CA1188633A - Method for recovering an essentially anhydrous desorbate as well as an apparatus for carrying out the method - Google Patents
Method for recovering an essentially anhydrous desorbate as well as an apparatus for carrying out the methodInfo
- Publication number
- CA1188633A CA1188633A CA000419675A CA419675A CA1188633A CA 1188633 A CA1188633 A CA 1188633A CA 000419675 A CA000419675 A CA 000419675A CA 419675 A CA419675 A CA 419675A CA 1188633 A CA1188633 A CA 1188633A
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- Prior art keywords
- desorption
- desorbate
- water
- medium
- desorption medium
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/26—Drying gases or vapours
- B01D53/261—Drying gases or vapours by adsorption
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
- B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/102—Carbon
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2257/00—Components to be removed
- B01D2257/80—Water
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Sorption Type Refrigeration Machines (AREA)
- Treating Waste Gases (AREA)
- Separation Of Gases By Adsorption (AREA)
- Drying Of Gases (AREA)
Abstract
ABSTRACT
In the recovery of substances such as solvents adsorbed on sorption agents, the water present means that the solvents have to be worked up.
Anhydrous recovery can be achieved if water is removed from the cycled gaseous desorption agent. An adsorptive dryer incorporated in the circuit stores this water, which, after the end of the desorption phase is available once more for remoistening the activated charcoal. This remoistening of the activated char-coal prevents a spontaneous ignition of the dry charcoal. In order to be able to transfer the heat as well as transfer the water from the sorption agent to the adsorptive dryer and back again, adsorptive dryers and regenerative heat stores are connected in series in the desorption circuit, wherein the cooler recovering the solvent by condensation is connected in front of both these structural elements. By means of this arrangement the heat of adsorption re-leased during the adsorption of water in the adsorptive dryer contributes to reducing the external energy requirement for the desorption. Conversely, the energy required for the desorption of the dryer becomes available during the cooling of the sorption agent. Excess thermal energy is thereby taken up by the regenerative heat store.
In the recovery of substances such as solvents adsorbed on sorption agents, the water present means that the solvents have to be worked up.
Anhydrous recovery can be achieved if water is removed from the cycled gaseous desorption agent. An adsorptive dryer incorporated in the circuit stores this water, which, after the end of the desorption phase is available once more for remoistening the activated charcoal. This remoistening of the activated char-coal prevents a spontaneous ignition of the dry charcoal. In order to be able to transfer the heat as well as transfer the water from the sorption agent to the adsorptive dryer and back again, adsorptive dryers and regenerative heat stores are connected in series in the desorption circuit, wherein the cooler recovering the solvent by condensation is connected in front of both these structural elements. By means of this arrangement the heat of adsorption re-leased during the adsorption of water in the adsorptive dryer contributes to reducing the external energy requirement for the desorption. Conversely, the energy required for the desorption of the dryer becomes available during the cooling of the sorption agent. Excess thermal energy is thereby taken up by the regenerative heat store.
Description
The invention relates to a method for recovering an essentially anhydrous desorbate with a cycled gaseous.desorption medium in the desorption of sorption materials charged in particular with solvents, wherein the desorp-tion medium is heated in a first heat exchanger before being introduced into the charged sorption material, desorbate and water vapour are at least par-tially removed, the latter adsorptively in an adsorption dryer, from the desorption medium charged with desorbate after the medium has left the sorption material by cooling in a second heat exchanger designed as a desorbate con-denser, and the cooled and dried desorption medium is then recycled by a circulation blower to the first heat exchanger.
The invention also relates to an appara~us for the partial implemen-tation of the method with a sorption agent vessel that is connected during the adsorption stage to purify an exhaust air or exhaust gas stream and that is connected for the desorption in a desorption medium cycle together with a desor-bate condenser, an adsorptive dryer, a heat sink, a circulation blower, and a first heat exchanger.
German OLS 29~2959 describes a method for recovering substances, preferably solvents, adsorbed on activated charcoal by desorption with a cir-culated gaseous desorption medium, in which the desorption medium charged with desorbate and leaving the desorbing adsorber is freed from water vapour in an adsorptive dryer connected behind the adsorber in the desorption circuit, and is then cooled in the desorbate condenser until the residual desorbate has condensed. ~or anhydrous recovery of desorbate, this prior method requires the adsorptive dryer be able to ta~e up all the water reaching the desorption circuit. This water is derived on the one hand from the production of an inert gas by combustion, for example of a hydrocarbon, while on the other hand in the purification of the exhaust gas by means of activated charcoal the water 5~
~L~81~633 present in the exhaust gas is adsorbed by the activated charcoal and is later at least partially expelled by the impurities being adsorbed. Both sources of water play a decisive role in estimating the amount of water occurring during the desorption. Accordingly, according to this method the aclsorptive dryer must be designed so that it takes up all the water in the system and that released in the desorption.
When designing the system it also has to be borne in mind that the temperature of the desorption medium rises towards the end of the desorption phase. The storage capability of the adsorptive dryer for water vapour is reduced by this rise in temperature, and if the dryer is dimensioned too small and is thus subjected to too high a loading, water vapour will undesirably be prematurely released. Since according to this prior method the water stored in the adsorptive dryer is intended to be used after the end of the desorption in the cooling phase for remoistening the activated charcoal, the dryer must have appropriately large dimensions.
The object of the present invention is thus to develop a method of the type described initially above in which the adsorptive dryer can be reduced to the necessary size for remoistening the sorption materials, which provides for a reliable and essentially anhydrous recovery of the desorpbate without the use of costly regulating technology, and which is economical to use. The object of the invention is also to provide an apparatus by means of which the method can be advantageously implemented.
To solve this objective, it is proposed according to the invention that the desorption medium is first of all cooled down to near the water saturation limit in the desorbate condenser in the initial phase of the desorp-tion stage before it is introduced into the adsorptive dryer~ whereby the cooled desorption medium with high water vapour saturation in this initial . .
~3;3~
phase flows to the adsorptive dryer and is then heated to dryness, that the desorption medium now charged with desorbate is completely cooled in the desorbate condenser in the desorption phase following the initial phase, and that during the cooling phase following this desorption phase the desorption mcdium now exiting hot from -the sorption materials flows uncooled to the adsorp-tive dryer.
This procedure ensures that, not only is the water removed from the activated charcoal and passed to the adsorptive dryer in the initial phase of the desorption stage~ but that, in addition, by the desorption of the adsorp-tive dryer with the aid of the heat stored in the sorption materials, the water stored in the adsorptive dryer is transferred back during the cooling phase to remoisten the activated charcoal.
This procedure has two basic advantages: firstly, a high relative humidity is achieved by the pre-cooling of the desorption medium charged with water during the initial phase, and the adsorptive dryer is operated at a low temperature. Deposition and storage capability are very high under these conditions. Moreover, the relative humidity of the desorption medium is reduced by the subsequent heating, and the expulsion of water from the sorption materials is favoured by the low relative humidity. The actual desorption takes place after the conclusion of this initial phase. For this, the desorbate condenser is operated with full cooling; the temperature of the desorption medium flowing to the adsorptive dryer is thereby lowered. The reduction in temperature means that the water stored in the adsorptive dryer is reliably retained. The cooling phase follows after the end of the desorption, and during this phase the temperature of sorption medium leaving the sorption materials rises. The de-sorbate condenser no longer cools the desorption medium in this phase, and the latter flows hot to the adsorptive dryer. Adsorptively bound water is expelled from the adsorptive dryer by this heat transfer and is passed to the sorption materials. Since the desorption medium is not heated during this phase, it flows cold to the sorption materials, which for their part now become progressively cooler. In this connection, the sorption materials take up the water expelled from the adsorptive dryer. Since the sorption materials are not charged with water, charging by an amount of 3 - 5% beyond the normal moisture level can occur; the adsorption is not thereby disturbed, and excess water is expelled together with the exhaust gas or air from the sorption materials.
A further development proposes adjusting the coolant flow through the desorbate condenser in order to change its cooling performance. It is furthermore proposed that the stream of desorption medium can be diverted par-tially or wholly around the desorbate condenser by means of an adjustable by-pass. Finally, it is proposed that the coolant flow through the desorbate condenser and/or the by-pass flow to circumvent the desorbate condenser can be regulated. These proposals ensure that, by adapting the cooling performance or adjusting the flow of desorption medium led past the desorbate condenser9 a reduced cooling performance is available or utilised during the initial phase, and that no more cooling takes place during tha cooling phase. In this connec-tion it is expedient to adjust the impact on the coolant flow and/or the 'oy-pass stream of the desorption medium by regulating the relevant conditions.
It is furthermore proposed to adjust or regulate the coolant flow through the desorbate condenser and/or the desorption medium flow through the by-pass depending on the water content of the desorption medium. In addition, it is proposed to use the rise in temperature of the desorption medium after leaving the sorption material as an indicator of the water content of the desorption medium. The adoption of the water content of the desorption medium as an adjustment or regulation parameter is advantageous for obtaining an anhydrous desorbate if predetermined time intervals for the initial phase, desorption phase and cooling phase cannot be retained in the case of quasi-stationary processes.
A simple indicator oF the water content of the desorption medium has proved to be its rise in temperature after leaving -the sorption material.
It is additionally proposed to post-cool the desorption medium between the desorbate condenser and adsorptive dryer in a further heat exchanger, and to preheat it in a heat exchanger connected behind the adsorptive dryer, in particular a heat exchanger connected behind the circulation blower, where-in the heat transportation from the post-cooling of the desorption medium to the preheating of the desorption medium is effected by means of a heat pump with a closed coolant circuit. This proposal is particularly advantageous when the condensation heat of the desorbateg which is otherwise dissipated by the cooling of the desorbate condenser, is to be used to preheat the cooled desorption medium after the drying. In this connection condensate is, of course, formed in the further heat exchanger operating as an after-cooler, and is led away together with the condensate from the desorbate condenser. Altering the occur-rence of the condensate can, in this connection, be e:Ffected by reducing the cooling performance o~ the desorbate condenser and/or by by-passing the desor-~0 bate condenser.
In order to carry out the method of the invention, an apparatus is provided which is characterised in that the desorbate condenser is arranged between the sorption agent vessel and the adsorptive dryer, wherein the sorp-tion agent vessel is filled with activated charcoal and the heat sink is formed as a heat store packed with gravel. The arrangement of the desorbate condenser between the sorption agent vessel and adsorptive dryer normally results in the undesirable occurrence of water in the desorbate condenser. However, by means of the special procedure according to the method of the invention, an essen-tially anhydrous desorbate can surprisingly be successfully recovered in this arrangement. This is based on the fact that the adsorptive dryer is kept at a low temperature during the decisive phases and thus has a high storage cap-ability for water. The cycled desorption medium is well dried and its relative humidity is already considerably reduced in the heat store. ~urthermore, the thermal energy stored in the heat store is utilised.
It is additionally proposed to employ in the adsorptive dryer zeo-litic molecular sieves as sorption material preferentially adsorbing water. It is moreover proposed that the volume of the sorption agents preferentially adsorbing water in the adsorptive dryer is 18 - 15% of the volume of the acti-vated charcoal used to purify the exhaust air/exhaust gas, and that the volume of the packed bed of gravel used in the heat store is about 15 - 35% of the volume of the activated charcoal employed.
The use of zeolitic molecular sieves in the adsorptive dryer as sorption agent preferentially adsorbing water has the substantial advantage that the water is incorporated on account of the pore structure of this sorption agent; the larger molecules of the organic desorbates cannot therefore displace the incorporated water molecules. The resultant design details for the adsorp-tive dryer and for the heat store are in each case related to the volume of the activated charcoal employed. The use of volume ratios is justified since the density of the activated charcoal and that of the molecular sieve employed depend on the charging or loading, and this factor must be taken into account when specifying mass ratio details. It is found that the adsorptive dryer can be reduced by about 50% compared with the design according to German OLS
2942959 by the method of the present invention.
The design of the heat sink as a heat store corresponds to the ~633 design of the heat store according to German OLS 2952127. In both cases the heat store serves as a heat source during the desorption phase since it is discharged during this phase. After the end of the desorp-tion phase the heat store is in a discharged state, i.e. cooled. In this state it is a heat sink :Eor the desorption medium flowing to it at a higher temperature. the desorption medium releases heat to the heat store, and a-t the s~le time cools. If it is not intended to utilise the heat added for the desorption of the sorption materials, the heat store is replaced by a cooler. In this case the heat added to the system for the desorption is dissipated via the cooler during the cooling phase; the desorption medium, which in this phase has to cool the sorption materials, is itself cooled.
The essence of the invention is described in more detail with the aid of the diagrammatic process flow charts according to Figures 1 to 3, while the course of the process is illustrated by the example of an ethanol desorp-tion with the aid of Figure 4. In Figures 1 to 3, the points A and B in each case denote the connection to sorption agent vessels, not shown in detail.
Pigure 1 shows the flow-through of the gaseous desorption agent, which comes from the sorption material and enters the system at A. The desorp-tion medium first of all flows to a desorbate condenser 1. A by-pass 2 with an adjustable throttle valve 2.1 enables the desorbate condenser to be by-passed, wherein the volume flow by-passing the desorbate condenser can be adjusted. Of course, instead of a by-pass the cooling performance of the desorbate condenser can also be adjusted by adjusting the flow and/or temperature of the coolant.
The desorption medium thereafter flows to a adsorptive dryer 4 containing a sorption agent such as silica gel or a molecular sieve that preferentially precipitates water vapour.
After leaving the adsorptive dryer 4, the now dried desorption medium reaches a hea~ sink 5, designed in this case as a heat store in accor-dance with German OLS 2952127. This heat store is first of all charged in the initial phase of desorption, i.e. heat can be added to the desorption medium ir. the heat store. A circulation blower 8 then conveys the gaseous desorption medium to a first heat exchanger 9, the thermal energy required for the desorp-tion being added. The heated desorption medium then flows to the connection point B and enters the sorption materials to be desorbed, following which it returns to point A. The desorbate condenser 1 is in addition provided with an outlet 3 for the condensed desorbate, while an outlet 7 is provided for remov-ing condensed water from the heat sink 5.
Figure 2 illustrates a similar scheme, although here the heat sink is simply designed as a cooler 6. It is obvious that this cooling arrangement is only operated if it is intended to cool the sorption materials in the cooling phase and the heating of the first heat exchanger 9 is switched off. Since in this procedure water condenses in the cooler, it is recommended in this case to recycle the water removed via the condensate outlet 7, to the sorption agent vessel, where it can be sprayed in through nozzles in order to moisten the activated charcoal.
The third process variant illustrated in Figure 3 basically corres-ponds to the preceding variants. In this case~ in order also to be able to utilise the condensation energy of the desorbate, an after-cooler 10 is simply connected behind the desorbate condenser 1, the primary side of which fully or partially takes over the cooling of the desorption medium during the desorp-tion phase, and from which the resultant desorbate condensate is removed via the outlet 3. The secondary side of this heat exchanger 10 is incorporated as an evaporator in a closed coolant circuit of a heat pump. The coolant evaporated in the evaporator is passed by a compressor 12 to a heat exchanger 11 connected ~f~3 as an after-heater, in the secondary side of which the coolant condenses with release of heat and ~rom which it is removed in liquid form via release valve 13. The depressurised coolant thel1 passes to the secondary side of the a:Eter-heater lO and C111 th~re evaporate by taking up heat. This hea-t is released as heat oE condensation ill the after-heater ll and is transferred to the desorp-tion medium. OE particular importance in this embodiment of the method is -the :Eact that the desorption medium can be cooled down to temperatures around -5C
since the residual water vapour content corresponds to a dew point far below 5C~ The condensing out of the desorbate as well as the storage capability of the adsorptive dryer 4 are substantially improved by this reduction in tem-perature.
In order to illustrate the method in more detail, an embodiment involving the purification of an exhaust air stream of 80,000 m3/h with a pollution emission of 600 kg/h of ethanol will be described. A double adsorber arrangement each of whose units contains 30 m3 activated charcoal is used, the adsorbers are operated alternately in adsorption and desorption modes. For desorption, the adsorbers are in each case connected to a desorption circuit consisting of a desorbate condenser, a heat store, a circulation blower, and a first heat exchanger; the arrangement corresponds to the process flow chart illustrated in Figure l. In this connection, an adsorption/desorption cycle lasts for 6 hours, both the adsorption and desorption stages being of equal length, i.e. 3 hours.
Figure 4 illustrates the temperature behaviour at different points of the desorption circuit. Curve l reproduces the temperature behaviour of the desorp~ion medium leaving the desorbate condenser. Curve 2 shows the temperature behaviour of the desorption medium behlnd the adsorptive dryerg curve 3 behind the heat store, curve 4 before entry into the sorption materials, and finally _ g _ curve 5 shows the temperature behaviour a:Eter leaving the sorption materials.
The temperature progressions can be interpreted in detail as follows: At the beginning of the desorption stage the sys-tem is initially inert and heating of the Eirst heat exchanger with saturated steam at 170C is initiated. The temperature oE the desorption medium entering the sorption materials ~curve ~) rises rapidly to about 155C and remains constant at this temperature. During the initial phase water is first of all expelled from the sorption agents.
The water concentration before the adsorptive dryer reaches a maximum value of about 16 g per m3. After 50 minutes the water concentration falls and the initial phase is now finished. During this initial phase the temperature of the desorption medium leaving the sorption materials - curve 5 - rises slightly, and reaches about 50C at the end of the initial phase. In the desorbate condenser the water-containing desorption medium leaving the sorption materials is only slightly cooledJ with the result that the temperature at the end of the initial phase is about 16C. In this connection, the temperature of the desorption medium remains in the region of 18C, the maximum water content being about 16 g per m3. The dew point is below 18C, and its value does not fall. The water expelled from the sorption materials is adsorbed in the adsorp-tive dryer, with the release of the corresponding heat of adsorption. This causes the temperature of the desorption medium (curve 2) leaving the active dryer to rise in the initial phase, and it reaches values of around 80C. To-wards the end of the initial phase, if no more heat o~ adsorption is released, the temperature falls to the level of that of the desorption medium leaving the sorption materials, and the curve 2 coincides with curve 1. The heat store is charged in this initial phase and releases heat to the desorption medium;
the temperature behaviour is reproduced i.n curve 3. Since the heat store is not fully charged by the preceding desorption, the temperature of the exiting ., ~ .
desorption medium initially rises Erom approx. 95C to about 135C, and then falls once more. The released heat of adsorption thlls delays the discharge of the heat store. The heat store is discharged towards the end of the initial phase, and the outlet temperature of the desorption medium Ealls to the temperature leveloE tlle medium leaving the desorbate condenser; the curve 3 then coincides with the curve 1.
The initial phase ends when the water has been expelled from the sorption materials. The end of the initial phase can as a rule be determined by the time that has elapsed. In the case of widely varying amounts of water, it is expedient to monitor the temperature of the desorption agent leaving the sorption materials. As long as water is desorbed, this temperature rises slowly, reaches a break point in the region of 50C, and then quickly rises.
This break point marks the end of the initial phase, as does the reduction in the water content, which can be measured analytically, for example by IR monitor-ing. The initial phase is followed by the actual desorption phase, during which the desorbate - in this case the accumulated ethanol - is expelled. In this connection the ethanol concentrations in the desorption medium before entry to the desorbate condenser reach values of around 270 g per m3. The desorption phase lasts one hour 20 minutes. During this time the desorbate condenser is operated under full cooling performance; the temperature of the desorption medium leaving the desorbate condenser falls to the region of +8C. The water stored in the adsorptive dryer is securely retained by this reduced temperature during the desorption phase, and the exit of water and thus occurrence of water in the desorbate condenser is prevented. During the desorption phase the temperature of the desorption medium entering the sorption materials remains constant at approx. 155~C. The temperature at the outlet side, which first of all rises quickly to approx. 130C, begins to rise more slowly in the region of maximum occurrence of desorbate) as a result of the desorption energy being supplied, and -finally - corresponding to curve 5 - approaches the temperature o:E the entering desorption medium of approx. 15SC. The end of the desorption phase is reached when the desorba-te has been completely expelled; the heating of the first heat exchanger is switched off; -the cooling phase now begins, in which the sorption materials have to be brought once more to the adsorption temperature.
The temperature of the desorption medium entering the sorption materials first of all falls sharply in the cooling phase corresponding to curve 43 and finally reaches the level of the adsorption temperature. Depending on the heat stored in the sorption materials, the desorption medium leaving the sorption materials has at the beginning of the cooling phase a temperature corresponding to the temperature of the desorption medium entering the sorption materials during the desorption phase of approx. 155C - curve 5. After a time delay this temperature first of all begins to fall slowly and then rapidly.
In this connection the curve 5 illustrating this temperature behaviour coin-cides with the curve l illustrating the temperature behaviour in the desorption medium behind the desorbate condenser and, after switching off the cooling or completely opening the by-pass, then rapidly rises and after a short time, governed by the unavoidable transfer of heat to the surrounding medium3 necessarily adjusts to the temperature of the desorption medium leaving the sorption materials. On continued cooling of the sorption materials the tempera-ture then falls until finally, towards the end of the cooling phase, corres-ponding to curve 1~ it has fallen below 100C. The desorption medium at this temperature entering the adsorptive dryer expels water from the latter, the necessary energy of desorption being provided from its heat content. For this reason the desorption medium leaving the adsorptive dryer, corresponding to 8~i331 curve 2, is at a lower temperature, which towards the end of the cooling phase and thus towards the end of the water desorption approaches the temperature of the desorption mediwm entering the adsorptive dryer. During the cooling phase the heat store has become hot through this sensible heat of the desorp-tion medium, and the desorption mediwn, which has released its heat to the heat store mass, leaves - corresponding to curve 3 - cooled from the heat store and towards the end of the cooling phase also reaches the level of -the adsorption temperature. The water expelled during the cooling phase - shown as a broken line measured behind the adsorptive dryer - corresponds in amount to the water stored during the initial phase. This expelled water is fully transferred back to the activated charcoal.
1,765 kg of ethanol having a water content of less than 0.1% was recovered at this temperature, corresponding to a recovery of 98.06%. The ethanol obtained is practically anhydrous. If the loss is converted as an emission to the purified amount of air, a mean residual loading of less than 150 mg/m3 is found. The water loading of the sorption agents of 240 kg was practically completely restored to the activated charcoal used as sorption agent.
For 30 m3 of activated charcoal having a dry mass of approx. 10,800 kg, this means a remoistening to a water content of 2.2%, and for this a molecular sieve volume of 3 m3 is sufficient.
The recovery could not have been substantially increased by the additional use of a heat pump. However, at leas-t a substantial part of the energy of condensation of the 1,765 kg of ethanol would have been available as heat energy for preheating the cold desorption medium. The basic difference compared with the described experimental procedure is the fact that during the ethanol concentration the heating of the first heat exchanger would have been able to be throttled, while the condensation temperature in the desorbate condenser would have been reduced by about 10 K. The temperature of the desorp-ti.on medium leaving the preheater would, using the heat pump, reach 52 - 55C
in the example. The amount oE heat thereby added, including that :From the operation o~ the heat pump, corresponds to the amolmt of heat by which the heat:ing per~ormance of the ~irst hea.t exchanger would have been ahle to be reduced.
The invention also relates to an appara~us for the partial implemen-tation of the method with a sorption agent vessel that is connected during the adsorption stage to purify an exhaust air or exhaust gas stream and that is connected for the desorption in a desorption medium cycle together with a desor-bate condenser, an adsorptive dryer, a heat sink, a circulation blower, and a first heat exchanger.
German OLS 29~2959 describes a method for recovering substances, preferably solvents, adsorbed on activated charcoal by desorption with a cir-culated gaseous desorption medium, in which the desorption medium charged with desorbate and leaving the desorbing adsorber is freed from water vapour in an adsorptive dryer connected behind the adsorber in the desorption circuit, and is then cooled in the desorbate condenser until the residual desorbate has condensed. ~or anhydrous recovery of desorbate, this prior method requires the adsorptive dryer be able to ta~e up all the water reaching the desorption circuit. This water is derived on the one hand from the production of an inert gas by combustion, for example of a hydrocarbon, while on the other hand in the purification of the exhaust gas by means of activated charcoal the water 5~
~L~81~633 present in the exhaust gas is adsorbed by the activated charcoal and is later at least partially expelled by the impurities being adsorbed. Both sources of water play a decisive role in estimating the amount of water occurring during the desorption. Accordingly, according to this method the aclsorptive dryer must be designed so that it takes up all the water in the system and that released in the desorption.
When designing the system it also has to be borne in mind that the temperature of the desorption medium rises towards the end of the desorption phase. The storage capability of the adsorptive dryer for water vapour is reduced by this rise in temperature, and if the dryer is dimensioned too small and is thus subjected to too high a loading, water vapour will undesirably be prematurely released. Since according to this prior method the water stored in the adsorptive dryer is intended to be used after the end of the desorption in the cooling phase for remoistening the activated charcoal, the dryer must have appropriately large dimensions.
The object of the present invention is thus to develop a method of the type described initially above in which the adsorptive dryer can be reduced to the necessary size for remoistening the sorption materials, which provides for a reliable and essentially anhydrous recovery of the desorpbate without the use of costly regulating technology, and which is economical to use. The object of the invention is also to provide an apparatus by means of which the method can be advantageously implemented.
To solve this objective, it is proposed according to the invention that the desorption medium is first of all cooled down to near the water saturation limit in the desorbate condenser in the initial phase of the desorp-tion stage before it is introduced into the adsorptive dryer~ whereby the cooled desorption medium with high water vapour saturation in this initial . .
~3;3~
phase flows to the adsorptive dryer and is then heated to dryness, that the desorption medium now charged with desorbate is completely cooled in the desorbate condenser in the desorption phase following the initial phase, and that during the cooling phase following this desorption phase the desorption mcdium now exiting hot from -the sorption materials flows uncooled to the adsorp-tive dryer.
This procedure ensures that, not only is the water removed from the activated charcoal and passed to the adsorptive dryer in the initial phase of the desorption stage~ but that, in addition, by the desorption of the adsorp-tive dryer with the aid of the heat stored in the sorption materials, the water stored in the adsorptive dryer is transferred back during the cooling phase to remoisten the activated charcoal.
This procedure has two basic advantages: firstly, a high relative humidity is achieved by the pre-cooling of the desorption medium charged with water during the initial phase, and the adsorptive dryer is operated at a low temperature. Deposition and storage capability are very high under these conditions. Moreover, the relative humidity of the desorption medium is reduced by the subsequent heating, and the expulsion of water from the sorption materials is favoured by the low relative humidity. The actual desorption takes place after the conclusion of this initial phase. For this, the desorbate condenser is operated with full cooling; the temperature of the desorption medium flowing to the adsorptive dryer is thereby lowered. The reduction in temperature means that the water stored in the adsorptive dryer is reliably retained. The cooling phase follows after the end of the desorption, and during this phase the temperature of sorption medium leaving the sorption materials rises. The de-sorbate condenser no longer cools the desorption medium in this phase, and the latter flows hot to the adsorptive dryer. Adsorptively bound water is expelled from the adsorptive dryer by this heat transfer and is passed to the sorption materials. Since the desorption medium is not heated during this phase, it flows cold to the sorption materials, which for their part now become progressively cooler. In this connection, the sorption materials take up the water expelled from the adsorptive dryer. Since the sorption materials are not charged with water, charging by an amount of 3 - 5% beyond the normal moisture level can occur; the adsorption is not thereby disturbed, and excess water is expelled together with the exhaust gas or air from the sorption materials.
A further development proposes adjusting the coolant flow through the desorbate condenser in order to change its cooling performance. It is furthermore proposed that the stream of desorption medium can be diverted par-tially or wholly around the desorbate condenser by means of an adjustable by-pass. Finally, it is proposed that the coolant flow through the desorbate condenser and/or the by-pass flow to circumvent the desorbate condenser can be regulated. These proposals ensure that, by adapting the cooling performance or adjusting the flow of desorption medium led past the desorbate condenser9 a reduced cooling performance is available or utilised during the initial phase, and that no more cooling takes place during tha cooling phase. In this connec-tion it is expedient to adjust the impact on the coolant flow and/or the 'oy-pass stream of the desorption medium by regulating the relevant conditions.
It is furthermore proposed to adjust or regulate the coolant flow through the desorbate condenser and/or the desorption medium flow through the by-pass depending on the water content of the desorption medium. In addition, it is proposed to use the rise in temperature of the desorption medium after leaving the sorption material as an indicator of the water content of the desorption medium. The adoption of the water content of the desorption medium as an adjustment or regulation parameter is advantageous for obtaining an anhydrous desorbate if predetermined time intervals for the initial phase, desorption phase and cooling phase cannot be retained in the case of quasi-stationary processes.
A simple indicator oF the water content of the desorption medium has proved to be its rise in temperature after leaving -the sorption material.
It is additionally proposed to post-cool the desorption medium between the desorbate condenser and adsorptive dryer in a further heat exchanger, and to preheat it in a heat exchanger connected behind the adsorptive dryer, in particular a heat exchanger connected behind the circulation blower, where-in the heat transportation from the post-cooling of the desorption medium to the preheating of the desorption medium is effected by means of a heat pump with a closed coolant circuit. This proposal is particularly advantageous when the condensation heat of the desorbateg which is otherwise dissipated by the cooling of the desorbate condenser, is to be used to preheat the cooled desorption medium after the drying. In this connection condensate is, of course, formed in the further heat exchanger operating as an after-cooler, and is led away together with the condensate from the desorbate condenser. Altering the occur-rence of the condensate can, in this connection, be e:Ffected by reducing the cooling performance o~ the desorbate condenser and/or by by-passing the desor-~0 bate condenser.
In order to carry out the method of the invention, an apparatus is provided which is characterised in that the desorbate condenser is arranged between the sorption agent vessel and the adsorptive dryer, wherein the sorp-tion agent vessel is filled with activated charcoal and the heat sink is formed as a heat store packed with gravel. The arrangement of the desorbate condenser between the sorption agent vessel and adsorptive dryer normally results in the undesirable occurrence of water in the desorbate condenser. However, by means of the special procedure according to the method of the invention, an essen-tially anhydrous desorbate can surprisingly be successfully recovered in this arrangement. This is based on the fact that the adsorptive dryer is kept at a low temperature during the decisive phases and thus has a high storage cap-ability for water. The cycled desorption medium is well dried and its relative humidity is already considerably reduced in the heat store. ~urthermore, the thermal energy stored in the heat store is utilised.
It is additionally proposed to employ in the adsorptive dryer zeo-litic molecular sieves as sorption material preferentially adsorbing water. It is moreover proposed that the volume of the sorption agents preferentially adsorbing water in the adsorptive dryer is 18 - 15% of the volume of the acti-vated charcoal used to purify the exhaust air/exhaust gas, and that the volume of the packed bed of gravel used in the heat store is about 15 - 35% of the volume of the activated charcoal employed.
The use of zeolitic molecular sieves in the adsorptive dryer as sorption agent preferentially adsorbing water has the substantial advantage that the water is incorporated on account of the pore structure of this sorption agent; the larger molecules of the organic desorbates cannot therefore displace the incorporated water molecules. The resultant design details for the adsorp-tive dryer and for the heat store are in each case related to the volume of the activated charcoal employed. The use of volume ratios is justified since the density of the activated charcoal and that of the molecular sieve employed depend on the charging or loading, and this factor must be taken into account when specifying mass ratio details. It is found that the adsorptive dryer can be reduced by about 50% compared with the design according to German OLS
2942959 by the method of the present invention.
The design of the heat sink as a heat store corresponds to the ~633 design of the heat store according to German OLS 2952127. In both cases the heat store serves as a heat source during the desorption phase since it is discharged during this phase. After the end of the desorp-tion phase the heat store is in a discharged state, i.e. cooled. In this state it is a heat sink :Eor the desorption medium flowing to it at a higher temperature. the desorption medium releases heat to the heat store, and a-t the s~le time cools. If it is not intended to utilise the heat added for the desorption of the sorption materials, the heat store is replaced by a cooler. In this case the heat added to the system for the desorption is dissipated via the cooler during the cooling phase; the desorption medium, which in this phase has to cool the sorption materials, is itself cooled.
The essence of the invention is described in more detail with the aid of the diagrammatic process flow charts according to Figures 1 to 3, while the course of the process is illustrated by the example of an ethanol desorp-tion with the aid of Figure 4. In Figures 1 to 3, the points A and B in each case denote the connection to sorption agent vessels, not shown in detail.
Pigure 1 shows the flow-through of the gaseous desorption agent, which comes from the sorption material and enters the system at A. The desorp-tion medium first of all flows to a desorbate condenser 1. A by-pass 2 with an adjustable throttle valve 2.1 enables the desorbate condenser to be by-passed, wherein the volume flow by-passing the desorbate condenser can be adjusted. Of course, instead of a by-pass the cooling performance of the desorbate condenser can also be adjusted by adjusting the flow and/or temperature of the coolant.
The desorption medium thereafter flows to a adsorptive dryer 4 containing a sorption agent such as silica gel or a molecular sieve that preferentially precipitates water vapour.
After leaving the adsorptive dryer 4, the now dried desorption medium reaches a hea~ sink 5, designed in this case as a heat store in accor-dance with German OLS 2952127. This heat store is first of all charged in the initial phase of desorption, i.e. heat can be added to the desorption medium ir. the heat store. A circulation blower 8 then conveys the gaseous desorption medium to a first heat exchanger 9, the thermal energy required for the desorp-tion being added. The heated desorption medium then flows to the connection point B and enters the sorption materials to be desorbed, following which it returns to point A. The desorbate condenser 1 is in addition provided with an outlet 3 for the condensed desorbate, while an outlet 7 is provided for remov-ing condensed water from the heat sink 5.
Figure 2 illustrates a similar scheme, although here the heat sink is simply designed as a cooler 6. It is obvious that this cooling arrangement is only operated if it is intended to cool the sorption materials in the cooling phase and the heating of the first heat exchanger 9 is switched off. Since in this procedure water condenses in the cooler, it is recommended in this case to recycle the water removed via the condensate outlet 7, to the sorption agent vessel, where it can be sprayed in through nozzles in order to moisten the activated charcoal.
The third process variant illustrated in Figure 3 basically corres-ponds to the preceding variants. In this case~ in order also to be able to utilise the condensation energy of the desorbate, an after-cooler 10 is simply connected behind the desorbate condenser 1, the primary side of which fully or partially takes over the cooling of the desorption medium during the desorp-tion phase, and from which the resultant desorbate condensate is removed via the outlet 3. The secondary side of this heat exchanger 10 is incorporated as an evaporator in a closed coolant circuit of a heat pump. The coolant evaporated in the evaporator is passed by a compressor 12 to a heat exchanger 11 connected ~f~3 as an after-heater, in the secondary side of which the coolant condenses with release of heat and ~rom which it is removed in liquid form via release valve 13. The depressurised coolant thel1 passes to the secondary side of the a:Eter-heater lO and C111 th~re evaporate by taking up heat. This hea-t is released as heat oE condensation ill the after-heater ll and is transferred to the desorp-tion medium. OE particular importance in this embodiment of the method is -the :Eact that the desorption medium can be cooled down to temperatures around -5C
since the residual water vapour content corresponds to a dew point far below 5C~ The condensing out of the desorbate as well as the storage capability of the adsorptive dryer 4 are substantially improved by this reduction in tem-perature.
In order to illustrate the method in more detail, an embodiment involving the purification of an exhaust air stream of 80,000 m3/h with a pollution emission of 600 kg/h of ethanol will be described. A double adsorber arrangement each of whose units contains 30 m3 activated charcoal is used, the adsorbers are operated alternately in adsorption and desorption modes. For desorption, the adsorbers are in each case connected to a desorption circuit consisting of a desorbate condenser, a heat store, a circulation blower, and a first heat exchanger; the arrangement corresponds to the process flow chart illustrated in Figure l. In this connection, an adsorption/desorption cycle lasts for 6 hours, both the adsorption and desorption stages being of equal length, i.e. 3 hours.
Figure 4 illustrates the temperature behaviour at different points of the desorption circuit. Curve l reproduces the temperature behaviour of the desorp~ion medium leaving the desorbate condenser. Curve 2 shows the temperature behaviour of the desorption medium behlnd the adsorptive dryerg curve 3 behind the heat store, curve 4 before entry into the sorption materials, and finally _ g _ curve 5 shows the temperature behaviour a:Eter leaving the sorption materials.
The temperature progressions can be interpreted in detail as follows: At the beginning of the desorption stage the sys-tem is initially inert and heating of the Eirst heat exchanger with saturated steam at 170C is initiated. The temperature oE the desorption medium entering the sorption materials ~curve ~) rises rapidly to about 155C and remains constant at this temperature. During the initial phase water is first of all expelled from the sorption agents.
The water concentration before the adsorptive dryer reaches a maximum value of about 16 g per m3. After 50 minutes the water concentration falls and the initial phase is now finished. During this initial phase the temperature of the desorption medium leaving the sorption materials - curve 5 - rises slightly, and reaches about 50C at the end of the initial phase. In the desorbate condenser the water-containing desorption medium leaving the sorption materials is only slightly cooledJ with the result that the temperature at the end of the initial phase is about 16C. In this connection, the temperature of the desorption medium remains in the region of 18C, the maximum water content being about 16 g per m3. The dew point is below 18C, and its value does not fall. The water expelled from the sorption materials is adsorbed in the adsorp-tive dryer, with the release of the corresponding heat of adsorption. This causes the temperature of the desorption medium (curve 2) leaving the active dryer to rise in the initial phase, and it reaches values of around 80C. To-wards the end of the initial phase, if no more heat o~ adsorption is released, the temperature falls to the level of that of the desorption medium leaving the sorption materials, and the curve 2 coincides with curve 1. The heat store is charged in this initial phase and releases heat to the desorption medium;
the temperature behaviour is reproduced i.n curve 3. Since the heat store is not fully charged by the preceding desorption, the temperature of the exiting ., ~ .
desorption medium initially rises Erom approx. 95C to about 135C, and then falls once more. The released heat of adsorption thlls delays the discharge of the heat store. The heat store is discharged towards the end of the initial phase, and the outlet temperature of the desorption medium Ealls to the temperature leveloE tlle medium leaving the desorbate condenser; the curve 3 then coincides with the curve 1.
The initial phase ends when the water has been expelled from the sorption materials. The end of the initial phase can as a rule be determined by the time that has elapsed. In the case of widely varying amounts of water, it is expedient to monitor the temperature of the desorption agent leaving the sorption materials. As long as water is desorbed, this temperature rises slowly, reaches a break point in the region of 50C, and then quickly rises.
This break point marks the end of the initial phase, as does the reduction in the water content, which can be measured analytically, for example by IR monitor-ing. The initial phase is followed by the actual desorption phase, during which the desorbate - in this case the accumulated ethanol - is expelled. In this connection the ethanol concentrations in the desorption medium before entry to the desorbate condenser reach values of around 270 g per m3. The desorption phase lasts one hour 20 minutes. During this time the desorbate condenser is operated under full cooling performance; the temperature of the desorption medium leaving the desorbate condenser falls to the region of +8C. The water stored in the adsorptive dryer is securely retained by this reduced temperature during the desorption phase, and the exit of water and thus occurrence of water in the desorbate condenser is prevented. During the desorption phase the temperature of the desorption medium entering the sorption materials remains constant at approx. 155~C. The temperature at the outlet side, which first of all rises quickly to approx. 130C, begins to rise more slowly in the region of maximum occurrence of desorbate) as a result of the desorption energy being supplied, and -finally - corresponding to curve 5 - approaches the temperature o:E the entering desorption medium of approx. 15SC. The end of the desorption phase is reached when the desorba-te has been completely expelled; the heating of the first heat exchanger is switched off; -the cooling phase now begins, in which the sorption materials have to be brought once more to the adsorption temperature.
The temperature of the desorption medium entering the sorption materials first of all falls sharply in the cooling phase corresponding to curve 43 and finally reaches the level of the adsorption temperature. Depending on the heat stored in the sorption materials, the desorption medium leaving the sorption materials has at the beginning of the cooling phase a temperature corresponding to the temperature of the desorption medium entering the sorption materials during the desorption phase of approx. 155C - curve 5. After a time delay this temperature first of all begins to fall slowly and then rapidly.
In this connection the curve 5 illustrating this temperature behaviour coin-cides with the curve l illustrating the temperature behaviour in the desorption medium behind the desorbate condenser and, after switching off the cooling or completely opening the by-pass, then rapidly rises and after a short time, governed by the unavoidable transfer of heat to the surrounding medium3 necessarily adjusts to the temperature of the desorption medium leaving the sorption materials. On continued cooling of the sorption materials the tempera-ture then falls until finally, towards the end of the cooling phase, corres-ponding to curve 1~ it has fallen below 100C. The desorption medium at this temperature entering the adsorptive dryer expels water from the latter, the necessary energy of desorption being provided from its heat content. For this reason the desorption medium leaving the adsorptive dryer, corresponding to 8~i331 curve 2, is at a lower temperature, which towards the end of the cooling phase and thus towards the end of the water desorption approaches the temperature of the desorption mediwm entering the adsorptive dryer. During the cooling phase the heat store has become hot through this sensible heat of the desorp-tion medium, and the desorption mediwn, which has released its heat to the heat store mass, leaves - corresponding to curve 3 - cooled from the heat store and towards the end of the cooling phase also reaches the level of -the adsorption temperature. The water expelled during the cooling phase - shown as a broken line measured behind the adsorptive dryer - corresponds in amount to the water stored during the initial phase. This expelled water is fully transferred back to the activated charcoal.
1,765 kg of ethanol having a water content of less than 0.1% was recovered at this temperature, corresponding to a recovery of 98.06%. The ethanol obtained is practically anhydrous. If the loss is converted as an emission to the purified amount of air, a mean residual loading of less than 150 mg/m3 is found. The water loading of the sorption agents of 240 kg was practically completely restored to the activated charcoal used as sorption agent.
For 30 m3 of activated charcoal having a dry mass of approx. 10,800 kg, this means a remoistening to a water content of 2.2%, and for this a molecular sieve volume of 3 m3 is sufficient.
The recovery could not have been substantially increased by the additional use of a heat pump. However, at leas-t a substantial part of the energy of condensation of the 1,765 kg of ethanol would have been available as heat energy for preheating the cold desorption medium. The basic difference compared with the described experimental procedure is the fact that during the ethanol concentration the heating of the first heat exchanger would have been able to be throttled, while the condensation temperature in the desorbate condenser would have been reduced by about 10 K. The temperature of the desorp-ti.on medium leaving the preheater would, using the heat pump, reach 52 - 55C
in the example. The amount oE heat thereby added, including that :From the operation o~ the heat pump, corresponds to the amolmt of heat by which the heat:ing per~ormance of the ~irst hea.t exchanger would have been ahle to be reduced.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Method for recovering an essentially anhydrous desorbate with a cycled gaseous desorption medium in the desorption of sorption materials, wherein the desorption medium is heated in a first heat exchanger before being introduced into the charged sorption material, desorbate and water vapour are at least partially removed, the latter adsorptively in an adsorptive dryer, from the desorption Medium charged with desorbate after the medium has left the sorption material by cooling in a second heat exchanger designed as a desorbate condenser, and the cooled and dried desorption medium is then recycled by a circulation blower to the first heat exchanger, the desorption medium being first of all cooled down to near the water saturation limit in the desorbate condenser in the initial phase of the desorption stage before it is introduced into the adsorptive dryer, whereby the cooled desorption medium with high water vapour saturation in this initial phase flows to the adsorptive dryer and is then heated dry, the desorption medium now charged with desorbate being com-pletely cooled in the desorbate condenser in the desorption phase following the initial phase, and during the cooling phase following the desorption phase the desorption medium now exiting hot from the sorption materials flows uncooled to the adsorptive dryer.
2. Method according to Claim 1, wherein the flow of coolant through the desorbate condenser can be adjusted in order to change the cooling performance thereof.
3. Method according to Claim 1, wherein the flow of the desorption medium can be completely or partially diverted around the desorbate condenser by means of an adjustable by-pass.
4. Method according to Claim 2 or 3, wherein the flow of coolant thro-ugh the desorbate condenser and/or the by-pass flow circumventing the desorb-ate condenser can be adjusted.
5. Method according to Claim 2, wherein the adjustment or regulation of the coolant flow through the desorbate condenser and/or the desorption medium flow through the by-pass is effected depending on the water content of the desorption medium.
6. Method according to Claim 5, wherein the rise in temperature of the desorption medium after leaving the sorption material is used as an indication of the water content of the desorption medium.
7. Method according to Claim 1, wherein the desorption medium between the desorbate condenser and adsorptive dryer is after-cooled in a further heat exchanger and is preheated in a further heat exchanger connected behind the adsorptive dryer, in a heat exchanger connected behind the circulation blower, wherein the transportation of heat from the after-cooling of the desorption medium to the preheating of the desorption medium is effected by means of a heat pump with a closed coolant circuit.
8. Method according to Claim 7, wherein preheating is effected in a heat exchanger connected behind the circulation blower.
9. Apparatus for carrying out the method according to Claim 1, com-prising a sorption agent vessel which is connected during the adsorption period to purify an exhaust air or exhaust gas stream and which is incorporated for the desorption in the circuit of a desorption medium together with a desorbate condenser, an adsorptive dryer, a heat sink, a circulation blower and a first heat exchanger, the desorbate condenser being arranged between the sorption agent vessel and adsorptive dryer, wherein the sorption agent vessel is packed with activated charcoal and the heat sink is designed as a heat store packed with gravel.
10. Apparatus according to Claim 9, wherein zeolitic molecular sieves are arranged in the adsorptive dryer as sorption agent preferentially adsorb-ing water.
11. Apparatus according to Claim 9 or 10, wherein the volume of the sorption agent in the adsorptive dryer preferentially adsorbing water is about 10 - 15% of the volume of the activated charcoal used to purify the exhaust air/exhaust gas, and that the volume of the packed gravel bed used in the heat store is about 15 - 35% of the volume of the activated charcoal employed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3201390A DE3201390A1 (en) | 1982-01-19 | 1982-01-19 | METHOD FOR RECOVERY OF AN essentially WATER-FREE DESORBATE, AND DEVICE FOR CARRYING OUT THE METHOD |
| DEP3201390.6 | 1982-01-19 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1188633A true CA1188633A (en) | 1985-06-11 |
Family
ID=6153330
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000419675A Expired CA1188633A (en) | 1982-01-19 | 1983-01-18 | Method for recovering an essentially anhydrous desorbate as well as an apparatus for carrying out the method |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4473381A (en) |
| JP (1) | JPS58150412A (en) |
| CA (1) | CA1188633A (en) |
| DE (1) | DE3201390A1 (en) |
| FR (1) | FR2519879B1 (en) |
| GB (1) | GB2113115B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3336427A1 (en) * | 1983-10-06 | 1985-04-18 | Linde Ag, 6200 Wiesbaden | METHOD AND DEVICE FOR REGENERATING ADSORBERS |
| JPS61257218A (en) * | 1985-05-10 | 1986-11-14 | Mitsubishi Heavy Ind Ltd | Dehumidifier |
| JPH0724737B2 (en) * | 1986-02-14 | 1995-03-22 | 三菱重工業株式会社 | Dehumidifier |
| EP0260481B1 (en) * | 1986-09-16 | 1991-04-17 | OTTO OEKO-TECH GMBH & CO. KG | Process and device for the separation and recovery of volatile solvents |
| DE3737408A1 (en) * | 1987-11-01 | 1989-05-11 | Schack & Co Rekuperator | METHOD FOR RECOVERY OF THE DESORBATE RESULTING FROM THE DESORPTION OF LOADED SORPTION MATERIALS, AND DEVICE THEREFOR |
| KR100391307B1 (en) * | 2001-06-04 | 2003-07-16 | 한라공조주식회사 | Method for preparing a solid film lubricant |
Family Cites Families (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2790505A (en) * | 1954-08-02 | 1957-04-30 | United Gas Corp | Methods of and means for dehydrating and processing fluid streams |
| NL281806A (en) * | 1955-11-10 | 1900-01-01 | ||
| FR1205833A (en) * | 1957-05-17 | 1960-02-04 | Birs Beteiligungs Und Verwaltu | Process for evaporating solutions and suspensions, apparatus for its implementation, products obtained and their applications |
| US2995208A (en) * | 1958-08-15 | 1961-08-08 | Phillips Petroleum Co | Adsorption process and apparatus |
| DE1544022B2 (en) * | 1963-02-15 | 1969-10-30 | Linde Ag, 6200 Wiesbaden | Process for the enrichment of a component in gas mixtures |
| US3674429A (en) * | 1971-01-06 | 1972-07-04 | Union Carbide Corp | Adsorption process for water and nitrogen oxides |
| US3756961A (en) * | 1971-06-02 | 1973-09-04 | Texaco Inc | Orbents regeneration of molecular sieves with regeneration of solid water ads |
| US3850592A (en) * | 1972-11-24 | 1974-11-26 | Deltech Eng Inc | Heat pump dryer |
| US3891410A (en) * | 1973-07-30 | 1975-06-24 | Paul M Hankison | Dehydrating compressed air and gases |
| DE2516223C3 (en) * | 1975-04-14 | 1978-12-14 | Linde Ag, 6200 Wiesbaden | Method and device for regenerating adsorbent |
| US4203734A (en) * | 1976-03-16 | 1980-05-20 | Ceagfilter Und Entstaubungstechnik Gmbh | Method and apparatus for the selective adsorption of vaporous or gaseous impurities from other gases |
| DE2702701C3 (en) * | 1977-01-24 | 1982-01-28 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8000 München | System for extracting water from humid air |
| GB1583491A (en) * | 1977-06-01 | 1981-01-28 | Cjb Developments Ltd | Adsorption heat pump |
| DE2738874C3 (en) * | 1977-08-29 | 1982-01-14 | M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8000 München | Process for obtaining water from atmospheric air and installation for carrying out the process |
| FR2460703A1 (en) * | 1979-07-06 | 1981-01-30 | Elf France | PROCESS FOR SEPARATING OR PURIFYING BLENDS USING AN ADSORBENT SOLID |
| DE2935147A1 (en) * | 1979-08-30 | 1981-03-26 | Linde Ag, 65189 Wiesbaden | METHOD FOR REMOVING LUBRICANT AGENTS AND LUBRICANT STEAMS FROM A GAS FLOW |
| FR2464744A1 (en) * | 1979-09-12 | 1981-03-20 | Ceag Verfahrenstechnik Gmbh | METHOD AND INSTALLATION FOR THERMAL REGENERATION OF ADSORBENT PRODUCTS LOADED |
| DE2952127C2 (en) * | 1979-12-22 | 1985-03-14 | Rekuperator KG Dr.-Ing. Schack & Co, 4000 Düsseldorf | Method and device for the thermal regeneration of loaded sorbent materials |
| DE2942959C2 (en) * | 1979-10-24 | 1986-07-17 | Rekuperator KG Dr.-Ing. Schack & Co, 4000 Düsseldorf | Process for the recovery of adsorbable substances |
| US4373935A (en) * | 1981-05-01 | 1983-02-15 | Union Carbide Corporation | Adsorption separation cycle |
-
1982
- 1982-01-19 DE DE3201390A patent/DE3201390A1/en active Granted
- 1982-11-26 FR FR8219900A patent/FR2519879B1/en not_active Expired
- 1982-12-17 JP JP57220370A patent/JPS58150412A/en active Granted
-
1983
- 1983-01-17 US US06/458,539 patent/US4473381A/en not_active Expired - Lifetime
- 1983-01-18 CA CA000419675A patent/CA1188633A/en not_active Expired
- 1983-01-19 GB GB08301405A patent/GB2113115B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2519879B1 (en) | 1987-01-30 |
| GB2113115B (en) | 1985-08-29 |
| JPH0127768B2 (en) | 1989-05-30 |
| FR2519879A1 (en) | 1983-07-22 |
| GB8301405D0 (en) | 1983-02-23 |
| JPS58150412A (en) | 1983-09-07 |
| GB2113115A (en) | 1983-08-03 |
| US4473381A (en) | 1984-09-25 |
| DE3201390A1 (en) | 1983-07-28 |
| DE3201390C2 (en) | 1987-05-27 |
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