Patent FR-2974519-A1 (FR)
Title: Purification of wet gaseous effluent containing volatile organic compound by performing adsorption step by passing gaseous effluent in adsorption column/adsorber, and performing first regeneration phase by heating first adsorbent bed
Inventor: THOMAS MICHEL
IPC: B01D53/04
Filed: 2011-04-27
Abstract: The process for purification of wet gaseous effluent containing volatile organic compound (VOC) to produce purified and dried gaseous effluent and to selectively and separately recover the VOC and water, comprises performing adsorption step by passing gaseous effluent in an adsorption column or an adsorber and by recovering the gaseous effluent, at the outlet of the adsorber, for dehydrating and purifying the VOC, where adsorption column or adsorber comprises two adsorption beds including a first adsorption bed that contains a solid hydrophilic adsorbent and a second adsorption bed. The process for purification of wet gaseous effluent containing volatile organic compound (VOC) to produce purified and dried gaseous effluent and to selectively and separately recover the VOC and water, comprises performing adsorption step by passing gaseous effluent in an adsorption column or an adsorber and by recovering the gaseous effluent, at the outlet of the adsorber, for dehydrating and purifying the VOC, where adsorption column or adsorber comprises two adsorption beds including a first adsorption bed that contains a solid hydrophilic adsorbent and a second adsorption bed that is adjacent to the first adsorption bed and contains a solid hydrophobic adsorbent for adsorbing the volatile organic compound, performing first regeneration phase by heating first selective adsorbent bed using microwave radiation in a generator placed around the adsorber and by flushing a regeneration gas at temperature close to ambient temperature against the current and the direction of flow performed in the adsorption phase, performing second regeneration phase by sending the regeneration gas to the adsorber while continuing the heating step of the first adsorption bed by the microwave, and performing cooling step by stopping the step of heating the first adsorption bed and cooling the two adsorption beds with the regeneration gas without microwave irradiation. The purification process is carried out by: the adsorption column or adsorber; and a regeneration phase of adsorbent beds comprising a heating phase by microwave of the first adsorption bed. During the step of heating the first adsorbent bed by microwave, the microwave is sent in pulsed mode over a period of 0.5-3 seconds. An interstitial velocity of the effluent gas in the adsorbent beds is 1-20 m / min. A frequency of the microwave generator is 2450 MHz. The solid adsorbent used in the first and the second bed is shaped in the form of beads, whose diameter is 0.5-1.6 mm and shaped in the form of extrudates having a diameter of 1.6 mm. The solid hydrophilic adsorbent used in the first bed is a faujasite zeolite with a molar ratio silicon/aluminum of less than 3, and the solid hydrophobic adsorbent used in the second bed is a faujasite zeolite with a molar ratio silicon/aluminum is greater than 100. The method further comprises introducing a intermediate bed between the first and the second adsorption bed, where the intermediate bed consists of a solid heat-insulating inert materials consisting of ceramic balls, and introducing a third selective hydrophilic adsorbent bed with respect to the water.