Process for capturing rubbish landfill gas carbon dioxide

Abstract

The invention discloses a process for capturing rubbish landfill gas carbon dioxide. The process combines technologies of gas membrane separation, low temperature liquidation and the like, and a landfill gas decarburization oxygen enrichment section and a carbon dioxide capturing section after landfill gas combustion are effectively integrated; liquefied natural gas is used as a fuel in the landfill gas combustion process after cooling in stages of the system, so that the concentration and calorific value of landfill gas methane component are increased; oxygen-enriched air is used as purging gas of landfill gas decarburization oxygen enrichment membrane component, so that the oxygen content in the mixed gas after entrapment gas in a carbon dioxide capturing and backflow link is mixed withosmotic gas of a third-level membrane component is increased, a nitrogen component in flue gas after landfill gas is combusted is effectively reduced, and the energy consumption of the carbon oxide capturing section after landfill gas combustion is reduced; in the membrane component oxygen enrichment section, the pressure of feeding gas is increased by utilizing energy provided by a compressing turbine expander in the two sections; the requirements of each link for heat energy and cold energy in the process are integrated effectively by a heat exchanger, and the energy utilization rate is increased.

Description

technical field [0001] The invention relates to the technical field of carbon dioxide capture and recovery, in particular to a carbon dioxide capture process for landfill gas. Background technique [0002] Since the industrial revolution, a large amount of fossil fuels have been burned, which has led to an increase in the concentration of carbon dioxide in the atmosphere, leading to global warming and the greenhouse effect is increasing. According to the fourth assessment report of the United Nations Intergovernmental Panel on Climate Change (IPCC), in the total warming effect of greenhouse gases, carbon dioxide contributes about 63%, and methane contributes about 18%, of which the carbon dioxide equivalent per ton of methane is 25. Methane emissions have increased sharply in recent years, approaching the most serious situation internationally recognized. Controlling methane emissions is the key to avoiding the aggravation of global warming. Methane is the key to quickly sl...

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Problems solved by technology

[0005] At present, the carbon dioxide capture technology mainly includes solvent absorption method, adsorption method, membrane separation method, low-temperature cryogenic separation method, etc. Although the alcohol amine absorption method is the most widely used, there is a problem that the regeneration temperature of the absorbent is relatively high, and the required energy consumption is relatively low. Large, the leakage or volatilization of chemical absorbents will cause environmental pollution

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