Industrial crude hydrogen purification and storage method and device based on γ-butyrolactone catalytic hydrogenation

Abstract

The present invention relates to a method and device for purifying and storing industrial crude hydrogen based on catalytic hydrogenation of gamma-butyrolactone, wherein the purification and storage method comprises: 2 The crude hydrogen is introduced into γ-butyrolactone for catalytic reaction, so that the hydrogen is stored in the molecules of 1,4-butanediol, realizing one-step separation and purification of crude hydrogen and catalytic hydrogen storage. Compared with the prior art, the present invention can realize one-step separation and purification of crude hydrogen and catalytic hydrogen storage, and can avoid CO and CO 2 The reaction temperature of side reactions such as hydrogenation to synthesize methanol is reduced, thereby obtaining high hydrogen storage efficiency and selectivity; when hydrogen is needed, high-purity hydrogen can be removed from 1,4-butanediol by a catalytic method; compared with traditional multi-step crude hydrogen purification methods such as water vapor shift-pressure swing adsorption-chemical absorption, the process reported in the present invention is short, efficient and low-cost.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy technology, and in particular to a method and device for purifying and storing crude hydrogen based on catalytic hydrogenation of gamma-butyrolactone. Background Art

[0002] Hydrogen is the cleanest energy source. It reacts with oxygen to release energy while only producing water. Since there are no other pollutants in the process, hydrogen energy utilization is considered to be one of the important means to achieve deep emission reduction and "dual carbon" goals. Currently, more than 80% of hydrogen comes from industrial processes such as coal gasification and natural gas reforming. As shown in Formula 1-2, the industrial hydrogen production process will be accompanied by a large amount of CO and CO2 gas impurities (25-50vol.%), and the existing industry usually uses the water vapor shift process (Formula 3), low-temperature methanation process (Formula 4), alcohol amine chemical absorption method, pressure swing adsorption and other process processes to extract hydrogen from crude hydrogen. The process involved is complicated and cumbersome, with large investment and high hydrogen loss. More importantly, the hydrogen separated by the above method still contains CO impurities in the order of hundreds of ppm, which will poison the precious metal catalysts such as Pt used in hydrogen fuel cells, thereby limiting the development of hydrogen energy application fields. It is urgent to develop simple and adaptable hydrogen separation and purification technology.

[0003] CH4+H2O→CO+3H2 (1)

[0004] C+H2O→CO+3H2 (2)

[0005] CO+H2O→CO2+H2 (3)

[0006] CO+3H2→CH4+H2O (4)

[0007] On the other hand, hydrogen storage and transportation also face bottleneck problems. Currently, hydrogen storage and transportation mainly adopt physical methods (high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, etc.), with low hydrogen storage density, and there are safety issues such as leakage, flammability, and explosion. The use of catalytic methods to store hydrogen in liquid organic unsaturated molecules, and then using catalytic methods to release it at the hydrogen use end, that is, organic liquid hydrogen storage technology, has gradually attracted people's attention. Existing organic liquid hydrogen storage molecules mainly include benzene derivatives and polycyclic aromatic hydrocarbons, heterocyclic aromatic hydrocarbons, carbazole and other types of compounds. For example, Chen Ping's team from Dalian Institute of Chemical Physics used sodium phenol / cyclohexanol as a hydrogen storage system and adopted Ru-based catalysts and Pt-based catalysts to realize the hydrogen storage cycle of the system (Adv Mater 2019, 31(50), e1902757.; Angew. Chem., Int. Ed. 2019, 58(10), 3102-3107.; J. Energy Chem. 2019, 39, 244-248.); Yi Chunhai's team from Xi'an Jiaotong University evaluated the feasibility of Pt-based catalyst-catalyzed benzyltoluene hydrogen storage cycle (ACS Catal. 2020, 10(18), 10661-10671.); Cheng Hansong's team from China University of Geosciences studied the dehydrogenation performance of Pd-based catalysts catalyzed by nitrogen-containing alkylcarbazoles (Int. J. Hydrogen Energy 2020,45(56),32168-32178.; Int.J. Hydrogen Energy 2021,46(15),9718-9729.).

[0008] For the above-mentioned mainstream organic liquid hydrogen storage molecules, in order to achieve better hydrogen storage performance, precious metal catalysts such as Pt, Pd, and Ru are usually used, and a higher reaction temperature is required. However, precious metal catalysts generally have a strong adsorption affinity for CO molecules. Even at extremely low CO partial pressures, the relevant precious metal catalysts can be strongly adsorbed by CO and poisoned and inactivated. Therefore, the organic liquid molecule hydrogenation storage system catalyzed by the above-mentioned precious metal catalysts cannot be effectively applied to the one-step separation and purification of crude hydrogen and catalytic hydrogenation storage, which is a technical problem that urgently needs to be solved. Summary of the invention

[0009] The purpose of the present invention is to provide a crude hydrogen purification and storage method and device based on γ-butyrolactone catalytic hydrogenation in order to overcome the defects of the above-mentioned prior art, which cleverly avoids the temperature range of CO and CO2 hydrogenation to synthesize byproducts such as methanol, so that highly selective hydrogenation and hydrogen storage can be achieved. In addition, the system uses a Cu-based catalyst, which has a strong tolerance to CO and CO2, so it shows a high hydrogenation activity. When using hydrogen, it can catalyze the dehydrogenation of 1,4-butanediol and obtain γ-butyrolactone.

[0010] The purpose of the present invention can be achieved by the following technical solutions:

[0011] The first aspect of the present invention provides an industrial crude hydrogen purification and storage method based on catalytic hydrogenation of γ-butyrolactone, comprising the following steps:

[0012] Crude hydrogen containing CO and CO2 is introduced into γ-butyrolactone for catalytic reaction, so that the hydrogen is stored in the molecules of 1,4-butanediol, achieving one-step separation and purification of the crude hydrogen and catalytic hydrogen storage.

[0013] Furthermore, the volume concentration of CO or CO2 in the crude hydrogen is less than 70%.

[0014] Furthermore, the catalyst of the catalytic reaction is a Cu-based catalyst.

[0015] Further, the process of the catalytic reaction is:

[0016]

[0017] Furthermore, the Cu-based catalyst comprises the following components in percentage by mass:

[0018] Cu 10~70

[0019] Carrier 30~90.

[0020] Furthermore, the carrier is selected from one or more of SiO2, Cr2O3, ZnO, ZrO2, and Al2O3.

[0021] Further preferably, the carrier is ZrO2.

[0022] Furthermore, in the catalytic reaction, the catalytic hydrogenation temperature is 140-200° C., and the reaction pressure is 0.01-10 MPa.

[0023] The second aspect of the present invention provides a device for the above-mentioned crude hydrogen purification and storage method, comprising a crude hydrogen storage tank, a γ-butyrolactone storage tank, a hydrogenation reactor and a hydrogenation product storage tank, wherein specifically:

[0024] The crude hydrogen storage tank is connected to the industrial hydrogen production section through pipelines;

[0025] The hydrogenation reactor is connected to the crude hydrogen storage tank and the γ-butyrolactone storage tank respectively, and the hydrogenation reactor is provided with a hydrogen-depleted tail gas outlet and a hydrogenation product outlet;

[0026] The hydrogenation product storage tank is connected to the hydrogenation product outlet through a pipeline to achieve the storage of purified hydrogen.

[0027] Furthermore, the hydrogenation reactor is a heterogeneous catalytic continuous flow reactor or a heterogeneous catalytic kettle reactor.

[0028] Compared with the prior art, the present invention has the following technical advantages:

[0029] 1) The present invention can realize one-step separation, purification and storage of crude hydrogen, thereby reducing the cost of hydrogen separation; hydrogen is stored in 1,4-butanediol, thereby reducing the storage and transportation cost of hydrogen and improving safety.

[0030] 2) The 1,4-butanediol and γ-butyrolactone used in the present invention are stable and non-toxic, are liquid at room temperature, have good selectivity / circulation, have mature hydrogenation and dehydrogenation technologies, have good low-temperature hydrogenation and dehydrogenation performance, do not require high-pressure storage and transportation equipment, and are safer than using high-pressure tank trucks to transport hydrogen.

[0031] 3) The γ-butyrolactone / 1,4-butanediol liquid coupled hydrogen storage system and catalyst provided by the present invention are moderately priced and have strong application prospects. In addition, the process is almost free of side reactions such as methanol synthesis involving CO and CO2 impurity gases. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the structure of a crude hydrogen purification and storage device based on catalytic hydrogenation of γ-butyrolactone in the present technical solution.

[0033] In the figure: 1. crude hydrogen storage tank, 2. γ-butyrolactone storage tank, 3. hydrogenation reactor, 4. hydrogenation product storage tank. DETAILED DESCRIPTION

[0034] In order to solve the problem of separating, purifying and storing hydrogen from crude hydrogen containing CO and CO2 in one step, the present invention uses a non-precious metal Cu-based catalyst that can tolerate high concentrations of CO and CO2, directly catalyzes the selective reaction of hydrogen with γ-butyrolactone in crude hydrogen to produce 1,4-butanediol, and achieves the selective reaction of hydrogen with γ-butyrolactone under the temperature condition of 140-200°C, stores hydrogen in 1,4-butanediol, and stores unreacted CO and / or CO2 tail gas or directly applies it to downstream. Under this temperature condition, hydrogen is not easy to react with CO and CO2 to form methanol.

[0035] Through the use of cheap non-precious metal Cu catalyst, the hydrogen in the crude hydrogen is catalyzed to react with γ-butyrolactone at 140-200°C, and the hydrogen is stored in the molecules of 1,4-butanediol, thereby achieving one-step separation and purification of crude hydrogen and catalytic hydrogen storage. Since the active catalytic component Cu has weak adsorption affinity with CO and CO2, the catalyst is not easily poisoned and deactivated; at the same time, the reaction temperature range of 140-200°C can avoid the reaction temperature (about 250°C) of side reactions such as hydrogenation of CO and CO2 to synthesize methanol, thereby obtaining high hydrogen storage efficiency and selectivity. When hydrogen is needed, high-purity hydrogen can be removed from 1,4-butanediol by catalytic methods. Compared with traditional multi-step crude hydrogen purification methods such as water vapor shift-pressure swing adsorption-chemical absorption, the process reported in the present invention is short, efficient and low-cost.

[0036] Therefore, the present invention provides a method for selectively separating, purifying and storing hydrogen from crude hydrogen in one step. The generated hydrogen storage medium 1,4-butanediol only needs to be stored in the same way as general chemicals, which is convenient for transportation. The subsequent 1,4-butanediol catalytic dehydrogenation technology is mature, and high-purity hydrogen can be easily obtained under mild conditions.

[0037] like Figure 1 As shown, the one-step separation, purification and storage system of hydrogen based on the selective catalytic hydrogenation reaction of hydrogen and γ-butyrolactone according to the present invention comprises a crude hydrogen buffer tank 1, a γ-butyrolactone storage tank 2, a hydrogenation product storage tank 4 and a hydrogenation reactor 3. The crude hydrogen obtained is connected to the inlet of the crude hydrogen buffer tank, and after pressure regulation in the buffer tank, it is transported to the hydrogenation reactor together with γ-butyrolactone, and converted into a hydrogen-rich 1,4-butanediol product under the action of a catalyst. Subsequently, the liquid product is input into the storage tank from the bottom of the reactor, and the hydrogen-poor CO / CO2 tail gas is discharged and collected for other uses.

[0038] The γ-butyrolactone catalytic hydrogenation reactor is a fixed bed or kettle reactor, which is equipped with electric heating wires, temperature sensors, pressure sensors, and hydrogenation catalysts. Crude hydrogen and γ-butyrolactone are introduced into the upper end of the reactor from a buffer / storage tank, and then hydrogenation reaction occurs under the action of Cu catalyst at a temperature of 140-200°C to obtain hydrogen storage product 1,4-butanediol and incompletely reacted γ-butyrolactone.

[0039] The present invention realizes the one-step separation, purification and storage of crude hydrogen, reduces the cost of hydrogen separation; stores hydrogen in 1,4-butanediol, reduces the storage and transportation cost of hydrogen and improves safety. Calculated based on a 500-ton ordinary liquid material storage tank, 500 tons of 1,4-butanediol will be able to produce about 22.3 tons of hydrogen. If a high-pressure long-tube trailer (200-300kg / car) is used to transport 22.3 tons of hydrogen, it will take about 74 to 110 train trips. If a tank truck is used to transport 500 tons of 1,4-butanediol / γ-butyrolactone equivalent to hydrogen, it will only take about 10 train trips, greatly reducing the transportation cost. In addition, 1,4-butanediol and γ-butyrolactone are stable and non-toxic, are liquid at room temperature, have good selectivity / circulation, have mature hydrogenation and dehydrogenation technologies, and have good low-temperature hydrogenation and dehydrogenation performance. They do not require high-pressure storage and transportation equipment, and are safer than using high-pressure tank trucks to transport hydrogen. In addition, the γ-butyrolactone / 1,4-butanediol liquid coupled hydrogen storage system and catalyst provided by the present invention are moderately inexpensive and have strong application prospects, and the process will not be accompanied by side reactions such as methanol synthesis involving CO and CO2 impurity gases.

[0040] The present invention is described in detail below in conjunction with specific embodiments. Any features such as preparation means, materials, structures or composition ratios not clearly described in this technical solution are regarded as common technical features disclosed in the prior art.

[0041] Example 1

[0042] The present embodiment adopts Cu / SiO2 catalyst, wherein the Cu mass fraction is 30% and the rest is SiO2. The Cu / SiO2 catalyst is paved in the reaction tube of the fixed bed, and the upper and lower gaps are filled with quartz sand. The catalyst is activated under H2 atmosphere and 250°C. The crude hydrogen containing CO (wherein the CO content is 16.7vol%, and the H2 content is 83.3vol%) and γ-butyrolactone are simultaneously passed into the fixed bed reactor and reacted at 170°C. The H2 content in the tail gas accounts for 78.9vol%, and the CO content is 21.1vol%, which can realize the storage of hydrogen, and the space-time yield of γ-butyrolactone can adjust its conversion rate and the corresponding hydrogen storage capacity.

[0043] Example 2

[0044] The present embodiment adopts Cu / ZrO2 catalyst, wherein the mass fraction of Cu is 10% and the rest is ZrO2. The Cu / ZrO2 catalyst is paved in the reaction tube of the fixed bed, and the gaps on the upper and lower sides are filled with quartz sand. The catalyst is activated under H2 atmosphere and 250°C. Crude hydrogen containing CO (wherein the CO content is 5vol%, and the H2 content is 95vol%) and γ-butyrolactone are simultaneously introduced into the fixed bed reactor and reacted at 140°C. The H2 content in the tail gas accounts for 94.4vol%, and the CO content is 5.6vol%. The conversion rate and the corresponding hydrogen storage capacity can be adjusted by adjusting the time-space yield of γ-butyrolactone.

[0045] Example 3

[0046] The present embodiment adopts Cu / Cr2O3-SiO2 catalyst, wherein the mass fraction of Cu is 30%, the mass fraction of Cr2O3 is 10%, and the rest is SiO2. The Cu / Cr2O3-SiO2 catalyst is paved in the reaction tube of the fixed bed, and quartz sand is used to fill the gaps on both sides. The catalyst is activated under H2 atmosphere and 250°C. Crude hydrogen containing CO (wherein the CO content is 82.5vol%, and the H2 content is 12.5vol%) and γ-butyrolactone are simultaneously introduced into the fixed bed reactor and reacted at 200°C. The H2 content in the tail gas accounts for 6.7vol%, and the CO content is 93.3vol%. The conversion rate and the corresponding hydrogen storage capacity can be adjusted by adjusting the time-space yield of γ-butyrolactone.

[0047] Example 4

[0048] The present embodiment adopts Cu / ZnO catalyst, wherein the mass fraction of Cu is 70% and the rest is ZnO. The Cu / ZnO catalyst is paved in the reaction tube of the fixed bed, and the gaps on the upper and lower sides are filled with quartz sand. The catalyst is activated under H2 atmosphere and 250°C. Crude hydrogen containing CO (wherein the CO content is 5vol%, and the H2 content is 95vol%) and γ-butyrolactone are simultaneously passed into the fixed bed reactor and reacted at 140°C. The H2 content in the tail gas accounts for 57.1vol%, and the CO content is 42.9vol%. The conversion rate and the corresponding hydrogen storage capacity can be adjusted by adjusting the space-time yield of γ-butyrolactone.

[0049] Example 5

[0050] This embodiment uses a Cu / ZrO2 catalyst, in which the mass fraction of Cu is 30% and the rest is ZrO2. The catalyst is activated in a H2 atmosphere at 250°C.

[0051] Cu / ZrO2 catalyst, γ-butyrolactone (concentration of 16.7 wt%), H2 and CO at different partial pressures were added to the reactor and reacted at 200°C for 1 hour, which can achieve effective storage and separation of H2. Table 1 is the relevant test results of this example.

[0052] Table 1. Experimental test results of γ-butyrolactone hydrogenation catalyzed by Cu / ZrO2 at different CO partial pressures

[0053]

[0054] Example 6

[0055] This embodiment uses a Cu / ZrO2 catalyst, in which the mass fraction of Cu is 30% and the rest is ZrO2. The catalyst is activated in a H2 atmosphere at 250°C.

[0056] Adding Cu / ZrO2 catalyst, γ-butyrolactone (concentration of 16.7 wt%), H2 and CO2 at different partial pressures into the reactor and reacting at 200°C for 1 hour can achieve effective storage and separation of H2. Table 2 is the relevant test results of this example.

[0057] Table 2. Experimental test results of γ-butyrolactone hydrogenation catalyzed by Cu / ZrO2 at different CO2 partial pressures

[0058]

[0059] Example 7

[0060] The present embodiment adopts Cu / SiO2 catalyst, wherein the Cu mass fraction is 30%, and the rest is SiO2. The Cu / SiO2 catalyst is paved in the reaction tube of the fixed bed, and the upper and lower gaps are filled with quartz sand. The catalyst is activated under H2 atmosphere and 250°C. The crude hydrogen containing CO and CO2 (wherein the CO content is 8.4vol%, the CO content is 16.7vol%, and the H content is 66.7vol%) and γ-butyrolactone are simultaneously passed into the fixed bed reactor and reacted at 170°C. The H2 content accounts for 29.3vol% in the tail gas, the CO content is 23.6vol%, and the CO2 content is 47.1vol%. The conversion rate and the corresponding hydrogen storage capacity can be adjusted by adjusting the space-time yield of γ-butyrolactone.

[0061] Example 8

[0062] This example illustrates the dehydrogenation of 1,4-butanediol. A Cu / SiO2 catalyst is used, wherein the mass fraction of Cu is 30% and the rest is SiO2. The Cu / SiO2 catalyst is laid in a fixed bed reaction tube, and quartz sand is used to fill the gaps on the upper and lower sides. The catalyst is activated under H2 atmosphere at 250°C. The reaction conditions for the dehydrogenation of 1,4-butanediol are: 180°C, 0.1MPa, liquid space velocity 0.2h -1 The final 1,4-butanediol conversion rate was 100%, and the H2 yield was 99%.

[0063] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A crude hydrogen purification and storage method based on catalytic hydrogenation of γ-butyrolactone, characterized in that: The steps include: The crude hydrogen containing CO and CO2 is introduced into γ-butyrolactone for catalytic reaction, so that the hydrogen is stored in the molecules of 1,4-butanediol, thus realizing the one-step separation and purification of the crude hydrogen and catalytic hydrogen storage; The volume concentration of CO or CO2 in the crude hydrogen is less than 70%; The catalyst of the catalytic reaction is a Cu-based catalyst; The process of the catalytic reaction is: ； In the catalytic reaction: the catalytic hydrogenation temperature is 140~200℃, and the reaction pressure is 0.01~10MPa; The Cu-based catalyst is: Cu / SiO2 catalyst, in which the mass fraction of Cu is 30% and the rest is SiO2; or, Cu / ZrO2 catalyst, in which the mass fraction of Cu is 10% and the rest is ZrO2; or, Cu / Cr2O3-SiO2 catalyst, in which the mass fraction of Cu is 30%, the mass fraction of Cr2O3 is 10%, and the rest is SiO2; or, Cu / ZnO catalyst, in which the mass fraction of Cu is 70% and the rest is ZnO; or, Cu / ZrO2 catalyst, in which the mass fraction of Cu is 30% and the rest is ZrO2.

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