摘要 |
A method and apparatus for the separation of C4 olefins (butene-1, trans-2-butene, cis-2-butene, etc.) and C4 paraffins (normal butane, isobutane, etc) from a C4 hydrocarbon mixed gas including butene-1, trans-2-butene, cis-2-butene, normal butane, isobutane, etc. is provided. The apparatus includes several adsorption towers loaded with an adsorbent which selectively adsorb olefins and two distillation towers for the separation of the mixture gases of olefins/desorbents and paraffins/desorbents respectively. The basic operating process of the adsorption tower comprises an adsorption step of selectively adsorbing C4 olefin from the feeding mixture, a C4 olefin rinse step of removing a small amount of C4 paraffins adsorbed together with C4 olefins, and a desorption step of desorbing C4 olefins by using a desorbent, and further comprises pressure equalization step, concurrent depressurization step, and accumulation pressure step to increase the yield and concentration of olefins depending on the operation pressure of the adsorption tower.
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