Alcohol amine desulfurization method and device for liquefied petroleum gas

Abstract

The invention provides a liquefied petroleum gas alcohol-amine desulfurization method and device. The alcohol-amine desulfurization method comprises the following steps: mixing an alcohol-amine water solution with hydrocarbon oil and a deoxidizer to remove the oxidizing substances from the alcohol-amine water solution, then removing the oil phase, contacting liquefied petroleum gas with the alcohol-amine water solution to carry out alcohol-amine desulfurization reactions, and collecting the liquefied petroleum gas product. The provided alcohol-amine desulfurization method and device can avoid or reduce the generation of disulfides or polysulfide, thus liquefied petroleum gas without disulfides or polysulfide can be provided for the next step alkali solution desulfurization process, the continuous operation of alcohol-amine desulfurization technology can be achieved, and the desulfuration efficiency of the alkali solution desulfurization process can be prominently improved.

Description

technical field [0001] The invention relates to a method and device for desulfurizing liquefied petroleum gas, in particular to a method and device for desulfurizing liquefied petroleum gas with alcohol amine. Background technique [0002] As we all know, MTBE (methyl tert-butyl ether) is the largest non-hydrocarbon high-octane blending component in gasoline in my country, which can significantly improve gasoline quality. However, under the current production conditions, the output MTBE obviously contains sulfides, generally the sulfur content reaches 60-300 mg / kg, and the sulfur content of MTBE produced by some manufacturers is sometimes as high as 2000 mg / kg. [0003] MTBE can be synthesized from isobutene and methanol under acidic conditions, and the industry directly uses liquefied petroleum gas containing isobutene as raw material, which greatly reduces the production cost of MTBE. However, the international standard for the sulfur content of civil liquefied petroleum ...

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that the energy consumption of re-distillation is high, and the second is that the boiling point of sulfide in C4 is not much different from that of light C4 such as isobutylene, so it is difficult to separate completely, and the sulfur content of the obtained MTBE is also difficult to remove to 10mg. / kg or less

But in fact, using peroxide or oxygen as oxidant has great safety hazards, and after oxidizing mercaptans to disulfides, it is necessary to distill the liquefied petroleum gas again to gasify all the liquefied petroleum gas to ensure the complete removal of disulfides. Separation, which requires very high operating energy consumption, and there is also the problem of re-entering the LPG after partial decomposition of disulfides or polysulfides

[0012] The existing liquefied petroleum gas desulfurization process has encountered a bottleneck: after the sulfur content is reduced to a certain level, no matter how much the cost is, the sulfur content will no longer be reduced or the improvement will be small, but it consumes doubled resources in vain: adding more devices, Use multiple additives, consume a large amount of lye and amine solution, and significantly increase the environmental protection treatment pressure of alkaline sewage

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