Wet startup sulfuration method of hydrocracking unit

Abstract

The invention relates to a wet startup sulfuration method of a hydrocracking unit. According to the invention, a part of recycle gas is heated by using a heating furnace, then a vulcanizing agent is introduced, and hydrogen sulfide is obtained after decomposition of the vulcanizing agent; then recycle gas rich in hydrogen sulfide is mixed with a second part of recycle gas, and mixed gas passes through a catalyst bed after reaching a desired temperature; light fraction startup oil is introduced at a low temperature, heavy fraction startup oil is introduced instead when the catalyst bed reaches a temperature of 235 to 300 DEG C, liquefied ammonia is introduced at the same time, and introduction of the vulcanizing agent is stopped; after introduction of the heavy fraction startup oil, final sulfuration of a catalyst is completed by using hydrogen sulfide obtained in a hydrogenolysis reaction of a sulfide in the startup oil, raw oil is directly introduced instead step by step after sulfuration is finished, and when 60 to 80% of raw oil is introduced, introduction of liquefied ammonia is stopped and normal production is started. Compared with the prior art, the method provided by the invention enables startup time to be shortened while guaranteeing performance of the catalyst and realizes safe and smooth startup.

Description

technical field [0001] The invention belongs to a processing method of oil refining technology, in particular to a wet start-up vulcanization method used in a hydrocracking unit. Background technique [0002] With the protection of the environment, environmental regulations around the world are becoming increasingly stringent, which requires the production of a large amount of clean, light and clean fuels. Hydrogenation technology is an effective means of cleaning products. Therefore, hydrogenation units have become the standard configuration of oil refineries. The number of hydrogenation units in China is increasing. [0003] The catalyst used in hydrogenation technology is a bifunctional catalyst, and its hydrogenation performance comes from metals. Metals are usually divided into two types: noble metals and non-noble metals, and non-noble metals mainly include Group VIB and Group VIII metals (such as Mo, W, Ni and Co etc.) elements, these metals are usually present in th...

AI Technical Summary

Problems solved by technology

Gas-phase vulcanization is also called dry vulcanization. Only vulcanizing agent is used in the vulcanization process. After the vulcanization, the temperature of the catalyst bed needs to be lowered to a safe temperature, and low-nitrogen start-up oil is introduced to wet the catalyst. Long, under the premise of complete smoothness, it usually takes at least 6 days from the beginning of vulcanization to the complete replacement of raw material oil, and there are factors that are not conducive to stable operation such as prone to large temperature fluctuations