A method for reducing the ratio of hydrogen to methane in catalytic cracking dry gas

Abstract

The invention discloses a method for reducing a ratio of hydrogen to methane in catalytic cracking dry gases, and belongs to the technical field of catalytic cracking of petroleum refining. The methodis characterized by comprising the following steps: a raw material for catalytic cracking, water and an emulsifier are mixed through a premixer, an obtained mixed material enters an emulsification device, emulsification is performed, wherein a mass ratio of the raw material for catalytic cracking to the water to the emulsifier is (97.3-99.4):(0.1-2):(0.5-0.7), emulsified oil obtained after emulsification directly enters a catalytic device, and a catalytic reaction is performed; and emulsification conditions in the emulsification device are that shear stirring is performed at 6000r / min-8000r / min, at the same time pressure in the emulsification device is kept to be 1.4Mpa-1.5Mpa, and a temperature is 125 DEG C-130 DEG C. According to the invention, the method of pretreating the catalytic cracking raw material under higher pressure and a higher temperature is adopted, thus dispersity and an atomization degree of the materials which enter catalytic cracking are improved, a cracking depthis improved, a yield of the catalytic dry gases is reduced, under the higher pressure and the higher temperature, through the premixer and the emulsification device, a stable emulsified liquid is formed by the catalytic cracking raw material, and therefore the ratio of the hydrogen to the methane in the catalytic cracking dry gases is greatly reduced.

Description

technical field [0001] A method for reducing the ratio of hydrogen to methane in catalytic cracking dry gas belongs to the technical field of catalytic cracking in petroleum refining. Background technique [0002] Catalytic cracking is a hydrogen self-equilibrium system. Among the catalytic cracking gas products, the dry gas is mainly composed of hydrogen, methane, ethylene and ethane. For a long time, people believed that the reason for the formation of dry gas was that a series of catalytic cracking reactions occurred in hydrocarbons during the catalytic cracking process to produce hydrogen, methane, ethylene and ethane, etc. [0003] At present, through literature research, it is found that (1) changing the structure of the nozzle is usually used to achieve sufficient mixing of the feed oil and the catalyst, reduce thermal cracking reactions in the FCC process, and reduce the yield of dry gas; (2) By emulsifying the catalytic cracking raw material and then carrying out t...

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Problems solved by technology

However, the existing technology is to emulsify the catalytic cracking feedstock at normal pressure and lower temperature (below 100°C). In the industrial production process, the preheating temperature of the catalytic cracking feedstock is usually relatively high, reaching about 140°C to 220°C. It is difficult to form a stable emulsified state at this temperature, and when the emulsified oil formed at normal pressure and low temperature enters the nozzle at the feed temperature of the catalytic device, it is easy to cause pressure fluctuations at the nozzle, which is not good for production

[0005] Chinese patent CN1680505 "catalytic cracking micro-explosion activator" mentions that the micro-explosion activator it adopts can reduce the hydrogen methane value, but the application does not have a specific implementation plan, in addition to the relationship between hydrogen and methane in dry gas No further studies and reports

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