CN218412405U

CN218412405U - Catalyst evaluation device for preparing dimethyl carbonate by gas-phase methanol carbonyl oxidation method

Info

Publication number: CN218412405U
Application number: CN202121483663.5U
Authority: CN
Inventors: 卢健余; 冯锦迪; 高翔; 李龙; 周益诚; 宋士金; 王旭; 任志明; 白木日根; 郝家善; 李政
Original assignee: Inner Mongolia Yigao Coal Chemical Technology Co ltd
Current assignee: Inner Mongolia Yigao Coal Chemical Technology Co ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-01-31
Anticipated expiration: 2031-06-30

Abstract

The utility model discloses a catalyst evaluation device of gaseous phase methyl alcohol carbonyl oxidation legal system dimethyl carbonate, it includes process gas unit, carbonylation reaction unit and gas analyzer, and carbonylation reaction unit includes blender, heater, first reactor, second reactor and third reactor. The advantages are that: 1. the three reactors of the carbonylation reaction unit can be connected in parallel for independent test and can also be used in series, the test method is flexible and various, and the test efficiency is high; 2. the circulating gas actually generated by a factory is treated and then used for the evaluation test of the catalyst, so that an actual industrial system can be simulated to the greatest extent, and the reference value of the test is improved; 3. meanwhile, the blending gas source is arranged, the type and the dosage of the blending gas source can be adjusted according to test requirements, and the circulating gas output by the process gas unit has higher regulation and control elasticity.

Description

Catalyst evaluation device for preparing dimethyl carbonate by gas-phase methanol carbonyl oxidation method

The technical field is as follows:

the utility model belongs to the technical field of catalyst engineering development and dimethyl carbonate production, concretely relates to catalyst evaluation device of gaseous phase methyl alcohol carbonyl oxidation legal system dimethyl carbonate.

Background art:

the main process for preparing ethylene glycol from coal is an oxalate method, namely a process for preparing polyester-grade ethylene glycol by taking coal as a raw material, respectively obtaining CO and H2 through gasification, transformation, purification, separation and purification, wherein the CO is synthesized through catalytic coupling and refined to produce oxalate, and then carrying out hydrogenation reaction with the H2 and refining. Product diversification of the oxalate synthetic process route and development of downstream products of oxalate: the related products and processes for preparing ethylene glycol from coal, which are being developed and have been successfully developed at present, include fuel ethanol from coal, synthetic oxalic acid, dimethyl carbonate, diphenyl carbonate and the like.

Among them, dimethyl carbonate is a new green chemical raw material, which is environmentally friendly and has better reaction activity, so that it can be used to replace the traditional oily solvent and toxic phosgene as raw material for producing Polycarbonate (PC). In view of the wide application range and the green and environment-friendly characteristic of dimethyl carbonate, the development of related industries in recent years drives the rapid increase of the demand of domestic dimethyl carbonate. The gas-phase methanol carbonyl oxidation method has the advantages of less generated byproducts, lower equipment requirement and low production cost, and is an important route for synthesizing the dimethyl carbonate.

The gas phase methanol carbonylation oxidation process is divided into two steps, and the reaction equation is as follows:

esterification reaction:

carbonylation reaction:

CO+2CH ₃ ONO→(CH ₃ O) ₂ CO+2NO

and (3) total reaction:

the process takes methanol, carbon monoxide, oxygen and nitric oxide as raw materials, methyl nitrite as an intermediate, a main product is organic dimethyl carbonate, and byproducts are dimethyl oxalate, dimethoxymethane and methyl formate.

Among them, the carbonylation reaction requires a catalyst, and the catalyst needs to be evaluated by a test means before the production. In the prior art for evaluating the dimethyl carbonate catalyst, raw material gases are mixed in proportion and then input into a single reaction tube for carbonylation reaction. And sampling points are arranged at the inlet and the outlet, and components are sampled and analyzed regularly for calculating the conversion rate, selectivity and other important data for evaluating the catalyst. The prior art mainly has two problems: 1. the reaction device can only evaluate a single catalyst under the environment of single experimental condition, the test method is single, and the test efficiency is low. 2. The existing catalyst evaluation device mostly adopts a single reaction tube to carry out carbonylation reaction, process gas is mixed by pure gas, industrial working conditions cannot be completely simulated, although the selectivity and the catalytic effect of main reactants under the action of a catalyst can be better reflected, the difference is too large compared with an industrial system, so that the laboratory-level evaluation of the catalyst can be carried out only, and the reference value for realizing industrialization in the future cannot be maximized.

The utility model has the following contents:

the utility model aims to provide a catalyst evaluation device of gaseous phase methyl alcohol carbonyl oxidation legal system dimethyl carbonate.

The utility model discloses implement by following technical scheme: a catalyst evaluation device for preparing dimethyl carbonate by a gas-phase methanol carbonyl oxidation method comprises a process gas unit, a carbonylation reaction unit and a gas analyzer, wherein the carbonylation reaction unit comprises a mixer, a heater, a first reactor, a second reactor and a third reactor, a process gas output port of the process gas unit is communicated with an inlet pipeline of the mixer, an outlet of the mixer is communicated with an inlet of the heater through a first reducing valve, an outlet of the heater is communicated with an inlet of a gas feed pipe, and a mass flowmeter is installed on the gas feed pipe; the outlet of the air feed pipe is respectively communicated with the inlets of the first reactor, the second reactor and the third reactor through branch pipes, and branch pipe control valves are arranged on the branch pipes; the outlet of the first reactor is respectively communicated with the inlets of a first communicating pipe and a first discharging pipe, and the outlet of the first communicating pipe is communicated with the inlet of the second reactor; the outlet of the second reactor is respectively communicated with the inlets of a second communicating pipe and a second discharge pipe, and the second communicating pipe is communicated with the inlet of the third reactor; the outlet of the third reactor is communicated with the inlet of a third discharge pipe; the outlets of the first discharge pipe, the second discharge pipe and the third discharge pipe are communicated with the inlet of a discharge header pipe; reaction control valves are arranged on the first communicating pipe, the first discharging pipe, the second communicating pipe, the second discharging pipe and the third discharging pipe; the outlet of the heater, the outlets of the first reactor, the second reactor and the third reactor are respectively provided with a first sampling point, a second sampling point, a third sampling point and a fourth sampling point, the first sampling point, the second sampling point, the third sampling point and the fourth sampling point are respectively communicated with the sampling ports of the four gas analyzers in a one-to-one correspondence mode through sampling pipes, and sampling control valves are installed on the sampling pipes.

Furthermore, the process gas unit comprises a rich MN processing unit, a rich NO processing unit and at least one gas source for gas mixing, each gas source for gas mixing is respectively communicated with an inlet of one gas mixing and distributing pipe, a gas mixing and distributing pressure reducing valve and a gas mixing and distributing control valve are arranged on the gas mixing and distributing pipe, and outlets of the rich MN processing unit, the rich NO processing unit and the gas mixing and distributing pipe are process gas output ports.

Further, the MN-rich processing unit comprises an MN supercharger, an MN condenser, an MN buffer tank, an MN liquid storage tank, an MN pump, an MN back pressure valve, an MN vaporizer, an MN gas storage tank, an MN pneumatic regulating valve and an MN control valve which are sequentially connected; and the outlet of the MN control valve is a process gas output port.

Furthermore, an outlet of the MN control valve is provided with a fifth sampling point, the fifth sampling point is communicated with a sampling port of the gas analyzer through a sampling pipe, and the sampling pipe is provided with a sampling control valve.

Further, the NO-rich treatment unit comprises an NO booster, an NO condenser, an NO buffer tank, an NO gas storage tank, an NO pressure reducing valve and an NO control valve which are connected in sequence; and the outlet of the NO control valve is a process gas output port.

Furthermore, an outlet of the NO control valve is provided with a sixth sampling point, the sixth sampling point is communicated with a sampling port of the gas analyzer through a sampling pipe, and the sampling pipe is provided with a sampling control valve.

Further, the blending gas source comprises at least one of a CO gas source, an N2 gas source, a CH4 gas source and a CO2 gas source.

Further, the device also comprises a separation unit for separating and recovering liquid-phase products, and the outlet of the discharge header pipe is communicated with the inlet of the separation unit.

Furthermore, the separation unit comprises a product cooler, a product buffer tank and a product storage tank which are sequentially connected, an inlet of the product cooler is communicated with an outlet of the discharge header pipe, an exhaust port of the product buffer tank is communicated with an inlet pipeline of the liquid-separating tank, and an exhaust port of the liquid-separating tank is sequentially communicated with a tail gas control valve and a tail gas flow meter.

Further, the gas mixing device further comprises a preheater arranged between the process gas output port and the inlet of the mixer, the process gas output port is communicated with the inlet of the preheater, and the outlet of the preheater is communicated with the inlet of the mixer.

The utility model has the advantages that: 1. the three reactors of the carbonylation reaction unit can be connected in parallel for independent test and can also be used in series, three catalysts can be evaluated simultaneously, and the comprehensive effect of two or three catalysts can also be evaluated, so that the test method is flexible and various and has high test efficiency; 2. MN-rich circulating gas and NO-rich circulating gas of the glycol industrial device outside the battery limits can be respectively treated by the MN-rich treatment unit and the NO-rich treatment unit and then sent to the carbonylation reaction unit, namely the circulating gas actually generated by a factory is treated and then used for the evaluation test of the catalyst, so that the actual industrial system can be simulated to the maximum extent, and the reference value of the test is improved; 3. meanwhile, the blending gas source is arranged, and the type and the dosage of the blending gas source can be adjusted according to the test requirement, so that the circulating gas output by the process gas unit has greater regulation and control elasticity; 4. can come out the liquid phase separation in the tail gas through setting up the separation element, carry out recycle, avoid the waste of material, the ethylene glycol tail gas system that can be sent into to exhaust tail gas simultaneously handles.

Description of the drawings:

in order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of the overall structure of the present invention.

FIG. 2 is a schematic view of a process gas unit.

FIG. 3 is a schematic diagram of a carbonylation reaction unit.

Process gas unit 1 and MN-rich processing unit 101The system comprises an NO-rich processing unit 102, an MN supercharger 103, an MN condenser 104, an MN buffer tank 105, an MN liquid storage tank 106, an MN pump 107, an MN back pressure valve 108, an MN vaporizer 109, an MN gas storage tank 110, an MN pneumatic regulating valve 111, an MN control valve 112, an NO supercharger 113, an NO condenser 114, an NO buffer tank 115, an NO gas storage tank 116, an NO pressure reducing valve 117, an NO control valve 118, a CO gas source 119, and N ₂ Gas source 120, CH ₄ Gas source 121, CO ₂ The carbonylation reaction unit 2 comprises a gas source 122, a gas mixing and distributing pipe 123, a gas mixing and distributing pressure reducing valve 124, a gas mixing and distributing control valve 125, a carbonylation reaction unit 2, a mixer 21, a heater 22, a first reactor 23, a second reactor 24, a third reactor 25, a first pressure reducing valve 26, a gas feeding pipe 27, a mass flow meter 28, a branch pipe 29, a branch pipe control valve 210, a first connecting pipe 211, a first discharging pipe 212, a second connecting pipe 213, a second discharging pipe 214, a third discharging pipe 215, a discharging main pipe 216, a reaction control valve 217, a preheater 218, a fifth sampling point 3, a sixth sampling point 5, a first sampling point 7, a second sampling point 8, a third sampling point 9, a fourth sampling point 10, a gas analyzer 11, a separation unit 15, a product cooler 151, a product buffer tank 152, a product storage tank 153, a liquid separation tank 154, a tail gas control valve 155 and a tail gas flow meter 156.

The specific implementation mode is as follows:

the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

As shown in fig. 1 to fig. 3, a catalyst evaluation device for preparing dimethyl carbonate by a gas-phase methanol carbonyl oxidation method comprises a process gas unit 1 and a carbonylation reaction unit 2, wherein the process gas unit 1 comprises an MN-rich processing unit 101, an NO-rich processing unit 102 and at least one gas blending source;

the MN rich processing unit 101 comprises an MN supercharger 103, an MN condenser 104, an MN buffer tank 105, an MN liquid storage tank 106, an MN pump 107, an MN back pressure valve 108, an MN vaporizer 109, an MN gas storage tank 110, an MN pneumatic regulating valve 111 and an MN control valve 112 which are sequentially connected; the outlet of the MN control valve 112 is a process gas outlet;

the NO-rich processing unit 102 comprises an NO booster 113, an NO condenser 114, an NO buffer tank 115, an NO storage tank 116, an NO pressure reducing valve 117 and an NO control valve 118 which are connected in sequence; the outlet of the NO control valve 118 is a process gas output.

The gas mixing and distributing source comprises a CO gas source 119, an N2 gas source 120, a CH4 gas source 121 and a CO2 gas source 122, each gas mixing and distributing source is respectively communicated with the inlet of one gas mixing and distributing pipe 123, and a gas mixing and distributing pressure reducing valve 124 and a gas mixing and distributing control valve 125 are arranged on the gas mixing and distributing pipe 123.

Sending MN-rich circulating gas with high methyl nitrite content outside a glycol device boundary area into an MN-rich processing unit 101, pressurizing by an MN supercharger 103, sending the MN-rich circulating gas into an MN condenser 104, separating the MN condenser 104 by three-stage condensation, cooling and separating methanol and methyl formate by a first-stage cooling and separating system, and further cooling to-10 ℃ by a second-stage cooling system to ensure that the methanol and the methyl formate are completely separated; and the mixed gas after the methanol and the methyl formate are separated by the secondary cooling and separating system enters a tertiary MN cooling and separating system. After being cooled to minus 30 ℃ by the three-stage MN cooling and separating system, separated MN is intermittently discharged into an MN buffer tank 105 for temporary storage and then is sent into 2 MN liquid storage tanks 106 connected in parallel; the MN pump 107 pumps the liquid in the MN liquid storage tank 106 to the MN vaporizer 109 to vaporize the raw material and collect the vaporized raw material into the MN gas storage tank 110, and the input amount and pressure of the MN-rich gas source can be adjusted by the MN pneumatic adjusting valve 111 and the MN control valve 112.

The method comprises the steps of sending the NO-rich circulating gas with high NO content outside a glycol device boundary area into an NO-rich processing unit 102, pressurizing the NO-rich circulating gas by an NO booster 113, then sending the NO-rich circulating gas into an NO condenser 114, performing secondary cooling separation on the NO condenser 114, cooling the NO-rich circulating gas to 15 ℃ by a primary cooling separation system to separate methanol and methyl formate, further separating the methanol and the methyl formate by a secondary cryogenic system to-10 ℃ to ensure complete separation of the methanol and the methyl formate, buffering the NO-rich circulating gas in an NO buffer tank 115, then sending the NO buffer tank 116 to store the NO-rich circulating gas, and adjusting the input amount and pressure of an NO-rich gas source through an NO pressure reducing valve 117 and an NO control valve 118.

In addition, the composition, the addition amount and the addition pressure of the added blending gas source can be adjusted by adjusting the opening and closing or the opening of the blending gas pressure reducing valve 124 and the blending gas control valve 125 corresponding to the CO gas source 119, the N2 gas source 120, the CH4 gas source 121 and the CO2 gas source 122 according to the test requirements.

The carbonylation reaction unit 2 comprises a mixer 21, a heater 22, a first reactor 23, a second reactor 24 and a third reactor 25, wherein a process gas output port of the process gas unit 1 is communicated with an inlet of a preheater 218, an outlet of the preheater 218 is communicated with an inlet of the mixer 21, an outlet of the mixer 21 is communicated with an inlet of the heater 22 through a first pressure reducing valve 26, an outlet of the heater 22 is communicated with an inlet of a gas feeding pipe 27, and a mass flow meter 28 is arranged on the gas feeding pipe 27. The process gas unit 1 is used for treating MN-rich circulating gas and NO-rich circulating gas from the outside of an ethylene glycol battery compartment by an MN-rich treatment unit 101 and an NO-rich treatment unit 102, preheating the MN-rich circulating gas and the NO-rich circulating gas with CO, N2, CH4 and CO2 by a preheater 218 according to a certain pressure and a certain proportion, and then adding the preheated circulating gas and the CO2 into a mixer 21 for mixing, and because the circulating gas actually generated in a factory is treated and then used for an evaluation test of a catalyst, the gas composition of an industrial device can be completely simulated, and the performance of the catalyst of the industrial device can be better evaluated; meanwhile, more test variables are provided by adjusting the pressure and components of the mixed gas, so that the adjustment range of test conditions is wider; the mixed gas discharged from the mixer 21 is heated by the heater 22 and then introduced into the gas supply pipe 27.

The outlet of the air supply pipe 27 is communicated with the inlets of the first reactor 23, the second reactor 24 and the third reactor 25 through a branch pipe 29, and a branch pipe control valve 210 is installed on the branch pipe 29; the outlet of the first reactor 23 is respectively communicated with the inlets of a first communicating pipe 211 and a first discharging pipe 212, and the outlet of the first communicating pipe 211 is communicated with the inlet of the second reactor 24; the outlet of the second reactor 24 is communicated with the inlets of a second communicating pipe 213 and a second discharging pipe 214, respectively, and the second communicating pipe 213 is communicated with the inlet of the third reactor 25; the outlet of the third reactor 25 communicates with the inlet of the third discharge pipe 215; the outlets of the first discharge pipe 212, the second discharge pipe 214, and the third discharge pipe 215 are all in communication with the inlet of a discharge manifold 216; reaction control valves 217 are installed on the first connection pipe 211, the first discharge pipe 212, the second connection pipe 213, the second discharge pipe 214, and the third discharge pipe 215.

The first reactor 23, the second reactor 24 and the third reactor 25 are arranged in parallel between the feed pipe 27 and the discharge header 216 through the branch pipe 29 and the first discharge pipe 212, the second discharge pipe 214, the third discharge pipe 215; different catalysts can be filled in the three reactors at the same time, the reaction control valves 217 on the first communicating pipe 211 and the second communicating pipe 213 are closed, the corresponding branch pipe control valve 210 and the reaction control valve 217 on the discharging pipe are opened, and the catalysts in the reactors are evaluated; then, by switching the branch pipe control valves 210 and the corresponding reaction control valves 217 on the inlet and the discharge pipe of the reactor, the system can be quickly switched to complete the evaluation of different catalysts, the operation is convenient and quick, and the test efficiency can be effectively improved.

In addition, the first reactor 23 and the second reactor 24 can be connected in series through a first communicating pipe 211, and the second reactor 24 and the third reactor 25 can be connected in series through a second communicating pipe; the series connection of the first reactor and the second reactor, the series connection of the second reactor and the third reactor, and the series connection of the first reactor, the second reactor and the third reactor can be realized by adjusting the opening and closing of each branch pipe control valve 210 and the reaction control valve 217, and further, the comprehensive catalytic effect of two or three catalysts can be evaluated.

The outlet of the heater 22, the outlets of the first reactor 23, the second reactor 24 and the third reactor 25 are respectively provided with a first sampling point 7, a second sampling point 8, a third sampling point 9 and a fourth sampling point 10, the outlet of the MN control valve 112 is provided with a fifth sampling point 3, the outlet of the NO control valve 118 is provided with a sixth sampling point 5, the first sampling point 7, the second sampling point 8, the third sampling point 9, the fourth sampling point 10, the fifth sampling point 3 and the sixth sampling point 5 are respectively communicated with the sampling ports of the six gas analyzers 14 in a one-to-one correspondence manner through sampling pipes, and the sampling control valves are installed on the sampling pipes.

First sampling point 7, the mixture is respectively to fifth sampling point 3 and sixth sampling point 5, it is gaseous with rich NO gas to richen MN carries out the analysis of sampling, second sampling point 8, third sampling point 9 and fourth sampling point 10 are then respectively to first reactor 23, second reactor 24, third reactor 25 exhaust product gas carries out the analysis of sampling, six gas analysis appearance 11 communicate with the sampling point that corresponds through the sampling pipe respectively, set up flowmeter measurement volume on the sampling pipe, through controlling the sampling control valve, can select one in 6 sampling points in real time to carry out online sampling analysis, accessible solenoid valve cuts off the sampling circuit when need not to sample.

The device also comprises a separation unit 15 for separating and recovering liquid-phase products, wherein the separation unit 15 comprises a product cooler 151, a product buffer tank 152 and a product storage tank 153 which are sequentially connected, an inlet of the product cooler 151 is communicated with an outlet of the discharge header pipe 216, an exhaust port of the product buffer tank 152 is communicated with an inlet pipeline of the liquid separation tank 154, and an exhaust port of the liquid separation tank 154 is sequentially communicated with a tail gas control valve 155 and a tail gas flow meter 156. The gas produced in the carbonylation reaction unit 2 is sent to a product cooler 151 (a hot water bath can be adopted, a temperature measuring point is arranged at an outlet, the temperature of circulating hot water is controlled through a cooling and heating integrated machine to prevent the cooler from being crystallized and blocked), dimethyl carbonate and dimethyl oxalate are condensed into a liquid phase, then the liquid phase enters a product buffer tank 152 for gas-liquid separation, the liquid level height in the product buffer tank 152 is measured by a differential pressure transmitter and is associated with a precise pneumatic control valve, and the liquid phase product is continuously put into a product storage tank 153; the gas phase separated from the product buffer tank 152 is sent to the separation tank 154 for separation again, and finally, the gas phase is sent to the ethylene glycol industrial device for treatment through the tail gas control valve 155 and the tail gas flow meter 156.

For convenience of control, the various valves involved in the evaluation device and the gas analyzer 11 are electrically connected with a computer (not shown in the figure), the opening and closing of the valves are controlled by the computer, and the analysis results are directly uploaded to the computer.

The above description is only for the preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A catalyst evaluation device for preparing dimethyl carbonate by a gas-phase methanol carbonyl oxidation method is characterized by comprising a process gas unit, a carbonylation reaction unit and a gas analyzer, wherein the carbonylation reaction unit comprises a mixer, a heater, a first reactor, a second reactor and a third reactor; the outlet of the air feed pipe is respectively communicated with the inlets of the first reactor, the second reactor and the third reactor through branch pipes, and branch pipe control valves are arranged on the branch pipes; the outlet of the first reactor is respectively communicated with the inlets of a first communicating pipe and a first discharging pipe, and the outlet of the first communicating pipe is communicated with the inlet of the second reactor; the outlet of the second reactor is respectively communicated with the inlets of a second communicating pipe and a second discharge pipe, and the second communicating pipe is communicated with the inlet of the third reactor; the outlet of the third reactor is communicated with the inlet of a third discharge pipe; the outlets of the first discharge pipe, the second discharge pipe and the third discharge pipe are all communicated with the inlet of a discharge header pipe; reaction control valves are arranged on the first communicating pipe, the first discharging pipe, the second communicating pipe, the second discharging pipe and the third discharging pipe; the outlet of the heater, the outlets of the first reactor, the second reactor and the third reactor are respectively provided with a first sampling point, a second sampling point, a third sampling point and a fourth sampling point, the first sampling point, the second sampling point, the third sampling point and the fourth sampling point are respectively communicated with the sampling ports of the four gas analyzers in a one-to-one correspondence mode through sampling pipes, and sampling control valves are installed on the sampling pipes.

2. The apparatus of claim 1, wherein the process gas unit comprises an MN processing unit, an NO processing unit and at least one gas blending gas source, each gas blending gas source is respectively communicated with an inlet of a gas blending gas pipe, a gas blending gas reducing valve and a gas blending gas control valve are installed on the gas blending gas pipe, and outlets of the MN processing unit, the NO processing unit and the gas blending gas pipe are process gas outlets.

3. The catalyst evaluation device for preparing the dimethyl carbonate by the gas-phase methanol carbonyl oxidation method according to claim 2, wherein the MN-rich processing unit comprises an MN supercharger, an MN condenser, an MN buffer tank, an MN liquid storage tank, an MN pump, an MN back pressure valve, an MN vaporizer, an MN gas storage tank, an MN pneumatic regulating valve and an MN control valve which are sequentially connected; and the outlet of the MN control valve is a process gas output port.

4. The device for evaluating the catalyst for preparing the dimethyl carbonate by the gas-phase methanol carbonyl oxidation method according to claim 3, wherein a fifth sampling point is arranged at an outlet of the MN control valve, the fifth sampling point is communicated with a sampling port of the gas analyzer through a sampling pipe, and the sampling pipe is provided with a sampling control valve.

5. The apparatus for evaluating a catalyst for preparing dimethyl carbonate by gas-phase methanol carbonyl oxidation according to any one of claims 2 to 4, wherein the NO-rich processing unit comprises a NO booster, a NO condenser, a NO buffer tank, a NO storage tank, a NO pressure reducing valve and a NO control valve which are connected in sequence; and the outlet of the NO control valve is a process gas output port.

6. The device for evaluating the catalyst for preparing the dimethyl carbonate by the gas-phase methanol carbonyl oxidation method according to claim 5, wherein a sixth sampling point is arranged at an outlet of the NO control valve, the sixth sampling point is communicated with a sampling port of the gas analyzer through a sampling pipe, and the sampling pipe is provided with a sampling control valve.

7. The apparatus of claim 2, wherein the blending gas source comprises at least one of a CO gas source, a N2 gas source, a CH4 gas source, and a CO2 gas source.

8. The apparatus for evaluating a catalyst for a process of preparing dimethyl carbonate by carbonylating methanol in a gas phase according to claim 1, 2, 3, 4, 6 or 7, further comprising a separation unit for separating and recovering a product in a liquid phase, wherein an outlet of said discharge header is connected to an inlet of said separation unit.

9. The apparatus according to claim 8, wherein the separation unit comprises a product cooler, a product buffer tank and a product storage tank which are connected in sequence, an inlet of the product cooler is communicated with an outlet of the discharge header pipe, an exhaust port of the product buffer tank is communicated with an inlet pipeline of the liquid-separation tank, and an exhaust control valve and an exhaust flowmeter are communicated with an exhaust port of the liquid-separation tank in sequence.

10. The apparatus of claim 1, 2, 3, 4, 6, 7 or 9, further comprising a preheater disposed between the process gas outlet and the inlet of the mixer, wherein the process gas outlet is connected to the inlet of the preheater, and the outlet of the preheater is connected to the inlet of the mixer.