A method for purifying hydrogen for fuel cell vehicles

Abstract

The application belongs to the field of hydrogen purification. Specifically disclosed is a hydrogen purification method for fuel cell vehicles. A hydrogen-containing source gas is purified by using two kinds of purification materials A and B in series to remove various trace impurities. Purification material A simultaneously removes aldehyde, acid, ammonia, CO2, halogen impurities, purification material B simultaneously removes CO, O2 and sulfur, and purification material A and purification material B jointly remove aldehyde, acid, ammonia, CO2, halogen, CO, O2 and sulfur impurities to obtain hydrogen for fuel cell vehicles. The method can be used to remove trace impurities such as aldehyde, acid, ammonia, CO2, halogen, CO, O2 and sulfur in high-purity hydrogen, and meets the national standard requirements for hydrogen for fuel cell vehicles.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydrogen purification, and particularly relates to removal and purification of trace amounts of aldehyde, acid, ammonia, CO2, halogen, CO, O2 and sulfur and the like impurities. BACKGROUND

[0002] Hydrogen energy will be one of the main energies of future society, and currently, all countries in the world have included hydrogen energy in the national development strategy. Hydrogen, as the main fuel of a proton exchange membrane fuel cell (PEMFC), greatly influences the performance of the cell. When hydrogen is derived from fossil fuel reforming or industrial by-product hydrogen or water electrolysis, it contains impurities brought from the raw material and some by-products, such as trace amounts of CO, O2, sulfur, aldehyde, acid, ammonia, CO2, halogen and the like. The presence of these impurities will affect the stable operation of the proton exchange membrane fuel cell, greatly shorten the use efficiency and service life of the proton exchange membrane fuel cell, and therefore, the content of impurities in the hydrogen for fuel cells must be controlled.

[0003] The national standard GB / T 37244-2018 for hydrogen for fuel cell vehicles requires that the formaldehyde is ≤0.01 ppm, the formic acid is ≤0.2 ppm, the NH3 is ≤0.1 ppm, the CO2 is ≤2 ppm, the total halide is ≤0.05 ppm, the CO is ≤0.2 ppm, the O2 is ≤5 ppm, and the sulfur is ≤0.004 ppm. Currently, the hydrogen for fuel cell vehicles has not been applied on a large scale, and small-scale PSA is mainly used to improve the purity of hydrogen. The aldehyde, acid, ammonia, CO2, halogen, CO, O2 and sulfur impurities after purification are mainly purified respectively, and there is no systematic solution.

[0004] Currently, the removal of O2 in hydrogen is the most sufficient, and the catalytic combustion catalyst of a noble metal system is generally used to generate water through the hydrogen-oxygen reaction, and the technology is mature and has been widely applied in industry.

[0005] Sulfur is a common poison for general industrial catalysts, and the removal of sulfur has also been widely and deeply studied. Generally, according to the tolerance of the downstream catalyst to sulfur, it is divided into rough desulfurization (~1 ppm), fine desulfurization (<0.1 ppm), and deep fine desulfurization (<0.01 ppm), and the index of <0.004 ppm in the hydrogen for fuel cell vehicles is the most stringent. The effective desulfurization material is a copper-zinc compound.

[0006] The removal of CO in hydrogen mainly includes four kinds: cryogenic, pressure swing adsorption (PSA), catalytic oxidation, methanation and complex removal. The cryogenic method must be considered in terms of economy, and the gas volume must reach several hundred thousand Nm 3The large-scale device on the / h, for the current small hydrogen energy industry almost no economic, and CO removal accuracy does not reach <0.2ppm national standard requirements; pressure swing adsorption is currently widely used in purification separation method, can be used for small and medium-sized industrial devices, through PSA on the one hand to improve the purity of hydrogen, so that it meets the national standard > 99.97% requirements, while also removed most of the impurities, including CO, the disadvantage is that the CO removal accuracy can not meet the national standard requirements, currently generally is used PSA series directional purification material two-step removal of hydrogen CO; catalytic oxidation removal of CO in hydrogen is currently a research hotspot, focus on improving the selectivity and low temperature activity of catalytic oxidation, catalytic oxidation method using scene is mainly methanol cracking hydrogen and hydrocarbon hydrogen percentage of CO content to <100ppm, for a few to tens of ppm of CO purification after PSA has heart no strength; methanation removal of CO in hydrogen obvious shortcomings, one is to remove CO while consuming three times the volume of hydrogen, two is the removal of temperature is high, the economic application of industrial is poor, three is the CO removal accuracy can not meet the <0.2ppm national standard requirements; Cu + And COπ complexation removal of CO in gas has a lot of research, among them, Professor Xie Youchang of Peking University under the guidance of the single molecule layer distribution theory developed PU-1 CO adsorbent is the most successful, and in large industrial device has been successfully applied, for the gas CO purification separation, but the complexation method is generally used for gas constant CO purification separation, can not meet the CO <0.2ppm national standard requirements.

[0007] CO removal also has a method, using the carrier loaded high dispersion CuO material and CO reaction, CO oxidation into CO2, but this material is generally used for trace CO removal in hydrocarbons and other inert materials, can not be used in hydrogen gas source, especially fuel cell vehicle hydrogen source of high purity hydrogen, because hydrogen is also a reducing gas, hydrogen and CuO reaction leads to material failure can not and CO removal.

[0008] For the purification of chlorine in halogen, the research and application are relatively sufficient, and the general industrial device requires ≤0.1ppm of chlorine.

[0009] For the purification of ammonia, the general index requirement is ≤0.1ppm.

[0010] For the purification of aldehyde and acid, the preliminary adsorption treatment is generally used respectively, and the treatment accuracy and adsorption capacity cannot be guaranteed.

[0011] For CO2 purification, molecular sieve is generally used for targeted adsorption.

[0012] For the purification of halogen, ammonia, aldehyde, acid, CO2, special purifying agent or adsorbent is generally used for separate treatment.

[0013] In summary, if aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur impurities are removed separately using conventional technologies, the inconsistent temperature, pressure, and space velocity requirements for each impurity purification process lead to complex purification procedures, cumbersome operations, large amounts of purification materials, and high operating costs. Furthermore, it easily results in impurity exceeding standards, compromising hydrogen quality, increasing the cost of hydrogen for fuel cell vehicles, severely reducing competitiveness, and significantly hindering the development of my country's hydrogen energy industry. Currently, the market urgently needs a simple purification process that can intensively purify and remove aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur impurities, meeting the requirements of the national standard GB / T37244-2018 for hydrogen used in fuel cell vehicles. Summary of the Invention

[0014] The technical problem to be solved by this invention is to address the shortcomings of existing technologies by providing a method for purifying hydrogen for fuel cell vehicles. This method can remove trace amounts of impurities such as aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur, with the content of each impurity meeting the national standards for hydrogen used in fuel cell vehicles.

[0015] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0016] A method for purifying hydrogen for fuel cell vehicles involves using two purification materials, A and B, connected in series to remove various trace impurities from the hydrogen-containing source gas. Purification material A simultaneously removes impurities such as aldehydes, acids, ammonia, CO2, and halogens, while purification material B simultaneously removes CO, O2, and sulfur. The combined use of purification materials A and B removes impurities such as aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur to obtain hydrogen for fuel cell vehicles.

[0017] Wherein: the purification material A is a molecular sieve modified with noble metals and rare earth metal oxides, wherein the noble metal is selected from at least one of Pt, Ru or Pd, and the rare earth metal oxide is selected from at least one of CeO2 or La2O3;

[0018] The purification material B is a composite of copper silicate with a malachite structure and type A molecular sieve, wherein the content of copper silicate with a malachite structure is 30-70%, and the balance is type A molecular sieve.

[0019] According to the above scheme, purification material A can simultaneously remove impurities such as aldehydes, acids, ammonia, CO2, and halogens at temperatures not exceeding 120℃ (e.g., 10℃ to 120℃). Purification material B can simultaneously remove trace amounts of CO, O2, and sulfur at temperatures between 60℃ and 120℃. Purification material A can be used alone at room temperature, and it has good performance at temperatures from room temperature to no higher than 120℃. To work in conjunction with purification material B for combined removal, purification material A can be used in the same temperature range as purification material B, within the range of 60-120℃.

[0020] According to the above scheme, the hydrogen-containing source gas is high-purity hydrogen gas that has been purified and refined. Specifically, the hydrogen-containing source gas can be hydrogen from different sources, such as hydrogen produced from coal, hydrogen produced from methanol cracking, industrial by-product hydrogen, and hydrogen produced from water electrolysis. Furthermore, it is purified and refined through processes such as pressure swing adsorption or cryogenic treatment to obtain high-purity hydrogen with increased purity. The purification and refinement process mainly aims to improve the purity of the hydrogen, raising it to over 99.9%. At the same time, a large number of impurities are also removed during this process.

[0021] According to the above scheme, depending on the impurity content in the specific hydrogen-containing source gas, the order of purification materials A and B can be interchanged. That is, the hydrogen-containing source gas to be treated can be purified by purification material A first and then by purification material B, or purified by purification material B first and then by purification material A. Both methods can remove impurities such as aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur. After removal, the content of each impurity in the high-purity hydrogen meets the requirements of the national standard GB / T37244-2018 for hydrogen used in fuel cell vehicles, namely, formaldehyde ≤ 0.01 ppm, formic acid ≤ 0.2 ppm, NH3 ≤ 0.1 ppm, CO2 ≤ 2 ppm, total halides ≤ 0.05 ppm, CO ≤ 0.2 ppm, O2 ≤ 5 ppm, and sulfur ≤ 0.004 ppm.

[0022] The purification material A provided by the present invention is specifically a modified molecular sieve material, which is obtained by modifying type A molecular sieves and noble metal ions and rare earth metal ions through ion exchange, molding, calcination and activation. The modified noble metal ions and rare earth metal ions are transformed into the above-mentioned noble metal and rare earth metal oxides loaded in the purification material. The inventors of this application have creatively discovered that a molecular sieve material obtained by modifying type A molecular sieves with the aforementioned precious metals and rare earth metal oxides can simultaneously remove trace amounts of impurities such as aldehydes, acids, ammonia, CO2, and halogens from hydrogen-containing source gases at temperatures not exceeding 120°C. The hydrogen-containing source gas can be hydrogen from various sources, such as hydrogen produced from coal, methanol cracking, industrial by-product hydrogen, or water electrolysis. Furthermore, it can be high-purity hydrogen obtained through purification processes such as pressure swing adsorption or cryogenic treatment, where the purification process primarily increases the hydrogen purity to over 99.9%. Simultaneously, a large number of impurities are also removed during this process. The purification material A in this process then selectively removes various impurities such as trace amounts of aldehydes, acids, ammonia, CO2, and halogens. After purification, the impurities such as aldehydes, acids, ammonia, CO2, and halogens meet the requirements of the national standard GB / T37244-2018 for hydrogen used in fuel cell vehicles, without generating new impurities.

[0023] In the purification material A provided by this invention, the noble metal is selected from at least one of Pt, Ru, or Pd, preferably from Pt, Ru, or Pd; the rare earth metal oxide is selected from at least one of CeO2 or La2O3, preferably from CeO2 or La2O3. The content of the noble metal in the purification material is 0.01–0.3 wt%; the content of the rare earth metal oxide in the purification material is 1–8 wt%.

[0024] The present invention also provides a method for preparing the above-mentioned purified material A, comprising the following steps:

[0025] Type A molecular sieves are subjected to ion exchange in a solution containing noble metal ions and rare earth metal ions. The resulting material after ion exchange is then subjected to molding, calcination and activation in sequence to obtain purified material A.

[0026] In the preparation method of purification material A provided by the present invention, the noble metal and the rare earth metal correspond to the noble metal and rare earth metal oxides in the above-mentioned purification material A. That is, the noble metal ion is selected from at least one of Pt ion, Ru ion, or Pd ion, preferably selected from Pt ion, Ru ion, or Pd ion; the rare earth metal ion is selected from at least one of Ce ion or La ion, preferably selected from Ce ion or La ion. In the solution containing noble metal ion and rare earth metal ion of the present invention, the content of the noble metal ion is 0.01-0.3 wt% based on metal; the content of the rare earth metal ion is 1-8 wt% based on metal oxide.

[0027] In some embodiments of the present invention, the solution containing noble metal ions and rare earth metal ions is a mixed solution of noble metal salts and rare earth metal salts; the noble metal salts include, but are not limited to, at least one of chloroplatinic acid, ruthenium chloride, or palladium chloride; the rare earth metal salts include, but are not limited to, at least one of cerium nitrate or lanthanum nitrate. The mixed solution of noble metal salts and rare earth metal salts in the present invention is an aqueous solution. If necessary, different amounts of hydrochloric acid, oxalic acid, acetic acid, or citric acid can be used as co-solvents for the noble metal salts and rare earth metal salts.

[0028] In the preparation method of the purification material A described in this invention, the type A molecular sieve is an 80-100 mesh powder, selected from 3A molecular sieve, 4A molecular sieve, or 5A molecular sieve, wherein the typical chemical composition of the 3A molecular sieve is as follows: The typical chemical composition of the 4A molecular sieve is as follows: The typical chemical composition of the 5A molecular sieve is as follows: All A-type molecular sieves described in this invention are commercially available.

[0029] The type A molecular sieve of this invention has a silicon-to-aluminum ratio of 1:1 and contains alkali metals or alkaline earth metals such as sodium, potassium, and calcium. It has a certain removal capacity for acidic substances such as acids, CO2, and halogens. After being modified with noble metals Pt / Ru / Pd and rare earth metals Ce / La, the type A molecular sieve adsorbs the above-mentioned noble metal and rare earth metal oxides, which further improves its purification accuracy for acidic substances such as acids, CO2, and halogens, so that it meets the requirements of formic acid ≤0.2ppm, CO2 ≤2ppm, and total halides ≤0.05ppm.

[0030] The A-type molecular sieve described in this invention has a pore size of 3–5 angstroms. Before modification, the A-type molecular sieve has a pore size of 3–5 angstroms. Through modification with noble metals Pt / Ru / Pd, followed by a reduction process, noble metal nanoparticles are formed inside the molecular sieve. This further adjusts the pore size of the purification material A, allowing hydrogen molecules with a critical diameter of 2.4 angstroms to pass through smoothly, while aldehydes with a diameter of 4.4–5 angstroms and ammonia molecules with a diameter of 3.8 angstroms cannot pass through, thus achieving a purification effect.

[0031] The method for preparing purified material A provided by the present invention involves ion exchange between the above-mentioned solution containing noble metal ions and rare earth metal ions and the above-mentioned type A molecular sieve, followed by washing, air-drying, drying, molding, calcining and activation of the ion-exchanged material to obtain purified material A.

[0032] This invention first involves ion exchanging the type A molecular sieve in a solution containing noble metal ions and rare earth metal ions. The ion exchange temperature is 20–100°C, and the ion exchange time is 0.5–100 h. The ion exchange is performed at least once, and multiple ion exchanges can be performed to ensure the required content of the active component. In some embodiments of this invention, the type A molecular sieve undergoes one ion exchange in the solution containing noble metal ions and rare earth metal ions at a temperature of 50–80°C and a time of 10–20 h. After the ion exchange, the qualified material is washed multiple times with pure water until no Cl is detected in the wash water using silver nitrate solution. - .

[0033] This invention involves ion exchanging a type A molecular sieve in a solution containing noble metal ions and rare earth metal ions, followed by molding the resulting material. Before molding, the ion-exchange material is first air-dried for 1–24 hours, then dried in air at 80–150°C for 2–6 hours, and finally molded. Specifically, the molding process involves mixing the dried material with a binder and then extruding the mixture. The resulting shape can be spherical, strip-shaped, or cylindrical.

[0034] This invention involves shaping the material obtained after ion exchange and then calcining the shaped material. The calcination temperature is 400–600°C, and the calcination time is 3–10 hours. Specifically, the calcination is carried out in an inert atmosphere; the inert atmosphere is a well-known inert atmosphere to those skilled in the art, such as a nitrogen atmosphere, a helium atmosphere, a neon atmosphere, or an argon atmosphere.

[0035] This invention involves calcining the shaped material and then activating the calcined material to obtain purified material A. Specifically, the activation process involves activating the material at 200–300°C for 3–5 hours in a hydrogen atmosphere. The purpose of this activation is to ensure that the precious metal exists in a zero valence state.

[0036] The purification material B provided by this invention is specifically a composite of chrysocolla-structured copper silicate and type A molecular sieve, wherein the content of chrysocolla-structured copper silicate is 30-70%, and the balance is type A molecular sieve. The chrysocolla-structured copper silicate is prepared by co-precipitation of copper ammonia solution and silica sol, followed by washing, drying, and calcination, and then compounded with type A molecular sieve to obtain the final product. More specifically, the chrysocolla-structured copper silicate can be mixed with a certain proportion of type A molecular sieve, ball-milled uniformly, and then sheeted to obtain the final product. The specific calcination temperature in this invention is 350-400℃.

[0037] The purified material B provided by this invention has a CuO to SiO2 molar ratio of 0.1 to 0.5:1 in the chrysocolla structure of copper silicate.

[0038] The type A molecular sieve in the purification material B provided by this invention is a commercially available 3A, 4A, or 5A molecular sieve.

[0039] Typical chemical composition of 3A molecular sieve: Typical chemical composition of 4A molecular sieve: Typical chemical composition of 5A molecular sieve

[0040] This invention provides a method for preparing purified material B, comprising the following steps:

[0041] (1) Prepare 0.05-1.0 mol / L copper ammonia solution and 0.1-1.0 mol / L silica sol, and pour them into a container with a stirrer and stir until homogeneous;

[0042] (2) The above solution is evaporated by steam heating, and the evaporated material is repeatedly washed with reverse osmosis pure water. The filtered material is dried at 100-150°C and then calcined at 350-400°C for 3-6 hours to obtain copper silicate with malachite structure.

[0043] (3) A type molecular sieve was added to copper silicate with a malachite structure in a certain proportion, ball milled, and shaped into sheets to obtain hydrogen purification material for fuel cell vehicles with a malachite structure.

[0044] According to the above scheme, the molar ratio of CuO to SiO2 in the malachite-structured copper silicate material is 0.1 to 0.5:1.

[0045] According to the above scheme, the copper ammonia solution is a solution generated by the reaction of copper salt and ammonia source substance. The ammonia source substance is 1.5 to 2 times the theoretical amount. The copper salt is selected from one or more combinations of copper nitrate, copper acetate, and copper chloride. The ammonia source substance is selected from one or more combinations of ammonia water, urea, and ammonium bicarbonate. The silica sol is a solution prepared from commercially available silica sol.

[0046] The hydrogen purification material B for fuel cell vehicles of the present invention can simultaneously remove trace amounts of CO, O2, and sulfur from hydrogen-containing source gas at a temperature of 60–120°C. The hydrogen-containing source gas can be hydrogen from various sources, such as coal-derived hydrogen, methanol cracking hydrogen, industrial by-product hydrogen, and water electrolysis hydrogen. Specifically, it can be high-purity hydrogen obtained through purification treatments such as pressure swing adsorption or cryogenic treatment, which improves the purity of the hydrogen. The purification treatment mainly aims to increase the purity of the hydrogen to over 99.9%. Simultaneously, a large number of impurities are also removed during this process. After purification, the impurities such as CO, O2, and sulfur meet the requirements of the national standard GB / T37244-2018 for hydrogen used in fuel cell vehicles: CO ≤ 0.2 ppm, O2 ≤ 5 ppm, and sulfur ≤ 0.004 ppm.

[0047] The main advantages of this patent are:

[0048] (1) Two purification materials, A and B, are used in series. One purification material removes aldehydes, acids, ammonia, CO2 and halogens, while the other removes CO, O2 and sulfur. The operating temperature is mild, and the purification is integrated and efficient. The required amount of purification material is small, the purification process is simple, the space required is small, the operation is convenient, and the operating cost is low.

[0049] (2) The purification method of the present invention can be used for integrated purification and removal of hydrogen for fuel cell vehicles. After purification, impurities such as aldehydes, acids, ammonia, CO2, and halogens meet the requirements of the national standard GB / T37244-2018 for hydrogen for fuel cell vehicles. Impurities such as CO, O2, and sulfur also meet the requirements of the national standard GB / T37244-2018 for hydrogen for fuel cell vehicles, while no new impurities are generated.

[0050] (3) The order of purification materials A and B can be adjusted according to the impurity content in the hydrogen source. If the content of aldehydes, acids, ammonia, CO2 and halogens in the hydrogen is relatively high, the A-B process can be used. That is, the hydrogen is first purified by purification material A to remove aldehydes, acids, ammonia, CO2 and halogens, and then purified by purification material B to remove CO, O2 and sulfur impurities. If the content of CO, O2 and sulfur impurities in the hydrogen is relatively high, the B-A process can be used. That is, the hydrogen is first purified by purification material B to remove CO, O2 and sulfur impurities, and then purified by purification material A to remove aldehydes, acids, ammonia, CO2 and halogens. Attached Figure Description

[0051] Figure 1 These are X-ray diffraction patterns of fresh copper silicate samples prepared under this patent, samples reduced with hydrogen, and samples directly used to remove CO, O2, and sulfur from hydrogen. Detailed Implementation

[0052] The invention will be further illustrated below with examples.

[0053] Example 1:

[0054] Preparation of purified materials A1-A6 and control samples D1-D4:

[0055] (1) Dissolve 0.05 g of chloroplatinic acid solution and 20 g of cerium nitrate hexahydrate in 100 g of hot water until completely dissolved. Pour in 100 g of 3A molecular sieve powder (80-100 mesh) and place in a 50°C constant temperature water bath for ion exchange for 20 hours. After filtration and washing to ensure compliance, air dry for 3 hours and then dry in air at 120°C. Add binder to the material and extrude into strips with a diameter of 3 mm. Calcine at 500°C for 3 hours and then activate at 250°C in a hydrogen atmosphere for 4 hours to obtain product A1 (containing 0.046% Pt and 7.8% CeO2 active components).

[0056] (2) Dissolve 0.15 g of ruthenium chloride hydrochloric acid solution and 8 g of lanthanum nitrate in 100 g of hot water until completely dissolved. Pour in 100 g of 4A molecular sieve powder (80-100 mesh) and place in an 80°C constant temperature water bath for ion exchange for 10 hours. After filtration and washing to ensure compliance, air dry for 10 hours and then dry in air at 140°C. Add binder to the material and form it into 3 mm diameter spheres. Calcine at 450°C for 5 hours and then activate at 200°C in a hydrogen atmosphere for 5 hours to obtain product A2 (containing 0.14% Ru and 3.9% La2O3 active components).

[0057] (3) Dissolve 0.3 g of palladium chloride hydrochloric acid solution and 4 g of cerium nitrate hexahydrate in 100 g of hot water until completely dissolved. Pour in 100 g of 5A molecular sieve powder (80-100 mesh) and place in a 70°C constant temperature water bath for ion exchange for 15 hours. After filtration and washing to ensure compliance, air dry for 3 hours and then dry in air at 130°C. After adding a binder to the material, extrude it into strips with a diameter of 4 mm, calcine at 500°C for 3 hours, and then activate it in a hydrogen atmosphere at 300°C for 3 hours to obtain the finished product A3 (containing 0.28% Pd and 1.55% CeO2 active components).

[0058] (4) Dissolve 0.1 g of platinum-containing chloroplatinic acid solution and 6 g of lanthanum nitrate in 100 g of hot water until completely dissolved. Pour in 100 g of 5A molecular sieve powder (80-100 mesh) and place in a 70°C constant temperature water bath for ion exchange for 15 hours. After filtration and washing to ensure compliance, air dry for 3 hours and then dry in air at 120°C. Add binder to the material and extrude into strips with a diameter of 3 mm. Calcine at 450°C for 6 hours and then activate at 220°C in a hydrogen atmosphere for 5 hours to obtain product A4 (containing 0.092% Pt and 2.9% La2O3 active components).

[0059] (5) Dissolve 0.2 g of ruthenium chloride hydrochloric acid solution and 5 g of cerium nitrate hexahydrate in 100 g of hot water until completely dissolved. Pour in 100 g of 4A molecular sieve powder (80-100 mesh) and place in an 80°C constant temperature water bath for ion exchange for 10 hours. After filtration and washing to ensure compliance, air dry for 10 hours and then dry in air at 140°C. Add binder to the material to form spheres with a diameter of 3 mm. Calcine at 450°C for 5 hours and then activate at 270°C in a hydrogen atmosphere for 3.5 hours to obtain product A5 (containing 0.18% Ru and 1.95% CeO2 active components).

[0060] (6) Dissolve 0.1 g of palladium chloride hydrochloric acid solution and 4 g of lanthanum nitrate in 100 g of hot water until completely dissolved. Pour in 100 g of 3A molecular sieve powder (80-100 mesh) and place in a 50°C constant temperature water bath for ion exchange for 20 hours. After filtration and washing to ensure compliance, air dry for 3 hours and then dry in air at 120°C. Add binder to the material and extrude into strips with a diameter of 4 mm. Calcine at 500°C for 3 hours and then activate at 250°C in a hydrogen atmosphere for 4 hours to obtain the finished product A6 (containing 0.092% Pd and 1.93% La2O3 active components).

[0061] Comparative Example 1

[0062] Commercially available 3A molecular sieves are designated as sample D1.

[0063] Comparative Example 2

[0064] (1) Dissolve 0.1 g of rhodium nitrate solution and 7.5 g of praseodymium nitrate hexahydrate in 100 g of hot water until completely dissolved. Pour in 100 g of 4A molecular sieve powder of 80-100 mesh and place in a constant temperature water bath at 50°C for ion exchange for 20 hours. After filtration and washing to ensure compliance, air dry for 3 hours and then dry in air at 120°C.

[0065] (2) After adding a binder to the material, it is extruded into strips with a diameter of 3 mm, calcined at 500°C for 3 hours, and then activated at 250°C in a hydrogen atmosphere for 4 hours to obtain the finished product D2, wherein D2 contains 0.092 wt% Rh and 2.7 wt% Pr6O. 11 Active components.

[0066] Comparative Example 3:

[0067] (1) Dissolve 0.1 g of palladium chloride hydrochloric acid solution in 100 g of hot water, pour in 100 g of 80-100 mesh 3A molecular sieve powder, put it in a 50℃ constant temperature water bath for ion exchange for 20 hours, filter, wash qualified, then air dry for 3 hours, and dry in air at 120℃.

[0068] (2) After adding a binder to the material, it is extruded into strips with a diameter of 4 mm, calcined at 500°C for 3 hours, and then activated at 250°C in a hydrogen atmosphere for 4 hours to obtain the finished product D3, wherein D3 contains 0.092 wt% Pd.

[0069] Comparative Example 4:

[0070] (1) Dissolve 4 g of lanthanum nitrate in 100 g of hot water until completely dissolved, pour in 100 g of 80-100 mesh 3A molecular sieve powder, place in a 50°C constant temperature water bath for ion exchange for 20 hours, filter, wash and qualified, then air dry for 3 hours, and dry in air at 120°C.

[0071] (2) After adding a binder to the material, it is extruded into strips with a diameter of 4 mm, calcined at 500°C for 3 hours, and then activated at 250°C in a hydrogen atmosphere for 4 hours to obtain the finished product D4, wherein D4 contains 1.93 wt% La2O3 active component.

[0072] The 10 samples A1–A6 and D1–D4 prepared above had a typical volume composition of 99.98% H2, 0.5 ppm formaldehyde, 10 ppm CO2, 0.6 ppm NH3, 1.6 ppm formic acid, and 1.1 ppm Cl. - The evaluation results for (a typical gas source after PSA purification and deep removal of sulfides and CO from industrial by-product hydrogen) are shown in Table 1:

[0073] Table 1

[0074]

[0075] Example 2:

[0076] Preparation of purified materials B1-B6:

[0077] (1) Prepare 2L of 0.05mol / L copper ammonia solution with copper nitrate and ammonia water, and prepare 2L of 0.3mol / L silica sol solution with commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness. Wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 120℃, and then calcine at 350℃ for 3 hours to obtain ~44g of malachite-structured copper silicate. Add 22g of 3A molecular sieve and ball mill for 5 hours. Shape the mixture into sheets to obtain ~66g of purified material B1 with malachite structure. The molar ratio of CuO to SiO2 in B1 is 0.17, and the content of malachite-structured copper silicate is 67%.

[0078] (2) Prepare 1 L of 0.2 mol / L copper ammonia solution with copper acetate and urea, and prepare 1 L of 0.4 mol / L silica sol solution with commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness. Wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 130°C, and then calcine at 400°C for 4 hours to obtain ~40 g of malachite-structured copper silicate. Add 80 g of 4A molecular sieve and ball mill for 5 hours. Shape the mixture into sheets to obtain ~120 g of purified material B2 with a malachite structure. The molar ratio of CuO to SiO2 in B2 is 0.5, and the content of malachite-structured copper silicate is 33%.

[0079] (3) Prepare 0.5 L of a 0.5 mol / L copper ammonia solution using copper chloride and ammonium bicarbonate, and prepare 1 L of a 0.75 mol / L silica sol solution using commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness, wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 140°C, and then calcine at 375°C for 3 hours to obtain ~65 g of copper silicate with a chalcocite structure. Add 65 g of 5A molecular sieve and ball mill for 5 hours, then sheet and shape to obtain ~130 g of purified material B3 with a chalcocite structure. The molar ratio of CuO to SiO2 in B3 is 0.33, and the content of copper silicate with a chalcocite structure is 50%.

[0080] (4) Prepare 0.25 L of a 0.07 mol / L copper ammonia solution using copper nitrate and ammonium bicarbonate, and prepare 0.5 L of a 1.0 mol / L silica sol solution using commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness, wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 150°C, and then calcine at 350°C for 6 hours to obtain ~44 g of copper silicate with a chrysocolla structure. Add 56 g of 3A molecular sieve and ball mill for 5 hours, then sheet and shape to obtain ~66 g of purified material B4 with a chrysocolla structure. The molar ratio of CuO to SiO2 in B4 is 0.35, and the content of copper silicate with a chrysocolla structure is 44%.

[0081] (5) Prepare 0.1 L of a 1.0 mol / L copper ammonia solution with copper acetate and ammonia water, and prepare 0.5 L of a 0.8 mol / L silica sol solution with commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness, wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 110°C, and then calcine at 400°C for 5 hours to obtain ~32 g of malachite-structured copper silicate. Add 48 g of 4A molecular sieve and ball mill for 5 hours, then sheet and shape to obtain ~80 g of purified material B5 with a malachite structure. The molar ratio of CuO to SiO2 in B5 is 0.25, and the content of malachite-structured copper silicate is 40%.

[0082] (6) Prepare 1 L of 0.15 mol / L copper ammonia solution with copper chloride and urea, and 1 L of 0.4 mol / L silica sol solution with commercially available 20% silica sol. Add both solutions to a container with a stirrer and stir until homogeneous. Steam heat the solution to dryness. Wash the material repeatedly with reverse osmosis purified water, dry the filtered material at 100°C, and then calcine at 350°C for 6 hours to obtain ~36 g of copper silicate with a malachite structure. Add 24 g of 5A molecular sieve and ball mill for 5 hours. Shape the mixture into sheets to obtain ~60 g of purified material B6 with a malachite-like structure. The molar ratio of CuO to SiO2 in B6 is 0.375, and the content of copper silicate with a malachite-like structure is 60%.

[0083] To avoid mutual interference between the XRD patterns of type A molecular sieves and malachite XRD patterns, Figure 1 These are X-ray diffraction patterns of a fresh sample (copper silicate with malachite structure) prepared under this patent, a sample after reduction with hydrogen (programmed temperature reduction, maximum temperature 230℃), and a sample after normal direct use for removing CO, O2, and sulfur from hydrogen. Among them: 1#: fresh material; 2#: material after hydrogen reduction; 3#: sample of fresh sample 1# after normal use for hydrogen purification in fuel cell vehicles for a period of time. Figure 1 The absorption peak lines of the chrysocolla standard card are also marked on it.

[0084] By comparing the X-ray diffraction pattern of the fresh sample #1 with the absorption peak positions of the malachite standard card, it can be confirmed that the copper silicate synthesized in this invention has a malachite structure.

[0085] The X-ray diffraction pattern of sample #1 shows a diffuse phase with no significant change in composition, indicating it is primarily an amorphous or microcrystalline substance. No Cu is present in the sample. 0 And Cu₂O. Sample #2 is the sample after hydrogen reduction, showing a strongest Cu₂O diffraction peak at 2θ = 36.5°; and a Cu₂O peak at 2θ = 43.3°. 0 The first strong diffraction peak appears at 2θ = 50.5 (°) with a Cu peak. 0 The second strongest diffraction peak is at 2θ = 36.5°, while the peak at 2θ = 62.5° is the Cu₂O diffraction peak. Sample #3's Cu₂O first strong diffraction peak at 2θ = 36.5° is stronger than that of sample #2, and its diffraction peak at 2θ = 62.5° is also stronger. Cu₂O at 2θ = 43.3°... 0 The diffraction peaks are weaker than those of sample #2, at 2θ = 50.5 (°) Cu 0 The second strongest diffraction peak of the sample was weaker than that of sample #2. This indicates that there was a significant difference in the X-ray diffraction peaks of the hydrogen-reduced sample and the fresh sample #1 of this invention after they had been used for a period of time for hydrogen purification in fuel cell vehicles. This suggests that the purification material of this invention has a different mechanism for purifying CO and other gases in fuel cell vehicles compared to the mechanism for hydrogen reduction, and that the hydrogen purification material of this invention possesses unique catalytic purification characteristics.

[0086] Comparative Example 1:

[0087] 1 L of a 0.15 mol / L copper ammonia solution was prepared using copper chloride and urea. 1 L of a 0.4 mol / L silica sol solution was prepared using commercially available 20% silica sol. The solutions were then poured into a stirred container and stirred until homogeneous. The solution was evaporated to dryness using steam heating. The material was repeatedly washed with reverse osmosis purified water and then dried at 100°C. The material was then calcined at 450°C for 6 hours to obtain approximately 30 g of material I. 20 g of 5A molecular sieve was added and the material was ball-milled for 5 hours. The mixture was then sheeted to obtain approximately 50 g of purified material C1.

[0088] Comparative Example 2:

[0089] Prepare 1L of 0.15mol / L copper chloride solution, and prepare 1L of 0.4mol / L silica sol solution using commercially available 20% silica sol. Add the solutions to a container with a stirrer and stir until homogeneous. Add sodium carbonate solution to co-precipitate and obtain a precipitate. Wash the precipitate repeatedly with reverse osmosis purified water, dry the filtered material at 100℃, and then calcine at 400℃ for 6 hours to obtain ~36g of material I. Add 24g of 4A molecular sieve and ball mill for 5 hours, then form into sheets to obtain ~60g of purified material C2.

[0090] The evaluation results of the eight samples prepared above in a typical volume composition of 99.98% H2, 70ppm O2, 8ppm CO, and 0.08ppm H2S (a typical gas source after industrial by-product hydrogen is purified by PSA) are shown in Table 2.

[0091] Table 2

[0092]

[0093] Example 3:

[0094] The A1-A6 prepared in Example 1 and the B1-B6 prepared in Example 2 were combined, with a typical volume composition of 99.98% H2, 70 ppm O2, 8 ppm CO, 0.08 ppm H2S, 0.5 ppm formaldehyde, 10 ppm CO2, 0.6 ppm NH3, 1.6 ppm formic acid, and 1.1 ppm Cl. - The evaluation results for (a typical gas source after industrial by-product hydrogen is purified by PSA) are shown in Table 3.

[0095] Table 3

[0096]

[0097]

[0098] Example 4:

[0099] The A1-A6 prepared in Example 1 and the B1-B6 prepared in Example 2 were combined, with a typical volume composition of 99.98% H2, 120ppm O2, 28ppm CO, 0.2ppm H2S, 0.5ppm formaldehyde, 10ppm CO2, 0.6ppm NH3, 1.6ppm formic acid, and 1.1ppm Cl. - The evaluation results for (a typical gas source after industrial by-product hydrogen is purified by PSA) are shown in Table 4.

[0100] Table 4

[0101]

[0102]

[0103] Example 5:

[0104] The A1-A6 prepared in Example 1 and the B1-B6 prepared in Example 2 were combined, with a typical volume composition of 99.98% H2, 40 ppm O2, 3 ppm CO, 0.08 ppm H2S, 0.8 ppm formaldehyde, 12 ppm CO2, 0.9 ppm NH3, 1.6 ppm formic acid, and 1.5 ppm Cl. -The evaluation results for (a typical gas source after industrial by-product hydrogen is purified by PSA) are shown in Table 5.

[0105] Table 5

[0106]

[0107]

[0108] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for purifying hydrogen for fuel cell vehicles, characterized in that: Two purification materials, A and B, are used in series to remove various trace impurities from the hydrogen-containing source gas. Purification material A simultaneously removes aldehydes, acids, ammonia, CO2, and halogens, while purification material B simultaneously removes CO, O2, and sulfur. The combined use of purification materials A and B removes aldehydes, acids, ammonia, CO2, halogens, CO, O2, and sulfur impurities to obtain hydrogen for fuel cell vehicles. Wherein: the purification material A is a molecular sieve modified with noble metals and rare earth metal oxides, wherein the noble metal is selected from at least one of Pt, Ru or Pd, and the rare earth metal oxide is selected from at least one of CeO2 or La2O3; The purification material B is a composite of copper silicate with a malachite structure and type A molecular sieve, wherein the content of copper silicate with a malachite structure is 30-70%, and the balance is type A molecular sieve.

2. The hydrogen purification method according to claim 1, characterized in that: Depending on the impurity content in the hydrogen-containing source gas, the order of purification materials A and B can be interchanged. That is, the hydrogen-containing source gas to be purified can be purified by purification material A first and then by purification material B, or purified by purification material B first and then by purification material A.

3. The hydrogen purification method according to claim 1, characterized in that: In the purified material A, the content of precious metals is 0.01~0.3 wt%; The rare earth metal oxides in the purified material contain 1 to 8 wt%.

4. The hydrogen purification method according to claim 1, characterized in that: In the purified material A, the noble metal is selected from Pt, Ru or Pd; The rare earth metal oxide is selected from CeO2 or La2O3.

5. The hydrogen purification method according to claim 1, characterized in that: The molar ratio of CuO to SiO2 in the chrysocolla structure copper silicate of the purified material B is 0.1~0.5:

1.

6. The hydrogen purification method according to claim 1, characterized in that: The purified material B is prepared by co-precipitation, washing, drying and calcination of copper ammonia solution and silica sol to obtain copper silicate with a malachite structure, which is then compounded with type A molecular sieve and shaped.

7. The hydrogen purification method according to claim 6, characterized in that: The roasting temperature is 350~400℃.

8. The hydrogen purification method according to claim 1, characterized in that: The molecular sieve in the purification material A is a 3A, 4A, or 5A molecular sieve. The type A molecular sieve in the purification material B is 3A, 4A, or 5A molecular sieve.

9. The hydrogen purification method according to claim 1, characterized in that: Purification material A removes aldehydes, acids, ammonia, CO2, and halogen impurities from hydrogen-containing source gas at a temperature not exceeding 120°C. Purification material B removes CO, O2, and sulfur from hydrogen-containing source gas at a temperature of 60-120°C. The hydrogen-containing source gas is purified high-purity hydrogen.

10. The hydrogen purification method according to claim 1, characterized in that: Purification material A and purification material B are used in the same temperature range of 60-120℃.

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