| 摘要 |
1,140,486. Separating hydrocarbons. TEXACO DEVELOPMENT CORP. Jan. 30, 1967 [Feb. 1, 1966], No.4476/67. Heading B1L. Straight chain C 10 -C 20 hydrocarbons are separated from a petroleum fraction by a substantially isothermal process comprising introducing the petroleum fraction into an adsorption zone, containing a molecular sieve (preferably Type 5A) at elevated temperature and pressure, to effect adsorption of the straight chain hydrocarbon components, the adsorption effluent being withdrawn, and the adsorption step terminated when the zone has been charged with a normal paraffin overcharge of from 0À5 to 15% by weight. The adsorption zone is then depressurized, to a pressure less than that used for adsorption, and purged, using a desorbing medium having a major portion of straight chain hydrocarbon having a lower carbon chain length than the shortest component of the charge admixture, to remove surface adsorbed components of the charge. The zone is next repressurized, to a pressure higher than the adsorption pressure, and desorbed by using a desorbing medium having the same composition as the medium used in the purge step, until between 70 and 90% by weight of the adsorbed hydrocarbons, in the pores of the selective adsorbent, have been removed by the desorbing medium and the cycle is repeated sequentially. |
