Abstract: The results of different types of hydrogenation units in the industrial application of LTAG process are compared. As an important means to adjust the ratio of diesel to gasoline, the hydrogenation unit of LTAG can adopt units such as hydrofining, heavy oil hydrotreating and hydro-upgrading, which can be combined with the catalytic cracking unit to achieve the purpose of reducing diesel and increasing the output of gasoline and LPG. Different modes of hydrogenation unit will lead to different properties of hydrogenated LCO, which will affect the conversion and selectivity in LTAG process. In the process of application, it is necessary to adjust the operating conditions of the FCC unit in accordance with the operating conditions of the hydrogenation unit, the changes in the nature of the hydrogenated LCO, the limitations of the operating range and other factors to obtain the best effect.

Key words: catalytic cracking, LTAG, hydrogenation unit, diesel, gasoline