gamma-valerolactone (GVL) and 2-methyltetrahydrofuran by gas phase and liquid phase hydrogenating a levulinic acid under a catalyst is mainly used as a general method for producing gamma-valerolactone (GVL) and 2-methyltetrahydrofuran, and more economical catalysts and processes have been used.
A catalyst including precious metal as a main component is mostly used as a catalyst hydrogenating the levulinic acid to manufacture 2-methyltetrahydrofuran. For example, U.S. Pat. No. 5,883,266 shows high yield with a Pd—Re-based catalyst, and in U.S. Pat. No. 6,045,611, 2-methyltetrahydrofuran is obtained at a relatively high yield by using a catalyst phase made of Ni, Co, Al, or Zr oxides as a catalyst not using precious metal. However, there is a problem in that all are operated at a high hydrogen pressure.
Further, precious metal is mainly used as the catalyst manufacturing gamma-valerolactone (GVL) from the levulinic acid to obtain high yield. For example, in U.S. Patent Laid-Open Publication No. 2003/0055270 and WO 2002/074760, Ru, Pd, Rh, and Pt are carried in Carbon, SiO2, TiO2, Al2O3, and zeolites to obtain high yield, and in a document by Applied Cat. A general, 272(2004), 249, a process of obtaining high yield by using a 5% Ru/carbon catalyst has been developed. However, problems are found in view of economic efficiency and stability in that the main component of the catalysts used in the aforementioned process is precious metal and operation is performed at a relatively high hydrogen pressure.
USPTO Backgrounds
USPTO Backgrounds