JPS60255103A - Rectification and/or stripping method and apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION One Book of the Invention The present invention is based on the invention, in which the lower part is heated and the upper part is cooled, and the heating and cooling are connected to each other by a heat pump. TECHNICAL FIELD The present invention relates to a method and apparatus for performing storage and/or stripping.

By blowing external gas or external steam into the prior art column, the partial pressure within the column is reduced in a known manner, and at the same time the temperature within the column is also reduced. This effect also applies to careful separation of substances - rectification.
It is also used for recycling by stripping cleaning agents in many chemical and physical cleaning processes. In this case, water vapor can be used most advantageously. The water vapor can be blown directly into the bottom of the column during hot heating or stripping, or, if the feed of the column already contains water, can be generated by external heating of the bottom. In this case, as is known, the heating device at the bottom of the column and the cooling device at the top of the column are connected to one another by means of a heat pump.

OBJECTS OF THE INVENTION It is an object of the invention to develop a method as mentioned in the introduction in such a way that the energy input can be reduced.

SUMMARY OF THE INVENTION The above-mentioned objects are solved according to the invention by driving a heat pump by the expansion of a gas or steam to perform work, which after being expanded is used as a strip gas in said column. It is.

Thermothermal methods generally state that the heat requirement at the bottom of the column consists essentially of three components: heating the liquid to the bottom temperature, introducing energy for the separation of the substances, and generating the strip vapor. It consists of letting. On the other hand, according to the present invention, in principle, a heat pump is interposed between the top and the bottom of the column, and the drive of the heat pump is performed by expansion that performs work, and the gas or steam is After expansion to perform work, it is used as a strip gas in the column. Such a method makes it possible to significantly reduce the energy input.

The use of water vapor to drive heat pumps by expansion, which performs work, has proven particularly suitable for the purpose. Such water vapor is suitable as a strip gas in the column.

According to a further embodiment of the method according to the invention, it is proposed that the heat pump is operated as a closed system with its own working medium. In this case, the working medium may be, for example, refrigerant R11. Alternatively, however, it is also possible to operate the heat pump as an open system and use the gas leaving the top of the column or the head condenser as the working medium. A so-called vapor compression method is carried out by such a method. As is known, vapor compression can be carried out both by compressors and by ejectors. In the former case, the compressor is driven by an expansion turbine, the exhaust steam of which is led to the bottom of the column, where it is used as strip gas, and the compressed steam is heated by a heat exchanger to the bottom of the column. It will be done. In the latter case, a portion of the steam condensed in the head cooling device is drawn out and expanded;
It is suitable for the purpose of being used in evaporative form for cooling the head of a column. After being compressed by the ejector, the steam is introduced into the bottom of the column together with the ejector's driving gas and used as strip gas.

Such a method of steam injection line steam compression allows a substantial reduction in steam consumption, which is particularly noticeable by the reduction in investment costs.

According to a further variant of the method according to the invention, it is proposed that the heat pump is additionally adapted to introduce heat from the bottom product, thereby cooling the bottom product. . This process is particularly suitable if the bottom product has to be further cooled before being discharged.

Further reductions in energy requirements can be achieved by configuring the heat pump in stages.

In this case, the cooling and/or heating of the substrate takes place in multiple stages, ie the heat pump is adapted to emit or accept heat at different temperature levels.

The invention further comprises a column, a bottom heating device and a head cooling device, the bottom heating device and the top cooling device being connected to each other by a heat pump. It relates to an apparatus for carrying out the method. This device is characterized in that a heat pump is connected to the expansion device according to the invention.

In this case, in particular, the heat pump can be configured as a closed system or as an open system, in the latter case being connected via conduits to the top of the column or to the condensation device at the top. Preferably, the expansion device is configured as an expansion turbine and is connected to the lower part of the column by a discharge conduit. Particularly in open systems, the expansion device can also be configured as an ejector. Furthermore, it is advantageous for the column to be provided with a liquid cut-off device below the head cooling device. Furthermore, if a closed system is used, a heat pump can be connected to the product conduit for the bottom product.

The method and device according to the invention can advantageously be used for the regeneration of cleaning agents for physical or chemical cleaning.

DESCRIPTION OF THE INVENTION In the following the invention will be explained in detail by means of embodiments shown schematically in two drawings.

In FIG. 1, a charge is introduced into a thermothermal column 2 by a conduit 1. This input is a solvent containing absorbed impurities or a mixture of substances to be separated. In the embodiment shown, a portion of the required strip steam is introduced into the lower part of the thermothermal column via line 3, which portion separates the material to be separated from the input in a countercurrent.

For example, 900 t/h of tetraethylene glycol dimethyl ether containing SO□ and having a temperature of 959 C are fed as input from a combustion gas desulfurization installation. SO□ is separated from the cleaning agent by means of strip steam (15 t/h, approx. 0.6 bar). The cleaning agent thus freed of SO□ is discharged from column 2 via line 4 at a temperature of 100'C and a pressure of 0.6 par.

A portion of the liquid is withdrawn from the lower part of the thermothermal column via line 5, heated in a heat exchanger 6, partially evaporated and returned to column 2 via line 7. The steam generated thereby serves to improve the stripping or rectifying action.

Strip steam containing SO□ is drawn off via conduit B;
It is cooled to about 65° C. by the circulating medium of the heat pump in the heat exchanger 9 and to about 309° C. by the cooling water in the cooling device 10, and then introduced into the separation device 11. The condensed strip vapor is withdrawn from the lower part of the separator 11 via a return conduit 12 and is partially fed to the head of the thermal column to serve as a return stream. The remaining portion is discharged via conduit 13 as surplus water. From the top of the separation device 11 to the conduit 1
4, a head product, ie, an amount of about 22.3 kmol/h of separated SO2 is discharged. This SO7 contains water vapor corresponding to the temperature within the separator ll.

The bottom heating device of the thermothermal column is driven in the heat exchanger 6 by a circulating medium. At that time, this circulating medium (45kg/5e
c) collection device 1 with a temperature of 110 °C upon condensation
6 will be introduced. Conduit 17 with condensate expansion valve 18
It passes through a heat exchanger 9, where it evaporates and is introduced into a compressor 20 through a conduit 19 in the form of vapor. 10.
The vapor compressed to 5 bar is introduced again via line I5 into the heat exchanger 6 and condensed again. The compressor 20 is driven according to the invention by a steam turbine 21 which itself receives intermediate pressure steam (lot/h,
30 bar, 300K). The outlet side of this turbine 21 is connected via the discharge conduit 3 to the bottom of the thermothermal column, and the discharge of the turbine having a temperature of 86° G and a pressure of 0.6 bar is carried out in the column as strip steam. made so that it can be used.

In contrast to the conventional method of carrying out steam heating, which requires approximately 20 t/h of steam for heating the bottom of the column, in contrast to the method according to the invention, only 101/h of steam is required. Only 100% of steam is required.

Furthermore, in the illustrated embodiment, a portion of the condensed circulating medium is branched off via a conduit 23 and a valve 2
4, evaporated in a heat exchanger 25 and then compressed via conduit 26! This shows that it can be guided to the entrance side of 20. In this case, heat exchange takes place on the bottom product which flows through line 26°. Being able to do this has the advantage that the heat content of the bottom product can also be utilized by the heat pump for heating the column.

According to FIG. 2, a physical solvent containing impurities, e.g.
01/h into the thermothermal tower 30. The thermal tower 30 is equipped with a bottom heating device 32 and a head cooling device 33,39. The head cooling device 33 is designed as a condensation-evaporation device. A liquid cut-off device, for example a Kaminboden, is arranged below the head cooling device.

In the illustrated embodiment, a conduit 35 is connected to the lower part of the thermothermal column 115.
8, having a temperature of °C and a pressure of 0.6 par;
5t/h of steam is introduced. The bottom of the column is at a temperature of 100° C. and a pressure of 0.6 Herr, allowing the SO2 to be stripped from the solvent by superheated steam. The solvent, thus freed of S02, leaves the column via line 36 at a temperature of 100° C. and a pressure of 0.6 Herr.

A portion of the regenerated solvent is heated in the bottom heating device 32 via conduit 37 and returned to the column.

The steam containing SO2 is cooled to 84°C in the head cooling device 33, and when most of the steam is condensed, 0.3 mol-χCO2,
4゜211101-χSO, and 95, 5n+o
A gaseous fraction of 480 kmol/h consisting of I-χH,0 is withdrawn. This fraction is cooled to 3066 by cooling water in the cooling device 39 and introduced into the separation device 40. From this separator 40, 8.2 t/h of water is introduced into the head of the column 30 via a conduit 41, and 7.9 t/h of water is introduced into the head of the column 30 via a conduit 51.
20 kmo, I/
A gaseous fraction h is drawn out, compressed in a compressor 42, and then discharged.

Condensation generated by cooling in the head cooling device 33 (approximately 9.
4 t/h) is discharged from the column via conduit 43 above liquid cut-off device 34. A portion of this condensate (approximately 1 t/h
) is fed back to the column via conduit 44 as a return stream below the liquid cutoff device 34, and is then fed to the column again as a return stream (approximately 5 t/h).
is led via conduit 45 into condensation-evaporation device 33 for cooling after being expanded in expansion valve 46 . The condensate is then evaporated and sucked off via the line 47 by the ejector 48 at a pressure of 0.42 bar. The remainder of the withdrawn condensate is discharged, for example for preparation of feed water.

In the steam injection line device or ejector 48, the steam from line 47 is compressed to 0.6 bar and introduced together with the working medium - 3.4 t/h of saturated steam from line 49 via line 35 into the lower part of the column. Ru.

A portion (10
, 5 t/h) is used in heat exchanger 32 for heating the solvent via conduit 50 at a pressure of 4.5 bar.

ADVANTAGES OF THE INVENTION As noted above, it can be seen that the present invention provides a rectification and/or stripping method and apparatus that has significantly reduced energy requirements compared to conventional methods.

[Brief explanation of drawings]

FIG. 1 is a schematic circuit diagram of a steam distillation apparatus according to the invention in which a heat pump with an auxiliary circulation circuit is used. FIG. 2 is a schematic circuit diagram of a regeneration device using a steam injection line-vapor compression device. 2.30...Thermal tower 6.9.25...Heat exchanger 10...Cooling device 11.40...Separation device 16...Collection Equipment 18.24.46・Expansion valve 20.42・・Compressor 21・・・Steam turbine 32・・Bottom heating device 33.39・・Head cooling Device 34...Liquid cutoff device 48...Ejector or steam injection line device 5 Engraving of drawings (no changes to the contents) 6 7 Procedural amendment April 9, 1985 Patent Office Official Manabu Shiga 1. Indication of the case Patent Application No. 044506 of 1985 2. Name of the invention Steaming and/or stripping method and apparatus 3. Person making the amendment Relationship to the case Patent applicant address Federal Republic of Germany Republic Day 6200 Wiesbaden Abraham Linkoln Strasse 21 Name Linde Akchenkesselschaft 4, Agent
■164 Address: 5-6 Yaetayo-cho, Nakano-ku, Tokyo "can be done." has been corrected as follows. "When possible, it is also possible to combine the two." (2) Correction as shown in the table below in the specification. Page Line Original Correction 112 Return Reflux 114 Return flow Reflux II 13 Collection device Accumulator 1414 Return flow Reflux 165 Collection device Accumulator procedure amendment (method) % formula % ■1 Name of the invention Rectification and/or stripping method and device 3. Relationship with the case of the person making the amendment Patent applicant address 21 Wiesbaden Abraham Linkoln Strasse 6200 Federal Republic of Germany Name Linde Akchengesellschaft 4, Agent
■164 Address: 5-6-23 Yayoi-cho, Nakano-ku, Tokyo Column for the representative of the patent applicant in the application form, documents and drawings certifying authority of representation 7, contents of amendments Appropriate application form, power of attorney, and appropriateness as per attached sheet Submit a drawing. 8. Attached documents (1) Application form (1 copy) (2) Power of attorney and translation (1 copy each) (3) Drawings 1i1 Procedural amendment 2 June 28, 1985 Patent Application No. 044506 of 1985 2, title of invention Retention and/or Stripping Method and Apparatus 3, Relation to the Amendment Case Patent Applicant Address 21 Wiesbaden-Abraham-Lincoln-Strasse 21, Day 6200, Federal Republic of Germany Name Linda Akchengesellschaft 4, Agent
■164 Address: 5-6-23 Yayoi-cho, Nakano-ku, Tokyo Column 6 of the title of the invention in the procedural amendment submitted on April 9, 1985, Contents of the amendment Procedural amendment submitted on April 9, 1985 The name of the invention was incorrectly written as ``Method and apparatus for distillation and/or stripping,'' but the correct name of the invention is ``Method and apparatus for distillation and/or stripping.'' Therefore, I have attached a procedural amendment that corrects the title of the invention, and I would appreciate your kindly replacing it with this procedural amendment. 7. Attached document procedural amendment 1 copy Procedural amendment April 9, 1985 Mr. Manabu Shiga, Patent Office official 1. Indication of the case 1985 Patent Application No. 044506 2. Title of the invention and/or Stripping method and device 3, relation to the case of the person making the amendment Patent applicant address: 21 Wieshaden-Abraham-Lincoln-Strasse, 6200 Days of the Federal Republic of Germany Name: Linda Akchengesellschaft 4, Agent
■164 Address: 5-6-23 Yayoi-cho, Nakano-ku, Tokyo Column 6 of the detailed description of the invention and brief description of the drawings in the specification, Contents of the amendment (1) Page 5 of the specification, line 6 “Katato” It is possible.'' was corrected as follows. "When possible, it is also possible to combine the two." (2) Correction as shown in the table below in the specification. Page Line Original Correction 112 Return Reflux 114 Return flow Reflux 1113 Collection device Accumulator 1414 Return flow Reflux 165 Collection device Accumulator

Claims (15)

[Claims] (1) A method of carrying out rectification and/or stripping in a column in which the lower part is heated and the upper part is cooled, the heating and cooling being coupled to each other by a heat pump. A distillation and/or stripping method, characterized in that the heat pump is driven by expansion of a gas or steam to perform work, and that the gas or steam is used as a stripping gas in the column after being expanded. . 2. A method as claimed in claim 1, characterized in that: (2) water vapor is used to drive the heat pump by expansion to perform work. (3) The method according to claim 1 or 2, characterized in that the heat pump is operated as a two-closed system with its own working medium. . (4) The heat pump is operated as an open system and uses gas leaving the top of the column as its working medium. The method described in section. (5) A portion of the vapor that condenses when the head of the tower is cooled is drawn out, expanded, and used in the evaporated state for cooling the head of the tower. the method of. (6) The method according to claim 5, characterized in that the vapor drawn out from the head of the column or a condensing device at the head is compressed in an ejector. (7) Any one of claims 1 to 6, characterized in that heat from the bottom product is additionally introduced into the heat pump, thereby cooling the bottom product. 1
The method described in section. (8) A method according to any one of claims 1 to 7, characterized in that the cooling and/or heating of the tower is carried out in multiple stages. (9) Rectification and/or stripping in a column having a bottom heating device and a top cooling device, the bottom heating device and the top cooling device being arranged to be connected to each other by a heat pump. Rectification and/or stripping device, characterized in that the heat pump is connected to an expansion device. 10. Device according to claim 9, characterized in that the heat pump is configured as a closed system. 11. Apparatus according to claim 9, characterized in that the heat pump is constructed as an open system and is connected via a conduit to the head of the column or to the head condensing device. (12) the expansion device is configured as an expansion turbine;
12. Device according to claim 10, characterized in that it is connected to the lower part of the column via a discharge conduit. (13) The device according to claim 11, wherein the expansion device is configured as an ejector. (14) The apparatus according to any one of claims 9 to 13, wherein the tower is provided with a liquid cutoff device below the head cooling device. 15. According to claim 9, 10 or 12, the heat pump is additionally connected to a product conduit for the product. equipment.