炭分子筛吸附脱除乙醛装置尾气乙烯中少量氧气和氮气的研究

Study of removal of O 2 and N 2 from C 2H 4 O 2 N 2 mixture by adsorption with carbon molecular sieve

采用重量法研究了Ｃ２Ｈ４、Ｏ２和Ｎ２在５Ａ沸石和炭分子筛上的吸附平衡和扩散动力学性质．结果表明，在５Ａ沸石上，Ｃ２Ｈ４的平衡吸附量和扩散速率均比Ｏ２和Ｎ２的大；在炭分子筛上，Ｃ２Ｈ４的平衡吸附量比Ｏ２和Ｎ２的大，而扩散速率则远小于Ｏ２和Ｎ２．模拟变压吸附评价表明：Ｃ２Ｈ４－Ｏ２－Ｎ２混合组分（含Ｏ２６．８％，Ｎ２３．０％）通过该炭分子筛时，Ｏ２和Ｎ２的穿透时间长，可获得合格的乙烯产品；该炭分子筛重复使用再生性能良好，是脱除乙醛装置尾气乙烯中少量氧气和氮气的理想吸附剂．

The adsorption and diffusion properties of C 2H 4, O 2 and N 2 on 5A zeolite and carbon molecular sieves were investigated respectively by gravimetric method. It is shown that the equilibrium adsorption amount of C 2H 4 is larger than that of O 2 and N 2 on 5A zeolite and carbon molecular sieves; the diffusivity of C 2H 4 is larger than that of O 2 and N 2 on 5A zeolite, however the diffusivity of O 2 and N 2 is much larger than that of C 2H 4 on the carbon molecular sieve. Ethylene with purity of 98% can be obtained when C 2H 4 O 2 N 2 mixture goes through the single column carbon molecular sieve. The increase of adsorption pressure is beneficial to the selective adsorption of O 2 and N 2. Therefore, O 2 and N 2 may be removed from C 2H 4 O 2 N 2 mixture by the carbon molecular sieve directly and the regenerative property of this adsorbent for depressurization is satisfactory.