天然气中微量组分对吸附剂性能的影响

Influence of Minor Components of Natural Gas on Adsorption Quality of a High Specific Surface Area Adsorbent

考察了天然气吸附剂LXC对天然气中微量组分C2H6,C3H8,CO2,N2的吸附和脱附特性及其对CH4吸附能力的影响。实验结果表明,天然气吸附剂LXC吸附CH4,C2H6,C3H8的吸附量依次增大,滞留比依次减小,不可逆吸附性增强;CO2在吸附剂上的吸附量和滞留量较大;N2的可逆吸附与脱附性能较好;天然气中C2H6,C3H8,CO2均能导致吸附剂LXC吸附CH4的能力降低。在20℃、充气压力3.5M Pa、放气压力0.1M Pa的条件下,吸附剂LXC对配制的混合气体经12次连续吸脱附后,其吸附能力下降27.5%。

The adsorption and desorption of ethane, propane, carbon dioxide, and nitrogen on natural gas adsorbent with high specific surface area were studied. Influence of C2H6, C3H8, CO2 and N2 upon storage capacity of adsorbent were also investigated. Mass and volume uptake of the adsorbent to CH4, C2H6 and C3H8 increased in the order CH4 less than or equal C2H6 less than or equal C3H8, but were reverse in order of desorption. The irreversible degree of C3H8 adsorption was higher than that of CO2, C2H6, folio wed by CH4, and the lowest was N2. The adsorption capacity of natural gas adsorbent to methane decreased after charge and discharge cycles due to heavy hydrocarbon and carbon dioxide in natural gas. The simulate mixture of methane containing ethane 4.30%, propane 4.96% and carbon dioxide 0.91% was used in study. The effective storage capacity at 25°C decreased by 27.5% after 12 cycles of adsorption and desorption. The charging and discharging pressure were 3.5 and 0.1 MPa respectively. Some measure and pretreatment should be take to control the concentration of minor components in natural gas as low as possible in order to keep adsorbent maintaining high methane-storing capacity and long working time.