热激励的CO_2置换CH_4水合物的实验研究

Experimental Study on the Replacement of Methane Hydrate by CO_2 with Thermal Excitation

CO_2置换CH_4水合物具有在开采天然气水合物的同时储藏CO_2的功能.天然气水合物因其可燃烧、燃烧后污染小、储量巨大等特点被认为是未来最有可能的能源替代品,但CO_2置换天然气水合物存在反应周期长、置换速率低的缺点.提出了一种借助CO_2水合物生成热量激励CH_4水合物分解的方法,在低温、高压的纯水体系中,研究了温度为275.15 K,置换压力分别为2.3、2.5、2.8、3.0 MPa时有热激励和无热激励两种置换反应的区别.研究结果表明,有热激励的置换反应,由于提供了额外的热量,使CH_4水合物更易分解,从而加速了置换反应的发生,提高了置换速率.

Replacement of methane hydrate by CO2 has advantages of gas hydrate exploitation and CO2 storage. Natural gas hydrate is considered as the most likely alternative energy in the future because of its combustibility, low pollution and huge reserves. However, replacement of natural gas hydrate by CO2 has the disadvantages of long reaction time and low replacement rate. A new method for decomposing methane hydrate by the heat from carbon dioxide hydrate generation was proposed. In the pure water system with temperature of 275.15 K, the replacement experiments under the pressure of 2.3,2.5, 2.8 and 3.0 MPa were performed with thermal excitation or not. The results showed that the replacement reaction with thermal excitation was accelerated by the additional heat from the formation of CO2 hydrate, causing easy decomposition of CH4 hydrate and the rising of replacement rate.