The Capture, Utilization, Storage of CO_2 in Methane Recovery

摘要

According to the problems that the coalbed methane resource was rich in deep seam in China, but the economic and technology conditions were limited, it would be hard to mine with a conventional method. The CO_2 capture, utilization and storage technology was provided (CO_2-ECBM). The application of the technology would not only improve the methane recovery ratio from deep and unminable layer, but also put CO_2 effectively in the deep layer for storage to reach a target of reducing emission. The study showed that a coal rank, coal seam pressure, coal seam permeability, injection time, injected gas types and others would affect to the recovery ratio of methane in a production mine. Therefore, before we use this technology, a rational evaluation should be conducted on the place location. So the capture and storage technology of CO_2 has an important significance in protecting the natural environment.Coalbed Methane production technology at home and abroad is the htac technology in the process of coalbed methane development. According to the occurrence state of coalbed methane and migration mechanism of coalbed methane, production ideas mainly from two aspects: One is to promote methane desorption, adsorption of methane in coal matrix state within the micro pores converted into the free state as soon as possible, expanding the rate of coal-bed methane from the coal matrix micro-fracture porosity to diffusion;;the second is to increase the gas flow channel, so that more methane gas is flowing through the wellbore coal fissures[1]. Currently coalbed methane technology is mainly used in the hydraulic fracturing, water conservancy slotted and gas injection technology of oil mining for increasing CBM production.The world has huge coal resources, and CO_2 has a high adsorption capacity in the coal, CO_2 adsorption capacity is 1.8 to 10 times more than methane[2l So the CO_2 storage in coal seams is one of the most attractive locations. This can not only increase the production of coalbed methane to offset the costs of sequestration but also use the methane to replace the coal for power generation, can significantly reduce greenhouse gas emissions[3].