椰壳活性炭低温变压吸附天然气中CO2/CH4实验

结合天然气液化储运过程中低温与常规变压吸附（PSA）工艺，提出低温变压吸附净化天然气工艺.用椰壳活性炭对CO₂和CH₄单组份气体进行静态吸附，以及CO₂/CH₄二元混合气体动态模拟吸附分离.利用静态体积法研究-30~25 ℃，1.2~2.5 MPa下CO2和0~4 MPa下CH₄在椰壳活性炭上的吸附行为，椰壳活性炭对两者的吸附量均随温度降低而增大.动态吸附分离实验压力为0.45，0.85，1.85 MPa，随温度或压力的降低，椰壳活性炭对CO₂/CH₄二元混合气体的分离因子不断增大，温度对其影响效果大于压力的影响，且在实验温度范围内CH₄的动态吸附量呈先增大后减小的变化趋势.研究表明，椰壳活性炭对天然气脱碳具有广阔的应用前景.

Experiment of Pressure Swing Adsorption of CO_2/CH_4 at Low Temperature Through Coconut Shell Activated Carbon

The natural gas purification technology through pressure swing adsorption (PSA) at low temperature was proposed based on the low temperature processing and the conventional PSA technology applied in liquefied natural gas storage and transport.Coconut shell activated carbon was used for the static adsorption of CO₂ and CH₄ component gas and the dynamic simulation of adsorption separation of binary mixedCO₂/CH₄ gas.At -30~25 ℃,the static volumetric method was used to investigate adsorption behavior of CO₂ under the pressure from 1.2~2.5 MPa and that of CH₄ under the pressure from 0~4 MPa,respectively.The results showed that the adsorption capacity of coconut shell activated carbon for both CO₂ and CH₄ increased with the decrease of temperature.Under the pressure of 0.45 MPa,0.85 MPa and 1.85 MPa for the dynamic tests,it was found that the separation factor will continue to increase with the decreases of temperature or pressure for binary mixedCO₂/CH₄ gas;besides,it was found the effect of temperature is greater than the impact of pressure;furthermore,the dynamic adsorption capacity of CH₄ increases at first and then decreases within the range of experiment temperature.The research shows that coconut shell activated carbon for natural gas decarburization has broad application prospects.