Application of multifunctional catalytic-adsorbent sodium ferrite in coke gasification for hydrogen production

Abstract

This invention discloses the application of the multifunctional catalyst / adsorbent sodium ferrite in coke gasification for hydrogen production, belonging to the field of gasification hydrogen production technology. NaFeO2 exhibits excellent catalytic activity in the coke steam gasification hydrogen production process and has a strong adsorption capacity for CO2. It promotes hydrogen production through Le Chatelier's principle, while the products formed by the adsorption reaction (Fe2O3 and Na2CO3) have strong catalytic effects on both the water-gas shift reaction and the gasification reaction, respectively. The heat generated by the adsorption reaction indirectly reduces the overall heat of reaction in gasification. The multifunctional catalyst / adsorbent NaFeO2 proposed in this invention achieves an H2 yield of 791.65 mL within 1 hour, with a purity as high as 97.3%.

Description

Technical Field

[0001] This invention relates to the field of gasification hydrogen production technology, specifically to the application of sodium ferrite, a multifunctional catalyst-adsorbent, in coke gasification hydrogen production. Background Technology

[0002] Due to the massive consumption of fossil fuels and the environmental problems caused by their combustion, hydrogen is widely recognized as one of the most promising renewable energy sources. Currently, mainstream hydrogen production methods heavily rely on fossil fuels such as natural gas and coal, which generate large amounts of carbon dioxide, exacerbating global climate change and the greenhouse effect. Current research is coupling carbon capture, utilization, and storage (CCUS) technology with hydrogen production processes to reduce CO2 emissions through in-situ CO2 capture while simultaneously improving H2 purity. Sodium-based catalysts are widely used in gasification hydrogen production processes, but traditional sodium-based catalysts have limited catalytic effects on water-gas shift reactions, only showing catalytic activity in gasification reactions, and suffer from problems such as difficulty in adsorbing CO2 at low partial pressures. In addition, iron can form alloys or composite catalysts with other metals for various hydrogen production reactions. Iron-based oxide catalysts have been extensively studied in high-temperature water-gas shift reactions, exhibiting high activity, good durability, and relatively low manufacturing costs. However, research on the application of iron oxide in enhanced gasification hydrogen production has not yet been reported. Therefore, finding a material with superior adsorption performance and good catalytic performance throughout the gasification hydrogen production process is the key to improving H2 purity and yield. Summary of the Invention

[0003] The purpose of this invention is to at least solve one of the technical problems existing in the prior art, and to provide the application of sodium ferrite, a multifunctional catalyst-adsorbent, in the production of hydrogen from coke gasification.

[0004] The technical solution of the present invention is as follows:

[0005] The application of sodium ferrite, a multifunctional catalytic-adsorbent, in the production of hydrogen from coke gasification involves mixing a carbon source and sodium ferrite, heating the mixture, and reacting it with water vapor to produce hydrogen.

[0006] As a preferred embodiment of the present invention, the molar ratio of sodium ferrite to carbon source is 0.25-1.

[0007] As a preferred embodiment of the present invention, the reaction temperature is 600-700℃.

[0008] As a preferred embodiment of the present invention, the carbon source includes one or more of wood, crop straw, herbaceous plants, and fossil carbon sources.

[0009] As a preferred embodiment of the present invention, the flow rate of water introduced during the reaction is 0.05-0.2 mL / min.

[0010] As a preferred embodiment of the present invention, nitrogen gas is introduced simultaneously with the reaction, and the nitrogen gas flow rate is 50-150 mL / min.

[0011] As a preferred embodiment of the present invention, the hydrogen purity is as high as 97.3%.

[0012] As a preferred embodiment of the present invention, sodium ferrite has catalytic activity and CO2 capture performance during the reaction process.

[0013] The beneficial effects of this invention are as follows: The NaFeO2 used in this invention exhibits excellent catalytic activity in the coke steam gasification hydrogen production process and has a strong adsorption capacity for CO2. It promotes hydrogen production through Le Chatelier's principle, while the products formed by the adsorption reaction (Fe2O3 and Na2CO3) have strong catalytic effects on both the water-gas shift reaction and the gasification reaction, respectively. The heat generated by the adsorption reaction indirectly reduces the overall heat of reaction in the gasification process. The multifunctional catalyst / adsorbent NaFeO2 proposed in this invention produces 791.65 mL of H2 within 1 hour, with a purity as high as 97.3%. Attached Figure Description

[0014] The accompanying drawings, which constitute a part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application.

[0015] Figure 1 The yield and purity of hydrogen produced by coke gasification under different comparative ratios;

[0016] Figure 2 Compare the effects of NaFeO2 and Na2CO3 on the hydrogen production from coconut shell charcoal at 650℃;

[0017] Figure 3 The effect of the molar ratio of NaFeO2 to C on enhanced coke gasification for hydrogen production;

[0018] Figure 4 The effect of different temperatures on NaFeO2-enhanced coke gasification for hydrogen production;

[0019] Figure 5 The performance of hydrogen production through gasification of different carbon materials;

[0020] Figure 6 XRD patterns of NaFeO2 before and after the hydrogen production reaction;

[0021] Figure 7 The graph shows the hydrogen production performance of NaFeO2. Detailed Implementation

[0022] The NaFeO2 described in this invention is a highly efficient multifunctional catalyst / adsorbent that exhibits excellent catalytic performance throughout the gasification process and superior CO2 adsorption capacity, maintaining effective adsorption even under low CO2 partial pressure.

[0023] To achieve the above objectives, the application of the multifunctional catalyst / adsorbent NaFeO2 described in this invention in coke gasification for hydrogen production includes the following:

[0024] Hydrogen was produced by reacting different carbon sources with NaFeO2 at different molar ratios and temperatures.

[0025] Specifically, the molar ratio of NaFeO2 to carbon source is 0.25-1, and the specific molar ratio can be 0.25, 0.5 or 1;

[0026] Specifically, the different temperatures are 600-700℃, and the specific molar ratio can be 600, 650 or 700℃;

[0027] In practice, the selected carbon source may include, but is not limited to, one or more of wood, crop straw, herbaceous plants, and fossil carbon sources. Specifically, it may be bamboo charcoal, coconut shell charcoal, anthracite, and bituminous coal, but is not limited to these.

[0028] More specifically, the NaFeO2 includes, but is not limited to, at least one of various NaFeO2 forms such as high-purity NaFeO2, NaFeO2 containing specific impurities, and NaFeO2 with different crystal forms.

[0029] Preferably, the adsorbent in the hydrogen production process is NaFeO2, which generates Fe2O3 and Na2CO3 during adsorption; that is, the gasification reaction catalyst in the hydrogen production process is NaFeO2 and the sodium component Na2CO3 generated in the adsorption reaction, and the water-gas shift reaction catalyst is the iron component Fe2O3 generated in the adsorption reaction.

[0030] Furthermore, hydrogen was produced by bamboo charcoal, calcium oxide with bamboo charcoal, and NaFeO2 with bamboo charcoal under the same experimental conditions, and the effects were compared.

[0031] In practice, NaFeO2 and Na2CO3 were used to produce hydrogen from coconut shell carbon under the same experimental conditions and the effects were compared.

[0032] In practice, XRD analysis can be used to analyze NaFeO2 and its byproducts in the hydrogen production process to further verify the catalytic effect of NaFeO2 on gasification and water-gas shift reactions and its adsorption effect on carbon dioxide.

[0033] Various exemplary embodiments of the present invention will be described in detail herein to further explain the technical solutions of the present invention. This detailed description should not be regarded as a limitation of the present invention, but should be understood as a more detailed explanation of some aspects, characteristics and embodiments of the present invention.

[0034] With regard to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0035] This invention discloses a multifunctional catalyst / adsorbent NaFeO2, and the products formed by its adsorption reaction (Fe2O3 and Na2CO3) have strong catalytic effects on water-gas shift and gasification reactions, respectively.

[0036] Comparative Example 1

[0037] 1g of bamboo charcoal was used in a gasification hydrogen production experiment at 700℃, a water flow rate of 0.1mL / min, and an N2 flow rate of 100mL / min. After the reaction, the CO2 yield was 90.17mL, the H2 yield was 93.74mL, and the purity was only 39.9%. (See details...) Figure 1 .

[0038] Comparative Example 2

[0039] Referring to Comparative Example 1, the reaction was carried out with pure bamboo charcoal replaced by a CaO to bamboo charcoal molar ratio of 0.5:1. After the reaction, the CO2 yield was 145.15 mL, the H2 yield was 188.07 mL, and the purity was 49.29%. See details below. Figure 1 After adding CaO, which can adsorb CO2, the concentration and yield of H2 increased, but the increase was small, and the purity of H2 remained very low.

[0040] Comparative Example 3

[0041] Referring to Comparative Example 2, the experiment was conducted with CaO replaced by NaFeO2. Under the same conditions, the CO2 yield was 215.00 mL, the H2 yield was 985.84 mL, and the H2 purity was 69.3%. See details below. Figure 1 Since NaFeO2 significantly increases H2 concentration and yield while greatly reducing CO2 concentration, it proves that the adsorption effect of NaFeO2 is far stronger than that of CaO.

[0042] Comparative Example 4

[0043] The adsorption and catalytic effects of NaFeO2 were evaluated using equimolar amounts of Na2CO3, and the results are as follows: Figure 2 As shown, when Na2CO3 is used as a catalyst to catalyze hydrogen production from coconut shell charcoal at 650℃, the H2 yield is 146.99 mL with a purity of 49.73%. However, when NaFeO2 is used as a catalyst, the H2 yield is 722.78 mL with a purity of 93.31%. The results indicate that NaFeO2 has a stronger catalytic effect than Na2CO3.

[0044] Example 1

[0045] The molar ratio of NaFeO2 to C was varied (0.25:1, 0.5:1, 0.75:1, and 1:1). As the molar ratio of NaFeO2 to C increased, the real-time H2 concentration increased to some extent. From 0.25:1 to 1:1, the H2 concentration increased from 78.5% to 97.3%. Conversely, the real-time concentrations of CO and CO2 decreased with increasing molar ratio. In terms of gas production, at 0.25:1, the CO production was 35.93 mL, the CO2 production was 127.82 mL, and the H2 production was 620.02 mL. When the molar ratio increased to 1:1, the CO production was only 4.58 mL, and the CO2 production was only 15.02 mL, far lower than at 0.25:1. At this point, the H2 production was the highest, at 791.65 mL, 27.7% higher than at 0.25:1, with an H2 purity of 97.3%. The results show that the higher the molar ratio of NaFeO2 to C, the higher the purity of H2, which can be adjusted according to actual needs. See details... Figure 3 .

[0046] Example 2

[0047] Parallel experiments with NaFeO2 were conducted at temperatures of 600℃, 650℃, and 700℃. The temperature was varied, and the resulting gas and its concentration were monitored. In practice, the optimal temperature can be selected by comprehensively considering both H2 purity and yield; see details below. Figure 4 .

[0048] Example 3

[0049] Different carbon sources were used in the experiment to study the applicability of NaFeO2 in hydrogen production. Anthracite produced 801.87 mL of H2, while bituminous coal produced 565.38 mL. Anthracite had the lowest H2 purity at 86.8%. In contrast, although coconut shell charcoal's H2 yield was slightly lower than that of anthracite, its purity was as high as 93.3%, 6.5% higher than anthracite. Considering both H2 purity and yield, coconut shell charcoal exhibited the best hydrogen production performance. Furthermore, the study noted that the hydrogen production performance of the four carbon materials under NaFeO2 enhancement was not significantly different, indicating that NaFeO2 has broad applicability in enhancing the hydrogen production performance of carbon materials and has relatively low requirements for carbon materials. See details... Figure 5 .

[0050] Example 4

[0051] By comparing the XRD patterns of NaFeO2 before and after hydrogen production, changes in the samples before and after the hydrogen production reaction can be observed. The results show that before hydrogen production, the diffraction peaks of NaFeO2 are dominant, indicating that the NaFeO2 prepared in this invention has high purity. After the hydrogen production reaction, the diffraction peaks of NaFeO2 basically disappear, and the XRD pattern shows that the diffraction peaks are mainly Na2CO3 and Fe2O3. See details... Figure 6 This indicates that NaFeO2 not only plays a catalytic role in hydrogen production but also adsorbs CO2. Furthermore, the adsorption process generates Na2CO3, which catalyzes the gasification reaction, and Fe2O3, which catalyzes the water-gas shift reaction.

[0052] This invention investigated the effect of NaFeO2 on hydrogen production via gasification under different conditions. The results showed that, under the conditions of a carrier gas flow rate of 50 mL / min, a water flow rate of 0.1 mL / min, and a temperature of 650℃, the optimal gasification hydrogen production was achieved when the molar ratio of NaFeO2 to coconut shell carbon was 1:1, yielding 791.65 mL of H2 with a purity as high as 97.3%. This demonstrates that NaFeO2 possesses extremely strong catalytic performance. For details, see [link to relevant documentation]. Figure 3 .

[0053] The real-time CO2 concentration was almost zero within 30 minutes after the start of the NaFeO2 hydrogen production reaction, and then slowly rose to 0.92%. This result indicates that NaFeO2 has extremely strong CO2 capture performance. (See details...) Figure 7 .

[0054] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. The application of sodium ferrite, a multifunctional catalytic-adsorbent, in coke gasification for hydrogen production, characterized in that... Hydrogen gas is produced by mixing a carbon source and sodium ferrite, heating the mixture, and reacting it with water vapor; the molar ratio of sodium ferrite to carbon source is 0.25-1. The reaction temperature is 600-700℃.

2. The application of the multifunctional catalyst-adsorbent sodium ferrite according to claim 1 in coke gasification for hydrogen production, characterized in that, The carbon source includes one or more of wood, crop straw, herbaceous plants, and fossil carbon sources.

3. The application of the multifunctional catalyst-adsorbent sodium ferrite according to claim 1 in coke gasification for hydrogen production, characterized in that, The hydrogen has a purity of up to 97.3%.

4. The application of the multifunctional catalyst-adsorbent sodium ferrite according to claim 1 in coke gasification for hydrogen production, characterized in that, Sodium ferrite has catalytic activity and CO2 capture performance during the reaction.

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