An adsorption device and a method for regenerating the adsorbent using the device. The adsorption device comprises an adsorption tower (20) and a device (10) supplying a desorption gas. The device (10) supplying a desorption gas comprises an absorption tower (12), an generator (11) and an absorbent crystallizer (141). The absorbent crystallizer (141) has an absorption solution inlet connected to the bottom of the absorption tower (12), an absorption solution outlet connected to the top of the generator (11), and an absorbent crystal outlet connected to the top of the absorption tower (12). A dry desorption gas conduit (123) is disposed on the top of the absorption tower (12) supplying a dry desorption gas to the adsorption tower (20), and a wet desorption gas conduit (124) is disposed on the bottom of the adsorption tower (20) leading a desorption gas finishing the desorption process into the absorption tower (12). The method for regenerating the adsorbent primarily comprises a desorption gas cycle and an absorption solution cycle which is an absorption heat pump cycle using the low temperature waste heat as heat source to achieve the heating and drying of the desorption gas.

An adsorption device and a method for regenerating the adsorbent

In the drying of ethanol by (a) passing the ethanol through sintered, granulated zeolite (I) of particle size 1-5 mm and (b) regenerating (I) by removing the accumulated water using heated inert gas, both stages are connected togther, operated continuously and carried out in apparatus for simultaneous drying of ethanol and regeneration of (I). An independent claim is included for apparatus for the process, consisting of a vertical ring (1) of several (I)-containing chambers (2), rotating slowly at 2-10 revolutions per hour. The side walls (3) of the chambers are permeable gratings and the ring of chambers is enclosed in a housing (4), in the lower part of which the liquid ethanol to be dried flows via an inlet opening (5) through the chambers and exits via an outlet opening (6) on the opposite side. The upper part of the chamber is the (I) reactivation region, in which inert carrier gas from a blower is pressed from an inlet pipe (7) through the chambers in countercurrent to the direction of rotation. The gas, with the entrained steam, exits through an outlet pipe (9) and is taken out of the system in a condenser (10), with cooling water inflow and outflow (11, 12), as condensed water (13) and a small amount of residual ethanol (14). In a second gas circuit, driven by a gas blower (15), inert gas still saturated with water vapor and converted into dried form by passage through the chambers is sucked out via a suction pipe (16), heated by a gas heater (17) to 350-400[deg]C (i.e. the temperature required to dry (I)) and fed into the system via an inlet pipe (18). Exothermic heat is extracted from the ethanol in a heat exchanger (19), with coolant inflow and outflow (20, 21), and the associated circulation pump (22) is used simultaneously for regulating the liquid filling height.

Dehydrating ethanol, especially to convert distillery product into fuel-grade ethanol, by passing ethanol through sintered, granulated zeolite and simultaneously regenerating the zeolite using heated inert gas

Dieter Eichler

Papers

Dehydrating ethanol, especially to convert distillery product into fuel-grade ethanol, by passing ethanol through sintered, granulated zeolite and simultaneously regenerating the zeolite using heated inert gas