Single-stage series diesel oil hydrofining method

Abstract

The invention discloses a hydrofining method. The method consists of: mixing diesel oil with hydrogen, introducing the mixed gas into a first reactor, leaving the mixed gas and a hydrofining catalyst to undergo a contact reaction under a low temperature and a high space velocity, with the catalyst taking metal Mo and Co as active components, and having an average pore size of 20-40 angstroms and a total acid amount of 0.2-1.0mmol / g; and leaving the effluent of a first reactor to enter a second reactor, letting the effluent and a hydrofining catalyst to undergo a contact reaction under a high temperature and a low space velocity, with the catalyst taking metal W and / or Mo and Ni as active components, and having an average pore size of 40-70 angstroms and a total acid amount of 1.0-3.0mmol / g. The method employs appropriate catalysts according to different reaction types, and is in favor of lowering the catalyst cost without influencing reaction activity. The method provided in the invention can be used for producing diesel oil with a sulfur content of less than 50 micrograms / g.

Description

technical field [0001] The invention relates to a hydrocarbon hydrogenation treatment method, in particular to a single-stage serial diesel oil hydrogenation refining method suitable for producing ultra-low sulfur diesel oil. Background technique [0002] With the improvement of people's awareness of environmental protection and the increasingly stringent environmental regulations, the production and use of clean vehicle fuels has increasingly become a development trend. The development of deep hydrodesulfurization technology for diesel oil has become a hot research topic at present. At present, the operation process of most diesel oil hydrotreating units is that the raw material oil is exchanged with refined diesel oil and reaction products, and then heated to the required reaction temperature by a heating furnace before entering the hydrotreating reactor. This is a conventional hydrogenation process. The advantage is that it is easy to operate, but for the production of u...

AI Technical Summary

Problems solved by technology

At present, the operation process of most diesel oil hydrotreating units is that the raw material oil is exchanged with refined diesel oil and reaction products, and then heated to the required reaction temperature by a heating furnace before entering the hydrotreating reactor. This is a conventional hydrogenation process. The advantage is that it is easy to operate, but for the production of ultra-low sulfur diesel, the reactor temperature and hydrogen distribution are very unreasonable. Since the industrial diesel hydrogenation reactor is an adiabatic reactor, there is a large axial temperature difference in the catalyst bed of the reactor. (The bed temperature difference of the deep hydrodesulfurization reactor is larger), the inlet feed temperature is often lower, and in order to control the reactor outlet temperature, it is necessary to inject cold hydrogen into the reactor

Since the production of ultra-low sulfur diesel needs to remove dibenzothiophene and dibenzothiophene sulfides containing steric hindrance, such as 4,6-DMDBT, and these sulfides are almost free when the reaction temperature is lower than 320°C. Therefore, the low-temperature reaction zone does not work for the removal of 4,6-DMDBT, while for simple sulfides such as mercaptans, thioethers, thiophenes, and simple dibenzothiophenes, at lower reaction temperatures and relatively It can be quickly removed at a high volumetric space velocity, but the traditional single-reactor bed depends on the natural temperature rise of the reaction heat and needs to reach the middle and lower part of the reactor before entering the high-temperature reaction zone. The low-temperature reaction section is too long, making the low-temperature zone The removal of 4,6-DMDBT cannot be continued after the simple sulfide removal is complete, which reduces the use efficiency of the catalyst in the low temperature reaction zone

Therefore, under the condition of a certain total volume space velocity, it is equivalent to increasing the volume space velocity in the high temperature section, which is not conducive to the overall performance of the catalyst.

At the same time, the use of a large amount of cold hydrogen also increases the hydrogen consumption and energy consumption of the device

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