A system and method for purifying and storing industrial crude hydrogen

Abstract

The invention discloses a purification and storage system and method for industrial crude hydrogen, and relates to the technical field of hydrogen energy. Firstly, an optimized catalyst is used to purify and store crude hydrogen from crude toluene, thereby solving the problem that the existing catalyst system is sensitive to impurities in industrial crude toluene. In addition, an industrial crude hydrogen purification and storage system is provided, comprising: a toluene tank, a centrifugal pump, a first heat exchanger, a second heat exchanger, a hydrogen compressor, a hydrogenation reactor, a circulating hydrogen compressor, a gas-liquid separator and a methylcyclohexane tank. Through the cooperation of various devices, the recycling of resources is realized, the interference of impurities in industrial crude hydrogen and crude toluene is eliminated, the separation and purification of hydrogen and the storage in methylcyclohexane are realized in one step, the convenience of hydrogen storage and transportation is effectively improved, and the cost of hydrogen is reduced.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy technology, and in particular to a system and method for purifying and storing industrial crude hydrogen. Background Art

[0002] The methods of producing hydrogen include industrial hydrogen production, water electrolysis, photocatalytic hydrogen production, and biological fermentation. Currently, 80% of hydrogen comes from industrial hydrogen production, including coal gasification, natural gas, and chlor-alkali by-product hydrogen production. However, a large amount of carbon and oxygen by-products (CO, CO2) are produced at the same time as hydrogen production. In order to purify industrial crude hydrogen, low-temperature water-gas shift, low-temperature methanation, pressure swing adsorption and other process flows are usually required. These process flows are cumbersome and require huge investments, which greatly increases the cost of hydrogen. In addition, the small amount of CO contained in hydrogen will poison the Pt electrode used in fuel cells, limiting the development of hydrogen energy in the field of new energy. Therefore, it is urgent to develop a simple and efficient crude hydrogen separation and purification technology.

[0003] On the other hand, due to the extremely low volumetric energy density of hydrogen, its storage and transportation costs restrict the commercial development of hydrogen energy. The storage and transportation of traditional hydrogen cylinders face the problems of low efficiency, poor safety and high cost, and it is difficult to meet the long-distance hydrogen transportation needs. The added value of crude hydrogen is low, and the cost of transporting it to hydrogen-demanding areas is high, resulting in a large amount of crude hydrogen being wasted due to its low practical value. Based on this, organic liquid hydrogen storage technology has received widespread attention. It uses chemical catalytic reactions to store hydrogen in liquid organic unsaturated molecules, and then reacts again at the use end to release hydrogen, completing the hydrogen cycle.

[0004] The physical and chemical properties of organic liquid hydrogen storage media are more stable, safe and reliable than hydrogen. Whether it is storage or transportation, organic hydrogen storage media in liquid form are more convenient and less expensive. However, industrial crude hydrogen contains more impurity components, the purification cost is high, and it is difficult to use directly. Organic liquid hydrogen storage molecules mainly select compounds with higher hydrogen storage density. At present, mature organic liquid hydrogen storage systems include benzene-cyclohexane, toluene-methylcyclohexane, dibenzyltoluene-perhydrodibenzyltoluene, and N-ethylcarbazole-dodecahydro-N-ethylcarbazole. In the toluene-methylcyclohexane system, there are higher requirements for the purity of the toluene used, usually refined toluene. This is because the existing catalyst system has a low tolerance for impurities in industrial crude toluene, and the hydrogenation efficiency of toluene will be significantly reduced. However, the process of refining crude toluene will increase the cost of raw materials and increase the difficulty of process design. Therefore, the catalyst system based on direct hydrogenation of crude toluene is crucial to the purification and storage and transportation technology of crude hydrogen. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a system and method for purifying and storing industrial crude hydrogen, which cleverly applies the reaction of toluene hydrogenation to efficiently remove impurity components in crude hydrogen, while achieving hydrogenation and hydrogen storage with a high conversion rate of crude toluene, and adopts non-precious metal catalysts. It has strong adaptability in the hydrogenation reaction of crude toluene containing more impurities and exhibits excellent hydrogen storage efficiency. At the hydrogen-using end, high-purity hydrogen can be obtained by dehydrogenating the hydrogenation product methylcyclohexane.

[0006] The technical solution provided by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for purifying and storing industrial crude hydrogen, which utilizes a crude toluene hydrogenation reaction to store hydrogen in an organic liquid hydrogen storage system to achieve the purification and storage of the industrial crude hydrogen.

[0008] A method for purifying and storing industrial crude hydrogen comprises the following steps:

[0009] S1. Activation: In the hydrogenation reactor, the catalyst is activated with pure hydrogen;

[0010] S2, pressurization: using crude hydrogen to increase the pressure of the reactor;

[0011] S3, hydrogenation: adding toluene into the reactor to carry out hydrogenation reaction.

[0012] As an embodiment, in S1, the activation treatment is to activate the catalyst with pure hydrogen for 4 to 6 hours in a hydrogenation reactor at normal pressure and 400 to 600°C.

[0013] In some embodiments, the activation treatment is performed at a temperature of 500° C. for 5 h.

[0014] As an embodiment, the pressure increasing treatment is to control the pressure of the reactor at 2-4 MPa.

[0015] As an embodiment, the pressure increasing treatment is to control the pressure of the reactor at 3-4 MPa.

[0016] In some embodiments, the pressure-increasing process is to control the pressure of the reactor at 4 MPa.

[0017] As an embodiment, the temperature of the hydrogenation reaction is 150-230 °C.

[0018] As an embodiment, the temperature of the hydrogenation reaction is 170-230 °C.

[0019] As an embodiment, the temperature of the hydrogenation reaction is 200-230 °C.

[0020] As an embodiment, the toluene contains liquid phase impurities at a mass concentration of no more than 10%, and the liquid phase impurities include one or more of benzene, ethylbenzene, saturated alkanes, styrene and xylene.

[0021] As an embodiment, the liquid phase impurities include benzene and ethylbenzene.

[0022] As an embodiment, the liquid phase impurities further include one or more of saturated alkanes, styrene and xylene.

[0023] As an embodiment, the catalyst is a supported catalyst, the active metal is one or more of Fe, Co and Ni, and the carrier is one or more of Al2O3, ZrO2, CeO2, MgO and SiO2.

[0024] As an embodiment, the mass ratio of active metal to carrier in the catalyst is (5~15): (85~95).

[0025] In some embodiments, the catalyst is Ni / CeO2, wherein the mass ratio of active metal Ni to carrier CeO2 is (10~15): (85~90).

[0026] As an embodiment, the preparation method of the catalyst is:

[0027] S11, preparing carrier powder: calcining a carrier salt to obtain an oxide carrier powder, wherein the carrier salt is a salt compound of any element selected from the group consisting of cerium, aluminum, silicon, zirconium and magnesium, including one or more of nitrate, acetate and oxalate;

[0028] S12, preparing active metal / carrier slurry: adding the carrier powder to an aqueous solution containing an active metal salt, stirring to form a slurry, and dispersing uniformly, wherein the active metal salt is a salt compound of any element of Fe, Co, and Ni, including one or more of nitrate, chloride, sulfate, and oxalate;

[0029] S13, preparing a catalyst precursor: drying the slurry, and then grinding it to obtain a powdered catalyst precursor;

[0030] S14, preparing a catalyst: calcining the catalyst precursor to obtain the catalyst.

[0031] As an embodiment, the carrier salt is one or more of cerium nitrate, cerium acetate and cerium oxalate.

[0032] In some embodiments, the carrier salt is cerium nitrate.

[0033] As an embodiment, the active metal salt is one or more of nickel nitrate, nickel chloride, nickel sulfate and nickel oxalate.

[0034] In some embodiments, the active metal salt is nickel nitrate.

[0035] As an embodiment, the calcination in S11 and / or S14 is carried out in air at a temperature of 400-600° C. and a time of 4-6 h.

[0036] In some embodiments, the calcination temperature is 500° C. and the calcination time is 5 h.

[0037] As an embodiment, the method for purifying and storing industrial crude hydrogen is applicable to crude hydrogen containing gas-phase impurities with a volume concentration of 1 to 10%, wherein the gas-phase impurities include CO and CO2.

[0038] As an embodiment, the gas-phase impurities further include one or more of CH4, O2 and H2O.

[0039] As an embodiment, the method for purifying and storing industrial crude hydrogen further includes S4, dehydrogenating the hydrogenated organic liquid to obtain pure hydrogen.

[0040] In a second aspect, the present invention provides an industrial crude hydrogen purification and storage system, which is a system applied to the above-mentioned industrial crude hydrogen purification and storage method, comprising: a toluene tank, a centrifugal pump, a first heat exchanger, a second heat exchanger, a hydrogen compressor, a hydrogenation reactor, a circulating hydrogen compressor, a gas-liquid separator and a methylcyclohexane tank, wherein:

[0041] The inlet of the hydrogen compressor is connected to an industrial crude hydrogen source to provide a hydrogen source for the hydrogenation reactor;

[0042] The toluene tank provides the heated hydrogenation substrate to the hydrogenation reactor through the centrifugal pump and the first heat exchanger;

[0043] The outlet of the hydrogenation reactor is connected to the inlet of the gas-liquid separator through the second heat exchanger, so that the hydrogenation reaction product is cooled before gas-liquid separation;

[0044] The gas outlet of the gas-liquid separator is connected to the circulating hydrogen compressor, and the gas is transported to the hydrogenation reactor through the circulating hydrogen compressor for circulating hydrogen utilization; the liquid outlet of the gas-liquid separator is connected to the methylcyclohexane tank, and the liquid is transported to the methylcyclohexane tank for storage.

[0045] As an embodiment, the industrial crude hydrogen purification and storage system further includes a third heat exchanger for performing heat exchange between the liquids flowing out of the hydrogenation reactor and the liquids flowing out of the centrifugal pump.

[0046] As an embodiment, the hydrogenation reactor is a fixed bed reactor.

[0047] As an embodiment, the hydrogenation reactor is a heterogeneous catalytic continuous flow fixed bed reactor.

[0048] As an embodiment, the industrial crude hydrogen purification and storage system further includes a dehydrogenation system for obtaining pure hydrogen.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The present invention uses crude toluene as a hydrogen storage medium, connecting the industrial crude hydrogen source with overcapacity and low price with the demand for high-purity hydrogen at the application end, changing the current development status of low added value of industrial hydrogen production hydrogen sources and large waste of industrial by-product hydrogen, and solving the safety problems of hydrogen during storage and transportation.

[0051] Specifically, in the traditional purification and storage of crude hydrogen, refined toluene is often required, while the present invention uses crude toluene, which has certain characteristics and advantages in terms of cost, process, resources, etc., as follows:

[0052] Cost: Crude toluene is usually a by-product or intermediate product in the industrial production process. It has a large output in the petrochemical and coal chemical industries and a relatively wide range of sources. Its price is much lower than that of refined toluene. Using crude toluene for hydrogen purification can reduce the cost of raw materials and improve the economy of the entire purification process. For large-scale industrial production, cost reduction can bring significant economic benefits;

[0053] Process: Refined toluene is often purified from crude toluene through strict treatment, which requires complex equipment and processes. The storage, transportation and use of refined toluene require high operating conditions and control measures to prevent impurities from mixing in, while the requirements for crude toluene are relatively low, which reduces the difficulty and risk of operation. In addition, the impurities in the crude toluene in the method provided by the present invention have relatively little impact on the catalyst and equipment, and have strong adaptability.

[0054] Resources: Using crude toluene to purify and store crude hydrogen can achieve the comprehensive utilization of industrial by-products, reduce resource waste and environmental pollution, and improve resource utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0056] Figure 1This is a system schematic diagram of the crude hydrogen purification and storage method in Example 21 of the present invention, wherein the arrow points to the flow direction of the gas or liquid in the pipeline. DETAILED DESCRIPTION

[0057] The present invention is described in detail below in conjunction with embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, some adjustments and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0058] This specific embodiment provides a method for purifying and storing crude hydrogen using crude toluene, which mainly generates methylcyclohexane from crude hydrogen and crude toluene under the action of a catalyst, and stores hydrogen in the methylcyclohexane, thereby achieving one-step purification and storage of industrial crude hydrogen.

[0059] The method is applicable to industrial crude hydrogen containing CO and CO2, and is particularly applicable to industrial hydrogen sources or industrial by-product hydrogen containing CO and CO2 at a volume concentration of 1 to 10%.

[0060] The method is applicable to industrial crude toluene containing benzene and ethylbenzene, and is particularly applicable to industrial crude toluene containing benzene and ethylbenzene in a mass concentration not exceeding 10%.

[0061] It should be noted that the starting point of the present invention is to improve the sensitivity of the catalyst to impurities so that crude toluene can be used in the purification and storage of crude hydrogen, but refined toluene is not excluded. Accordingly, the method for purifying and storing industrial crude hydrogen provided by the present invention for refined toluene also has excellent effects, which will not be described in detail in the present invention.

[0062] The method for purifying and storing crude hydrogen using crude toluene is described in detail below through Examples 1 to 20.

[0063] Example 1

[0064] In this embodiment, in the method for purifying and storing crude hydrogen using crude toluene, the raw materials are crude hydrogen, crude toluene and a catalyst, wherein:

[0065] Crude hydrogen is industrial crude hydrogen containing 1 vol.% CO and 5 vol.% CO2;

[0066] Crude toluene is industrial crude toluene containing 1 wt.% benzene and 3 wt.% ethylbenzene;

[0067] The catalyst is Ni / CeO2 catalyst, in which the mass fraction of Ni element is 10% and the rest is CeO2;

[0068] The catalyst dosage was 1 g, the crude toluene feed rate was 3.18 mL / h, and the hydrogen flow rate was 100 mL / min.

[0069] In this embodiment, the method for purifying and storing crude hydrogen using crude toluene comprises the following steps:

[0070] S1. Activation: The catalyst was activated with pure hydrogen at normal pressure and 500 °C for 5 h.

[0071] S2. Pressure increase: Use crude hydrogen to increase the pressure to 3 MPa.

[0072] S3. Hydrogenation: The crude toluene is pumped into the reactor by a plunger pump, and the crude toluene is hydrogenated at 170°C.

[0073] S4. Separation: Separating methylcyclohexane from the product after the hydrogenation reaction.

[0074] It should be noted that the catalyst in this embodiment is loaded into a hydrogenation reactor, and the steps of activation, pressurization and hydrogenation involved are all completed in the hydrogenation reactor.

[0075] In this embodiment, a fixed bed reactor is used as the hydrogenation reactor, and the catalyst bed is placed in the insulation section of the reactor. The gaps above and below are filled with quartz sand and separated by quartz wool.

[0076] The catalytic process involved in the above method includes:

[0077]

[0078]

[0079]

[0080] In this embodiment, the preparation method of Ni / CeO2 catalyst is:

[0081] (1) Preparation of CeO2 carrier powder:

[0082] The cerium nitrate was calcined at 500 °C in air atmosphere for 5 h to obtain CeO2 carrier powder;

[0083] (2) Preparation of active metal / carrier slurry:

[0084] Dissolve nickel nitrate in deionized water, add CeO2 carrier powder and stir to form a slurry. The mass of deionized water is 0.5 times the mass of CeO2 carrier powder, and perform ultrasound for 15 minutes to obtain a uniform slurry.

[0085] (3) Preparation of catalyst precursor:

[0086] The slurry was dried at 100 °C for 12 h, and then ground to 40-60 mesh to obtain catalyst precursor powder;

[0087] (4) Preparation of catalyst:

[0088] The catalyst precursor powder was calcined at 500 °C in air atmosphere for 5 h to obtain Ni / CeO2 catalyst.

[0089] It should be noted that, in this embodiment, the amount of each substance in the catalyst is configured with the active metal Ni and the carrier powder CeO2 in a mass ratio of 1:9.

[0090] Example 2

[0091] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0092] The catalyst was replaced with: Ni / Al2O3 catalyst, in which the mass fraction of Ni element was 10% and the rest was Al2O3;

[0093] The Al2O3 carrier powder is prepared by calcining aluminum nitrate at 500°C in an air atmosphere for 5 hours to obtain the Al2O3 carrier powder, and according to the preparation method of the catalyst in Example 1, the CeO2 carrier powder is replaced by the Al2O3 carrier powder to obtain a Ni / Al2O3 catalyst.

[0094] Example 3

[0095] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0096] The catalyst was replaced with: Ni / ZrO2 catalyst, in which the mass fraction of Ni element was 10% and the rest was ZrO2;

[0097] The ZrO2 carrier powder is prepared by calcining zirconium nitrate in an air atmosphere at 500°C for 5 hours to obtain the ZrO2 carrier powder, and according to the catalyst preparation method in Example 1, the CeO2 carrier powder is replaced by the ZrO2 carrier powder to obtain a Ni / ZrO2 catalyst.

[0098] Example 4

[0099] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0100] The catalyst was replaced with: Ni / MgO catalyst, in which the mass fraction of Ni element was 10% and the rest was MgO;

[0101] The MgO carrier powder is prepared by calcining magnesium nitrate in an air atmosphere at 500°C for 5 hours to obtain the MgO carrier powder, and according to the catalyst preparation method in Example 1, the CeO2 carrier powder is replaced with the MgO carrier powder to obtain a Ni / MgO catalyst.

[0102] Example 5

[0103] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0104] The catalyst was replaced with: Ni / SiO2 catalyst, in which the mass fraction of Ni element was 10% and the rest was SiO2;

[0105] The SiO2 carrier powder is prepared by calcining the silica sol in an air atmosphere at 500°C for 5 h to obtain the SiO2 carrier powder, and according to the preparation method of the catalyst in Example 1, the CeO2 carrier powder is replaced by the SiO2 carrier powder to obtain a Ni / SiO2 catalyst.

[0106] Example 6

[0107] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0108] The catalyst was replaced with: Fe / CeO2 catalyst, in which the mass fraction of Fe element was 10% and the rest was CeO2;

[0109] Among them, the active metal is replaced by Ni with Fe. In the preparation method of the catalyst, in the preparation of the active metal / carrier slurry, nickel nitrate is replaced by iron nitrate to obtain Fe / CeO2 catalyst.

[0110] Example 7

[0111] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0112] The catalyst was replaced with: Co / CeO2 catalyst, in which the mass fraction of Co element was 10% and the rest was CeO2;

[0113] Among them, the active metal is replaced by Co from Ni. In the preparation method of the catalyst, in the preparation of the active metal / carrier slurry, nickel nitrate is replaced by cobalt nitrate to obtain a Co / CeO2 catalyst.

[0114] Detection and analysis of Examples 1 to 7

[0115] After the crude toluene hydrogenation reaction, the mass concentrations of methylcyclohexane, toluene, benzene, ethylbenzene and toluene conversion in the products were detected, and the performance data of the catalyst are listed in Table 1. It can be seen that the catalyst composed of different active metals and carriers has a greater influence on the crude hydrogenation reaction of crude toluene. Among them, the active metal is Ni, and the carrier is Al2O3, CeO2 and SiO2, which show a good toluene conversion rate. Ni / CeO2 can reach a methylcyclohexane concentration of 70.3%. When CeO2 is used as a carrier and Fe and Co, which are also transition metals, are used, poor toluene hydrogenation activity is shown, indicating that the active metal Ni is also important for the hydrogenation reaction.

[0116] Table 1 Performance data of catalysts in Examples 1 to 7

[0117]

[0118] Example 8

[0119] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0120] The mass ratio of active metal Ni element and carrier CeO2 in the catalyst is 5:95.

[0121] Example 9

[0122] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0123] The mass ratio of active metal Ni element and carrier CeO2 in the catalyst is 15:85.

[0124] Example 10

[0125] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0126] S3. The pressure in the reactor rises to 2 MPa.

[0127] Embodiment 11

[0128] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0129] S3. The pressure in the reactor rises to 4 MPa.

[0130] Example 12

[0131] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0132] S4. The temperature of the crude toluene hydrogenation reaction is 150 °C.

[0133] Embodiment 13

[0134] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0135] S4. The temperature of the crude toluene hydrogenation reaction is 200 °C.

[0136] Embodiment 14

[0137] The steps of this embodiment are basically the same as those of embodiment 1, except that:

[0138] S4. The temperature of the crude toluene hydrogenation reaction is 230 °C.

[0139] Detection and analysis of Examples 8 to 14

[0140] After the crude toluene hydrogenation reaction, the mass concentrations of methylcyclohexane, toluene, benzene, and ethylbenzene in the product and the toluene conversion rate were detected, and the performance data of the catalyst are listed in Table 2. It can be seen that the active metal Ni content, reaction temperature, and reaction hydrogen pressure all have a significant effect on the toluene hydrogenation reaction. The appropriate amount of metal Ni content can reduce the content of metal Ni while maintaining a high conversion rate, thereby reducing the cost of the catalyst.

[0141] Since industrial crude hydrogen and crude toluene contain other impurities that can undergo hydrogenation reactions, when the hydrogen pressure in the reactor is low, the toluene hydrogenation reaction will be inhibited and the conversion rate will be significantly reduced. However, excessively high hydrogen pressure does not always promote the conversion rate of the reaction, and excessively high pressure will increase the difficulty of reactor design.

[0142] By regulating the temperature of the reactor, toluene can be almost completely converted into methylcyclohexane, and the benzene and ethylbenzene in the crude toluene can also be hydrogenated at the same time.

[0143] Table 2 Performance data of catalysts in Examples 8 to 14

[0144]

[0145] Embodiment 15

[0146] The steps of this embodiment are basically the same as those of embodiment 13, except that:

[0147] The crude hydrogen is industrial crude hydrogen containing 1 vol.% CO, 5 vol.% CO2 and 2% CH4.

[0148] Example 16

[0149] The steps of this embodiment are basically the same as those of embodiment 13, except that:

[0150] The crude hydrogen is industrial crude hydrogen containing 1 vol.% CO, 5 vol.% CO2, 2 vol.% CH4 and 0.5 vol.% O2.

[0151] Embodiment 17

[0152] The steps of this embodiment are basically the same as those of embodiment 13, except that:

[0153] The crude hydrogen is industrial crude hydrogen containing 1 vol.% CO, 5 vol.% CO2, 2 vol.% CH4, 0.5 vol.% O2 and 0.5 vol.% H2O.

[0154] Detection and analysis of Examples 15 to 17

[0155] After the crude toluene hydrogenation reaction, the mass concentrations of methylcyclohexane, toluene, benzene, and ethylbenzene in the products and the toluene conversion rate are detected as performance data of the catalyst and are listed in Table 3. It can be seen that for industrial crude hydrogen with different impurity systems, the crude hydrogen purification and storage methods provided in the present application can achieve a conversion rate of more than 94%, and the impurities basically do not cause other side reactions.

[0156] Table 3 Performance data of catalysts in Examples 15 to 17

[0157]

[0158] Embodiment 18

[0159] The steps of this embodiment are basically the same as those of Embodiment 17, except that:

[0160] The crude toluene is industrial crude toluene containing 1 wt.% of benzene, 3 wt.% of ethylbenzene and 3 wt.% of saturated alkanes (cyclohexane, ethylcyclohexane).

[0161] Embodiment 19

[0162] The steps of this embodiment are basically the same as those of Embodiment 17, except that:

[0163] The crude toluene is industrial crude toluene containing 1 wt.% of benzene, 3 wt.% of ethylbenzene, 3 wt.% of saturated alkanes (cyclohexane, ethylcyclohexane) and 0.5 wt.% of styrene.

[0164] Embodiment 20

[0165] The steps of this embodiment are basically the same as those of Embodiment 17, except that:

[0166] The crude toluene is industrial crude toluene containing 1 wt.% of benzene, 3 wt.% of ethylbenzene, 3 wt.% of saturated alkanes (cyclohexane, ethylcyclohexane), 0.5 wt.% of styrene and 1 wt.% of xylene.

[0167] Detection and analysis of Examples 18 to 20

[0168] After the crude toluene hydrogenation reaction, the mass concentrations of methylcyclohexane, toluene, benzene, and ethylbenzene in the product are detected as performance data of the catalyst and are listed in Table 4. It can be seen that for industrial crude toluene with different impurity systems, the crude hydrogen purification and storage method provided in the present application can achieve a toluene conversion rate of more than 98%, and the aromatic compounds additionally added to the crude toluene can also undergo hydrogenation reaction under the same conditions to generate corresponding saturated alkanes, and the saturated alkanes will not be converted.

[0169] Table 4 Conversion rate of each substance in crude toluene in Examples 18 to 20 (unit: %)

[0170]

[0171] This specific embodiment also provides a device for purifying and storing crude hydrogen using crude toluene, which is suitable for the application of the above-mentioned method for purifying and storing crude hydrogen using crude toluene, as shown in Example 21.

[0172] Embodiment 21

[0173] This embodiment provides a device for purifying and storing crude hydrogen using crude toluene, such as Figure 1 As shown, it includes: a toluene tank, a hydrogen compressor, a hydrogenation reactor, a circulating hydrogen compressor, a gas-liquid separator and a methylcyclohexane tank, wherein:

[0174] The inlet of the hydrogen compressor is connected to an industrial crude hydrogen source to provide a hydrogen source for the hydrogenation reactor;

[0175] The toluene tank provides hydrogenation substrates, such as industrial crude toluene, to the hydrogenation reactor;

[0176] The outlet of the hydrogenation reactor is connected to the inlet of the gas-liquid separator;

[0177] The gas-liquid separator is used for gas-liquid separation. The gas outlet of the gas-liquid separator is connected to the circulating hydrogen compressor, and the gas is transported to the hydrogenation reactor through the circulating hydrogen compressor for circulating hydrogen utilization; the liquid outlet of the gas-liquid separator is connected to the methylcyclohexane tank, and the liquid is transported to the methylcyclohexane tank for storage, thereby realizing the purification and storage of hydrogen.

[0178] The hydrogenation reactor in this embodiment is a heterogeneous catalytic continuous flow fixed bed reactor.

[0179] In this embodiment, a centrifugal pump, a first heat exchanger and a second heat exchanger are also provided, wherein:

[0180] A centrifugal pump, connected to the outlet of the toluene tank, is used to transport the hydrogenation substrate;

[0181] The first heat exchanger is provided between the centrifugal pump and the hydrogenation reactor, that is, before the hydrogenation substrate enters the hydrogenation reactor, it is first heated by the first heat exchanger;

[0182] The second heat exchanger is arranged between the hydrogenation reactor and the gas-liquid separator, that is, after the product after the hydrogenation reaction leaves the hydrogenation reactor, it is cooled by the second heat exchanger.

[0183] Furthermore, a third heat exchanger (such as a shell and tube heat exchanger) is provided to utilize heat transfer between the high-temperature liquid and the low-temperature liquid to achieve pre-cooling of the high-temperature liquid and pre-heating of the low-temperature liquid.

[0184] Specifically, in this embodiment, the liquid after the hydrogenation reaction (with a relatively high temperature) flowing out of the hydrogenation reactor and the crude toluene (with a relatively low temperature) flowing out of the toluene tank flow into different heat exchange tubes in the third heat exchanger, respectively, to achieve pre-cooling of the hydrogenation reaction product and pre-heating of the crude toluene. In this way, by recycling the waste heat, energy consumption can be reduced and resources can be saved.

[0185] In summary, the present invention provides a method for purifying and storing industrial crude hydrogen. By adjusting the process conditions, the hydrogenation of toluene and the hydrogenation reactions of other impurity carbon oxides and aromatics can be achieved simultaneously, the concentration of tail hydrogen can be increased and the hydrogen can be stored in methylcyclohexane. The phenomenon of oil-water stratification can be clearly observed in the liquid product after the reaction, indicating that the carbon oxides in the industrial crude hydrogen have undergone hydrogenation reactions, generating methane and water, and completing the purpose of separating hydrogen and impurities and purifying hydrogen; and further experiments have proved that the common impurities in industrial crude toluene and industrial crude hydrogen have little effect on the hydrogenation reaction. The purification and storage method provided by the present invention can well realize the purification and storage of crude hydrogen. Compared with the traditional industrial hydrogen production separation and purification method, the present invention realizes the hydrogenation of impurity components in industrial crude hydrogen and crude toluene under mild conditions, eliminates the cumbersome and expensive separation steps, stores hydrogen in methylcyclohexane, improves the convenience and reliability of transportation and storage, has a short process flow, high separation efficiency and low hydrogen cost.

[0186] Furthermore, by designing a purification and storage system for industrial crude hydrogen, which is used for the above-mentioned industrial crude hydrogen purification and storage method, crude toluene and crude hydrogen are introduced into a hydrogenation reactor through a feed pipe respectively, crude toluene reacts with hydrogen under the action of a catalyst, the product after the reaction is transported to a gas-liquid separator for gas-liquid separation, the separated liquid product methylcyclohexane is used to release hydrogen at the use end, and the separated gas is pressurized by a circulating hydrogen compressor and then returned to the hydrogenation reactor to achieve recycling. Through the coordination of various devices, the interference of impurities in industrial crude hydrogen and crude toluene is eliminated, and the separation and purification of hydrogen and its storage in methylcyclohexane are achieved in one step, which effectively improves the convenience of hydrogen storage and transportation and reduces the cost of hydrogen.

[0187] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for purifying and storing industrial crude hydrogen, characterized in that: The following steps are involved: S1. Activation: In the hydrogenation reactor, the catalyst is activated with pure hydrogen; S2, pressurization: using crude hydrogen to increase the pressure of the reactor; S3, hydrogenation: adding toluene into the reactor to carry out a hydrogenation reaction, thereby purifying and storing the industrial crude hydrogen; The catalyst is a supported catalyst, the active metal is Ni, and the carrier is CeO2; the mass ratio of the active metal to the carrier in the catalyst is (10-15):(85-90); The preparation method of the catalyst is: S11, preparing carrier powder: calcining a carrier salt in air at a temperature of 400-600° C. for 4-6 hours to obtain an oxide carrier powder, wherein the carrier salt is a salt compound of cerium, including one or more of nitrate, acetate and oxalate; S12, preparing active metal / carrier slurry: adding the carrier powder to an aqueous solution containing an active metal salt, stirring to form a slurry, and dispersing uniformly, wherein the active metal salt is a salt compound of the Ni element, including one or more of nitrate, chloride, sulfate and oxalate; S13, preparing a catalyst precursor: drying the slurry, and then grinding it to obtain a powdered catalyst precursor; S14, preparing a catalyst: calcining the catalyst precursor in air at a temperature of 400 to 600° C. for 4 to 6 hours to obtain the catalyst; The crude hydrogen is crude hydrogen containing gas phase impurities at a volume concentration of 1 to 10%, wherein the gas phase impurities include CO and CO2; The toluene contains liquid impurities with a mass concentration not exceeding 10%, and the liquid impurities include one or more of benzene, ethylbenzene, saturated alkanes, styrene and xylene.

2. The method for purifying and storing industrial crude hydrogen according to claim 1, characterized in that: It also includes one or more of the following technical features: In A and S1, the activation treatment is to activate the catalyst with pure hydrogen for 4 to 6 hours in a hydrogenation reactor at normal pressure and 400 to 600°C; B. The pressure-raising treatment is to control the pressure of the reactor at 3-4 MPa; C. The temperature of the hydrogenation reaction is 170-230°C.

3. The method for purifying and storing industrial crude hydrogen according to claim 1, characterized in that: The gas phase impurities also include one or more of CH4, O2 and H2O.

4. An industrial crude hydrogen purification and storage system, which is a system applied to the industrial crude hydrogen purification and storage method according to any one of claims 1 to 3, characterized in that: The system comprises: a toluene tank, a centrifugal pump, a first heat exchanger, a second heat exchanger, a hydrogen compressor, a hydrogenation reactor, a circulating hydrogen compressor, a gas-liquid separator and a methylcyclohexane tank, wherein: The inlet of the hydrogen compressor is connected to an industrial crude hydrogen source to provide a hydrogen source for the hydrogenation reactor; The toluene tank provides the heated hydrogenation substrate to the hydrogenation reactor through the centrifugal pump and the first heat exchanger; The outlet of the hydrogenation reactor is connected to the inlet of the gas-liquid separator through the second heat exchanger, so that the hydrogenation reaction product is cooled before gas-liquid separation; The gas outlet of the gas-liquid separator is connected to the circulating hydrogen compressor, and the gas is transported to the hydrogenation reactor through the circulating hydrogen compressor for circulating hydrogen utilization; the liquid outlet of the gas-liquid separator is connected to the methylcyclohexane tank, and the liquid is transported to the methylcyclohexane tank for storage.

5. The industrial crude hydrogen purification and storage system according to claim 4, characterized in that: The industrial crude hydrogen purification and storage system further comprises a third heat exchanger for heat exchange between the liquids flowing out of the hydrogenation reactor and the liquids flowing out of the centrifugal pump.

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