阅读说明：本技术 甲醇裂解制氢装置催化剂的钝化方法 (Passivation method of catalyst of methanol cracking hydrogen production device ) 是由 李洪亮 陈建业 房海霞 于 2021-06-16 设计创作，主要内容包括：本发明涉及甲醇裂解制氢装置技术领域,是一种甲醇裂解制氢装置催化剂的钝化方法,该甲醇裂解制氢装置催化剂的钝化方法,按下述方法进行：将脱盐水输送至循环系统中,当循环系统中甲醇水溶液浓度＜5%时,向反应器中通入少量压缩空气,使得反应器中的铜系催化剂开始钝化,持续向反应器中通入压缩空气,当反应器中的空气含量升至20%时,反应器温度逐渐下降,当反应器温度无变化时,钝化结束,继续向反应器中通入压缩空气,吹干反应器,更换铜系催化剂。本发明甲醇裂解制氢装置催化剂的钝化方法钝化时间短,人员操作方便,工艺简单易行,有效的解决了现有甲醇裂解制氢装置催化剂的钝化方法钝化时间长的问题。(The invention relates to the technical field of methanol cracking hydrogen production devices, in particular to a method for passivating a catalyst of a methanol cracking hydrogen production device, which is carried out according to the following steps: conveying desalted water into a circulating system, introducing a small amount of compressed air into the reactor when the concentration of the methanol aqueous solution in the circulating system is less than 5%, so that the copper catalyst in the reactor starts to be passivated, continuously introducing the compressed air into the reactor, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, finishing passivation when the temperature of the reactor is unchanged, continuously introducing the compressed air into the reactor, drying the reactor, and replacing the copper catalyst. The passivation method of the catalyst of the methanol cracking hydrogen production device has the advantages of short passivation time, convenient operation by personnel and simple and feasible process, and effectively solves the problem of long passivation time of the passivation method of the catalyst of the existing methanol cracking hydrogen production device.)

1. A passivation method of a catalyst of a methanol cracking hydrogen production device is characterized by comprising the following steps: firstly, stopping feeding methanol, sequentially conveying desalted water in a desalting storage tank to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to the desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of an adsorption hydrogen extraction working section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.1-0.2 MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, passivating the copper catalyst in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor, drying the reactor, and replacing the copper catalyst.

2. The method for passivating catalyst of a methanol cracking hydrogen production plant according to claim 1, wherein the heat transfer oil is one of mineral type heat transfer oil, alkyl diphenyl ether type heat transfer oil, biphenyl and diphenyl ether type heat transfer oil or alkyl benzene type heat transfer oil.

3. The method for passivating catalyst of a methanol cracking hydrogen production device according to claim 1 or 2, wherein in the fourth step, compressed air is introduced for 1.0h to 1.5 h.

Technical Field

The invention relates to the technical field of methanol cracking hydrogen production devices, and discloses a method for passivating a catalyst of a methanol cracking hydrogen production device.

Background

The technological process of the methanol cracking hydrogen production device comprises the steps of mixing methanol and desalted water, pressurizing, vaporizing and overheating the mixture, allowing the mixture to enter a reactor, reacting the mixture under the action of a catalyst to generate a mixed gas of hydrogen, carbon dioxide, carbon monoxide and the like, and performing pressure swing adsorption separation (PSA) separation on the mixed gas to obtain pure hydrogen and high-purity hydrogen at one time. The methanol cracking hydrogen production device uses a copper catalyst, the filled copper catalyst is in an oxidation state, elemental copper has an activity effect on the reaction, and the copper catalyst in the oxidation state is reduced and activated before the methanol cracking hydrogen production device is started to be changed into the active elemental copper. When the copper catalyst needs to be replaced at the end of the use period of the copper catalyst, the elemental copper needs to be passivated into an oxidized state and can be discharged, if the copper catalyst is not passivated, the reactor is directly opened for discharging, so that the reactor is directly contacted with a large amount of oxygen at the opening moment and emits a large amount of heat, and the copper is poor in heat resistance and can be melted. The liquid copper cools and condenses while flowing down, blocking the reactor tubes, and thus damaging the equipment. The existing passivation method of the catalyst of the methanol cracking hydrogen production device comprises the steps of firstly cutting out a circulating system, connecting the circulating system with a Roots blower to form closed loop circulation, then starting the Roots blower to enable the circulating system to start gas phase circulation, slowly introducing a small amount of compressed air into a reactor, and determining whether passivation is finished or not by monitoring the temperature of the reactor, wherein the passivation time is as long as about 7 days, passivation can only be carried out in a single set, each set of passivation needs 7 days on average, and the disassembly, filling and reduction of a copper catalyst need 19 days, so that the normal production of the methanol cracking hydrogen production device is greatly influenced, and the production reduction of a company is caused.

Disclosure of Invention

The invention provides a method for passivating a catalyst of a methanol cracking hydrogen production device, overcomes the defects of the prior art, and can effectively solve the problem of long passivation time of a copper catalyst of the existing methanol cracking hydrogen production device.

The technical scheme of the invention is realized by the following measures: a passivation method of a catalyst of a methanol cracking hydrogen production device is carried out according to the following steps: firstly, stopping feeding methanol, sequentially conveying desalted water in a desalting storage tank to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to the desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of an adsorption hydrogen extraction working section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.1-0.2 MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, starting passivation of a copper catalyst (elemental copper) in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor, drying the reactor, and replacing the copper catalyst (in an oxidation state).

The following is further optimization or/and improvement of the technical scheme of the invention:

the heat transfer oil is one of mineral heat transfer oil, alkyl biphenyl ether type heat transfer oil, biphenyl and biphenyl ether type heat transfer oil or alkyl benzene type heat transfer oil.

And in the fourth step, the compressed air is introduced for 1.0 to 1.5 hours.

The passivation method of the catalyst of the methanol cracking hydrogen production device has the advantages of short passivation time, convenient operation by personnel and simple and feasible process, and effectively solves the problem of long passivation time of the passivation method of the catalyst of the existing methanol cracking hydrogen production device.

Drawings

FIG. 1 is a process flow diagram of a methanol cracking hydrogen production plant of the present invention.

Detailed Description

The present invention is not limited by the following examples, and specific embodiments may be determined according to the technical solutions and practical situations of the present invention. The various chemical reagents and chemical articles mentioned in the invention are all the chemical reagents and chemical articles which are well known and commonly used in the prior art, unless otherwise specified; the percentages in the invention are mass percentages unless otherwise specified; the solution in the present invention is an aqueous solution of water as a solvent, for example, a hydrochloric acid solution is an aqueous hydrochloric acid solution, unless otherwise specified.

The invention is further described below with reference to the following examples:

example 1: as shown in the attached figure 1, the passivation method of the catalyst of the methanol cracking hydrogen production device is carried out according to the following method: firstly, stopping feeding methanol, sequentially conveying desalted water in a desalting storage tank to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to the desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of an adsorption hydrogen extraction working section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.1-0.2 MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, starting passivation of a copper catalyst (elemental copper) in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor, drying the reactor, and replacing the copper catalyst (in an oxidation state).

The passivation method of the catalyst of the existing methanol cracking hydrogen production device has longer passivation time, firstly, a circulating system is cut out and connected with a Roots blower to form closed loop circulation, then the Roots blower is started to enable the circulating system to start gas phase circulation, a small amount of compressed air is slowly introduced into a reactor, whether passivation is finished or not is determined by monitoring the temperature of the reactor, the passivation time is as long as about 7 days, and the disassembly, filling and reduction of a copper catalyst take 19 days, so that the normal production of the methanol cracking hydrogen production device is greatly influenced, and the production reduction is caused.

In the invention, when the content of methanol in the circulating system is more than or equal to 5 percent, the methanol can react to generate hydrogen under a copper catalyst, and the hydrogen can reduce copper oxide into elemental copper, therefore, the passivation method of the methanol cracking hydrogen production device catalyst firstly adopts desalted water to reduce the content of the methanol in the circulating system, utilizes vaporization overheating of the desalted water to take away heat of heat conducting oil for supplying heat to a reactor, shortens the cooling time of the reactor, when the content of the methanol is less than 5 percent, the temperature of the reactor is reduced from the initial 240 ℃ to 150 ℃ to 160 ℃, at the moment, a small amount of compressed air is conveyed into the reactor, so that the copper catalyst (elemental copper) in the reactor starts to be passivated, because the passivation reaction is an exothermic reaction, when a small amount of compressed air is introduced into the reactor, the temperature of the reactor just starts to rise, but continues along with the passivation reaction, the temperature of the reactor is continuously reduced, so that when a small amount of compressed air is introduced into the reactor, the air content in the reactor is 0.2%, when the temperature in the reactor is monitored to be not more than 250 ℃, the compressed air is continuously introduced into the reactor, when the air content in the reactor is increased to 20%, the temperature of the reactor is continuously reduced, when the temperature of the reactor is unchanged, the flow of desalted water is gradually reduced until the desalted water stops, and the passivation is finished.

Compared with the passivation method of the catalyst of the existing methanol cracking hydrogen production device, the passivation method of the catalyst of the methanol cracking hydrogen production device firstly reduces the content of methanol in a circulating system through desalted water, takes away the temperature of heat conducting oil by utilizing the vaporization of the desalted water, shortens the cooling time of a reactor, and then introduces compressed air into the reactor to lead the copper catalyst (simple substance copper) to start passivation so as to obtain the copper catalyst in an oxidation state.

Example 2: as an optimization of the above embodiment, the conduction oil is one of mineral type conduction oil, alkyl diphenyl ether type conduction oil, biphenyl and diphenyl ether type conduction oil or alkyl benzene type conduction oil.

Example 3: as an optimization of the above embodiment, in the fourth step, the time for introducing the compressed air is 1.0h to 1.5 h.

Example 4: the passivation method of the catalyst of the methanol cracking hydrogen production device is carried out according to the following method: firstly, stopping feeding methanol, sequentially conveying desalted water to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to a desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of the adsorption hydrogen extraction section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.1MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, passivating the copper catalyst (simple substance copper) in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor for 1.0h, drying the reactor, and replacing the copper catalyst, wherein the heat transfer oil is mineral heat transfer oil.

Example 5: the passivation method of the catalyst of the methanol cracking hydrogen production device is carried out according to the following method: firstly, stopping feeding methanol, sequentially conveying desalted water to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to a desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of the adsorption hydrogen extraction section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.2MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, passivating the copper catalyst (simple substance copper) in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor for 1.5 hours, drying the reactor, and replacing the copper catalyst, wherein the heat transfer oil is alkyl biphenyl ether type heat transfer oil.

Example 6: the passivation method of the catalyst of the methanol cracking hydrogen production device is carried out according to the following method: firstly, stopping feeding methanol, sequentially conveying desalted water to a heat exchanger, a vaporizer, a superheater, a reactor, a heat exchanger, a cooler and a water washing tower, and then conveying the desalted water back to a desalting storage tank to form a circulating system, reducing the concentration of a methanol water solution in the circulating system through the desalted water, and simultaneously supplying heat to the reactor through heat conducting oil; secondly, when the concentration of the methanol water solution in the reactor is monitored to be less than 5%, stopping the operation of the adsorption hydrogen extraction section, reducing the pressure of a circulating system, continuously conveying desalted water into the circulating system when the pressure of the circulating system is reduced to 0.15MPa, reducing the temperature of the reactor by using heat conduction oil, introducing compressed air into the reactor when the temperature of the reactor is reduced to 150-160 ℃, so that the air content in the reactor is 0.2%, and at the moment, passivating the copper catalyst (simple substance copper) in the reactor; thirdly, continuously introducing compressed air into the reactor when the temperature in the reactor is kept to be not more than 250 ℃, gradually reducing the temperature of the reactor when the air content in the reactor is increased to 20%, gradually reducing the flow of desalted water until the desalted water stops when the temperature of the reactor is not changed, and stopping heat-conducting oil transportation after passivation is finished; and fourthly, after the desalted water feeding is stopped, continuously introducing compressed air into the reactor for 1.2 hours, drying the reactor, and replacing the copper catalyst, wherein the heat conduction oil is biphenyl and biphenyl ether type heat conduction oil.

By adopting the passivation method of the catalyst of the methanol cracking hydrogen production device in the embodiments 4 to 6, the passivation time is 2 days, so that compared with the passivation method of the catalyst of the methanol cracking hydrogen production device, the passivation time is greatly shortened.

In conclusion, the passivation method of the catalyst of the methanol cracking hydrogen production device has the advantages of short passivation time, convenient operation by personnel and simple and feasible process, and effectively solves the problem of long passivation time of the existing passivation method of the catalyst of the methanol cracking hydrogen production device.

The technical characteristics form an embodiment of the invention, which has strong adaptability and implementation effect, and unnecessary technical characteristics can be increased or decreased according to actual needs to meet the requirements of different situations.