Method for extracting liquefied gas and pentane from refinery tail gas

Abstract

The invention discloses a method for extracting a liquefied gas and pentane from a refinery tail gas. The method sequentially comprises the following steps: (1) a refinery tail gas desulfurization process; (2) a gas separation process; and (3) a rectification process. According to the method for extracting the liquefied gas and the pentane from the refinery tail gas, on the basis that the refinery tail gas is used as a fuel gas after being simply desulfurized by a refinery tail gas utilization device in the background art, the gas separation process and the rectification process are added; the refinery tail gas from which hydrogen sulfide is removed is separated into the liquefied gas comprising ethylene, isobutene, methane, ethane, propane, isobutane and normal butane, the pentane and above alkane thereof, and hydrogen, carbon dioxide, nitrogen and a trace amount of light dydrocarbon below C2; the liquefied gas comprising the ethylene, the isobutene, the methane, the ethane, the propane, the isobutane and the normal butane, and the pentane and the above alkane thereof are further separated to obtain a liquefied gas product, a pentane product and above alkane products with relatively high use value. Resources are fully utilized.

Description

technical field [0001] The invention relates to a method for extracting liquefied gas and pentane from refinery tail gas. Background technique [0002] figure 2 A refinery tail gas utilization device is shown. Such as figure 2 As shown, the pressure of the refinery tail gas from each process of the refinery is 0.4MPa-0.6MPa, the temperature is normal temperature, and the composition (V / V%) is: ethylene 0.0-0.10, butene 0.02-0.05, methane 10.00-15.00, Ethane 9.00-13.00, propane 3.0-7.0, isobutane 1.5-2.5, n-butane 1.0-2.0, pentane and above pentane 0.6-2.8, hydrogen 50.0-60.0, carbon dioxide 0.10-1.0, nitrogen 4.0-9.0 and hydrogen sulfide 0.01-0.04. [0003] The refinery tail gas first enters the desulfurization tower 11 through the lower inlet pipeline 111 of the desulfurization tower 11, and contacts with the desulfurizer N-methyldiethanolamine, which is the lean amine liquid, which enters the desulfurization tower 11 through the upper inlet pipeline 112 of the desulfur...

AI Technical Summary

Problems solved by technology

[0006] At present, because domestic refineries do not pay enough attention to the utilization of this part of tail gas, they only use it as fuel gas after simple desulfurization, and fail to make maximum use of this part of tail gas, resulting in a certain waste of resources

Images