Patent ID: 6022398
Filing Date: 2000-02-08
Classification: B01D

Abstract:
An adsorptive separation and isobutane purification process comprising(a) an adsorption step in which an isobutane-containing gas is supplied to one of at least two adsorption beds and purified isobutane emerging from the one of said at least two adsorption beds is transferred to a surge tank;(b) a first pressure equalization step in which the pressure of the one of said at least two adsorption beds which has undergone said adsorption step is adjusted to equal the pressure in another of said at least two adsorption beds;(c) a desorption step with a vacuum pump to regenerate an adsorption bed which has undergone said adsorption and said first pressure equalization steps;(d) a low pressure purge step to remove impurities from the bulk space of an adsorption bed which has undergone said desorption step including flowing in a counter-current direction a portion of purified isobutane while said vacuum pump is running;(e) a second pressure equalization step in which the pressure in one of said at least two adsorption beds which has undergone said low pressure purge step and the pressure in another of said at least two adsorption beds which has undergone said adsorption step are adjusted to be equal; and(f) a pressurization step in which a portion of the purified isobutane stored in said surge tank is transferred to at least one of said two adsorption beds which has undergone said low pressure purge and said second pressure equalization steps.