Studies On Catalysts And Hydroprocessing Technology Of Low-temperature Coal Tar

Coal tar is inevitable byproduct of coal pyrogenation process. Along with the development of economy, the coal chemical industry is developing rapidly, coal tar production yield increased quickly, which make the intensive processing of coal tar become an ignored important industry. As new bench energy, production of clean fuel oil from low-temperature coal tar is strategic to alleviate serious energy crisis.According to the temperature of coal pyrolysis, coal tar can be divided into three kinds: low- temperature coal tar, medium coal tar and high temperature coal tar. The chemical composition, property and utilization of high-temperature coal tar are different from that of low-temperature. For low-temperature coal tar, because of its component low concentration, the main research direction is hydrogenation for fuel oil. This paper focuses on the research in hydrogenation catalysts and hydroprocessing technology for production of clean fuel oil form low-temperature coal tar. Low-temperature coal tar was selected as raw materials in this study.Modified kaolin orγ- A1₂0₃ supported Mo, Ni, Co; W catalysts were prepared by impregnation method. The XRD, SEM, EDS, BET and TG-DTA techniques were employed to investigate the structure and characteristic of the catalyst. The behaviors of the catalysis were investigated using toluene, naphthalene and Octane as the model compounds to strengthen the hydrogenation saturated, hydrogenation catalyst open loop, hydrogenation broken chains activity. This paper builds a set of coal tar hydrogenation experiment device successfully, subject part of which is two paragraphs fixed-bed reactor. Target products of coal tar hydrogenation experiment are gasoline and diesel. This study examined the activity of catalyst and screened the optimal catalyst grading scheme. The affection of process conditions, such as pressure and airspeed, on production was investigated. Combined with hydrogenation reaction kinetics calculation results, this study determined the optimum process conditions of hydrogenation experiment is pressure 6-8MPa, temperature 360-380℃, liquid hourly space velocity 0.4-0.8 h^-1, and volume ratio of H₂ to oil 1600.