CN214991236U - Complete device for preparing acrylic acid by using cyclic propylene oxidation method - Google Patents
Complete device for preparing acrylic acid by using cyclic propylene oxidation method Download PDFInfo
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- CN214991236U CN214991236U CN202121039690.3U CN202121039690U CN214991236U CN 214991236 U CN214991236 U CN 214991236U CN 202121039690 U CN202121039690 U CN 202121039690U CN 214991236 U CN214991236 U CN 214991236U
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- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 title claims abstract description 73
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 title claims abstract description 73
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 title claims abstract description 69
- 238000007254 oxidation reaction Methods 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 41
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- 238000007670 refining Methods 0.000 claims abstract description 138
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 65
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- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims description 71
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- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Chemical compound [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 4
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- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The utility model discloses a complete device for preparing acrylic acid by a circulating propylene oxidation method, which comprises a feeding oxidation reaction unit, a circulating quenching absorption unit and a product refining unit. The liquid phase of the feeding oxidation reaction unit is connected with the circulating quenching absorption unit through a pipeline, the gas phase at the top of the circulating quenching absorption unit is connected with the feeding oxidation reaction unit through a pipeline, the liquid phase of the circulating quenching absorption unit is connected with the product refining unit through a pipeline, the product refining unit is provided with a discharge pipeline which is connected with an acrylic acid product tank area and produces a finished product, and the tail gas of the product refining unit is sent to a waste gas incineration treatment system. The utility model discloses a reactor continuous reaction, tail gas realization circulation reaction has increased the reaction depth, improves the product yield, through accurate polymerization inhibitor and the air of adding, has improved product rectification separation efficiency, adopts DCS control system, has improved the automation level of device, is favorable to product quality stability.
Description
Technical Field
The utility model relates to the technical field of chemical equipment, concretely relates to complete equipment for preparing acrylic acid by a circulating propylene oxidation method.
Background
In recent years, with the increase of the use amount of the super absorbent resin and the washing assistant, the market demand of acrylic acid products is further pulled, the application of the acrylic acid is greatly expanded, the acrylic acid products which are originally widely applied are favored, and the updating development of the industrial production method and the process of the acrylic acid is promoted. The production process of acrylic acid has undergone the cyanoethanol process, REPPE (REPPE) process (oxo process), ketene process, acrylonitrile hydrolysis process and propylene oxidation process, and the former 4 processes have been gradually eliminated for technical and economic reasons. The acrylic acid devices newly built and expanded after the 80 s in the 20 th century all adopt a propylene oxidation method. The propylene oxidation process has sufficient raw material sources (propylene, air and steam), and the core of the process is the selection of the catalyst and the optimized combination of the process. Through many years of exploration, the propylene oxidation method is improved in the aspects of catalysts and processes, the one-step method and the two-step method are mainly used for producing acrylic acid through propylene oxidation, and the two-step method is the current main acrylic acid production method due to the fact that the two-step method is reliable in technology, high in product yield, stable in product quality and high in economic benefit.
The key to the industrial scale-up of the mature production method is the device. The requirements of catalysts and process improvement of propylene oxidation method for production devices are higher and higher, especially, the factors of flammability and explosiveness, poisonous raw materials or semi-finished products and the like exist in the process of producing acrylic acid by propylene oxidation method, most of the existing acrylic acid production devices are not suitable for new processes and market demands in the aspects of automation of operation, explosion prevention, energy conservation, product stability and the like, and face a rigorous challenge, under the promotion of process improvement, the heat exchange mode and the selection of heat exchange media of reactors of acrylic acid production devices by propylene oxidation method, and the materials and the heat exchange effect of equipment are greatly improved, the new processes also provide higher requirements for the refrigeration effect and the energy conservation performance of refrigeration equipment, and simultaneously, because of the change of the labor market in China and the stipulations of labor guarantee laws and regulations on labor intensity of workers, the automation of production devices must be improved to reduce labor intensity, therefore, the market needs a production device for preparing acrylic acid by using a propylene oxidation method, which has high operation automation degree, explosion prevention, energy conservation, stable product quality and long-period operation.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a complete device for preparing acrylic acid by a circulating propylene oxidation method aiming at the defects in the prior art.
The technical scheme of the utility model is that:
a complete set of equipment for preparing acrylic acid by a circulating propylene oxidation method comprises a feeding oxidation reaction unit, a circulating quenching absorption unit and a product refining unit, wherein a liquid phase outlet of the feeding oxidation reaction unit is connected with the circulating quenching absorption unit through a pipeline, a top gas phase line of the circulating quenching absorption unit is connected with the feeding oxidation reaction unit through a pipeline, a liquid phase line of the circulating quenching absorption unit is connected with the product refining unit through a pipeline, the product refining unit is provided with a discharge pipeline which is connected with an acrylic acid product tank region and produces a finished product, and a tail gas of the product refining unit is sent to a waste gas incineration treatment system;
the feeding oxidation reaction unit comprises a propylene preheating system, a reaction gas supply system, a main reaction system and a secondary reaction system which are sequentially connected through pipelines, and the reaction gas supply system is also provided with branch lines and is communicated with the secondary reaction system;
the propylene preheating system comprises a liquid propylene tank, a propylene gas eliminator, a propylene evaporator and a propylene superheater which are sequentially connected through pipelines, and a discharge line of the propylene superheater is communicated with the reaction gas supply system.
Preferably, the reaction gas supply system comprises a medium-pressure steam line, a feeding air compressor, a steam mixer, a main reactor feeding mixer, a secondary reactor feeding mixer and a circulating air compressor, wherein the steam mixer is provided with three feeding lines and is respectively connected with the medium-pressure steam line, the feeding air compressor and the circulating air compressor, the main reactor feeding mixer is provided with a plurality of feeding lines and is respectively connected with the propylene superheater and the steam mixer, and a discharging line of the main reactor feeding mixer is connected with the main reaction system;
the feeding air compressor and the circulating air compressor are respectively provided with a secondary reaction branch and are both connected with the secondary reactor feeding mixer, and a discharging line of the secondary reactor feeding mixer is communicated with the secondary reaction system.
Preferably, the main reaction system comprises a main reactor, an electric heater, a cooling circulating pump, a cooler and a cooling medium storage tank which are connected in sequence; the main reactor is a tubular fixed bed reactor, the tubes of the main reactor are filled with a catalyst, a mixed salt constant-temperature medium is filled between the tubes of the main reactor, a fin cooler is arranged at the lower part of the main reactor, and the main reactor feed mixer is communicated with the main reactor;
the secondary reaction system comprises a secondary reactor, a secondary electric heater, a secondary cooling circulating pump, a secondary cooler and a secondary cooling medium storage tank which are sequentially connected, mixed hydrocarbon constant-temperature medium is filled between the tubes of the secondary reactor, the secondary reactor feeding mixer is communicated with the secondary reactor, and the secondary reactor is connected with the circulating quenching absorption unit.
Preferably, the circulating quenching absorption unit comprises a reactant cooler, an acrylic acid buffer tank, a spray condenser, a quenching absorption waterline, a tower bottom circulating liquid polymerization inhibitor line, an absorption water polymerization inhibitor line, an unreacted gas tank and a quenching absorption tower;
the quenching absorption tower is provided with a plurality of liquid phase feeding lines and is respectively communicated with a spray condenser, a quenching absorption waterline and an absorption water polymerization inhibitor line, the quenching absorption tower is provided with a plurality of gas phase feeding lines and is respectively communicated with the reactant cooler and the tower bottom circulating liquid polymerization inhibitor line, the quenching absorption tower is provided with a gas phase discharging pipe and is communicated with the unreacted gas tank, the quenching absorption tower is provided with a liquid phase discharging pipe and is communicated with the acrylic acid buffer tank and the product refining unit, and the reactant cooler is connected with the secondary reactor.
Preferably, the product refining unit comprises a light component removal unit, an acetic acid removal unit, a refining unit and a heavy component removal unit which are connected in sequence through pipelines;
the lightness-removing unit comprises a lightness-removing tower, a lightness-removing tower condenser, a lightness-removing tower tail condenser, a lightness-removing tower liquid receiving tank, a lightness-removing tower vacuum pump, a blow-down tank recovery tank, a gas condenser, a toluene tank, a recycled water cooler, a wastewater tank, a lightness-removing tower reboiler pump, a lightness-removing tower reboiler, a lightness-removing air line, a tower bottom polymerization inhibitor line, a toluene reflux polymerization inhibitor line and a lightness-removing tower bottom pump;
the lightness-removing tower is provided with a plurality of feed inlets and is respectively connected with the quenching absorption tower, the acrylic acid buffer tank, the lightness-removing air line, the tower bottom polymerization inhibitor line and the toluene reflux polymerization inhibitor line, the lightness-removing tower is provided with a plurality of discharge outlets and is respectively connected with the lightness-removing tower bottom pump and the lightness-removing tower condenser, and the lightness-removing tower bottom pump is connected with the acetic acid removal unit;
the lightness-removing tower condenser is provided with a gas-phase discharge line and a liquid-phase discharge line, the gas-phase discharge line of the lightness-removing tower condenser is sequentially connected with a lightness-removing tower tail condenser, a lightness-removing tower vacuum pump, an emptying tank recovery tank and a gas condenser to form a lightness-removing waste gas treatment line, the liquid-phase discharge line of the lightness-removing tower condenser is connected with a lightness-removing tower liquid receiving tank, the lightness-removing tower liquid receiving tank is provided with a plurality of discharge lines and is respectively connected with the toluene tank, the recycle water cooler and the waste water tank, and the lightness-removing tower condenser, the lightness-removing tower liquid receiving tank, the toluene tank, the recycle water cooler and the waste water tank form a lightness-removing waste liquid treatment line;
the liquid receiving tank of the light component removal tower is provided with a gas phase discharging line and is connected with the light component removal tower; the light component removal tower, a light component removal tower reboiler pump and a light component removal tower reboiler are sequentially connected to form a circulation closed circuit.
Preferably, the acetic acid removing unit comprises an acetic acid removing tower, a acetic acid removing tower condenser, a acetic acid removing tower tail condenser, a acetic acid removing tower liquid receiving tank, a acetic acid removing tower steam jet pump, a acetic acid removing tower jet pump condenser, a acetic acid removing tower reboiler pump, a acetic acid removing tower reboiler, a acetic acid removing tower bottom pump, a acetic acid removing air line, a tower top distillate polymerization inhibitor line and a reflux liquid polymerization inhibitor line;
the de-acetic acid tower is provided with a plurality of feed inlets and is respectively connected with the light component removal tower bottom pump, a de-acetic acid air line and a reflux polymerization inhibitor line, the de-acetic acid tower is provided with a plurality of discharge outlets and is respectively connected with the de-acetic acid tower bottom pump and a de-acetic acid tower condenser, and the de-acetic acid tower bottom pump is connected with the refining unit;
the feed inlet of the condenser of the de-acetic acid tower is also connected with a tower top distillate polymerization inhibitor line, the condenser of the de-acetic acid tower is provided with a gas-phase discharge line and a liquid-phase discharge line, the gas-phase discharge line of the condenser of the de-acetic acid tower is connected with the ejector pump condenser of the de-acetic acid tower to form a de-acetic acid waste gas treatment line, and the gas-phase discharge line of the condenser of the de-acetic acid tower is sequentially connected with the liquid receiving tank of the de-acetic acid tower and a reflux liquid polymerization inhibitor line to form a de-acetic acid circulation treatment device;
the de-acetic acid tower, a de-acetic acid tower reboiler pump and a de-acetic acid tower reboiler are connected in sequence to form a circulation closed circuit.
Preferably, the refining unit comprises a refining tower, a refining tower condenser, a refining tower tail condenser, a refining tower liquid receiving tank, a refining tower jet pump condenser, a light component liquid receiving tank, an acrylic acid finished product cooler, an acrylic acid finished product tank, a refining tower reboiler pump, a refining tower reboiler, a refining tower bottom pump, a tower top distillate polymerization inhibitor line and a reflux liquid polymerization inhibitor line;
the refining tower is provided with a plurality of feed inlets and is respectively connected with the acetic acid removal tower bottom pump, the heavy film removal evaporator, the refining tower liquid receiving tank and the reflux polymerization inhibitor line, the refining tower is provided with a plurality of discharge outlets and is respectively connected with the refining tower bottom pump and the refining tower condenser, and the refining tower bottom pump is connected with the heavy removal unit;
the refining tower condenser is provided with a gas-phase discharging line and is sequentially connected with the refining tower tail condenser, the refining tower jet pump and the refining tower jet pump condenser to form a refined waste gas treatment line, and the refining tower condenser is provided with a liquid-phase discharging line and is sequentially connected with the refining tower liquid receiving tank, the acrylic acid finished product cooler and the acrylic acid finished product tank to form an acrylic acid finished product line;
the liquid receiving tank of the refining tower is provided with a branch line and is connected with the polymerization inhibitor line of the distillate at the top of the tower;
the refining tower, a refining tower reboiler pump and a refining tower reboiler are sequentially connected to form a circulation closed circuit.
Preferably, the de-weight unit comprises a de-weight thin film evaporator, a de-weight medium-pressure steam line, a de-weight pump, a de-weight thin film evaporator condenser, a dimer tank, a dimer pump and a barreling area, wherein the de-weight thin film evaporator is connected with the refining tower bottom pump;
the heavy film removal evaporator, the heavy film removal pump, the heavy film removal evaporator condenser, the dimer tank, the dimer pump and the barreling area are sequentially connected to form a product heavy line;
the upper part of the heavy-film removal evaporator is connected with the heavy-medium pressure removal steam line, and the upper part of the heavy-film removal evaporator is provided with a pipeline and is connected with the refining tower to form a heavy-cycle removal treatment structure.
Preferably, the device is provided with automatic remote temperature, pressure and flow detection and control equipment, an advanced and reliable Distributed Control System (DCS) is adopted, important process temperature, pressure and flow parameters are remotely monitored, controlled and operated, and are recorded and alarmed, meanwhile, a Safety Instrument System (SIS) is adopted to realize safety interlocking and emergency stop of the device, the safety of the device is improved, and the remote temperature, pressure and flow detection and control equipment is respectively and electrically connected with the equipment.
Compared with the prior art, the utility model, have following advantage:
1. the utility model discloses a double reactor continuous reaction, the design of business turn over material in proper order has prolonged reaction time, and unreacted gas circulation continues the reaction to first reactor, has increased the reaction degree of depth, has improved the product yield, realizes the controllable target of product quality stability.
2. The main reactor of the device adopts a fin cooler design, so that the cooling effect of reaction materials is improved, side reactions are inhibited, and the corrosion of equipment is delayed.
3. In the product refining process, a material line is evaporated, and a polymerization inhibitor is quantitatively added into a return line, so that the polymerization inhibition precision and effect are greatly improved, later heavy components are separated by adopting a film evaporation technology, the separation efficiency of intermediate products and byproducts is improved, and the product purity is improved.
4. The reactor of the device adopts fused salt to cool and produce steam, thereby improving the energy recycling rate of the device and being beneficial to energy conservation and consumption reduction.
5. The distillation tower adopts a combined design of a flow-through tower plate and a filler, fully utilizes the liquid phase and gas phase dynamics principles, reduces material polymerization and improves material separation efficiency.
6. This device adopts DCS control system to carry out centralized management and long-range dispersion accurate control to production process, improves the automation level of enterprise and management level, reduces workman's intensity of labour, is favorable to product quality control.
Drawings
Fig. 1 is a schematic structural view of the present invention;
in the figure: the system comprises a feed oxidation reaction unit A, a 1-propylene preheating system A, a 2-reaction gas supply system A, A3-main reaction system A, a 4-secondary reaction system B, a circulating quenching absorption unit B, a product refining unit C1-light removal unit C2-acetic acid removal unit C3-refining unit and a product refining unit C4-heavy removal unit;
1-liquid propylene tank, 2-propylene degasser, 3-propylene evaporator, 4-propylene superheater, 5-medium pressure steam line, 6-feed air compressor, 7-steam mixer, 8-main reactor feed mixer, 9-secondary reactor feed mixer, 10-circulating air compressor, 11-main reactor, 111-electric heater, 112-cooling circulating pump, 113-cooler, 114-cooling medium storage tank, 12-secondary reactor, 121-secondary electric heater, 122-secondary cooling circulating pump, 123-secondary cooler, 124-secondary cooling medium storage tank, 13-reactant cooler, 14-quench absorption tower, 141-acrylic acid buffer tank, 142-spray condenser, 143-quench absorption water line, 144-bottom circulating liquid polymerization inhibitor line, 145-absorbing water polymerization inhibitor line, 15-unreacted gas tank, 16-lightness-removing tower, 161-lightness-removing tower condenser, 162-lightness-removing tower tail condenser, 163-lightness-removing tower liquid-receiving tank, 164-lightness-removing tower vacuum pump, 165-emptying tank recovery tank, 166-gas condenser, 167-toluene tank, 168-reuse water cooler, 169-waste water tank, 1610-lightness-removing tower reboiler pump, 1611-lightness-removing tower reboiler, 1612-lightness-removing air line, 1613-bottom polymerization inhibitor line, 1614-toluene reflux polymerization inhibitor line, 1615-lightness-removing tower bottom pump, 17-acetic acid removing tower, 171-acetic acid removing tower condenser, 172-acetic acid removing tower tail condenser, 173-acetic acid removing tower liquid-receiving tank, 174-acetic acid removing tower steam jet pump, 175-a condenser of a jet pump of a de-acetic acid tower, 176-a reboiler of the de-acetic acid tower, 177-a reboiler of the de-acetic acid tower, 178-a bottom pump of the de-acetic acid tower, 179-a de-acetic acid air line, 1710-a polymerization inhibitor line of a distillation product at the top of the de-acetic acid tower, 1711-a polymerization inhibitor line of a de-acetic acid reflux liquid, 18-a refining tower, 181-a condenser of the refining tower, 182-a condenser at the tail of the refining tower, 183-a liquid receiving tank of the refining tower, 184-a jet pump of the refining tower, 185-a jet pump condenser of the refining tower, 186-a liquid receiving tank of light components, 187-a cooler of finished acrylic acid, 188-a finished product tank of acrylic acid, 189-a pump of the refining tower reboiler, 1811-a bottom pump of the refining tower, 1812-a polymerization inhibitor line of the distillation product at the top of the refining tower, 1813-a polymerization inhibitor line of the refining reflux liquid, 19-thin film evaporator, 191-medium pressure vapor stripping line, 192-heavy pump, 193-thin film evaporator condenser, 194-dimer pot, 195-dimer pump, 196-barreling zone.
Detailed Description
In the following description, numerous implementation details are set forth in order to provide a more thorough understanding of the present invention. It should be understood, however, that these implementation details should not be used to limit the invention. That is, in some embodiments of the invention, details of these implementations are not necessary. In addition, some conventional structures and components are shown in simplified schematic form in the drawings.
Example one
Referring to fig. 1, a complete set of equipment for preparing acrylic acid by a circulating propylene oxidation method comprises a feed oxidation reaction unit A, a circulating quenching absorption unit B and a product refining unit C. The liquidus of the feeding oxidation reaction unit A is connected with the circulating quenching absorption unit B through a pipeline, the top gas phase line of the circulating quenching absorption unit B is connected with the feeding oxidation reaction unit A through a pipeline, the liquidus of the circulating quenching absorption unit B is connected with the product refining unit C through a pipeline, the product refining unit C is provided with a discharge pipeline which is connected with an acrylic acid product tank area and produces a finished product, and the tail gas of the product refining unit C is sent to a waste gas incineration treatment system.
The feed oxidation reaction unit A comprises a propylene preheating system A1, a reaction gas supply system A2, a main reaction system A3 and a secondary reaction system A4.
The propylene preheating system A1 is formed by connecting a liquid propylene tank 1, a propylene degasser 2, a propylene evaporator 3 and a propylene superheater 4 in sequence, and the discharge line of the propylene superheater 4 is connected with a main reactor feed mixer 8.
The discharge line of a feeding air compressor 6 of a reaction gas supply system A2 is divided into two paths, one path is sequentially connected with a steam mixer 7, a main reactor feeding mixer 8 and a main reactor 11, and the other path is sequentially connected with a secondary reactor feeding mixer 9 and a secondary reactor 12. An unreacted gas tank 15 at the top of the quenching absorption tower 14 is compressed by a circulating air compressor 10 and then is divided into two paths, wherein one path enters a steam mixer 7 and the other path enters a secondary reactor feeding mixer 9. The medium pressure steam line 5 and the unreacted gas tank 15 are connected with a steam mixer 7 and then connected with a main reactor feed mixer 8, and the main reactor feed mixer 8 is connected with a main reactor 11.
The main reactor 11, the feeding air compressor 6 and the circulating air compressor 10 are connected with the secondary reactor 12 through the secondary reactor feeding mixer 9.
The main reaction system A3 is composed of a main reactor 11, an electric heater 111, a cooling circulation pump 112, a cooler 113 and a cooling medium storage tank 114 which are connected in sequence. The main reactor 11 is a tubular fixed bed reactor, catalysts are filled in the tubes, mixed salt constant temperature media are arranged among the tubes, preferably KNO3, NaNO2, NaNO3= 50-55, 37-42, 3-13, a fin cooler is arranged at the lower part, and circulating water is led in the fin cooler.
The secondary reaction system A4 is composed of a secondary reactor 12, a secondary electric heater 121, a secondary cooling circulation pump 122, a secondary cooler 123 and a secondary cooling medium storage tank 124 which are connected in sequence. A mixed hydrocarbon constant temperature medium, preferably a ditolyl ether-synthetic hydrocarbon mixture, is arranged between the tubes of the secondary reactor 12, and the discharge line of the secondary reactor 12 is connected with the feed inlet of a quenching absorption tower 14 through a reactant cooler 13.
The circulating quenching absorption unit B is formed by connecting a reactant cooler 13, an acrylic acid buffer tank 141, a spray condenser 142, a quenching absorption waterline 143, a tower bottom circulating liquid polymerization inhibitor line 144, an absorption water polymerization inhibitor line 145 and an unreacted gas tank 15 with a quenching absorption tower 14 respectively.
The product refining unit C further purifies the crude acid aqueous solution with the concentration of about 50 percent from the circulating quenching absorption unit B, separates impurities and prepares an acrylic acid finished product meeting the purity requirement, and mainly comprises a light component removal tower 16, an acetic acid removal tower 17, a refining tower 18, a heavy film removal evaporator 19, material lines and the like.
A light component removal air line 1612, a bottom polymerization inhibitor line 1613, and a reactant feed line from the quench absorption tower 14 are connected to the light component removal tower 16; the lightness-removing column 16, a lightness-removing column condenser 161, a lightness-removing column tail condenser 162, a lightness-removing column vacuum pump 164, an emptying tank recovery tank 165 and a gas condenser 166 are connected in sequence; the lightness-removing column condenser 161 and the lightness-removing column tail condenser 162 are connected with a lightness-removing column liquid receiver 163; the lightness-removing column liquid receiving tank 163 is sequentially connected with a toluene reflux polymerization inhibitor line 1614 and a lightness-removing column 16 through a pump; the lightness-removing column liquid receiving tank 163 is sequentially connected with the toluene tank 167 through a pump; the lightness-removing tower liquid receiving tank 163 is connected with a waste water tank 169 through a pump; the lightness-removing column liquid receiving tank 163 is connected to a reuse water cooler 168 via a pump.
The light component removal tower 16, a light component removal tower reboiler 1610 and a light component removal tower reboiler 1611 are sequentially connected to form a circulation closed circuit, and the light component removal tower 16, a light component removal tower bottom pump 1615 and a acetic acid removal tower 17 are sequentially connected.
A light component removal tower bottom pump 1615 and a acetic acid removal air line 179 are connected with the acetic acid removal tower 17; the acetic acid removing tower 17, a acetic acid removing tower top distillate polymerization inhibitor line 1710, an acetic acid removing tower condenser 171, an acetic acid removing tower tail condenser 172, an acetic acid removing tower steam jet pump 174 and an acetic acid removing tower jet pump condenser 175 are connected in sequence; the condenser 171 of the acetic acid removing tower and the condenser 172 at the tail of the acetic acid removing tower are connected with a liquid receiving tank 173 of the acetic acid removing tower; the liquid receiving tank 173 of the acetic acid removing tower is sequentially connected with a acetic acid removing reflux polymerization inhibitor line 1711 and the acetic acid removing tower 17 through a pump; the liquid receiving tank 173 of the acetic acid removal tower is connected with the light component removal tower 16 through a pump.
The acetic acid removing tower 17, a acetic acid removing tower reboiler pump 176 and a acetic acid removing tower reboiler 177 are connected in sequence to form a circulation closed loop; the acetic acid removing tower 17, the acetic acid removing tower bottom pump 178 and the refining tower 18 are connected in sequence.
A refining tower 18, a refining tower top distillate polymerization inhibitor line 1812, a refining tower condenser 181, a refining tower tail condenser 182, a refining tower jet pump 184, a refining tower jet pump condenser 185, a light component liquid receiving tank 186 and a light component removal tower 16 are connected in sequence; the refining tower condenser 181 and the refining tower tail condenser 182 are connected with a refining tower liquid receiving tank 183; the refining tower liquid receiving tank 183 is connected with a refining reflux polymerization inhibitor line 1813 and the refining tower 18 through a pump; the liquid receiving tank 183 of the refining tower is connected in sequence with an acrylic acid finished product cooler 187 and an acrylic acid finished product tank 188 through a pump.
The refining tower 18, a refining tower reboiler pump 189 and a refining tower reboiler 1810 are sequentially connected to form a circulation closed circuit; the refining column 18, a refining column bottom pump 1811 and the heavy film removal evaporator 19 are connected in this order.
The heavy-film removal evaporator 19 adopts a heavy-medium pressure steam removal line 191 for jacket heating; the heavy film removing evaporator 19, the refining tower 18 and the refining tower bottom pump 1811 are connected in sequence to form a circulation closed circuit.
The heavy film removal evaporator 19, the heavy film removal pump 192, the heavy film removal evaporator condenser 193 and the dimer tank 194 are connected in sequence; the dimer tank 194 is connected to a dimer pump 195, one of which circulates the dimer tank 194 itself and the other of which goes to a barreling section 196.
The process flow is as follows:
a process of a feed oxidation reaction unit:
propylene preheat system a1 flow scheme: the liquid propylene tank 1 from the propylene tank area firstly enters a propylene gas eliminator 2 for buffering and gas elimination, and then enters a propylene evaporator 3 for vaporization.
In the propylene evaporator 3, the gas phase pressure at the upper part of the propylene evaporator 3 is adjusted to 0.60MPa by cooling water with the temperature of 8 ℃; the liquid level of the propylene evaporator 3 is controlled to be 50 percent by adjusting the adding amount of propylene by an electromagnetic valve.
The propylene was superheated by a propylene superheater 4, and the temperature of the discharge line of the propylene gas was controlled to 50. + -. 5 ℃ for the purpose of superheating.
The propylene gas from the propylene superheater 4 is adjusted and controlled in flow rate, and then enters a main reactor feed mixer 8 to be mixed with the humidified air.
Flow of a reaction gas supply system A2: fresh air is divided into two paths after being dedusted and compressed by a feeding air compressor 6, one path is sent to a main reactor feeding mixer 8 through a steam mixer 7, and the other path is sent to a secondary reactor feeding mixer 9. An unreacted gas tank 15 from the top of the quenching absorption tower 14 is compressed by a circulating air compressor 10 and then is divided into two paths, wherein one path enters a steam mixer 7 and the other path enters a secondary reactor feeding mixer 9. The medium pressure steam line 5 from the pipe network and the unreacted gas tank 15 are mixed in the steam mixer 7 and then enter the main reactor feed mixer 8, and are mixed with the superheated propylene in the main reactor feed mixer 8 and then enter the main reactor 11. The molar ratio of the mixed gases in the main reactor feed mixer 8 is: propylene: oxygen: water vapor: the top gas of the quenching absorption tower is 0.9-1.2: 1.6-l.9: 0.9-l.1: 1.9-2.4, and can be adjusted according to the unreacted gas tank 15 from the top of the quenching absorption tower 14. Under the catalysis of Mo-Bi system, acrolein and partial acrylic acid are generated.
The gas, water, nitrogen and acrolein at the discharge line of the quenching section of the main reactor 11 and the air sent by the feeding air compressor 6, and the unreacted gas sent by the circulating air compressor 10 are fully mixed in the feeding mixer 9 of the secondary reactor and then enter the secondary reactor 12. The molar ratio of the mixed gas and the oxygen in the secondary reactor feeding mixer 9 to the propylene added in the first reactor is 0.4-0.6: 0.9-1.2, and the temperature of the mixed gas is 215-245 ℃. The secondary reactor 12 is a tubular fixed bed reactor, and acrolein is further oxidized to generate acrylic acid under the action of a Mo-V catalyst.
Main reaction system a3 flow: the main reactor 11 is a tubular fixed bed reactor, the inside of the tubular fixed bed reactor is filled with a catalyst, and the reaction materials from the main reactor feeding mixer 8 rapidly undergo catalytic reaction at a certain temperature through a catalyst bed layer to generate products such as acrolein and part of acrylic acid. Mixed salt constant temperature media (KNO3: NaNO2: NaNO3= 50-55: 37-42: 3-13) are arranged among the tubes of the main reactor 11, in order to remove reaction heat, the temperature of the mixed salt constant temperature media in the main reactor 11 is kept uniform, the main reactor 11 is provided with a mixed salt constant temperature media circulating system which is composed of an electric heater 111, a cooling circulating pump 112 and a cooler 113, and the mixed salt constant temperature media are forced to circulate among the tubes of the main reactor 11 by adopting the cooling circulating pump 112: a strand of molten salt enters an electric heater 111 in a lower loop, the molten salt is heated by an electric heating element and then enters an upper loop to return to a cooling circulating pump 112 (the electric heater 111 is mainly used for heating the molten salt during starting, supplying heat and preserving heat of a system when feeding is stopped), another strand of molten salt enters a shell layer of a cooler 113 in a discharge line of the cooling circulating pump 112, the cooler 113 heats process aquatic steam to reduce the temperature of the molten salt, the molten salt returns to the cooling circulating pump 112 through a cooling medium storage tank 114 after being cooled, and then returns to a main reactor 11, and the temperature of a mixed salt constant temperature medium is controlled to be about 300-350 ℃.
The lower part of the main reactor 11 is provided with a fin cooler, circulating water is introduced into the fin cooler to quench the reacted gas, so that the generated acrolein is prevented from being easily deeply oxidized to generate CO and CO2, and the temperature of the gas on the discharge line of the main reactor 11 is controlled to be about 180-220 ℃ by adjusting the water quantity flowing through the fin cooler.
Flow of secondary reaction system a 4: the secondary reactor 12 is a tubular fixed bed reactor, the tubular fixed bed reactor is filled with a catalyst, and the reaction materials from the secondary reactor feeding mixer 9 rapidly perform catalytic reaction at a certain temperature through a catalyst bed layer to generate acrylic acid and partial byproducts. A mixed hydrocarbon constant temperature medium (a mixture of xylyl ether and synthetic hydrocarbon) is arranged between the tubes of the secondary reactor 12, in order to remove reaction heat, the temperature of the mixed hydrocarbon constant temperature medium in the secondary reactor 12 is kept uniform, the secondary reactor 12 is provided with a mixed hydrocarbon constant temperature medium circulating system which consists of a secondary electric heater 121, a secondary cooling circulating pump 122, a secondary cooler 123 and a secondary cooling medium storage tank 124, the secondary cooling circulating pump 122 is adopted, and the mixed hydrocarbon constant temperature medium is forced to circulate between the tubes of the main reactor 11: the circulation process is the same as that of the main reactor 12, and the temperature of the mixed hydrocarbon constant-temperature medium is controlled to be about 240-270 ℃. The reaction gas in the secondary reactor 12 is fed into a quenching absorption tower 14 through a reactant cooler 13.
And (3) a circulating quenching absorption unit B flow: the reaction gas in the secondary reactor 12 enters a reactant cooler 13, is cooled to 150 ℃ and 180 ℃ by using reclaimed water, and then is quenched in an absorption tower 14. The steam generated in the reactant cooler 13 enters the plant steam pipe network. Controlling the gas phase pressure at the upper part of the reactant cooler 13 to be 0.28-0.35MPa by adjusting the exhaust amount; the liquid level in the reactant cooler 13 was controlled to 50% by adjusting the amount of water added using a flow meter.
The circulation line of the tower bottom liquid of the quenching absorption tower 14 is divided into two parts, one part is used for tower bottom circulation, the other part is sent to the spray condenser 142 to be cooled and then sprayed into the tower, the acrylic acid in the reaction gas is quenched and absorbed, and the unabsorbed reaction gas is further absorbed by fresh desalted water provided by the quenching absorption water line 143 at the upper part. Acrylic acid is prevented from polymerizing by adding a quantitative amount of a polymerization inhibitor (copper salt, phenothiazine, hydroquinone, benzil and oxygen) to the bottom circulating liquid polymerization inhibitor line 144 and the water-absorbing polymerization inhibitor line 145. The bottom liquid of the quenching absorption tower 14 contains about 50 percent of acrylic acid, and the bottom liquid is pumped into a light component removal tower of a product refining unit through an acrylic acid buffer tank 141.
And (3) product refining unit C flow:
light ends removal unit C1 flow: the lightness-removing column 16 separates water and acetic acid from acrylic acid by azeotropic distillation. The entrainer used was toluene. Water, acetic acid and toluene are distilled out from the top of the lightness-removing tower 16 as an azeotrope through reduced pressure distillation, the distillate is partially condensed by cooling water through a lightness-removing tower condenser 161, the condensate flows into a lightness-removing tower liquid-receiving tank 163, the uncondensed gas enters a lightness-removing tower tail condenser 162 and is further condensed by cooling water, the condensate also flows into the lightness-removing tower liquid-receiving tank 163, the noncondensable gas from the lightness-removing tower tail condenser 162 enters an emptying tank recovery tank 165 through a water circulation lightness-removing tower vacuum pump 164, and the noncondensable gas condensed by a gas condenser 166 is discharged to a waste gas incineration treatment system.
The light component removal tower is divided into two areas by a partition in the liquid receiving tank 163: an aqueous phase zone and a toluene zone. The inflowing condensate was layered in the aqueous phase and the upper toluene layer overflowed to the toluene zone. The toluene in the toluene zone is pumped out of the tank by two pumps, one of which is regulated and controlled to flow back to the lightness-removing tower 16; the other is sent to a toluene tank 167, adjusted to maintain a liquid level in the toluene zone of 50%. The water in the water phase area is also pumped out of the tank in two ways, one way is cooled by circulating water through a reuse water cooler 168 and then is pumped and reused as working water; the other path controls the interface of the water phase region to be 50% by adjusting the flow to the waste water tank 169 in cascade.
The bottom liquid of the light component removal column 16 is an acrylic acid liquid containing a small amount of acetic acid. And a part of the waste gas is pumped into a light component removal tower reboiler 1611 by a light component removal tower reboiler pump 1610 to carry out forced circulation, and the light component removal tower reboiler 1611 adopts low-pressure steam for heating and controls the temperature of the tower bottom through cascade regulation. The other part is sent to a de-acetic acid tower 17 by a de-light tower bottom pump 1615 for further de-acetic acid, and the liquid level at the bottom of the tower is controlled to be 50% by adjusting the sending amount in a cascade mode.
The material adding line of the light component removing tower 16 mainly comprises a light component removing air line 1612, a tower bottom polymerization inhibitor line 1613 and a toluene reflux polymerization inhibitor line 1614, and the reactants in the tower are effectively prevented from polymerizing by accurately adjusting the injection amount of the material lines.
Deacetic acid unit C2 scheme: the acetic acid removal column 17 is a plate column using a flow passing plate. Acetic acid, water, toluene and a small amount of acrylic acid are distilled out from the top of the acetic acid removing tower 17 through reduced pressure distillation, and the distillate is condensed through a condenser 171 of the acetic acid removing tower; the condensate flows into a liquid receiving tank 173 of the de-acetic acid tower, the non-condensable gas enters a tail condenser 172 of the de-acetic acid tower for further condensation, the condensate also flows into the liquid receiving tank 173 of the de-acetic acid tower, and the non-condensable gas from the tail condenser 172 of the de-acetic acid tower is discharged to the waste gas incineration treatment system through a vapor jet pump 174 of the de-acetic acid tower and a jet pump condenser 175 of the de-acetic acid tower.
The liquid in the liquid receiving tank 173 of the de-acetic acid tower is pumped out of the tank by two pumps, and one pump flows back to the interior of the de-acetic acid tower 17 from the top of the tower; the other path is refluxed from the top of the tower to the light component removal tower 16 for re-dehydration.
The bottom liquid of the acetic acid removing tower 17 is an acrylic acid liquid containing a small amount of heavy components. One part is pumped into a reboiler 177 of the acetic acid removing tower by a reboiler 176 of the acetic acid removing tower for forced circulation, and the other part is sent to the 8 th plate of the refining tower 18 by a bottom pump 178 of the acetic acid removing tower for further removing heavy components.
The material adding line of the acetic acid removing tower 17 mainly comprises an acetic acid removing air line 179, an acetic acid removing tower top evaporation product polymerization inhibitor line 1710 and an acetic acid removing reflux liquid polymerization inhibitor line 1711, and the polymerization of reactants in the tower is effectively prevented by accurately adjusting the injection amount of the material line.
Purification unit C3 scheme: the refining column 18 is primarily intended to remove heavy components. Acrylic acid is distilled from the top of the refining tower 18 by reduced pressure distillation, the distillate is partially condensed by a refining tower condenser 181, condensate flows into a refining tower liquid receiving tank 183, uncondensed gas enters a refining tower tail condenser 182 for partial condensation, the condensate flows into the refining tower liquid receiving tank 183, the discharged uncondensed gas is pumped into a refining tower jet pump condenser 185 by a refining tower jet pump 184, the condensate flows into a light component liquid receiving tank 186 for collection and then is pumped into a lightness-removing tower 16 for cyclic distillation, and the uncondensed gas in the refining tower jet pump condenser 185 is discharged into a waste gas incineration treatment system.
The liquid in the liquid receiving tank 183 of the refining tower is pumped out of the tank by two pumps, and one pump flows back to the refining tower 18 from the top of the tower; the other path is taken as a product and is cooled to 20 ℃ by an acrylic acid finished product cooler 187, and then the product is sent to an acrylic acid finished product tank 188.
The bottom liquid of the refining column 18 is a heavy component containing a small amount of acrylic acid. A part of the water is pumped into a refining tower reboiler 1810 by a refining tower reboiler pump 189 for forced circulation; the other part is sent to the heavy component removal thin film evaporator 19 by the polishing column bottom pump 1811 to be vacuum evaporated to recover acrylic acid in the heavy component.
The material adding line of the refining tower 18 mainly comprises a refining tower top distillate polymerization inhibitor line 1812 and a refining reflux liquid polymerization inhibitor line 1813, and the polymerization of reactants in the tower is effectively prevented by accurately adjusting the injection amount of the material line.
De-duplication unit C4 flow: the heavy component removal thin film evaporator 19 is jacketed with a heavy component removal medium pressure steam line 191 to perform vacuum evaporation of the bottom liquid from the refining column 18 to recover acrylic acid in the heavy component. The gas mainly containing acrylic acid distilled from the top is returned to the bottom of the refining column 18 for cyclic distillation refining.
The bottom liquid of the thin film evaporator 19 is sent by a heavy removal pump 192, cooled by a thin film evaporator condenser 193 and discharged into a dimer tank 194, the dimer in the dimer tank 194 is sent by a dimer pump 195, one path is circulated in the dimer tank 194 itself, and the other path is sent to a barreling area 196.
The present invention is not limited to the above-described embodiments, and various changes can be made within the knowledge range of those skilled in the art without departing from the spirit of the present invention, and the changed contents still belong to the protection scope of the present invention.
Claims (9)
1. A complete equipment for preparing acrylic acid by a circulating propylene oxidation method is characterized in that: the device comprises a feeding oxidation reaction unit, a circulating quenching absorption unit and a product refining unit, wherein a liquid phase outlet of the feeding oxidation reaction unit is connected with the circulating quenching absorption unit through a pipeline, a top gas phase line of the circulating quenching absorption unit is connected with the feeding oxidation reaction unit through a pipeline, a liquid phase line of the circulating quenching absorption unit is connected with the product refining unit through a pipeline, the product refining unit is provided with a discharge pipeline which is connected with an acrylic acid product tank area and produces a finished product, and a tail gas of the product refining unit is sent to a waste gas incineration treatment system;
the feeding oxidation reaction unit comprises a propylene preheating system, a reaction gas supply system, a main reaction system and a secondary reaction system which are sequentially connected through pipelines, and the reaction gas supply system is also provided with branch lines and is communicated with the secondary reaction system;
the propylene preheating system comprises a liquid propylene tank, a propylene gas eliminator, a propylene evaporator and a propylene superheater which are sequentially connected through pipelines, and a discharge line of the propylene superheater is communicated with the reaction gas supply system.
2. The plant for preparing acrylic acid by the oxidation of recycle propylene according to claim 1, wherein: the reaction gas supply system comprises a medium-pressure steam line, a feeding air compressor, a steam mixer, a main reactor feeding mixer, a secondary reactor feeding mixer and a circulating air compressor, wherein the steam mixer is provided with three feeding lines and is respectively connected with the medium-pressure steam line, the feeding air compressor and the circulating air compressor, the main reactor feeding mixer is provided with a plurality of feeding lines and is respectively connected with the propylene superheater and the steam mixer, and a discharging line of the main reactor feeding mixer is connected with the main reaction system;
the feeding air compressor and the circulating air compressor are respectively provided with a secondary reaction branch and are both connected with the secondary reactor feeding mixer, and a discharging line of the secondary reactor feeding mixer is communicated with the secondary reaction system.
3. The plant for producing acrylic acid by the oxidation of propylene with recycle according to claim 2, wherein: the main reaction system comprises a main reactor, an electric heater, a cooling circulating pump, a cooler and a cooling medium storage tank which are connected in sequence; the main reactor is a tubular fixed bed reactor, the tubes of the main reactor are filled with a catalyst, a mixed salt constant-temperature medium is filled between the tubes of the main reactor, a fin cooler is arranged at the lower part of the main reactor, and the main reactor feed mixer is communicated with the main reactor;
the secondary reaction system comprises a secondary reactor, a secondary electric heater, a secondary cooling circulating pump, a secondary cooler and a secondary cooling medium storage tank which are sequentially connected, mixed hydrocarbon constant-temperature medium is filled between the tubes of the secondary reactor, the secondary reactor feeding mixer is communicated with the secondary reactor, and the secondary reactor is connected with the circulating quenching absorption unit.
4. The plant for producing acrylic acid by the oxidation of propylene with recycle according to claim 3, wherein: the circulating quenching absorption unit comprises a reactant cooler, an acrylic acid buffer tank, a spray condenser, a quenching absorption waterline, a tower bottom circulating liquid polymerization inhibitor line, an absorption water polymerization inhibitor line, an unreacted gas tank and a quenching absorption tower;
the quenching absorption tower is provided with a plurality of liquid phase feeding lines and is respectively communicated with a spray condenser, a quenching absorption waterline and an absorption water polymerization inhibitor line, the quenching absorption tower is provided with a plurality of gas phase feeding lines and is respectively communicated with the reactant cooler and the tower bottom circulating liquid polymerization inhibitor line, the quenching absorption tower is provided with a gas phase discharging pipe and is communicated with the unreacted gas tank, the quenching absorption tower is provided with a liquid phase discharging pipe and is communicated with the acrylic acid buffer tank and the product refining unit, and the reactant cooler is connected with the secondary reactor.
5. The plant for producing acrylic acid by the oxidation of propylene with recycle according to claim 4, wherein: the product refining unit comprises a light component removal unit, an acetic acid removal unit, a refining unit and a heavy component removal unit which are connected in sequence through pipelines;
the lightness-removing unit comprises a lightness-removing tower, a lightness-removing tower condenser, a lightness-removing tower tail condenser, a lightness-removing tower liquid receiving tank, a lightness-removing tower vacuum pump, a blow-down tank recovery tank, a gas condenser, a toluene tank, a recycled water cooler, a wastewater tank, a lightness-removing tower reboiler pump, a lightness-removing tower reboiler, a lightness-removing air line, a tower bottom polymerization inhibitor line, a toluene reflux polymerization inhibitor line and a lightness-removing tower bottom pump;
the lightness-removing tower is provided with a plurality of feed inlets and is respectively connected with the quenching absorption tower, the acrylic acid buffer tank, the lightness-removing air line, the tower bottom polymerization inhibitor line and the toluene reflux polymerization inhibitor line, the lightness-removing tower is provided with a plurality of discharge outlets and is respectively connected with the lightness-removing tower bottom pump and the lightness-removing tower condenser, and the lightness-removing tower bottom pump is connected with the acetic acid removal unit;
the lightness-removing tower condenser is provided with a gas-phase discharge line and a liquid-phase discharge line, the gas-phase discharge line of the lightness-removing tower condenser is sequentially connected with a lightness-removing tower tail condenser, a lightness-removing tower vacuum pump, an emptying tank recovery tank and a gas condenser to form a lightness-removing waste gas treatment line, the liquid-phase discharge line of the lightness-removing tower condenser is connected with a lightness-removing tower liquid receiving tank, the lightness-removing tower liquid receiving tank is provided with a plurality of discharge lines and is respectively connected with the toluene tank, the recycle water cooler and the waste water tank, and the lightness-removing tower condenser, the lightness-removing tower liquid receiving tank, the toluene tank, the recycle water cooler and the waste water tank form a lightness-removing waste liquid treatment line;
the liquid receiving tank of the light component removal tower is provided with a gas phase discharging line and is connected with the light component removal tower; the light component removal tower, a light component removal tower reboiler pump and a light component removal tower reboiler are sequentially connected to form a circulation closed circuit.
6. The plant for producing acrylic acid by the oxidation of propylene with recycle according to claim 5, wherein: the de-acetic acid unit comprises a de-acetic acid tower, a de-acetic acid tower condenser, a de-acetic acid tower tail condenser, a de-acetic acid tower liquid receiving tank, a de-acetic acid tower steam jet pump, a de-acetic acid tower jet pump condenser, a de-acetic acid tower reboiler pump, a de-acetic acid tower reboiler, a de-acetic acid tower bottom pump, a de-acetic acid air line, a tower top distillate polymerization inhibitor line and a reflux liquid polymerization inhibitor line;
the de-acetic acid tower is provided with a plurality of feed inlets and is respectively connected with the light component removal tower bottom pump, a de-acetic acid air line and a reflux polymerization inhibitor line, the de-acetic acid tower is provided with a plurality of discharge outlets and is respectively connected with the de-acetic acid tower bottom pump and a de-acetic acid tower condenser, and the de-acetic acid tower bottom pump is connected with the refining unit;
the feed inlet of the condenser of the de-acetic acid tower is also connected with a tower top distillate polymerization inhibitor line, the condenser of the de-acetic acid tower is provided with a gas-phase discharge line and a liquid-phase discharge line, the gas-phase discharge line of the condenser of the de-acetic acid tower is connected with the ejector pump condenser of the de-acetic acid tower to form a de-acetic acid waste gas treatment line, and the gas-phase discharge line of the condenser of the de-acetic acid tower is sequentially connected with the liquid receiving tank of the de-acetic acid tower and a reflux liquid polymerization inhibitor line to form a de-acetic acid circulation treatment device;
the de-acetic acid tower, a de-acetic acid tower reboiler pump and a de-acetic acid tower reboiler are connected in sequence to form a circulation closed circuit.
7. The plant for producing acrylic acid by the oxidation of propylene with recycle according to claim 6, wherein: the refining unit comprises a refining tower, a refining tower condenser, a refining tower tail condenser, a refining tower liquid receiving tank, a refining tower jet pump condenser, a light component liquid receiving tank, an acrylic acid finished product cooler, an acrylic acid finished product tank, a refining tower reboiler pump, a refining tower reboiler, a refining tower bottom pump, a tower top distillate polymerization inhibitor line and a reflux liquid polymerization inhibitor line;
the refining tower is provided with a plurality of feed inlets and is respectively connected with the acetic acid removal tower bottom pump, the heavy film removal evaporator, the refining tower liquid receiving tank and the reflux polymerization inhibitor line, the refining tower is provided with a plurality of discharge outlets and is respectively connected with the refining tower bottom pump and the refining tower condenser, and the refining tower bottom pump is connected with the heavy removal unit;
the refining tower condenser is provided with a gas-phase discharging line and is sequentially connected with the refining tower tail condenser, the refining tower jet pump and the refining tower jet pump condenser to form a refined waste gas treatment line, and the refining tower condenser is provided with a liquid-phase discharging line and is sequentially connected with the refining tower liquid receiving tank, the acrylic acid finished product cooler and the acrylic acid finished product tank to form an acrylic acid finished product line;
the liquid receiving tank of the refining tower is provided with a branch line and is connected with the polymerization inhibitor line of the distillate at the top of the tower;
the refining tower, a refining tower reboiler pump and a refining tower reboiler are sequentially connected to form a circulation closed circuit.
8. The plant for the production of acrylic acid by the oxidation of propylene with recycle according to claim 7, wherein: the heavy component removal unit comprises a heavy component removal film evaporator, a heavy component removal medium-pressure steam line, a heavy component removal pump, a heavy component removal film evaporator condenser, a dimer tank, a dimer pump and a barreling area, wherein the heavy component removal film evaporator is connected with the refining tower bottom pump;
the heavy film removal evaporator, the heavy film removal pump, the heavy film removal evaporator condenser, the dimer tank, the dimer pump and the barreling area are sequentially connected to form a product heavy line;
the upper part of the heavy-film removal evaporator is connected with the heavy-medium pressure removal steam line, and the upper part of the heavy-film removal evaporator is provided with a pipeline and is connected with the refining tower to form a heavy-cycle removal treatment structure.
9. The plant for preparing acrylic acid by the oxidation of recycle propylene according to claim 1, wherein: this device installation automation long-range temperature, pressure, flow detection and control equipment adopt advanced reliable Distributed Control System (DCS), carry out remote monitoring, control and operation to important technology temperature, pressure and flow parameter to record and report to the police, adopt Safety Instrument System (SIS) simultaneously, realize the safety interlock and the emergency stop of device, improve the device security, long-range temperature, pressure, flow detection and control equipment with respectively with the equipment electricity is connected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121039690.3U CN214991236U (en) | 2021-05-17 | 2021-05-17 | Complete device for preparing acrylic acid by using cyclic propylene oxidation method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121039690.3U CN214991236U (en) | 2021-05-17 | 2021-05-17 | Complete device for preparing acrylic acid by using cyclic propylene oxidation method |
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| CN214991236U true CN214991236U (en) | 2021-12-03 |
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