NOVELTY - 9C hydrocarbon byproduct, from production of ethane, is mixed with hydrogen in presence of metal catalyst containing nickel, copper, palladium, ruthenium or platinum, and oxide carrier or carbon material. The hydrogenated material is heated in a hydrogenation reactor in the presence of sulfide catalyst and gas-liquid separated to obtain extracted product in the liquid. The sulfide catalyst comprises nickel-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten and cobalt-molybdenum-tungsten, and oxide carrier or carbon material.    USE - Cracking of 9C hydrocarbon byproduct used for cracking 5C hydrocarbon (claimed), used for high grade petrol and higher aromatic solvent.    ADVANTAGE - The process is simple, economical, has high selectivity and high catalyst activity.    DETAILED DESCRIPTION - 9C hydrocarbon byproduct is mixed with hydrogen in a raw material pump in presence of loaded catalyst, heated using a heat exchanger and led into first portion of a hydrogenation reactor, at 30-120 degrees C, hydrogen partial pressure of 1-6 MPa and air flow of 0.5-4.0 hour-1, controlling the volume ratio of hydrogen to oil to 100-1000:1. The loaded metal catalyst comprises nickel, copper, palladium, ruthenium or platinum in an amount of 0.1-30 wt.%, oxide carrier or carbon material having diplopore composition structure. The heated hydrocarbon is led into the second portion of the hydrogenation reactor at 200-350 degrees C, hydrogen partial pressure of 1-6 MPa, air flow of 0.5-4 hour-1 and controlling the volume ratio of hydrogen to oil to 100-1000:1. The mixture from the hydrogenation reactor is led to a gas-liquid separator and the extracted product is obtained as liquid. The hydrogen and other gases are reused for heating reaction system. A sulfide catalyst comprising nickel-molybdenum, nickel-tungsten, nickel-molybdenum-tungsten and cobalt-molybdenum-tungsten, and oxide carrier or carbon material is used in the cracking process. The oxide carrier is silica, alumina, titania, silica-alumina or alumina-titania.