甲烷在活性炭上的超临界温度吸附实验及理论分析

为研发ANG吸附剂,本文选择比表面积为2074m2.g-1的活性炭SAC-02,在温度区间263.15K～313.15K、压力范围0 MPa～8MPa,应用Setaram PCT Pro E&E测量甲烷在SAC-02活性炭上的吸附等温线,并由D-A方程、Clausius-Clapeyron方程和Virial方程标绘分析了实验数据。结果表明,当压力高于0.08MPa时,确定参数后的D-A方程预测实验数据的相对误差小于5%;甲烷在SAC-02活性炭上的等量吸附热反映了甲烷在能量非均匀表面吸附的特点,数值为13.99kJ.mol-1～17.57 kJ.mol-1,极限吸附热随温度呈线性变化,其平均值为19.43kJ.mol-1。

Experiment and theoretical analysis of methane adsorption on activated carbon under supercritical temperature

For the development of adsorbent for adsorption of natural gas(ANG),Setaram PCT Pro E&E was employed to measure the isotherms of methane adsorption on the activated carbon SAC-02 with specific surface area of 2074 m2·g-1 over a temperature range of 263.15K-313.15K and a pressures range of 0-8MPa.Dubinin and Astakhov's equation(D-A equation),Clausius-Clapeyron equation and Virial plot were used to fit and analyze the adsorption data.The results showed that when the pressure was higher than 0.08MPa,the modified D-A model could much accurately predict the adsorption data with a mean relative error of less than 5%;the isosteric heat of methane adsorption on the activated carbon was 13.99kJ·mol-1-17.57 kJ·mol-1,which revealed the adsorption of methane on energy heterogeneous surface;the limit isosteric heat of methane adsorption linearly changes with temperature,and the average value was 19.43kJ·mol-1.