Crude helium refining system and method thereof

Abstract

The invention relates to the technical field of crude helium refining, in particular to a crude helium refining system, which comprises a catalytic dehydrogenation system, a helium drying system, a medium-pressure low-temperature condensation system, a normal-temperature pressure swing adsorption system and a pure helium compression system. The catalytic dehydrogenation system, the helium drying system, the medium-pressure low-temperature condensation system, the normal-temperature pressure swing adsorption system and the pure helium compression system are sequentially connected through pipelines; the refining method comprises the steps of catalytic dehydrogenation, drying, medium-pressure low-temperature condensation, normal-temperature pressure swing adsorption and pure helium compression storage. When crude helium is used as raw material gas to produce pure helium, under the condition that the product quality is the same as that of an existing process, the total yield of the productis increased, the operation pressure of the device is reduced, the liquid nitrogen consumption of the whole device is reduced, low-temperature switching is avoided, and the operability of the deviceis improved.

Description

technical field [0001] The invention relates to the technical field of helium preparation, in particular to a crude helium refining system and method. Background technique [0002] The refining (purification) of helium is an essential and important link in the process of extracting helium from natural gas. It undertakes the task of processing crude helium (generally containing He: 50%-70%) to pure helium (generally requiring He > 99.995%). Crude helium mainly includes impurities including neon, hydrogen, oxygen argon, nitrogen methane, carbon monoxide, carbon dioxide, etc. Helium refining (purification) process mainly includes catalytic oxidative dehydrogenation, compression, drying, condensation, adsorption and other processes. The adsorption process can be divided into low-temperature adsorption and pressure-swing adsorption. Existing devices at home and abroad generally adopt the scheme of "high-pressure low-temperature condensation + low-temperature adsorption and tem...

AI Technical Summary

Problems solved by technology

[0004] 1) The operating pressure of the equipment is high, and it needs to work under high pressure (10-20Mpag). It has high requirements for the reliable operation of "low temperature-high temperature" valves under high pressure, high requirements for heat exchange of multiple streams under high pressure, and high and low pressure switching operations. The operation is cumbersome and has potential risks;

[0005] 2) For a long time, the main heat exchange of the existing process is difficult to be reasonable. Due to the influence of switching loss and adsorption heat, it is difficult to effectively recover the cooling capacity of low-temperature pure helium after adsorption, resulting in high consumption of liquid nitrogen;

[0006] 3) When high-pressure helium products are not needed, (for example, liquid helium products need to be produced), it is necessary to decompress high-pressure crude helium, which has the problem of unreasonable utilization of pressure to a certain extent;

Images