Economically efficient process for the hydrogenation of butyraldehyde to butanol

Abstract

The application discloses an economic and efficient butyl aldehyde hydrogenation butanol production process, a part of butyl aldehyde raw materials is supplemented from a separation washer, butyl aldehyde raw materials are used to wash butanol and heavy components in circulating gas; the remaining part of butyl aldehyde raw materials is supplemented from a butyl aldehyde vaporizer, after preheating, mixed circulating gas is mixed with excess hydrogen gas returned from a liquid phase hydrogenation reactor, a part of high-temperature mixed circulating gas is sent to the bottom of the butyl aldehyde vaporizer, butyl aldehyde raw materials are fully vaporized, and heavy components in the butyl aldehyde raw materials are discharged from the bottom; the remaining part of high-temperature mixed circulating gas is bypassed to the outlet of the butyl aldehyde vaporizer, and the temperature of reaction gas feed is increased to meet the temperature requirement of the reaction gas feed. The combined process of gas phase hydrogenation and liquid phase hydrogenation solves the problem that the inlet of the existing gas phase hydrogenation reactor contains a certain amount of butanol and heavy components; butyl aldehyde raw materials are supplemented at two positions of the gas phase hydrogenation system, butyl aldehyde raw materials are used to wash butanol and heavy components in circulating gas, and the gas phase hydrogenation effect is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogenation, and particularly relates to an economic and efficient butyraldehyde hydrogenation process for producing butanol. BACKGROUND

[0002] Butanol is an important chemical raw material, which is mainly used for producing butyl acrylate, butyl acetate and butyl phthalate. The carbonyl synthesis method is a main process for producing butanol, and the process is that propylene is subjected to hydroformylation with synthesis gas to generate butyraldehyde, and butyraldehyde is subjected to catalytic hydrogenation to obtain butanol. A reaction formula of butyraldehyde hydrogenation for producing butanol is as follows:

[0003] CH3CH2CH2CHO+H2→CH3CH2CH2CH2OH

[0004] The hydrogenation process includes a gas-phase hydrogenation process, a liquid-phase hydrogenation process and a combined process of the gas-phase hydrogenation and the liquid-phase hydrogenation. The existing gas-phase hydrogenation process has problems of low butyraldehyde conversion rate, low butanol product yield, short catalyst service life and the like, because the reactor inlet contains a certain amount of butanol and heavy components, the butanol inhibits the butyraldehyde conversion rate, and the heavy components cause the catalyst to be deactivated due to high-temperature coking. The existing liquid-phase hydrogenation process has problems of low butanol selectivity, low butanol product yield, poor butanol product quality and the like, because the inlet butyraldehyde concentration is high, the reaction temperature is high, and the butyraldehyde is prone to polymerization, condensation and other side reactions. The existing combined process of the gas-phase hydrogenation and the liquid-phase hydrogenation mainly aims at solving the incomplete gas-phase hydrogenation reaction, and performing secondary hydrogenation on a small amount of residual butyraldehyde in the gas-phase hydrogenation product to ensure the product quality. SUMMARY

[0005] The application aims to overcome the deficiencies of the prior art and provide an economic and efficient butyraldehyde hydrogenation process for producing butanol.

[0006] To achieve the above object, the application provides an economic and efficient butyraldehyde hydrogenation process for producing butanol, which comprises the following steps.

[0007] A part of butyraldehyde raw material is supplemented from the separation and washing device, gas-liquid separation is performed on the gas-phase hydrogenation product gas flowing out from the bottom of the gas-phase hydrogenation reactor in the separation and washing device, and the butyraldehyde raw material is used to wash the butanol and heavy components in the circulating gas, while the butyraldehyde raw material is vaporized;

[0008] The remaining part of butyraldehyde raw material is supplemented from the butyraldehyde vaporizer, the low-pressure hydrogen gas from outside is mixed with the circulating gas compressed by the circulating gas compressor to form mixed circulating gas, the mixed circulating gas enters the circulating gas preheater, is preheated by the gas-phase hydrogenation product gas from the bottom of the gas-phase hydrogenation reactor, is mixed with the excess hydrogen gas returned from the liquid-phase hydrogenation reactor, is further heated by the heater, and is divided into two streams, one part of the high-temperature mixed circulating gas is sent to the bottom of the butyraldehyde vaporizer to fully vaporize the butyraldehyde raw material, and the heavy components in the butyraldehyde raw material are discharged from the bottom; the remaining part of the high-temperature mixed circulating gas is bypassed to the outlet of the butyraldehyde vaporizer to increase the temperature of the reaction gas feed to meet the requirement of the reaction gas feed temperature, and enters the gas-phase hydrogenation reactor to produce butanol by hydrogenation reaction.

[0009] Further, the gas-phase hydrogenation product gas from the bottom of the gas-phase hydrogenation reactor is divided into two streams, one part of the gas-phase hydrogenation product gas enters the hydrogen gas preheater to preheat the high-pressure hydrogen gas, and the remaining part of the gas-phase hydrogenation product gas enters the circulating gas preheater to preheat the mixed circulating gas; the high-pressure hydrogen gas enters the hydrogen gas preheater, is preheated by the gas-phase hydrogenation product gas, enters the hydrogen gas purification tank, and is sent to the liquid-phase hydrogenation reactor after removing the impurities harmful to the liquid-phase hydrogenation catalyst.

[0010] Further, the gas-phase hydrogenation product gas recovered after the heat recovery of the hydrogen gas preheater and the circulating gas preheater is combined, enters the liquid-phase hydrogenation feed preheater to preheat the butyraldehyde-containing crude butanol from the bottom of the separation scrubber after being further pressurized by the liquid-phase hydrogenation feed pump, and then the butyraldehyde-containing crude butanol is sent to the liquid-phase hydrogenation reactor to produce butanol by hydrogenation reaction, the excess hydrogen gas is returned to the butyraldehyde vaporizer by the heater, and the crude butanol is sent to the butanol rectification section.

[0011] Further, the circulating gas from the top of the separation scrubber and the hydrogen gas recovered by the hydrogen gas recovery device are pressurized by the circulating gas compressor; the purge mixed gas from the outlet of the circulating gas compressor enters the hydrogen gas recovery device, the recovered hydrogen gas returns to the inlet of the circulating gas compressor by its own pressure, and the purge gas is sent out of the boundary.

[0012] Further, the reaction pressure in the gas-phase hydrogenation reactor is 0.3-1.0 MPa, and the reaction temperature is 100-200℃.

[0013] Further, the reaction pressure in the liquid-phase hydrogenation reactor is 2.0-4.0 MPa, and the reaction temperature is 50-150℃.

[0014] Further, the separation scrubber comprises a separation section at the lower part and a washing section at the upper part, and the washing section is filled with packing.

[0015] Compared with the prior art, the present application has the following beneficial effects:

[0016] 1) The present application adopts a combined process of gas phase hydrogenation and liquid phase hydrogenation, solves the problem that the inlet of the existing gas phase hydrogenation reactor contains a certain amount of butanol and heavy components; butyraldehyde raw material is supplemented at two positions of the gas phase hydrogenation system, butyraldehyde raw material is used to wash butanol and heavy components in the circulating gas, and the effect of gas phase hydrogenation is ensured;

[0017] 2) The present application only needs one circulating gas heater, the process is simple, the number of equipment is small, can meet the requirements of butyraldehyde raw material vaporization and reaction gas feeding temperature at the same time, does not need butyraldehyde vaporizer circulating pump, butyraldehyde vaporizer heater and reaction gas feeding heater in the existing process, can avoid high temperature residence of butyraldehyde in the bottom of the vaporizer and the butyraldehyde vaporizer heater, reduce the generation of high polymer of butyraldehyde due to high temperature, improve the yield of butanol product, at the same time, can reduce the investment and operation energy consumption of the device. Part of the butyraldehyde raw material does not participate in the gas phase hydrogenation reaction, only participates in the liquid phase hydrogenation reaction.

[0018] 3) The present application adopts a combined process of gas phase hydrogenation and liquid phase hydrogenation, the process is simple, can effectively improve the yield of butanol product, prolong the service life of the gas phase hydrogenation catalyst, reduce the investment and operation energy consumption of the butyraldehyde hydrogenation device. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The present application is the process flow diagram of the present application economic and efficient butyraldehyde hydrogenation production butanol process. DETAILED DESCRIPTION

[0020] The present application will be further described in detail below in combination with the drawings and specific examples, so that the present application can be more clearly understood.

[0021] The process flow diagram of the present application economic and efficient butyraldehyde hydrogenation production butanol process is shown in Figure 1

[0022] 10-50% of butyraldehyde raw material is supplemented from the separation scrubber, gas-liquid separation is carried out on the gas phase hydrogenation product gas flowing out from the bottom of the gas phase hydrogenation reactor in the separation scrubber, and butyraldehyde raw material is used to wash butanol and heavy components in the circulating gas, the butanol content in the circulating gas is washed from 0.5mol% to 0.001mol% or less, butanol returning to the gas phase hydrogenation reactor is effectively reduced, and butyraldehyde conversion rate is improved; heavy components in the butyraldehyde raw material are also washed at the same time of washing butanol, heavy components returning to the gas phase hydrogenation reactor are effectively reduced, the defect that the catalyst is deactivated by high temperature coking caused by heavy components is prevented, and the service life of the gas phase hydrogenation catalyst is prolonged.

[0023] ​10-50% of the butyraldehyde feedstock is supplemented from the separation scrubber, and 70-95% of the butyraldehyde feedstock is vaporized in the separation scrubber. The vaporization of butyraldehyde lowers the temperature at the outlet of the separation scrubber, and more heat from the gaseous phase hydrogenation product gas can be recovered through the circulating gas preheater, thereby reducing the heat consumption of the subsequent heater and the consumption of cold energy of the cooler.

[0024] In the prior art, the content of butanol in the gas phase hydrogenation reactor inlet gas is about 0.4 mol%, and in the present application, the content of butanol in the gas phase hydrogenation reactor inlet gas is less than 0.001 mol%, which reduces the content of butanol in the gas phase hydrogenation reactor feedstock, and is beneficial to the rightward movement of the chemical equilibrium, thereby improving the conversion rate of butyraldehyde. In the prior art, all butyraldehyde feedstock is supplemented from the butyraldehyde vaporizer, and since the operating temperature of the butyraldehyde vaporizer is relatively high (60-80°C), the washing effect of butyraldehyde on butanol and heavy components in the circulating gas in the butyraldehyde vaporizer is not obvious. In the present application, part of the butyraldehyde feedstock is supplemented from the separation scrubber, and the circulating gas is washed at room temperature (25-40°C), which can effectively reduce the content of butanol and heavy components in the circulating gas. The butyraldehyde feedstock supplemented from the separation scrubber enters the bottom liquid phase crude butanol under the action of gas-liquid equilibrium, and the rest is vaporized and enters the circulating gas.

[0025] 50-90% of the butyraldehyde feedstock is supplemented from the butyraldehyde vaporizer, the low-pressure hydrogen gas from outside is mixed with the circulating gas flowing out from the top of the separation scrubber after being compressed by the circulating gas compressor to form mixed circulating gas, the mixed circulating gas is preheated by the gaseous phase hydrogenation product gas from the bottom of the gas phase hydrogenation reactor, and is mixed with excess hydrogen gas returned from the liquid phase hydrogenation reactor, and the mixed circulating gas is further heated by the heater and is divided into two streams, 30-80% of the high-temperature mixed circulating gas is sent to the bottom of the butyraldehyde vaporizer to fully vaporize the butyraldehyde feedstock, and the heavy components in the butyraldehyde feedstock are discharged from the bottom. The rest of the high-temperature mixed circulating gas is bypassed to the outlet of the butyraldehyde vaporizer to raise the temperature of the reaction gas feedstock to meet the temperature requirement of the reaction gas feedstock, and enters the gas phase hydrogenation reactor to produce butanol through hydrogenation reaction.

[0026] Therefore, the present application only needs one circulating gas preheater, the process is simple, the number of equipment is less, the requirements of butyraldehyde raw material vaporization and reaction gas feeding temperature can be met at the same time, the butyraldehyde vaporizer circulating pump, the butyraldehyde vaporizer heater and the reaction gas feeding heater in the existing process are not needed, the high-temperature residence of butyraldehyde in the bottom of the butyraldehyde vaporizer and the butyraldehyde vaporizer heater can be avoided, the generation of high polymer of butyraldehyde due to high temperature is reduced, the butanol product yield is improved, the device investment and the operation energy consumption can be reduced. The butyraldehyde vaporizer mainly has three functions, one is to vaporize butyraldehyde raw material, the second is to wash butanol and heavy components contained in the circulating gas, and the third is to separate heavy components contained in the butyraldehyde raw material. 10-50% of butyraldehyde raw material is supplemented from the separator washer, in the separator washer, the butyraldehyde raw material is used to effectively wash butanol and heavy components in the circulating gas, and the circulating gas can not pass through the butyraldehyde vaporizer. In the present application, the high-temperature circulating gas is partially bypassed to the butyraldehyde vaporizer outlet, the vaporization temperature is controlled by adjusting the bypass gas amount ratio, the butyraldehyde raw material can be fully vaporized without additional vaporization of heavy components contained in the butyraldehyde raw material, and the reaction gas feeding temperature can reach the catalyst activation temperature requirement.

[0027] The gas phase hydrogenation product gas flowing out from the bottom of the gas phase hydrogenation reactor is divided into two streams, 1-10% of the gas phase hydrogenation product gas enters the hydrogen preheater for preheating high-pressure hydrogen, and the rest enters the circulating gas preheater for preheating mixed circulating gas (i.e. circulating gas and low-pressure hydrogen), after recovering heat respectively, the gas phase hydrogenation product gas is combined and enters the liquid phase hydrogenation feed preheater to preheat the crude butanol containing 1-15wt% butyraldehyde flowing out from the bottom of the separator washer after being further pressurized by the liquid phase hydrogenation feed pump, then the crude butanol containing 1-15wt% butyraldehyde is sent to the liquid phase hydrogenation reactor to produce butanol by hydrogenation reaction, the excess hydrogen is returned to the butyraldehyde vaporizer by the heater to enter the gas phase hydrogenation circulation, and the crude butanol is sent to the butanol rectification section.

[0028] The gas phase hydrogenation product gas is used to preheat hydrogen, circulating gas and liquid phase hydrogenation feed (i.e. crude butanol containing 1-15wt% butyraldehyde), a part of the gas phase hydrogenation reactor outlet product gas is used to preheat high-pressure hydrogen, and the rest is used to preheat circulating gas and low-pressure hydrogen, after recovering heat respectively, the gas phase hydrogenation product gas is combined and further preheats the liquid phase hydrogenation feed, realizing full recovery and utilization of heat. Compared with the gas phase hydrogenation catalyst, the liquid phase hydrogenation catalyst has higher requirements for hydrogen raw material, and a hydrogen purification tank needs to be additionally provided to further purify the hydrogen raw material.

[0029] The high-pressure hydrogen from outside enters the hydrogen preheater, is preheated by the gas phase hydrogenation product gas, enters the hydrogen purification tank, after removing impurities harmful to the liquid phase hydrogenation catalyst, is sent to the liquid phase hydrogenation reactor.

[0030] The top circulating gas of the separation scrubber and hydrogen recovered by the hydrogen recovery device are introduced into a circulating gas compressor for pressurization; 1-10% of the mixed gas discharged from the outlet of the circulating gas compressor is released into the hydrogen recovery device, and the recovered hydrogen returns to the inlet of the circulating gas compressor by its own pressure, and the released gas is sent out of the system. The hydrogen in the released mixed gas is recovered by using the pressure difference of the circulating gas compressor and the hydrogen recovery device, and the circulating gas discharged from the outlet of the compressor enters the hydrogen recovery device, and the recovered hydrogen returns to the inlet of the circulating gas compressor by its own pressure. Therefore, the recovered hydrogen can be returned to the system without the need for a pressurizing device, thereby reducing the investment of the device. The hydrogen recovery device can adopt a pressure swing adsorption process or other processes.

[0031] The combined process of gas-phase hydrogenation and liquid-phase hydrogenation is adopted, and the liquid-phase hydrogenation is connected in series after the gas-phase hydrogenation. Under normal working conditions, the liquid-phase hydrogenation undertakes 1-15% (proportion of butyraldehyde raw material total feed) of butyraldehyde hydrogenation load. When the activity of the gas-phase hydrogenation catalyst decreases at the end of the working condition, the service life of the gas-phase hydrogenation catalyst can be prolonged and the continuous operation cycle of the hydrogenation device can be prolonged by additionally increasing the load of the liquid-phase hydrogenation.

[0032] In the above, the reaction pressure in the gas-phase hydrogenation reactor is 0.3-1.0 MPa, and the reaction temperature is 100-200℃; the reaction pressure in the liquid-phase hydrogenation reactor is 2.0-4.0 MPa, and the reaction temperature is 50-150℃.

[0033] In the present application, the separation scrubber is based on the separator, and a washing section is added, the washing section is filled with structured packing, which is used for washing the circulating gas and butyraldehyde vaporization, and provides sufficient contact time and contact area through the packing.

[0034] Embodiment

[0035] The butyraldehyde raw material (flow rate 10 t / h) from outside the system is divided into two streams, 38% of the butyraldehyde raw material is supplemented from the separation scrubber, and 62% of the butyraldehyde raw material is supplemented from the butyraldehyde vaporizer. The low-pressure hydrogen gas (flow rate 2400 Nm 3(h) mixed with the recycle gas compressed by the recycle gas compressor to form mixed recycle gas (the mixed recycle gas comprises recycle gas and hydrogen gas), the mixed recycle gas enters the recycle gas preheater, is preheated to 100°C by the gaseous phase hydrogenation product gas from the bottom of the gaseous phase hydrogenation reactor, is mixed with the excess hydrogen gas returned from the liquid phase hydrogenation reactor, the mixed recycle gas (i.e. the recycle gas and hydrogen gas) is further heated to 174°C by the heater, is divided into two streams, 42% of the high temperature mixed recycle gas is sent to the bottom of the butyraldehyde vaporizer, the temperature of the gaseous phase outlet of the butyraldehyde vaporizer is controlled to 68°C, the butyraldehyde is fully vaporized, and the heavy components in the butyraldehyde raw material are discharged from the system at the bottom. 58% of the high temperature mixed recycle gas is bypassed to the outlet of the butyraldehyde vaporizer, the temperature of the reaction gas feed is increased to 120°C, and enters the gaseous phase hydrogenation reactor to produce butanol by hydrogenation reaction.

[0036] The gaseous phase hydrogenation product gas at a temperature of 120°C is divided into two streams, 3% of which enters the hydrogen gas preheater to preheat the high pressure hydrogen gas, and the rest enters the recycle gas preheater to preheat the mixed recycle gas (i.e. the recycle gas and low pressure hydrogen gas), the heat is recovered respectively, and then the gaseous phase hydrogenation product gas is combined and enters the liquid phase hydrogenation feed preheater to further preheat the crude butanol containing 4wt% butyraldehyde from the bottom of the separation scrubber, the gaseous phase hydrogenation product gas is cooled to 40°C by circulating water in the cooler, and then enters the separation scrubber from the lower part, and the gas-liquid separation in the gaseous phase hydrogenation product gas and the recycle gas washing are completed in the separation scrubber. 38% of the butyraldehyde raw material is supplemented from the separation scrubber, and the butyraldehyde raw material is used to wash the butanol and heavy components in the recycle gas in the separation scrubber, the butyraldehyde washes the butanol in the recycle gas from 0.54mol% to 0.0005mol%, and the heavy components are also washed down, and the temperature of the recycle gas at the top of the separation scrubber is 26°C.

[0037] The recycle gas at the top of the separation scrubber (the gas amount is about 32000Nm 3 (h) is mixed with the hydrogen gas recovered by the hydrogen gas recovery device, and enters the recycle gas compressor, and the pressure is increased from 0.45MPa to 0.55MPa. 1000Nm 3 / h of the release mixed gas enters the hydrogen gas recovery device, the recovered hydrogen gas returns to the inlet of the recycle gas compressor by its own pressure, and the release gas (the gas amount is about 80Nm 3 / h) is sent out of the boundary.

[0038] The high pressure hydrogen gas (the flow rate is 800Nm 3 / h) into the hydrogen gas preheater, preheated to 80°C by the gaseous phase hydrogenation product gas, into the hydrogen gas purifier, after removing the impurities harmful to the liquid phase hydrogenation catalyst, into the liquid phase hydrogenation reactor. The crude butanol containing 4wt% butyraldehyde at the bottom of the separation scrubber, pressurized to 3.0MPa by the liquid phase hydrogenation feed pump and sent into the liquid phase hydrogenation feed preheater preheated to 80°C, into the liquid phase hydrogenation reactor, hydrogenation reaction occurs to produce butanol, the excess hydrogen gas returns to the butyraldehyde vaporizer through the heater into the gaseous phase hydrogenation circulation loop, the crude butanol is sent to the butanol rectification section.

[0039] Compared with the existing gaseous phase hydrogenation process, the heater load is reduced by 520kW, and correspondingly, the cooler load is reduced by 520kW. In the gaseous phase hydrogenation reactor, the butyraldehyde conversion rate is greater than the gaseous phase hydrogenation catalyst life, which can reach more than 10 years.

Claims

1. A process for the production of butanol by hydrogenation of butyraldehyde, characterized in that: The method comprises the following steps: A part of butyraldehyde raw material is fed from a separation scrubber, gas-liquid separation is performed on the gas-phase hydrogenation product gas flowing out from the bottom of the gas-phase hydrogenation reactor, and the butanol and heavy components in the circulating gas are scrubbed by the butyraldehyde raw material, while the butyraldehyde raw material is vaporized; The remaining butyraldehyde raw material is fed from a butyraldehyde vaporizer, low-pressure hydrogen gas from outside is mixed with the circulating gas flowing out from the top of the separation scrubber after being compressed by a circulating gas compressor to form mixed circulating gas, the mixed circulating gas enters a circulating gas preheater, is preheated by the gas-phase hydrogenation product gas from the bottom of the gas-phase hydrogenation reactor, is mixed with excess hydrogen gas returned from the liquid-phase hydrogenation reactor, and is further heated by a heater and then is divided into two streams, one part of the high-temperature mixed circulating gas is sent to the bottom of the butyraldehyde vaporizer to fully vaporize the butyraldehyde raw material, and the heavy components in the butyraldehyde raw material are discharged from the bottom; The remaining high-temperature mixed circulating gas is bypassed to the outlet of the butyraldehyde vaporizer to increase the reaction gas feed temperature to meet the reaction gas feed temperature requirement, and enters the gas-phase hydrogenation reactor to produce butanol through hydrogenation reaction; The gas-phase hydrogenation product gas flowing out from the bottom of the gas-phase hydrogenation reactor is divided into two streams, one part of the gas-phase hydrogenation product gas enters a hydrogen gas preheater to preheat high-pressure hydrogen gas, and the remaining gas-phase hydrogenation product gas enters a circulating gas preheater to preheat the mixed circulating gas; the high-pressure hydrogen gas enters the hydrogen gas preheater, is preheated by the gas-phase hydrogenation product gas, enters a hydrogen gas purification tank, is removed of impurities harmful to the liquid-phase hydrogenation catalyst, and is sent to the liquid-phase hydrogenation reactor; The gas-phase hydrogenation product gas after recovering heat in the hydrogen gas preheater and the circulating gas preheater is combined, enters a liquid-phase hydrogenation feed preheater, preheats the butyraldehyde-containing crude butanol flowing out from the bottom of the separation scrubber after being further pressurized by a liquid-phase hydrogenation feed pump, and then the butyraldehyde-containing crude butanol is sent to the liquid-phase hydrogenation reactor to produce butanol through hydrogenation reaction, excess hydrogen gas is returned to the butyraldehyde vaporizer through a heater, and the crude butanol is sent to a butanol rectification section.

2. The process according to claim 1, c h a r a c t e r i s e d in that: The circulating gas at the top of the separation scrubber and the hydrogen gas recovered by a hydrogen gas recovery device are pressurized by a circulating gas compressor; The purge mixed gas introduced from the outlet of the circulating gas compressor enters the hydrogen gas recovery device, the recovered hydrogen gas returns to the inlet of the circulating gas compressor by its own pressure, and the purge gas is sent out of the system.

3. The process according to claim 1, c h a r a c t e r i z e d i n that: The reaction pressure in the gas-phase hydrogenation reactor is 0.3-1.0 MPa, and the reaction temperature is 100-200℃.

4. The process according to claim 1, c h a r a c t e r i z e d i n that: The reaction pressure in the liquid-phase hydrogenation reactor is 2.0-4.0 MPa, and the reaction temperature is 50-150℃.

5. The process according to claim 1, wherein: The separation scrubber comprises a separation section at the lower part and a scrubbing section at the upper part, and the scrubbing section is filled with packing.

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