WO2019174063A1

WO2019174063A1 - Chemical reaction apparatus and application thereof

Info

Publication number: WO2019174063A1
Application number: PCT/CN2018/080015
Authority: WO
Inventors: 安丽华
Original assignee: 安丽华
Priority date: 2018-03-16
Filing date: 2018-03-22
Publication date: 2019-09-19
Also published as: CN108440281B; CN108440281A

Abstract

Disclosed is a chemical reaction apparatus, the apparatus comprising: a reaction unit, a separation unit, and a recovery unit; the reaction unit, the separation unit, and the recovery unit are connected in sequence; and the reaction unit comprises a three-phase bubbling bed synthesis reactor. Also disclosed are a reaction apparatus and a method for preparing methyl methacrylate. The present apparatus is used for preparing methyl methacrylate, and has the advantages of high raw material conversion rate, high target product yield, and good selectivity for methyl methacrylate.

Description

Chemical reaction device and its application

Technical field

The application relates to a chemical reaction device and an application thereof, and belongs to the technical field of chemical material preparation and chemical engineering.

Background technique

Methyl methacrylate (MMA) is an important organic chemical raw material, mainly used in the production of plexiglass (polymethyl methacrylate, PMMA), also used in the manufacture of other resins, plastics, coatings, adhesives, lubrication Agents, wood and cork sizing agents, motor coil impregnating agents, paper glazing agents, printing auxiliaries and insulating infusion materials, etc., are widely used. In recent years, the demand for electronic/electrical/optical products, display signs, various lighting equipment and lamps in the Asian market has been strong, which has promoted the rapid development of the MMA industry. While the demand for transparent resins for toys, stationery and other items continues to increase, the demand for backlights for LCD core components and advertising signs has also grown.

At present, the industrial production technology of the world MMA mainly includes the acetone cyanohydrin method (ACH method), the improved acetone cyanohydrin method, the ethylene carbonylation method and the isobutylene method.

The acetone cyanohydrin method is the earliest MMA production method in industrialization. The method was first developed by the United States 璐彩特公司. At present, this method is still the main method for producing MMA. The reason is that the acetone cyanohydrin process is simple and the technology is getting better. Therefore, the acetone cyanohydrin method has always been a relatively economical production method. The process first reacts acetone and hydrocyanic acid under a basic catalyst to form acetone cyanohydrin, which is then reacted with concentrated sulfuric acid to form methacrylamide sulfate, and methacrylamide sulfate is reacted with aqueous methanol to form MMA. The method produces more waste acid by-product, and there are two kinds of waste acid treatment: ammonium sulfate recovery method and sulfuric acid recovery method. At present, several companies in the world use a methyl methacrylate unit in combination with a sulfuric acid recovery unit, such as Mitsubishi Rayon Corporation of Japan.

Methacrylic acid-methanol esterification method After more than 20 years of research and development work in Japan, Mitsubishi Rayon Company first industrialized a new route. The advantages are that the technology is mature and reliable, the raw materials are easy to obtain, the product quality is good, and the environmental impact is small; the disadvantages are that the equipment is more complicated, the process is more complicated, the catalyst life is short, and the total yield is low. Therefore, shortening the process flow and increasing the service life of the catalyst are one of the effective ways to improve the method.

Dr. Hayashi of Japan's catalyst found in 2006 that nanogold (gold-lead alloy) can efficiently catalyze the oxidative esterification of various alcohols, including ethanol, propanol, butanol, allyl alcohol and methacrylol. In the subsequent research, Asahi Kasei discovered that the core-shell nano-gold catalyst (Au@NiOx) can efficiently catalyze the co-oxidation of methacrolein and methanol to MMA, and at the same time build the world's first methyl acrolein-methanol one-step ester. Industrialization device of the Chemical Law (II generation).

However, so far, the isobutylene technology is still in the hands of foreign-funded enterprises, and the domestically developed isobutylene technology has rarely been commercialized. If you want to use the isobutylene method to produce MMA in China, solving the technical source will be the first problem. Therefore, it is necessary to strengthen research and development efforts to develop MMA with independent intellectual property rights, especially the methacrolein-methanol oxidative esterification method in the isobutylene method. The process requires only two reaction steps. First, the oxidation of isobutylene to methacrolein is relatively mature. Secondly, MMA is prepared by oxidative esterification of methacrolein and methanol, and the technology is now monopolized by Asahi Kasei of Japan. Therefore, the development of special catalysts and high-efficiency reactors and separation processes and engineering techniques for catalyzing the oxidative esterification of methacrolein and methanol and the separation of reaction products are the key to the development of proprietary methyl methacrylate (MMA). .

Summary of the invention

According to an aspect of the present application, there is provided a chemical reaction apparatus for preparing methyl methacrylate, which has the advantages of high conversion of a raw material, high yield of a target product, and good selectivity of methyl methacrylate.

The chemical reaction device of the present application is characterized in that the device comprises:

Reaction unit, separation unit, recovery unit;

The reaction unit, the separation unit, and the recovery unit are sequentially connected;

Wherein the reaction unit comprises a three-phase bubbling bed synthesis reactor.

Optionally, the apparatus comprises a gas, liquid and solid three-phase bubbling bed MMA synthesis reactor, an extraction separation tower, a purge gas scrubbing tower, a methanol recovery tower, and a methacrolein (MAL). The liquid tank and the auxiliary equipment of the component system include a feed pump, a heater, a condenser, a gas-liquid separator and the like. The reactor comprises a catalytic reaction section and a catalyst settling section, and a cooling device, a gas liquid distributor, a gas distributor, etc. are arranged in the catalytic reaction section; a liquid production filter element assembly is arranged in the catalyst settling section.

Optionally, the three-phase bubbling bed synthesis reactor comprises: a catalytic reaction section and a catalyst settling section; a cross-sectional area of at least one position of the catalytic reaction section is smaller than a cross section of at least one position of the catalyst settling section area;

The catalytic reaction zone is located below the settling section of the catalyst.

Optionally, the cross-sectional area of the catalytic reaction section at any position is smaller than the cross-sectional area of any position of the catalyst settling section;

The catalytic reaction section and the catalyst settling section are coaxially connected.

Optionally, the length of the settling section of the catalyst is less than the length of the catalytic reaction section.

The catalytic reaction section has a diameter ranging from 20 to 10000 mm and a length ranging from 100 to 50,000 mm;

The diameter of the catalyst settling section is 1.2 to 3.0 times the diameter of the catalytic reaction section, and the length is 0.1 to 0.8 of the length of the catalytic reaction section.

Optionally, the catalytic reaction section of the reactor has a diameter ranging from 50 to 5000 mm and a length ranging from 300 to 30,000 mm.

Optionally, the catalyst settling section of the reactor has a diameter of 1.5 to 2.0 times the catalytic reaction section and a length of 0.2 to 0.6 of the catalytic reaction section. A liquid production filtration unit is disposed in the settling section of the catalyst.

Optionally, the catalytic reaction section of the reactor has a diameter ranging from 20 to 10000 mm, and a heat collecting device, a gas distributor, and a gas-liquid distributor are disposed in a length ranging from 100 to 50,000 mm.

Optionally, the catalytic reaction section comprises a heat taking device, a gas distributor and a gas liquid distributor; the catalyst settling section comprises a liquid extraction filtering unit.

Optionally, the catalytic reaction section comprises a catalytic reaction section cylinder, a heat taking device, a gas liquid distributor, and a gas distributor; wherein the heat taking device, the gas liquid distributor and the gas distributor are located in the catalytic reaction barrel in vivo;

The catalyst settling section comprises a catalyst settling section cylinder and a filtering unit; wherein the filtering unit is located in the catalyst settling section cylinder.

The catalytic reaction section cylinder is coaxially connected with the catalyst settling section cylinder; the diameter of the catalytic reaction section cylinder is smaller than the diameter of the catalyst settling section cylinder.

Optionally, the bubbling bed reactor is a gas, liquid, solid three-phase bubbling bed MMA synthesis reactor; the reactor comprises a catalytic reaction section and a catalyst settling section, and a cooling device, a gas liquid is disposed in the catalytic reaction section A distributor, a gas distributor, etc.; a liquid production filter element assembly is disposed in the catalyst settling section.

Optionally, the catalytic reaction section and the catalyst settling section are two-stage cylinders; the catalytic reaction section is provided with a gas distributor (composed of a distribution main pipe and a branch pipe and a distribution cap), and a gas-liquid distributor (by a distribution plate) It is composed of a plurality of distributor units, a heat taking device (the plurality of heat taking units are arranged in parallel), and a liquid production filtering unit (composed of a plurality of sets of filters in parallel) in the cylinder of the catalyst settling section.

Optionally, the heat taking device comprises at least one set of heat taking unit, an inlet manifold of the cooling liquid, and an outlet manifold of the cooling liquid;

Wherein, the heat taking unit is connected to an inlet manifold of the cooling liquid and an outlet manifold of the cooling liquid;

The inlet manifold of the coolant and the outlet manifold of the coolant are located at an upper portion of the cylinder of the catalytic reaction section;

The inlet manifold of the coolant is at the inlet of the reactor, and the outlet manifold of the coolant is located at the outlet of the reactor on the outer wall of the cylinder of the catalytic reaction section.

Optionally, the operating medium of the heat taking device is a cooling liquid, and the cooling liquid is selected from at least one of water, brine, and aqueous glycol solution, and the operating medium in the cylinder includes a raw material solution, a catalyst solid particle, and a nitrogen. Oxygen mixture and reaction product. In the methyl methacrylate synthesis system, the reaction product is methyl methacrylate.

The heat take-up device is used for cooling of the reactor, and the heat removal device is used to achieve rapid heat removal, thereby improving product selectivity.

Optionally, the heat taking device is composed of a manifold in which the coolant enters and exits the reactor and a plurality of groups of heat taking units are connected in parallel.

Optionally, the set of heat extraction units includes a downcomer and at least one riser;

The lower portion of the riser tube is connected to the downcomer tube and is evenly distributed in a circle; the riser tube merges at the top tube to form an outlet tube, and the diameter of the outlet tube is the same as the diameter of the down tube;

Wherein the downcomer is connected to the inlet manifold of the coolant; the riser is connected to the outlet manifold of the coolant.

Each group of heat take-up units consists of a downcomer and several risers.

The heat taking unit functions to increase the flow rate of the cooling liquid, enhance the heat transfer efficiency, and also function to aggregate the rising bubbles of the oxygen-containing gas mixture in the reactor cylinder into large bubbles, thereby improving the reaction efficiency.

The coolant inlet and the coolant outlet are located on the outer wall of the reactor cylinder; the inlet manifold and the outlet manifold of the coolant are disposed at an upper portion of the cylinder, and the coolant enters the heat-receiving unit installed inside the cylinder from the inlet. The pipe is lowered and returned to the coolant outlet pipe through the heat exchange of the riser pipe to cool the reaction system.

Optionally, the drop tube has a diameter ranging from 10 to 200 mm;

The number of the risers is 1-10;

The riser diameter is 1/8-1/2 of the diameter of the downcomer.

Optionally, the downcomer has a diameter ranging from 20 to 100 mm.

Optionally, the upper limit of the diameter of the downcomer is selected from the group consisting of 20 mm, 25 mm, 40 mm, 100 mm, and 200 mm; and the lower limit is selected from the group consisting of 10 mm, 20 mm, 25 mm, 40 mm, and 100 mm.

Optionally, the number of risers is 2-6, and the lower part is connected with the down pipe, and is circularly distributed. The diameter of the riser is 1/6 to 1/4 of the diameter of the down pipe, and the riser pipe joins the top pipe to form a The outlet pipe has the same diameter as the down pipe; the length of the heat take-up unit ranges from 200 to 6000 mm, and can be installed in the reactor by modules, single or multiple groups.

Alternatively, the heat extraction unit may be installed inside the reactor in modules, in a single group or in multiple groups.

Optionally, the at least one set of heat take-up units is in parallel;

The length of the heat extraction unit is 100 to 10000 mm;

The heat taking unit is vertically located in the cylinder of the catalytic reaction section, and is evenly distributed in a square shape, and the distance between each heat taking unit is 20-2000 mm.

Optionally, the upper limit of the length of the heat extraction unit is selected from 800 mm and 10000 mm; and the lower limit is selected from 100 mm and 800 mm.

Optionally, the distance of each of the heat take-up units is 50-1000 mm. For example, any point in the range of any two of 50 mm, 100 mm, 200 mm, 300 mm, 400 mm, 500 mm, 600 mm, and the above point values. The spacing between the heat take-up units may be equal or unequal. Preferably, the spacing between the heat take-up units is equal.

Optionally, the gas liquid distributor comprises a distribution plate and a distribution cap; the gas liquid distributor is located at the bottom of the catalytic reaction section cylinder.

The working mechanism of the distributor:

The high specific surface microporous interface effect of the distribution cap is used to achieve high dispersion of the gas-liquid mixture and form a uniform jet, and the catalyst particles are suspended in the reactor to achieve high-efficiency mass transfer and heat transfer of the mixed gas mixture and the catalyst particles.

Optionally, the average pore size of the distribution plate is between 1 and 50 μm, and the opening ratio is 0.01% to 2.0%;

The number of the dispensing caps is 10-5000;

The dispensing cap has a diameter of 5-100 mm and a length or height of 5-100 mm;

The dispensing cap is a hollow cylinder or a cone;

The arrangement of the dispensing caps on the distribution plate is selected from at least one of an equilateral triangle and a square, and the arrangement pitch is 15 to 200 mm.

Optionally, the dispensing cap is a hollow cylinder or a cone processed from at least one of a metal sintered wire mesh, a metal sintered powder, and a ceramic powder.

Optionally, the upper limit of the average pore diameter on the distribution plate is selected from the group consisting of 20 μm and 50 μm; and the lower limit is selected from 1 μm and 20 μm.

Optionally, the upper limit of the opening ratio on the distribution plate is selected from 0.05% and 2.0%; and the lower limit is selected from 0.01% and 0.05%. Optionally, a gas-liquid distributor is disposed at the bottom of the catalytic reaction section of the reactor, and the distribution plate and the distribution cap are disposed;

Optionally, the average pore diameter on the distribution plate is between 5 and 20 μm, the open cell ratio is between 0.02% and 1.5%, and the number of the distribution caps is between 20 and 1000.

Optionally, the distribution cap has a diameter of 10-50 mm, a length or a height of 20-50 mm, and the distribution cap is arranged on the distribution plate from at least one of an equilateral triangle and a square, and the spacing is 40. ~100mm.

Optionally, a gas distributor is disposed at the bottom of the catalytic reaction section of the reactor, which acts to form a uniform gas-liquid mixture of the feed mixed gas and the feed liquid.

Optionally, the gas distributor comprises a distributor main pipe and a distributor pipe branch, and each distributor pipe branch is connected to a main pipe of the distributor;

The gas distributor is located at the bottom of the catalytic reaction section cylinder; the gas distributor is positioned lower than the gas liquid distributor.

Optionally, the gas distributor main pipe has a diameter of 10-500 mm and a length of 20-8000 mm;

The number of the distributor branch pipes is 1-500, the diameter is 5-300 mm, and the length is 50-5000 mm;

The number of openings in the distributor branch pipe is 2-1000, the diameter is 0.1-10 mm, and the opening ratio is 10% to 60% of the total pipe cross-sectional area.

The distributor comprises a distributor head and a distributor branch.

Optionally, the gas distributor head has a diameter of 20-300 mm and a length of 50-5000 mm.

Optionally, the upper limit of the diameter of the gas distributor main pipe is selected from 15 mm and 500 mm; and the lower limit is selected from 10 mm and 15 mm.

Optionally, the upper limit of the length of the gas distributor main pipe is selected from the group consisting of 80 mm, 120 mm, 180 mm, and 8000 mm; and the lower limit is selected from the group consisting of 20 mm, 80 mm, 120 mm, and 180 mm.

Optionally, the upper limit of the aperture of the opening in the distributor branch is selected from 0.5 mm and 10 mm; and the lower limit is selected from 0.1 mm and 0.5 mm.

Optionally, the number of the distributor branches is 2 to 200, the diameter is 50-100 mm, and the length is 100-2500 mm, and each distributor branch is connected to the distributor main pipe.

Optionally, the number of openings in the distributor branch is 20-500, the diameter is 0.2-20 mm, and the opening ratio is 20%-40% of the total tube cross-sectional area.

Optionally, the catalytic reaction section includes a gas feed port, a liquid feed port, and a catalyst slurry outlet;

The gas feed port is located on an outer wall of the bottom of the catalytic reaction section cylinder and is connected to the gas distributor;

The liquid feed port is located at a bottommost end of the bottom of the catalytic reaction section cylinder;

The catalyst slurry exits the outer wall of the bottom of the catalytic reaction section cylinder at a position higher than the gas inlet.

Optionally, the catalytic reaction section cylinder has a diameter ranging from 20 to 10000 mm and a length ranging from 100 to 50,000 mm;

The diameter of the cylinder of the catalyst settling section is 1.2 to 3.0 times that of the cylinder of the catalytic reaction section;

The length of the catalyst settling section cylinder is 0.1 to 0.8 of the catalytic reaction section cylinder.

Optionally, the upper limit of the diameter of the catalytic reaction section cylinder is selected from the group consisting of 100 mm, 150 mm, 200 mm, 5000 mm, and 10000 mm; and the lower limit is selected from the group consisting of 20 mm, 100 mm, 150 mm, 200 mm, and 5000 mm.

Optionally, the upper limit of the length of the catalytic reaction section cylinder is selected from 1000 mm, 30000 mm, and 50000 mm; and the lower limit is selected from 100 mm, 1000 mm, and 30000 mm.

Optionally, the diameter of the catalyst settling section of the reactor is 1.5 to 2.0 times the diameter of the cylinder of the catalytic reaction section, and the length is 0.2 to 0.6 of the length of the cylinder of the catalytic reaction section. A liquid production filtration unit is disposed in the settling section of the catalyst.

The catalyst settling section of the reactor realizes gas-liquid separation effectively by expanding the diameter to reduce the flow rate of the reaction mixed gas liquid to achieve the large particle sedimentation of the catalyst.

Optionally, the catalytic reaction section cylinder has a diameter ranging from 50 to 5000 mm and a length ranging from 300 to 30000 mm.

Optionally, the filtering unit is a liquid extraction filtering unit;

The liquid production filtration unit is composed of at least one set of filters and connecting tubes.

The function of the liquid production filtration unit is to achieve effective separation of the reaction mixed liquid and the catalyst solid particles. In practice, each group of filters is equipped with a backflush and backwash system to avoid filter blockage.

Optionally, the at least one set of filters is connected in parallel;

The number of sets of the filter is 1-20;

The filter has a diameter of 20-500 mm and a length or height of 50-1000 mm;

The number of filters in each group is 1-20.

Optionally, the liquid extraction filter unit is composed of 2 to 8 sets of filters and connecting tubes thereof, the filter has a diameter of 50-200 mm, a length or a height of 100-500 mm, and the number of filters per set is 2 ~10.

Optionally, the filter is a hollow cylinder or a cone processed from at least one of a metal sintered wire mesh, a metal sintered powder, and a ceramic powder.

Optionally, the filter is a hollow cylinder or a cone;

The filter has an average filtration accuracy of 1 to 50 μm.

Optionally, the filter has an average filtration accuracy of 5 to 20 μm.

Optionally, the catalyst settling section further comprises a liquid recovery outlet;

The liquid recovery outlet is located on an outer wall of the cylinder of the catalyst settling section;

The liquid recovery port is connected to the filtration unit.

Optionally, the reactor further includes a purge gas outlet and a catalyst slurry inlet; the purge gas outlet is located at a top end of the catalyst settling section cylinder;

The catalyst slurry inlet is located on an outer wall of the catalyst settling section cylinder.

Optionally, the reactor comprises a liquid feed port, a gas feed port, a liquid production port, a purge gas outlet, a catalyst slurry inlet, a catalyst slurry outlet, a coolant inlet, a coolant outlet, and a catalytic reaction cylinder Body, catalyst settling section cylinder, gas liquid distributor, liquid production filtering unit, heat taking device, gas distributor;

The catalytic reaction section cylinder is located below the catalyst settling section cylinder.

Optionally, the reactor further comprises a transition section;

The transition section is located between the catalytic reaction section and the catalyst settling section;

The cross-sectional area of at least one location of the transition section is between a cross-sectional area of at least one location of the catalytic reaction section and a cross-sectional area of at least one location of the catalyst settling section.

Optionally, the cross-sectional area of any position of the catalytic reaction section is smaller than the cross-sectional area of any position of the settling section of the catalyst;

a cross-sectional area at any position of the transition section between a cross-sectional area at any position of the catalytic reaction section and a cross-sectional area at any position of the catalyst settling section;

The transition section, the catalytic reaction section and the catalyst settling section are coaxially connected.

Optionally, the cross-sectional area of at least one location of the transition section is different from the cross-sectional area of any other at least one location.

Optionally, the transition section includes a transition section cylinder.

The catalytic reaction section cylinder is located below the catalyst settling section cylinder; the transition section cylinder is located between the catalytic reaction section cylinder and the catalyst settling section cylinder;

Optionally, the reactor is used under the conditions of a temperature of 20 to 200 ° C and a pressure of 0.1 to 10.0 MPa.

Alternatively, the reactor is a three-phase bubble column reactor for the oxidative esterification of alcohols or aldehydes.

Optionally, the reactor is a methyl methacrylate synthesis reactor.

Optionally, the reactor comprises a catalytic reaction section and a catalyst settling section, a cooling device, a gas liquid distributor, a gas distributor, and the like are disposed in the catalytic reaction section; a liquid production filter element assembly is disposed in the catalyst settling section.

Optionally, the apparatus comprises a gas, liquid, solid three-phase bubble-bed synthesis reactor employing a gas-liquid-solid three-phase reaction.

Optionally, the apparatus further comprises an extraction separation column for separating the reaction mixture produced from the reactor.

Optionally, the system further comprises an extraction separation column disposed between the first gas liquid separator and the feed recovery column.

Optionally, the system further comprises an extraction separation column disposed between the first gas liquid separator and the methanol recovery column.

Optionally, the system further comprises an extraction separation column using at least one of a rotary disk extraction column, a packed extraction column, or any combination in series.

Optionally, the separation unit comprises a first separator and an extraction separation column;

The first separator is connected to the reaction unit;

The extraction separation column is coupled to the first separator.

Optionally, a liquid production outlet of the reaction unit is connected to an inlet of the first separator;

The oil phase discharge port of the first separator is connected to the lower feed port of the extraction separation column.

Optionally, the top of the extraction separation column has a crude product extraction port and a connecting line.

Optionally, the system further comprises a purge gas scrubber that uses salt-containing process water as a detergent to scrub and absorb material from the reactor.

Preferably, the system further comprises a purge gas scrubber, the purge gas scrubber being disposed between the second gas liquid separator and the feed recovery column.

Optionally, the system further comprises a purge gas scrubber, the purge gas scrubber being disposed between the second gas liquid separator and the methanol recovery column.

Optionally, the system further comprises a purge gas scrubbing tower using at least one of a structured packed column, a packed packed column, and a plate column, or any combination thereof.

Optionally, the separation unit comprises a purge gas scrubbing tower;

A gas phase outlet of the first separator is coupled to an inlet of the purge gas scrubber.

Optionally, a top of the purge gas scrubbing tower is provided with a purge gas vent and a connecting line.

Optionally, the separation unit further includes a second separator;

The reaction unit, the second separator, and the purge gas scrubbing column are connected in sequence.

Optionally, the purge gas outlet of the reaction unit is connected to the inlet of the second separator;

The top discharge port of the second separator is connected to the inlet of the purge gas scrubber.

Optionally, the purge gas outlet of the reaction unit is connected to the second separator through a purge gas condenser;

a purge gas outlet of the three-phase bubbling bed synthesis reactor is connected to a feed port of the purge gas condenser;

a discharge port of the purge gas condenser is connected to an inlet of the second separator;

The second separator is connected to the purge gas scrubbing tower through a second control valve;

a top discharge port of the second separator is connected to an inlet of the second control valve;

An outlet of the second control valve is coupled to an inlet of the purge gas scrubber.

Optionally, the separation unit comprises a purge gas scrubbing tower;

The inlet of the purge gas scrubber is connected to the reaction unit.

Optionally, the separation unit further includes a purge gas condenser and a second separator;

Optionally, the system further comprises a feed recovery column for recovering the wash liquor and the feedstock from the aqueous phase of the extractor.

Optionally, the system further includes a raw material recovery column disposed before the raw material dosing tank, after the gas scrubbing tower and the extraction separation column are purged.

Optionally, the system further comprises a methanol recovery tower using at least one of a structured packed column, a random packed column, and a plate column, or any combination thereof.

Optionally, the system further comprises a methanol recovery column disposed before the MAL dosing tank, after the gas scrubbing column and the extraction separation column are purged.

Optionally, the recovery unit comprises a raw material recovery tower;

The raw material recovery column is connected to the separation unit.

Optionally, the separation unit comprises an extraction separation column and a purge gas scrubbing tower;

An inlet of the raw material recovery tower is connected to an outlet of the purge gas scrubbing tower;

The bottom discharge port of the extraction separation column is connected to the feed port of the raw material recovery column.

Optionally, the separation unit further includes a first separator;

An inlet of the first separator is connected to a liquid recovery port of the three-phase bubbling bed synthesis reactor;

An oil phase discharge port of the first separator is connected to a lower feed port of the extraction separation column;

The aqueous phase outlet of the first separator is connected to the feed port of the raw material recovery column.

Optionally, the recovery unit further comprises a circulating extract liquid cooler;

a bottom discharge port of the raw material recovery tower is connected to a feed port of the circulating extract liquid cooler;

The discharge port of the circulating extract cooler is connected to the upper feed port of the extraction separation column and the upper feed port of the purge gas scrubber.

Optionally, the system further comprises a raw material dosing tank for arranging the process materials fed by the reactor to meet specific process requirements, including the ratio of each raw material, the pH of the raw material liquid, etc., to ensure the safety and stability of the reaction. run.

Optionally, the device further includes a preparation unit;

The preparation unit is connected to the reaction unit;

The stock preparation unit includes a feed port of each raw material and a connecting line.

Optionally, the preparation unit is connected to the reaction unit through a reaction liquid feed pump and a feed heater;

The discharge port of the preparation unit is connected to the inlet of the reaction liquid feed pump;

An outlet of the reaction liquid feed pump is connected to an inlet of the feed heater;

The outlet of the feed heater is connected to the feed port of the three-phase bubbling bed synthesis reactor.

Optionally, the recovery unit comprises a raw material recovery tower;

The raw material recovery tower is connected to the separation unit;

The top discharge port of the raw material recovery tower is connected to the feed port of the stock preparation unit.

Optionally, the separation unit comprises a purge gas scrubber, a purge gas condenser and a second separator;

The three-phase bubbling bed synthesis reactor, the purge gas condenser, the second separator, and the purge gas are sequentially connected;

The bottom discharge port of the second separator is connected to the inlet of the stock preparation unit.

The first separator is connected to the reaction unit;

The extraction separation column is connected to the first separator;

The water phase discharge port branch of the first separator is connected to the inlet of the stock preparation unit.

Optionally, the device comprises a three-phase bubbling bed synthesis reactor, a three-phase bubbling bed synthesis reactor inlet and outlet connection, a first separator, an extraction separation column, a raw material recovery tower, a circulating extract liquid cooler, a raw material liquid Preparation tank, reaction liquid feed pump, feed heater, feed gas heater, purge gas condenser, second separator, purge gas scrubber, first control valve, second control valve, catalyst feed port , a gas release outlet, a catalyst discharge port, a heat take-off device, a gas liquid distributor, a liquid production filter unit, a gas distributor, a liquid feed port;

a purge gas outlet of the three-phase bubbling bed synthesis reactor is connected to the purge gas condenser;

a liquid extraction filter unit of the three-phase bubbling bed synthesis reactor is connected to the first separator;

a bottom liquid inlet of the three-phase bubbling bed synthesis reactor is connected to the feed heater;

The catalyst feed port, the purge gas outlet, the catalyst discharge port, and the liquid feed port are all located on an outer wall of the three-phase bubbling bed synthesis reactor;

The heat taking device, the gas liquid distributor, the liquid production filtering unit, and the gas distributor are all located in the three-phase bubbling bed synthesis reactor;

The oil phase discharge port of the first separator is connected to the lower feed port of the extraction separation column;

The bottom discharge port of the extraction separation column is connected to the feed port of the raw material recovery tower;

The discharge port of the circulating extract liquid cooler is connected to the inlet of the upper portion of the extraction separation column and the inlet of the upper portion of the purge column;

The top discharge port of the raw material recovery tower is connected to the feed port of the raw material liquid preparation tank;

The discharge port of the raw material liquid preparation tank is connected to the inlet of the reaction liquid feed pump;

The outlet of the reaction liquid feed pump is connected to the inlet of the feed heater;

The outlet of the feed heater is connected to the liquid feed port and constitutes a liquid system circulation with the three-phase bubbling bed synthesis reactor;

The discharge port of the purge gas condenser is connected to the inlet of the second separator;

a bottom discharge port of the second separator is connected to an inlet of the raw material liquid preparation tank;

The outlet of the second control valve is connected to the inlet of the purge gas scrubbing tower;

a top discharge port of the first separator is connected to an inlet of the first control valve;

The main branch of the water phase discharge port of the first separator is connected to the inlet of the raw material liquid preparation tank, and the secondary branch is connected to the feed port of the raw material recovery tower;

The outlet of the first control valve is connected to the inlet of the purge gas scrubbing tower;

a crude product production outlet and a connecting line are arranged at the top of the extraction separation tower;

a top of the purge gas scrubbing tower is provided with a purge gas vent and a connecting pipeline;

The raw material liquid preparation tank is provided with a feed port and a connection line of each raw material.

Optionally, the process wastewater is removed from the bottom of the feed recovery column.

Optionally, the raw material liquid preparation tank is a methacrolein liquid distribution tank;

The raw material recovery tower is a methanol recovery tower;

The methacrolein dosing tank comprises a raw material MAL feed port, a methanol feed port, a polymerization inhibitor feed port, a lye feed port and a connecting line.

Optionally, the first separator and the second separator are both gas-liquid separators.

Alternatively, the device is used for the oxidative esterification of alcohols or aldehydes.

Optionally, the reactor is a methyl methacrylate synthesis reactor.

In another aspect of the present application, there is provided a reaction apparatus for producing methyl methacrylate, characterized by comprising at least one of the devices described in any one of the above.

Optionally, the apparatus for preparing methyl methacrylate (MMA) comprises a gas, liquid and solid three-phase bubbling bed MMA synthesis reactor connected to each other, an extraction separation tower, and a purge gas purge The tower, the methanol recovery tower, the methacrolein (MAL) dosing tank, and the accessory equipment of the component system include a feed pump, a heater, a condenser, a gas-liquid separator, and the like. The reactor comprises a catalytic reaction section and a catalyst settling section, and a cooling device, a gas liquid distributor, a gas distributor, etc. are arranged in the catalytic reaction section; a liquid production filter element assembly is arranged in the catalyst settling section.

Optionally, the system comprises a gas, liquid and solid three-phase bubbling bed MMA synthesis reactor, which uses a nano gold catalyst to oxidize methyl methacrylaldehyde (MAL) with methanol and oxygen in the air in one step. The reaction produces MMA.

Optionally, the system further comprises an extraction separation column for separating the reaction mixture containing MMA, methanol, water, etc., which is produced from the reactor.

Optionally, the system further comprises a purge gas scrubber that uses salt-containing process water as a detergent to scrub and absorb methanol, MAL, etc. from the purge gas from the reactor.

Optionally, the system further comprises a methanol recovery column for recovering the wash liquor and methanol from the aqueous phase of the extractor.

Optionally, the system further comprises a methacrolein (MAL) dosing tank for configuring the process feed of the reactor to meet specific process requirements, including aldol ratio, pH, resistance The content of the polymerization agent ensures the safe and stable operation of the reaction.

In another aspect of the present application, there is provided a method of producing methyl methacrylate, characterized in that the method employs at least one of the devices described in any of the above.

Optionally, the method at least includes:

(a) passing the raw material into the reaction unit for reaction;

(b) The material obtained by the reaction in the reaction unit is passed through a separation unit and a recovery unit to carry out phase separation and recovery of the raw materials.

Optionally, the method at least includes:

1) arranging a catalyst slurry using deionized water and catalyst particles, and adding the catalyst slurry to a three-phase bubbling bed synthesis reactor through a catalyst feed port;

2) introducing nitrogen gas from the air feed line of the three-phase bubbling bed synthesis reactor, keeping the catalyst in a suspended state in the three-phase bubbling bed synthesis reactor, and establishing the reaction system pressure;

3) adding methanol to the extraction separation column;

4) adding a methanol aqueous solution to the methanol recovery column to establish a total reflux of methanol at the top of the column;

5) adding methanol to the methacrolein dosing tank, and then turning on the feed pump;

6) Establish a three-phase bubbling bed synthesis reactor - extraction separation tower - methanol recovery tower - methacrolein dosing tank - reaction liquid feed pump - three-phase bubbling bed synthesis reactor methanol solution cycle, while three The water in the phase bubble column synthesis reactor is replaced with methanol and excess water is removed in the methanol recovery column;

7) establishing a water circulation of the extraction separation tower-methanol recovery tower-chirping gas scrubbing tower by adding brine;

8) heating the reaction temperature of the circulating methanol into the reactor through the feed heater;

9) adding a methacrolein, a polymerization inhibitor, and a lye to the methacrolein dosing tank, so that the reactor feed reaches the aldol ratio, the pH value, and the polymerization inhibitor content required for the reaction;

10) gradually synthesizing the reactor into a three-phase bubbling bed into an oxygen-containing gas heated to a desired temperature, and simultaneously opening a heat take-up device of the reactor;

11) reacting methacrolein, methanol and oxygen into the three-phase bubbling bed synthesis reactor under the action of a catalyst;

12) After the reaction, the liquid product enters the extraction separation tower through the liquid phase outlet of the reactor for extraction and separation, and the crude MMA is taken from the top, and the subsequent purification system is introduced, and the methanol aqueous solution is taken out at the bottom to enter the methanol recovery tower to recover the methanol;

13) After the reaction, the gas is condensed and separated, and then washed to the washing tower for safe discharge, and the bottom is washed to enter the methanol recovery tower to recover methanol;

14) The process wastewater produced by the reaction is taken out at the bottom of the methanol recovery tower and cooled to the anhydrous treatment system.

Optionally, the catalyst slurry has a mass concentration of 5% to 50%; and the catalyst has a particle size of 5 nm to 500 nm;

The mass ratio of methacrolein to methanol in the methacrolein dosing tank is 1:1 to 10; the pH of the solution is 6 to 12; and the content of the polymerization inhibitor is 5 to 60 ppm;

In the purge gas scrubbing column and the extraction separation column, the salt content in the washing aqueous solution and the extracting aqueous solution is 5 wt% to 30 wt%;

The volume of oxygen in the oxygen-containing gas is 5-50%, and the oxygen-containing gas enters the reactor through the gas distributor;

The reaction temperature of the reaction is 20 to 200 ° C, and the reaction pressure is 0.1 to 10 MPa.

As a specific embodiment, the method uses methacrolein (MAL), methanol and an oxygen-containing gas as raw materials, and prepares MMA by one-step oxidation esterification using a nano-gold catalyst disclosed at home and abroad, and provides corresponding MMA purification. Separation method. Specifically, the method includes the following steps:

(1) A certain concentration of the particulate catalyst slurry is added to the reactor by using deionized water to reach a certain liquid level;

(2) introducing nitrogen gas from the air feed line of the reactor to keep the catalyst in a suspended state in the reactor while establishing a reaction system pressure;

(3) adding methanol to the extraction column to establish a certain liquid level;

(4) adding a methanol aqueous solution to the methanol recovery column to establish a total methanol reflux at the top of the column;

(5) adding methanol to the methacrolein (MAL) dosing tank, and opening the feed pump after reaching a certain liquid level;

(6) Establish a reactor-extraction column-methanol recovery tower-MAL dosing tank-feed pump-reactor methanol solution circulation, while replacing the water in the reactor with methanol and removing excess water in the methanol recovery tower ;

(7) establishing a water circulation of the extraction tower-methanol recovery tower-chiating gas scrubbing tower by adding a certain concentration of brine;

(8) heating the circulating methanol entering the reactor to a certain temperature by a feed heater;

(9) by adding methacrolein, a polymerization inhibitor, and an alkali solution to a methacrolein (MAL) dosing tank, so that the reactor feed reaches a prescribed aldol ratio, pH value, and polymerization inhibitor content;

(10) gradually introducing a certain concentration of oxygen-containing gas to the reactor after heating to a predetermined temperature, and simultaneously opening the heat extraction system of the reactor;

(11) The methacrolein (MAL), methanol and oxygen entering the reactor form MMA and trace by-products under the action of the catalyst;

(12) After the reaction, the liquid phase product (MMA, methanol, water, MAL, etc.) enters the extraction separation column through the liquid phase outlet of the reactor for extraction and separation, and the crude MMA (oil phase) is taken from the top and enters the subsequent purification system. Extracting methanol aqueous solution (aqueous phase) into a methanol recovery tower to recover methanol;

(13) After the reaction, the gas (nitrogen, a small amount of oxygen, methanol, MAL, etc.) is separated by condensation and then washed to the washing tower for safe discharge, and the bottom is washed to enter the methanol recovery tower to recover methanol;

(14) The process wastewater produced by the reaction is taken out at the bottom of the methanol recovery tower and cooled to the anhydrous treatment system.

Optionally, the catalyst adopts a nano gold catalyst prepared by the catalyst preparation method under the patent No. CN101815579; and a certain concentration, catalyst quality is arranged in the gas, liquid and solid three-phase bubbling bed MMA synthesis reactor of the present invention. The concentration range is 5% to 50%.

Optionally, the catalyst has a mass concentration of from 10% to 30%.

Optionally, in the catalyst, the catalyst particle size ranges from 5 nm to 500 nm.

Optionally, the catalyst particle size ranges from 20 nm to 100 nm.

Optionally, the mass ratio of methacrolein:methanol in the reactor feed solution is 1:1 to 10, preferably 1:2 to 5.

Optionally, the mass ratio of methacrolein:methanol:water in the reactor feed solution is 1-3:3:4-6.

Optionally, the pH of the solution in the reactor feed solution is from 6 to 12, preferably from 7 to 10.

Optionally, the alkali solution is added to at least one of potassium hydroxide, sodium hydroxide, and magnesium hydroxide.

Optionally, the reactor feed solution is added in an amount of from 5 to 60 ppm, preferably from 10 to 30 ppm.

Optionally, the inhibitor is added to at least one of hydroquinone, 1,4-ethyl-tert-butyl-4,2-nitrosophenol, and 2,4-dimethyl-6-tert-butylphenol. Kind.

Optionally, in the washing column and the extraction column, the salt content in the washing aqueous solution and the extracting aqueous solution is at a concentration of 5% to 30%, preferably 10% to 20%.

Alternatively, the salt is added to at least one of sodium carbonate, sodium hydrogencarbonate, sodium hydrogen phosphate, and sodium dihydrogen phosphate.

Optionally, in the oxygen-containing mixture, the non-oxygen gas is nitrogen, preferably, the content of oxygen is 5-50%, preferably 10-20%, preferably, the mixed gas is entered through the gas distributor. Reactor.

Alternatively, the reaction temperature of the reaction is 20 to 200 ° C, and the reaction pressure is 0.1 to 10 MPa. Preferably, the reaction temperature of the reaction is 60 to 90 ° C, and the reaction pressure is 0.2 to 0.8 MPa.

The application provides a reaction system and a separation method for preparing methyl methacrylate (MMA), the device comprises a gas, liquid and solid three-phase bubbling bed MMA synthesis reactor and an extraction separation tower connected to each other. The venting scrubber, the methanol recovery tower, the methacrolein (MAL) dosing tank, and the accessory equipment of the component system include a feed pump, a heater, a condenser, a gas-liquid separator, and the like. The present application also discloses a method for preparing methyl methacrylate (MMA), which uses methacrolein (MAL), methanol and oxygen in air as raw materials, and uses a domestic and international patented nano gold catalyst in one step. MMA is prepared by oxidative esterification and the corresponding MMA purification separation method is provided.

The beneficial effects that can be produced by this application include:

1) The reaction system and separation method for preparing methyl methacrylate (MMA) provided by the present application can realize continuous production of methyl methacrylate (MMA), and can quickly remove the heat of the material, which is favorable for methyl group. The direct oxidation of the acrolein esterification reaction;

2) The reaction system and separation method for preparing methyl methacrylate (MMA) provided by the present application can realize the stabilization of the catalyst by a proprietary gas-liquid distributor during the direct oxidative esterification reaction of methacrolein Suspension in a fully mixed state, while greatly reducing the wear of the catalyst particles and reducing the consumption of the catalyst;

3) The reaction system and separation method for preparing methyl methacrylate (MMA) provided by the present application can successfully separate methanol and methyl methacrylate in the extraction separation tower, and consume energy compared with the conventional separation method. Saving 30 to 50%;

4) The reaction system and separation method for preparing methyl methacrylate (MMA) provided by the present application have the advantages of high raw material conversion rate, high target product yield, and good selectivity of methyl methacrylate (MMA).

DRAWINGS

1 is a schematic diagram of a reaction system and a separation method for preparing methyl methacrylate (MMA) in a preferred embodiment of the present application;

2 is a schematic structural view of a production apparatus of the present application.

List of parts and reference numbers:

1-反应器1-reactor	2-第一分离器2-first separator	3-萃取分离塔3-extraction separation tower
4-甲醇回收塔4-methanol recovery tower	5-循环萃取液冷却器5-cycle extract cooler	6-MAL溶液配制罐6-MAL solution preparation tank
7-反应液进料泵7-reaction liquid feed pump	8-进料加热器8-feed heater	9-原料气加热器9-feed gas heater
10-驰放气冷凝器10-chirp gas condenser	11-第二分离器11-Second separator	12-驰放气洗涤塔12-Chi deflation scrubber
13-第一控制阀13-first control valve	14-第二控制阀14-second control valve	15-催化剂进料口15-catalyst feed port
16-驰放气出口16-Chi venting outlet	17-催化剂卸料口17-catalyst discharge port	18-取热装置18-heating device
19-气液分布器19-gas liquid distributor	20-液体采出过滤单元20-liquid extraction filter unit	21-气体分布器21-gas distributor
22-液体进料口22-liquid feed port

22-liquid feed port; 2'-gas feed port; 3'-liquid tapping port; 16-chirping gas outlet;

15-catalyst feed port; 17-catalyst discharge port; 7'-coolant inlet; 8'-coolant outlet; 9'-catalytic reaction section cylinder; 10'-catalyst settling cylinder; 19-gas liquid Dispenser; 20-liquid extraction filter unit; 18-heat take-up unit; 21-gas distributor.

detailed description

The reaction system of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the drawings and the description are intended to illustrate the reaction system of the present invention more clearly, without limiting the invention.

The present invention provides a reaction system and a separation method for preparing methyl methacrylate (MMA), the apparatus comprising a reactor 1 inlet and outlet connection, comprising: a purge gas outlet 16 on the reactor 1 and the purge The gas condenser 21 is connected, the liquid extraction filter unit 20 on the reactor 1 is connected to the first separator 2, and the bottom liquid inlet 22 on the reactor 1 is connected to the feed heater 8; The inside of the first reactor is provided with a heat extraction device.

Other devices are connected as follows:

The oil phase discharge port of the first separator 2 is connected to the lower feed port of the extraction separation column 3;

The bottom discharge port of the extraction separation column 3 is connected to the feed port of the methanol recovery column 4;

The bottom discharge port of the methanol recovery column 4 is connected to the feed port of the circulating extract liquid cooler 5;

The discharge port of the circulating extract liquid cooler 5 is connected to the feed port of the upper portion of the extraction separation column 3 and the purge gas scrubbing tower 12;

The top discharge port of the methanol recovery tower 4 is connected to the feed port of the MAL solution preparation tank 6;

The discharge port of the MAL solution preparation tank 6 is connected to the inlet of the reaction liquid feed pump 7;

The outlet of the reaction liquid feed pump 7 is connected to the inlet of the feed heater 8; and constitutes a liquid system circulation with the reactor 1;

The discharge port of the purge gas condenser 10 is connected to the inlet of the second separator 11;

The bottom discharge port of the second separator 11 is connected to the inlet of the MAL solution preparation tank 6;

The top discharge port of the second separator 11 is connected to the inlet of the second control valve 14;

The outlet of the second control valve 14 is connected to the inlet of the purge gas scrubbing tower 12;

The top discharge port of the first separator 2 is connected to the inlet of the first control valve 13;

The main branch of the aqueous phase discharge port of the first separator 2 is connected to the inlet of the MAL solution preparation tank 6, and the secondary branch is connected to the inlet of the methanol recovery tower 4;

The outlet of the first control valve 13 is connected to the inlet of the purge gas scrubbing tower 12;

a coarse MMA production outlet and a connecting line are arranged at the top of the extraction separation tower 3;

a top of the purge gas scrubbing tower 12 is provided with a purge gas vent and a connecting line;

The MAL solution preparation tank 6 is provided with a raw material MAL, a methanol, a polymerization inhibitor, a feed inlet of a lye and a connecting line;

In the present invention, a catalyst slurry inlet is provided in the upper portion of the reactor for adding fresh catalyst slurry disposed in water during initial operation and operation of the apparatus; and at the same time, a catalyst slurry recovery port is disposed in the lower portion of the reactor for device parking. The catalyst slurry is produced during the process or part of the old catalyst is produced during the operation.

In a preferred embodiment of the present invention, the reactor is a gas-liquid-liquid three-phase bubbling bed reactor, comprising a catalytic reaction section and a catalyst settling section two-stage cylinder; a gas distributor (composed of a distribution main pipe and a branch pipe and a distribution cap), a gas-liquid distributor (composed of a distribution plate and a plurality of distributor units), a heat-receiving device (a plurality of heat-receiving units are connected in parallel), and a catalyst settling cylinder A liquid production filtration unit (composed of multiple sets of filters in parallel) is provided; it is suitable for direct oxidative esterification of methyl methacrylate under the conditions of temperature 20-200 ° C and pressure of 0.1-10.0 MPa.

The catalytic reaction section of the reactor has a diameter ranging from 50 to 5000 mm, and a heat collecting device, a gas distributor, and a gas-liquid distributor are disposed within a length ranging from 300 to 30,000 m.

In a preferred embodiment of the present invention, the catalytic reaction section is provided with a heat taking device, wherein the operating medium of the heat taking device is a cooling liquid, and the cooling liquid may be water, brine or ethylene glycol aqueous solution. First, the operating medium in the cylinder includes a raw material solution, a catalyst solid particle, a nitrogen-oxygen mixed gas, and a reaction product methyl methacrylate.

The heat taking device is used for the cooling of the reactor, and the heat removal device is used to achieve rapid deheating, thereby improving the selectivity of the methyl methacrylate product.

In a preferred embodiment of the present invention, the heat take-up device is composed of a manifold in which the coolant enters and exits the reactor and a plurality of groups of heat take-up units are connected in parallel.

Each group of heat take-up units consists of a downcomer and a number of risers;

The function of the heat taking unit is to increase the flow rate of the cooling liquid, enhance the heat transfer efficiency, and also function to increase the reaction efficiency by agglomerating the rising bubbles of the oxygen-containing gas mixture in the reactor cylinder to form a large bubble.

In a preferred embodiment of the present invention, the coolant inlet and the coolant outlet are disposed on the outer wall of the reactor cylinder; the inlet manifold and the outlet manifold of the coolant are disposed at the upper portion of the cylinder, and the coolant enters through the inlet. The descending pipe of each heat taking unit installed inside the cylinder passes through the rising pipe and exchanges heat and returns to the coolant outlet pipe to flow out to cool the reaction system.

In a preferred embodiment of the present invention, the heat take-up unit is vertically disposed in the reactor cylinder, uniformly distributed in a square shape, and the distance between each heat take-up unit is 50-1000 mm, for example, 50 mm, 100 mm, 200 mm, 300 mm. Any value in the range of any two of 400mm, 500mm, 600mm and above. The spacing between the heat take-up units may be equal or unequal. Preferably, the spacing between the heat take-up units is equal.

In a preferred embodiment of the present invention, a drop tube on the heat take-up unit has a diameter ranging from 20 to 100 mm, and the number of risers is 2-6, and the lower portion is connected to the down tube, and is circularly distributed and raised. The diameter of the pipe is 1/6 to 1/4 of the diameter of the down pipe. The riser pipe joins the top pipe to form an outlet pipe. The diameter of the outlet pipe is the same as the diameter of the down pipe. The length of the heat take-up unit ranges from 200 to 6000 mm. Groups or groups are installed inside the reactor.

In a preferred embodiment of the present invention, a gas distributor is disposed at the bottom of the catalytic reaction section of the reactor, and functions to form a uniform gas-liquid mixture of the feed mixed gas and the feed liquid;

The gas distributor comprises a distributor main pipe and a distributor branch pipe.

In a preferred embodiment of the invention, the gas distributor head has a diameter of 20-300 mm and a length of 50-5000 mm.

In a preferred embodiment of the invention, the number of distributor branches is 2-200, the diameter is 50-100 mm, and the length is 100-2500 mm, and each distributor branch is connected to the distributor main pipe.

In a preferred embodiment of the present invention, the number of openings in the distributor branch is 20-500, the diameter is 0.2-20 mm, and the opening ratio is 20%-40% of the total tube cross-sectional area.

In a preferred embodiment of the present invention, a gas-liquid distributor is disposed at the bottom of the catalytic reaction section of the reactor, and a distribution plate and a distribution cap are disposed;

The working mechanism of the distributor:

The high specific surface microporous interface effect of the distribution cap is used to achieve high dispersion of the gas-liquid mixture and form a uniform jet, and the catalyst particles are suspended in the reactor to achieve high-efficiency mass transfer and heat transfer of the mixed gas mixture and the catalyst particles;

In a preferred embodiment of the present invention, the distribution unit is a hollow cylinder or a cone processed from at least one of a metal sintered wire mesh, a metal sintered powder, and a ceramic powder, and the average pore diameter on the distribution unit is Between 5 and 20 μm, the opening ratio is between 0.02% and 1.5%; the number of the dispensing caps is 20-1000.

In a preferred embodiment of the present invention, the dispensing cap has a diameter of 10-50 mm and a length or height of 20-50 mm, and the distribution cap is arranged on the distribution plate from at least one of an equilateral triangle and a square. The spacing is 40-100 mm.

In a preferred embodiment of the present invention, the catalyst settling section of the reactor has a diameter of 1.5 to 2.0 times that of the catalytic reaction section and a length of 0.2 to 0.6 of the catalytic reaction section, and a liquid production filtration unit is disposed therein.

In a preferred embodiment of the present invention, the liquid extraction filter unit is composed of 2 to 8 sets of filters and connecting tubes thereof, and the filter has a diameter of 50-200 mm and a length or height of 100-500 mm. The number of group filters is 2 to 10.

In a preferred embodiment of the present invention, the filter is a hollow cylinder or a cone processed by at least one of a metal sintered wire mesh, a metal sintered powder, and a ceramic powder, and the average filtration precision is 5-20 μm. .

In a preferred embodiment of the invention, the liquid recovery filter unit functions to effect efficient separation of the reaction mixture liquid and the catalyst solid particles. In practice, each group of filters is equipped with a backflush and backwash system to avoid filter blockage.

The present application is described in detail below with reference to the embodiments, but the application is not limited to the embodiments.

The starting materials and catalysts in the examples of the present application are commercially available unless otherwise stated.

The conversion rate is calculated as follows:

(Amount of converted reactant / initial amount of the reactant) * 100%.

The yield is calculated as follows:

(The amount of product actually obtained / theoretically the amount of product obtained) * 100%.

Example 1 Methyl methacrylate reaction device

As shown in FIG. 1, the apparatus comprises a three-phase bubbling bed synthesis reactor, a three-phase bubbling bed synthesis reactor inlet and outlet connection, a first separator, an extraction separation tower, a raw material recovery tower, a circulating extract liquid cooler, Raw material liquid preparation tank, reaction liquid feed pump, feed heater, feed gas heater, purge gas condenser, second separator, purge gas scrubber, first control valve, second control valve, catalyst Feed port, purge gas outlet, catalyst discharge port, heat take-off device, gas liquid distributor, liquid production filter unit, gas distributor, liquid feed port;

The main branch of the water phase discharge port of the first separator is connected to the inlet of the raw material liquid preparation tank, and the secondary branch is connected to the feed port of the methanol recovery tower;

The raw material liquid preparation tank is provided with a feeding port and a connecting line of each raw material;

The process wastewater is removed from the bottom of the raw material recovery tower;

The raw material liquid preparation tank is a methacrolein liquid distribution tank;

The raw material recovery tower is a methanol recovery tower;

The feedstock MAL feed port, the methanol feed port, the polymerization inhibitor feed port, the feed inlet of the lye, and the connection line are located on the methacrolein dosing tank.

Wherein, the three-phase bubbling bed synthesis reactor comprises a liquid feed port, a gas feed port, a liquid production port, a purge gas outlet, a catalyst slurry inlet, a catalyst slurry outlet, a coolant inlet, a coolant outlet, Catalytic reaction section cylinder, catalyst settling section cylinder, gas-liquid distributor, liquid production filtering unit, heat taking device, gas distributor.

Using the apparatus shown in Figure 2, the reactor structure:

Reactor catalytic reaction section: cylinder height 1000mm, diameter 100mm;

The internal arrangement of the cylinder is as follows:

1. Heat taking unit: vertically located in the reactor barrel; the number is 1 group, the length is 800mm, the diameter of the down tube is 20mm, the diameter of the riser is 6mm, the number is 4, and the diameter of the riser pipe is 20mm;

2. Gas distributor: the diameter of the main pipe is 10 mm; the length is 80 mm;

The branch pipe has a diameter of 5 mm and a number of four;

The aperture of the opening on the branch pipe is 0.5 mm; the number of openings is 12;

Each branch pipe is connected to the main pipe;

3. Gas-liquid distributor: the diameter of the distribution plate is 100mm;

The distribution plate has a distribution cap: the number is 8; it is a metal sintered wire mesh hollow cylinder;

The average pore size on the distribution plate was 0.02 mm; the open cell ratio was 0.05%;

The dispensing cap has a diameter of 5 mm and a height of 10 mm;

The distribution caps are arranged on the distribution plate in an equilateral triangle with a pitch of 15 mm.

Reactor catalytic settling section: cylinder height 500mm, diameter 200mm;

The internal arrangement of the cylinder is as follows:

Liquid extraction filter unit: consists of a set of filters and their connecting tubes, the filter has a diameter of 50 mm and a length of 200 mm, and the number of filters per set is four.

The filter is a hollow cylinder machined from a metal sintered wire mesh with an average filtration accuracy of 5 μm.

The upper part of the reactor is provided with a catalyst slurry inlet (adding port) for adding fresh catalyst slurry disposed in water during initial operation and operation of the apparatus; and at the same time, a catalyst slurry outlet (harvesting outlet) is disposed at the lower part of the reactor. It is used to extract catalyst slurry during the process of stopping the plant or to collect part of the old catalyst during the operation.

Example 2

Using the reaction apparatus (reaction system and separation method) provided in Example 1, methyl methacrylate was prepared under different reaction conditions with different feed conditions and catalyst contents, while continuous separation test, feed conditions and catalyst contents were as follows. Table 1 shows the reaction conditions as shown in Table 2.

The reaction system and the separation method specifically include:

1) a certain concentration of particulate catalyst slurry (catalyst solid particle nano-gold 30% aqueous solution) is added to the reactor by using deionized water to reach 80% liquid level;

2) introducing nitrogen gas from the air feed line of the reactor to keep the catalyst in a suspended state in the reactor while establishing a reaction system pressure;

3) Add methanol to the extraction column to establish a certain liquid level (80% liquid level);

4) adding a methanol aqueous solution to the methanol recovery column to establish a total methanol reflux at the top of the column;

5) Add methanol to the methacrolein (MAL) dosing tank, and open the feed pump after reaching a certain liquid level (80% liquid level);

6) Establish a reactor-extraction column-methanol recovery tower-MAL dosing tank-feed pump-reactor to a certain methanol concentration aqueous solution cycle, while replacing the water in the reactor with methanol and removing excess in the methanol recovery tower Water

7) establishing a water circulation of the extraction tower-methanol recovery tower-chirping gas scrubbing tower by adding a certain concentration of brine (15 wt% aqueous NaCl solution);

8) heating the circulating methanol entering the reactor to the reaction temperature by the feed heater;

9) By adding methacrolein, a polymerization inhibitor (1,4-ethyl tert-butyl-4,2-nitrosophenol), a lye (magnesium hydroxide) to a methacrolein (MAL) dosing tank ), so that the reactor feed reaches the specified aldol ratio, pH value, polymerization inhibitor content;

10) gradually introducing a certain concentration of oxygen-containing gas (nitrogen, 85 vol.%; oxygen 15 vol.%) to the reactor after heating to the reaction temperature, and simultaneously opening the heat extraction system of the reactor;

11) The methacrolein (MAL), methanol and oxygen entering the reactor form MMA and trace by-products under the action of the catalyst;

12) After the reaction, the liquid phase product (MMA, methanol, water, MAL, etc.) enters the extraction separation column through the liquid phase outlet of the reactor for extraction and separation, and the crude MMA (oil phase) is taken from the top, and the subsequent purification system is adopted. Extracting methanol from aqueous methanol (aqueous phase) into methanol recovery column;

13) After the reaction, the gas (nitrogen, a small amount of oxygen, methanol, MAL, etc.) is separated by condensation, and then washed to the washing tower for safe discharge, and the bottom is washed to enter the methanol recovery tower to recover methanol;

Wherein the polymerization inhibitor is 1,4-ethyl-tert-butyl-4,2-nitrosophenol;

The catalyst is nano gold; the preparation method provides a nano gold catalyst prepared by a catalyst preparation method according to the CN101815579 patent.

Table 1 Feed conditions and catalyst concentration

Table 2 Reaction conditions

实验编号Experiment number	温度(℃)Temperature (°C)	压力(MPa)Pressure (MPa)
11	6060	0.20.2
22	8080	0.40.4
33	100100	0.60.6
44	120120	0.60.6

The reaction results are shown in Table 3:

Table 3 Reaction results

The results of continuous separation experiments are shown in Table 4:

Table 4 Separation results

It can be seen from the above reaction results that the methyl methacrylate can be obtained with high yield and selectivity by the method of the invention, and the separation of methanol, water, methyl methacrylate and the like in the reaction mixture can be efficiently realized, and is strictly Controlling the methanol content of the purge gas ensures safe production of the unit.

The above description is only a few examples of the present application, and is not intended to limit the scope of the application. However, the present application is disclosed in the preferred embodiments, but is not intended to limit the application, any person skilled in the art, It is within the scope of the technical solution to make a slight change or modification with the technical content disclosed above, which is equivalent to the equivalent embodiment, without departing from the technical scope of the present application.

Claims

A chemical reaction device, characterized in that the device comprises:

Reaction unit, separation unit, recovery unit;

The reaction unit, the separation unit, and the recovery unit are sequentially connected;

Wherein the reaction unit comprises a three-phase bubbling bed synthesis reactor.
The apparatus according to claim 1, wherein said three-phase bubbling bed synthesis reactor comprises: a catalytic reaction section and a catalyst settling section;

a cross-sectional area of at least one location of the catalytic reaction section that is less than a cross-sectional area of at least one location of the settling section of the catalyst;

The catalytic reaction zone is located below the settling section of the catalyst.
The apparatus according to claim 1, wherein said separation unit comprises a first separator and an extraction separation column;

The first separator is connected to the reaction unit;

The extraction separation column is coupled to the first separator.
The apparatus according to claim 3, wherein a liquid recovery port of said reaction unit is connected to an inlet of said first separator;

The oil phase discharge port of the first separator is connected to the lower feed port of the extraction separation column.
The apparatus according to claim 3, wherein the top of the extraction separation column has a crude product recovery port and a connecting line.
The apparatus according to claim 3, wherein said separation unit comprises a purge gas scrubbing tower;

A gas phase outlet of the first separator is coupled to an inlet of the purge gas scrubber.
The apparatus according to claim 6, wherein the top of the purge gas scrubbing tower is provided with a purge gas vent and a connecting line.
The apparatus according to claim 6, wherein said separation unit further comprises a second separator;

The reaction unit, the second separator, and the purge gas scrubbing column are connected in sequence.
The apparatus according to claim 8, wherein a purge gas outlet of said reaction unit is connected to an inlet of said second separator;

The top discharge port of the second separator is connected to the inlet of the purge gas scrubber.
The apparatus according to claim 8, wherein the purge gas outlet of the reaction unit is connected to the second separator through a purge gas condenser;

a purge gas outlet of the three-phase bubbling bed synthesis reactor is connected to a feed port of the purge gas condenser;

a discharge port of the purge gas condenser is connected to an inlet of the second separator;

The second separator is connected to the purge gas scrubbing tower through a second control valve;

a top discharge port of the second separator is connected to an inlet of the second control valve;

An outlet of the second control valve is coupled to an inlet of the purge gas scrubber.
The apparatus according to claim 1, wherein said separation unit comprises a purge gas scrubbing tower;

The inlet of the purge gas scrubber is connected to the reaction unit.
The apparatus according to claim 11, wherein said separating unit further comprises a purge gas condenser and a second separator;

a purge gas outlet of the three-phase bubbling bed synthesis reactor is connected to a feed port of the purge gas condenser;

a discharge port of the purge gas condenser is connected to an inlet of the second separator;

The second separator is connected to the purge gas scrubbing tower through a second control valve;

a top discharge port of the second separator is connected to an inlet of the second control valve;

An outlet of the second control valve is coupled to an inlet of the purge gas scrubber.
The apparatus according to claim 1, wherein said recovery unit comprises a raw material recovery column;

The raw material recovery column is connected to the separation unit.
The apparatus according to claim 13, wherein said separation unit comprises an extraction separation column and a purge gas scrubbing tower;

An inlet of the raw material recovery tower is connected to an outlet of the purge gas scrubbing tower;

The bottom discharge port of the extraction separation column is connected to the feed port of the raw material recovery column.
The apparatus according to claim 14, wherein said separation unit further comprises a first separator;

An inlet of the first separator is connected to a liquid recovery port of the three-phase bubbling bed synthesis reactor;

An oil phase discharge port of the first separator is connected to a lower feed port of the extraction separation column;

The aqueous phase outlet of the first separator is connected to the feed port of the raw material recovery column.
The apparatus according to claim 14, wherein said recovery unit further comprises a circulating extract liquid cooler;

a bottom discharge port of the raw material recovery tower is connected to a feed port of the circulating extract liquid cooler;

The discharge port of the circulating extract cooler is connected to the upper feed port of the extraction separation column and the upper feed port of the purge gas scrubber.
The device according to claim 1, wherein said device further comprises a stock preparation unit;

The preparation unit is connected to the reaction unit;

The stock preparation unit includes a feed port of each raw material and a connecting line.
The apparatus according to claim 17, wherein said preparation unit is connected to said reaction unit through a reaction liquid feed pump and a feed heater;

The discharge port of the preparation unit is connected to the inlet of the reaction liquid feed pump;

An outlet of the reaction liquid feed pump is connected to an inlet of the feed heater;

The outlet of the feed heater is connected to the feed port of the three-phase bubbling bed synthesis reactor.
The apparatus according to claim 17, wherein said recovery unit comprises a raw material recovery column;

The raw material recovery tower is connected to the separation unit;

The top discharge port of the raw material recovery tower is connected to the feed port of the stock preparation unit.
The apparatus according to claim 17, wherein said separation unit comprises a purge gas scrubber, a purge gas condenser and a second separator;

The three-phase bubbling bed synthesis reactor, the purge gas condenser, the second separator, and the purge gas are sequentially connected;

The bottom discharge port of the second separator is connected to the inlet of the stock preparation unit.
The apparatus according to claim 17, wherein the separation unit comprises a first separator and an extraction separation column;

The first separator is connected to the reaction unit;

The extraction separation column is connected to the first separator;

The water phase discharge port branch of the first separator is connected to the inlet of the stock preparation unit.
The apparatus according to claim 1, wherein said apparatus comprises a three-phase bubbling bed synthesis reactor, a three-phase bubbling bed synthesis reactor inlet and outlet connection, a first separator, an extraction separation column, and a raw material recovery tower. , circulating extract liquid cooler, raw material liquid preparation tank, reaction liquid feed pump, feed heater, feed gas heater, purge gas condenser, second separator, purge gas scrubber, first control valve, a second control valve, a catalyst feed port, a purge gas outlet, a catalyst discharge port, a heat take-off device, a gas liquid distributor, a liquid production filter unit, a gas distributor, and a liquid feed port;

a purge gas outlet of the three-phase bubbling bed synthesis reactor is connected to the purge gas condenser;

a liquid extraction filter unit of the three-phase bubbling bed synthesis reactor is connected to the first separator;

a bottom liquid inlet of the three-phase bubbling bed synthesis reactor is connected to the feed heater;

The catalyst feed port, the purge gas outlet, the catalyst discharge port, and the liquid feed port are all located on an outer wall of the three-phase bubbling bed synthesis reactor;

The heat taking device, the gas liquid distributor, the liquid production filtering unit, and the gas distributor are all located in the three-phase bubbling bed synthesis reactor;

The oil phase discharge port of the first separator is connected to the lower feed port of the extraction separation column;

The bottom discharge port of the extraction separation column is connected to the feed port of the raw material recovery tower;

a bottom discharge port of the raw material recovery tower is connected to a feed port of the circulating extract liquid cooler;

The discharge port of the circulating extract liquid cooler is connected to the inlet of the upper portion of the extraction separation column and the inlet of the upper portion of the purge column;

The top discharge port of the raw material recovery tower is connected to the feed port of the raw material liquid preparation tank;

The discharge port of the raw material liquid preparation tank is connected to the inlet of the reaction liquid feed pump;

The outlet of the reaction liquid feed pump is connected to the inlet of the feed heater;

The outlet of the feed heater is connected to the liquid feed port and constitutes a liquid system circulation with the three-phase bubbling bed synthesis reactor;

The discharge port of the purge gas condenser is connected to the inlet of the second separator;

a bottom discharge port of the second separator is connected to an inlet of the raw material liquid preparation tank;

a top discharge port of the second separator is connected to an inlet of the second control valve;

The outlet of the second control valve is connected to the inlet of the purge gas scrubbing tower;

a top discharge port of the first separator is connected to an inlet of the first control valve;

The main branch of the water phase discharge port of the first separator is connected to the inlet of the raw material liquid preparation tank, and the secondary branch is connected to the feed port of the raw material recovery tower;

The outlet of the first control valve is connected to the inlet of the purge gas scrubbing tower;

An inlet of the raw material recovery tower is connected to an outlet of the purge gas scrubbing tower;

a crude product production outlet and a connecting line are arranged at the top of the extraction separation tower;

a top of the purge gas scrubbing tower is provided with a purge gas vent and a connecting pipeline;

The raw material liquid preparation tank is provided with a feed port and a connection line of each raw material.
The apparatus of claim 22 wherein said process wastewater is removed from the bottom of the feed recovery column.
The apparatus according to claim 22, wherein said raw material liquid preparation tank is a methacrolein liquid preparation tank;

The raw material recovery tower is a methanol recovery tower;

The methacrolein dosing tank comprises a raw material MAL feed port, a methanol feed port, a polymerization inhibitor feed port, a lye feed port and a connecting line.
A reaction apparatus for producing methyl methacrylate, comprising at least one of the devices according to any one of claims 1 to 24.
A method of producing methyl methacrylate, characterized in that the method employs at least one of the devices according to any one of claims 1 to 24.
The method of claim 26 wherein said method comprises at least:

(a) passing the raw material into the reaction unit for reaction;

(b) The material obtained by the reaction in the reaction unit is passed through a separation unit and a recovery unit to carry out phase separation and recovery of the raw materials.
The method of claim 26 wherein said method comprises at least:

1) arranging a catalyst slurry using deionized water and catalyst particles, and adding the catalyst slurry to a three-phase bubbling bed synthesis reactor through a catalyst feed port;

2) introducing nitrogen gas from the air feed line of the three-phase bubbling bed synthesis reactor, keeping the catalyst in a suspended state in the three-phase bubbling bed synthesis reactor, and establishing the reaction system pressure;

3) adding methanol to the extraction separation column;

4) adding a methanol aqueous solution to the methanol recovery column to establish a total reflux of methanol at the top of the column;

5) adding methanol to the methacrolein dosing tank, and then turning on the feed pump;

6) Establish a three-phase bubbling bed synthesis reactor - extraction separation tower - methanol recovery tower - methacrolein dosing tank - reaction liquid feed pump - three-phase bubbling bed synthesis reactor methanol solution cycle, while three The water in the phase bubble column synthesis reactor is replaced with methanol and excess water is removed in the methanol recovery column;

7) establishing a water circulation of the extraction separation tower-methanol recovery tower-chirping gas scrubbing tower by adding brine;

8) heating the reaction temperature of the circulating methanol into the reactor through the feed heater;

9) adding a methacrolein, a polymerization inhibitor, and a lye to the methacrolein dosing tank, so that the reactor feed reaches the aldol ratio, the pH value, and the polymerization inhibitor content required for the reaction;

10) gradually synthesizing the reactor into a three-phase bubbling bed into an oxygen-containing gas heated to a desired temperature, and simultaneously opening a heat take-up device of the reactor;

11) reacting methacrolein, methanol and oxygen into the three-phase bubbling bed synthesis reactor under the action of a catalyst;

12) After the reaction, the liquid product enters the extraction separation tower through the liquid phase outlet of the reactor for extraction and separation, and the crude MMA is taken from the top, and the subsequent purification system is introduced, and the methanol aqueous solution is taken out at the bottom to enter the methanol recovery tower to recover the methanol;

13) After the reaction, the gas is condensed and separated, and then washed to the washing tower for safe discharge, and the bottom is washed to enter the methanol recovery tower to recover methanol;

14) The process wastewater produced by the reaction is taken out at the bottom of the methanol recovery tower and cooled to the anhydrous treatment system.
The method according to claim 28, wherein the catalyst slurry has a mass concentration of 5% to 50%; and the catalyst has a particle size of 5 nm to 500 nm;

The mass ratio of methacrolein to methanol in the methacrolein dosing tank is 1:1 to 10; the pH of the solution is 6 to 12; and the content of the polymerization inhibitor is 5 to 60 ppm;

In the purge gas scrubbing column and the extraction separation column, the salt content in the washing aqueous solution and the extracting aqueous solution is 5 wt% to 30 wt%;

The volume of oxygen in the oxygen-containing gas is 5-50%, and the oxygen-containing gas enters the reactor through the gas distributor;

The reaction temperature of the reaction is 20 to 200 ° C, and the reaction pressure is 0.1 to 10 MPa.