Studies For Hydronrocessing On Coal Tar From Polygeneration System In Huainan

In China, the coal reserves are huge compared to the oil reserves. With the development of the economy, the portion of imported oil is getting higher. However, transforming coal tar into gasoline and diesel by hydrotreating at low temperature is an alternative way to solve the oil lacking problem. At present, applications in domestic and foreign countries of gasoline and diesel producing with low-temperature coal tar hydrogenation process is not common, and the theoretical research is inadequate as well. In recent years, we investigated coal tar hydrogenation refining process in-depth, mainly focused on reaction mechanism and the impact of reaction conditions. This work is funded by the relevant national and international cooperation projects.Befoe the hydrogenation experiments, the coal tar’s dehydration, desalting and retort treatment are done to obtain needed distillate (<300℃). The workflow and working principles of the fixed bed hydrogenation differential/integral reaction bench are also introduced in this work.Coal tar hydrogenation refining is a very complex process, which involves Hydrodeoxygenation (HDO), hydrodearomatization (HDA), hydrodenitrogenation (HDN), hydrodesulfurization (HDS) reactions. We used Ni2P/MCM-41catalyst to catalyse the hydrogenation reactions. The reaction pathways and mechanism of the HDO, HDA, HDN and HDS reactions were well studied based on the product analyses and literature searching. Several catalysts are effective for increasing hydrogenation activity for HDO, HDA, HDN and HDS reactions, the temperature also shows great influence on hydrogenation activity.The influence of reaction conditions such as temperature, pressure, liquid hourly space velocity (LHSV) and hydrogen to oil ratio to the production of the hydrogenation process were investigated in this work. A commercial catalyst is used for the experiments. The best catalytic performance for HDO was obtained at T=375℃, P (H2)=6Mpa, LHSV=1.0h-1, hydrogen to oil ratio=1500. the best hydrogenation performance which means the largest production of alkanes, alkenes and alkynes and cycloalkanes was found on the condition of T=325℃, P (H2)=6Mpa, LHSV=1.0h-1, hydrogen to oil ratio=1000.