Method for preparing high-purity methane through adsorption separation methane and nitrogen in simulated moving bed

Abstract

The invention relates to low-quality methane development and utilization in the field of clean energy and discloses a method for preparing high-purity methane through adsorption separation methane andnitrogen in a simulated moving bed. The simulated moving bed system is formed by connecting a plurality of adsorbent packed towers with one another, and is provided with five gas inlets and outlets,so that the multiple connected towers are segmented into four areas. During operation, adsorbents in the packed towers do not flow, and are switched and moved to a packed tower at a set time intervalby virtue of the five gas inlets and outlets, and due to repeated frequent switched movements, counter-current flow is formed between the adsorbents in the towers and an gaseous phase, and the methaneand nitrogen separation efficiency is improved. Moreover, each packed tower is sequentially subjected to low-concentration methane adsorption, replacement of methane in a nitrogen concentration towerwith methane, replacement of methane in the towers with carbon dioxide and carbon dioxide vacuum desorption, and the high-purity methane gas is obtained by continuously adsorbing and concentrating the low-concentration methane raw gas. The method disclosed by the invention is low in cost and applicable to low-quality methane concentration, and the high-purity methane gas with the purity of 90% and the recovery rate of 90% can be obtained.

Description

technical field [0001] The invention relates to the technical field of low-quality methane utilization in the field of clean energy, in particular to a method for preparing high-purity methane by simulating moving bed adsorption and separation of methane and nitrogen. Background technique [0002] Energy and environmental issues are two basic issues closely related to today's sustainable development. After entering the 21st century, the economy's excessive dependence on energy has led to prominent environmental problems. The rapid growth of my country's economy has a strong demand for energy consumption. However, the current energy consumption pattern dominated by coal and oil has overwhelmed my country's fragile natural environment. The environment Pollution has threatened human existence. Methane is a high-quality fuel with large natural reserves, high calorific value, and the highest hydrogen / carbon ratio. It plays an important role in the energy system and is a cleaner e...

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Problems solved by technology

[0005] The simulated moving bed adsorption separation technology is a modern separation method. At present, there are many studies on the simulated moving bed technology in the field of liquid phase mixture separation at home and abroad, and a lot of experience has been accumulated, but for the basic theoretical research on the simulated moving bed adsorption separation process of the gas phase mixture blank

Regarding the adsorption and separation of methane and nitrogen by the gas phase simulated moving bed technology, no similar research reports at home and abroad have been found after searching the open literature

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