Process and equipment for liquefying air-containing coal-bed gas

Abstract

The invention discloses a liquefaction technology for coal-bed gas with air, comprising compressing and purifying technology, refrigeration technology and liquefaction and separation technology. Double-grade rectifying method in low temperature is applied in the liquefaction and separation technology. Liquefaction and separation are carried out in low temperature and it is provided with high separation purity and good safety. The purity of liquefied natural gas can achieve more than 99% and the content of firedamp drained in air is only 1% or so. The resource is recycled efficiently. The invention also provides liquefaction equipment for the coal-bed gas with air.

Description

technical field [0001] The invention relates to a gas liquefaction separation equipment and process, in particular to a liquefaction process and equipment for air-containing coal bed gas. Background technique [0002] Coalbed methane is also called unconventional natural gas or mine gas, and its main component is methane. It is not only a precious clean energy, but also an important chemical raw material. my country's coalbed methane resources are extremely rich, but the development is relatively small, and there is almost no industrial application. It is known that my country's coal-bed methane discharged into the atmosphere every year accounts for one-third of the total coal-bed methane emitted by coal mining in the world. This not only causes serious air pollution, but also wastes resources. [0003] The characteristic of coalbed methane is that the output of a single well is not very high. Except for the nearby use, it is often uneconomical to lay pipelines for export....

AI Technical Summary

Problems solved by technology

In particular, the coalbed methane extracted during the coal mining process has low pressure, low methane content, and air is mixed in it. Oxygen in the air is a dangerous combustion accelerant, which brings difficulties to the processing and transportation of coalbed methane. It is even more serious to empty and waste. This problem has not been well resolved.

In the previous methods, the purity of the separation is difficult to meet the requirements, and some of them need to be heated. The air-containing coalbed methane is easy to explode at high temperature, and there are potential safety hazards, so it has not been applied.

The application of cryogenic rectification to the separation and liquefaction of air-containing coalbed methane has not yet been proposed, let alone a specific process.

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