Method for preparing high-quality hydrogen by coupling oxygen-enriched flue gas baking and gasification of bamboo reed
By using oxygen-enriched flue gas baking and gasification coupling technology, the problem of poor raw material properties of Reed sphaerocephala was solved, and efficient preparation of hydrogen and synthetic fuels was achieved, improving hydrogen yield and gasification reaction efficiency.
Patent Information
- Application Number
- CN202511648239.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-01-20
AI Technical Summary
Existing nitrogen atmosphere baking methods cannot effectively improve the properties of Reed hyacinth raw materials, resulting in hydrogen yields that are difficult to meet the requirements of industrial applications, and the gasification reaction efficiency is low.
Using oxygen-enriched flue gas (CO2+O2) as the atmosphere for baking and gasification, the O/C ratio is reduced and the H/C ratio is increased by optimizing the baking process, and carbon is converted into CO/H2 during the gasification process, thus achieving the preparation of high-quality hydrogen.
It significantly improved the quality of Reed sphaerocephala raw materials and the efficiency of gasification reaction, increased hydrogen yield, optimized syngas composition, reduced the risk of equipment slagging, and achieved efficient hydrogen and synthetic fuel production.
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Figure CN121361765A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of clean utilization and efficient conversion of biomass energy, and particularly relates to a method for preparing high-quality hydrogen by baking and coupling gasification of reed in oxygen-rich flue gas. BACKGROUND
[0002] As a high-yield perennial herb energy plant, reed has the advantages of fast growth, high yield and strong adaptability, and is widely considered as an important raw material for future biomass energy. However, the reed raw material has defects such as high moisture content, high O / C ratio, low calorific value and high ash content, and direct gasification often leads to poor gas quality and low reaction efficiency, especially the hydrogen production rate is difficult to meet the industrial application demand.
[0003] However, the existing nitrogen (N2) atmosphere baking method can improve the properties of the raw material to a certain extent, but due to the lack of effective carbon conversion and ash activation regulation, the reaction activity and gasification performance of the obtained baking product are still limited.
[0004] Therefore, it is urgent to provide a reed pretreatment and conversion method which can not only improve the properties of the reed raw material, but also strengthen the hydrogen production reaction in the gasification process to meet the demand for green hydrogen and synthetic fuel preparation. SUMMARY
[0005] The present application relates to the technical field of clean utilization and efficient conversion of biomass energy, and particularly relates to a method for preparing high-quality hydrogen by baking and coupling gasification of reed in oxygen-rich flue gas.
[0006] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions: The present application provides a method for preparing high-quality hydrogen by baking and coupling gasification of reed in oxygen-rich flue gas, comprising the following steps: Pretreatment: crushing and drying the reed to obtain pretreated reed; Oxygen-rich flue gas baking: baking the pretreated reed in a first oxygen-rich flue gas atmosphere to obtain baked material; Gasification: gasifying the baked material in a second oxygen-rich flue gas atmosphere to collect the gas product, thereby completing the preparation of high-quality hydrogen by baking and coupling gasification of reed in oxygen-rich flue gas.
[0007] Preferably, the moisture content of the pretreated reed is ≤3%.
[0008] Preferably, the baking temperature is 220-300℃, and the baking time is 15-45min.
[0009] Preferably, the first oxygen-rich flue gas comprises CO2 and O2, the volume fraction of CO2 in the first oxygen-rich flue gas is 88-95%, and the volume fraction of O2 in the first oxygen-rich flue gas is 5-12%.
[0010] As preferred, the temperature of the gasification is 700-900℃.
[0011] As preferred, the second oxygen-enriched flue gas comprises CO2 and O2; the volume fraction of CO2 in the second oxygen-enriched flue gas is 88-95%; the volume fraction of O2 in the second oxygen-enriched flue gas is 5-12%.
[0012] As preferred, the gaseous product is used for preparing hydrogen-rich synthesis gas.
[0013] Via the technical solution described above, compared with the prior art, the present application has the following beneficial effects: (1) Significant improvement of feed quality: using oxygen-enriched flue gas (CO2+O2) as the roasting atmosphere, the raw material shows obvious quality improvement. After roasting, the O / C ratio decreases significantly, while the H / C ratio remains at a high level, indicating that the carbon skeleton structure is optimized while still retaining strong hydrogen-empowering potential. At the same time, the high heating value (HHV) of the raw material is improved, the fuel quality is significantly improved, and the flue ratio is reduced, showing that the hindering effect of ash on the gasification reaction is effectively weakened. Compared with the roasting effect under nitrogen atmosphere, the oxygen-enriched flue gas condition not only more effectively promotes the deoxidation process of the raw material, but also significantly enhances the quality improvement effect, thereby providing a higher quality solid fuel basis for subsequent gasification reactions.
[0014] (2) Improvement of gas composition: using oxygen-enriched flue gas (CO2+O2) as the gasification agent for roasting products shows significant advantages over inert nitrogen conditions. Experimental results show that the hydrogen proportion in the oxygen-enriched flue gas gasification process can reach 10.2%, which is significantly higher than the 7.3% under nitrogen atmosphere; the carbon monoxide (CO) proportion is increased to 17.2%, which is almost twice the 8.8% under nitrogen atmosphere; the final synthesis gas (H2+CO) content reaches 27.4%, which is nearly 70% higher than the 16.1% under nitrogen atmosphere, reflecting a strong synergistic effect. Further analysis shows that the product after oxygen-enriched flue gas roasting exhibits the best reaction activity under oxygen-enriched flue gas gasification conditions, with the largest increase in hydrogen yield, indicating that both the water gas reaction (C+H2O→CO+H2) and the CO2 gasification reaction (C+CO2→2CO) are significantly promoted; at the same time, the simultaneous increase in CO and H2 content not only improves the gasification efficiency, but also ensures that the obtained gas has higher synthetic fuel value, highlighting the unique advantages of the oxygen-enriched flue gas roasting-gasification integrated technology.
[0015] (3) Coupling gain: oxygen-enriched flue gas baking makes the feedstock "cleaner and carbon more concentrated", and oxygen-enriched flue gas gasification makes "carbon more efficiently converted into CO / H2", and the coupling of the two achieves the synergy of "feedstock grade quality improvement" and "high-temperature reaction efficiency improvement" as a whole, reduces the risk of equipment slagging and improves the effective gasification output per unit of raw material.
[0016] (4) Environmental and system benefits: industrial flue gas / CO2 can be used as process gas to achieve short-range recycling of CO2; in large-scale applications, CO2 direct discharge intensity can be reduced, and energy / material coupling recovery can be achieved. BRIEF DESCRIPTION OF DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description.
[0018] Figure 1 A process flow diagram of a method for preparing high-quality hydrogen by oxygen-enriched flue gas baking and coupling gasification of reed according to the present application; Figure 2 Gas product composition after gasification of Example 1 and Comparative Examples 1-3; wherein the abscissa from left to right is Comparative Example 1, Example 1, Comparative Example 2, and Comparative Example 3. DETAILED DESCRIPTION
[0019] The present application provides a method for preparing high-quality hydrogen by oxygen-enriched flue gas baking and coupling gasification of reed, the process flow diagram of which is shown in Figure 1 The method comprises the following steps: Pre-treatment: crushing and drying reed to obtain pre-treated reed; Oxygen-enriched flue gas baking: baking the pre-treated reed under a first oxygen-enriched flue gas atmosphere to obtain baked material; Gasification: gasifying the baked material under a second oxygen-enriched flue gas atmosphere to collect the gas product, i.e., completing the preparation of high-quality hydrogen by oxygen-enriched flue gas baking and coupling gasification of reed.
[0020] In the present application, the moisture content of the pre-treated reed is preferably ≤3%, further preferably 2-3%, and more preferably 2.6%.
[0021] In the present application, the baking temperature is preferably 220-300°C, further preferably 250-280°C, and more preferably 260°C; and the baking time is preferably 15-45 min, further preferably 30-40 min, and more preferably 30 min.
[0022] In the present application, the first oxygen-enriched flue gas preferably comprises CO2 and O2; the volume fraction of CO2 in the first oxygen-enriched flue gas is preferably 88-95%, further preferably 89-92%, and more preferably 90%; the volume fraction of O2 in the first oxygen-enriched flue gas is preferably 5-12%, further preferably 8-11%, and more preferably 10%. Through the oxygen-enriched flue gas roasting process, the present application can effectively reduce the O / C ratio of the bamboo sample, maintain the H / C ratio, reduce part of the volatile matter, significantly improve the high heating value (HHV) of the solid product, and reduce the flue ratio, so as to exhibit better pyrolysis-gasification reactivity and high-quality hydrogen product generation potential in the subsequent gasification process.
[0023] In the present application, the temperature of the gasification is preferably 700-900℃, further preferably 780-820℃, and more preferably 800℃.
[0024] In the present application, the second oxygen-enriched flue gas preferably comprises CO2 and O2; the volume fraction of CO2 in the second oxygen-enriched flue gas is preferably 88-95%, further preferably 89-92%, and more preferably 90%; the volume fraction of O2 in the second oxygen-enriched flue gas is preferably 5-12%, further preferably 8-11%, and more preferably 10%. Through the oxygen-enriched flue gas gasification process, CO2 can effectively promote the conversion of carbon sequestration to CO through the Boudouard reaction (C+CO2→2CO), and synergistically act with the water gas reaction (C+H2O→CO+H2), so as to significantly promote the generation of H2 while improving the CO content in the synthesis gas, and effectively regulate the H2 / CO ratio.
[0025] In the present application, the product gas is sampled in real time online, and the main components such as CO, H2, CO2, CH4 and N2 are analyzed by gas chromatography (GC), and the obtained data can be used as a control basis for process operation, and also provides scientific support for product gas quality evaluation and subsequent optimization.
[0026] In the present application, the gas product also includes downstream conversion, for example, the gas product is used to prepare hydrogen-rich synthesis gas. The present application does not limit the specific method of downstream conversion, and the conventional method in the art can be used. For example, the method of downstream conversion is: the gas product is dedusted and condensed to remove tar, and then adjusted for CO2 content through water washing or absorption process, and then desulfurized to obtain clean gas; according to different target products, the clean gas is deeply purified and the composition is regulated by pressure swing adsorption (PSA), membrane separation or catalytic shift, so as to effectively improve the hydrogen purity or adjust the H2 / CO ratio; the purified gas is directly introduced into a synthesis device to prepare high-value-added fuels, such as Fischer-Tropsch synthesis or methanol synthesis.
[0027] In the present application, the unreacted CO2 in the tail gas generated in the gasification process is recycled to the roasting process or the oxygen-enriched flue gas atmosphere of the gasification process after being collected and compressed, thereby achieving efficient recycling of carbon resources. At the same time, the heat released in the gasification process is utilized through waste heat recovery to compensate for the energy consumption of the roasting process and assist in drying the raw materials, thereby building a closed-loop system of energy and matter, which not only improves the overall energy efficiency of the system, but also further enhances the environmental friendliness and economic feasibility of the process.
[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.
[0029] Embodiment 1
[0030] The present embodiment provides a method for preparing high-quality hydrogen from oxygen-enriched flue gas roasting coupled gasification of Arundo donax, comprising the following steps: (1) Pretreatment: crushing Arundo donax to 250-400 μm, drying at 105℃ for 12 h to obtain pretreated Arundo donax; the initial parameters of the pretreated Arundo donax are as follows: moisture content of 2.6%, ash content of 6.20%, volatile matter of 95.50%, initial H / C of 1.64996, O / C of 0.74240, and HHV of 18.0006 MJ·kg -1 ; (2) Oxygen-enriched flue gas roasting: roasting the pretreated Arundo donax under a first oxygen-enriched flue gas atmosphere, the oxygen-enriched flue gas composition being CO290%+O210%, the gas flow being 200 mL·min -1 , the roasting temperature parameters being: increasing the temperature to 260℃ at a rate of 10℃·min -1 , keeping the temperature at 260℃ for 30 min, and cooling to room temperature to obtain roasted material; taking the roasted material for detection, the H / C being 1.28494, the O / C being 0.51263, the HHV being 21.138 MJ·kg -1 , and the flue ratio being 0.08595; (3) Gasification: gasifying the roasted material under a second oxygen-enriched flue gas atmosphere, the oxygen-enriched flue gas composition being CO290%+O210%, the gas flow being 200 mL·min -1 , and the gasification temperature being 800℃; after 30 min, sampling the gaseous products and using GC for analysis, the CO2 being 66.4%, the CO being 17.2%, the H2 being 10.2%, and the CH4 being 6.2%; The method of this embodiment is denoted as oxygen-enriched flue gas-260℃→oxygen-enriched flue gas-800℃.
[0031] Comparative Example 1
[0032] This comparative example provides a method for preparing hydrogen by baking and coupling gasification of bamboo, as described in Example 1, except that the baking atmosphere is a nitrogen atmosphere.
[0033] The method of this comparative example is denoted as N2-260°C→oxygen-enriched flue gas-800°C.
[0034] Comparative Example 2
[0035] This comparative example provides a method for preparing hydrogen by baking and coupling gasification of bamboo, as described in Example 1, except that the baking atmosphere is a nitrogen atmosphere and the gasification atmosphere is a nitrogen atmosphere.
[0036] The method of this comparative example is denoted as N2-260°C→N2-800°C.
[0037] Comparative Example 3
[0038] This comparative example provides a method for preparing hydrogen by baking and coupling gasification of bamboo, as described in Example 1, except that the gasification atmosphere is a nitrogen atmosphere.
[0039] The method of this comparative example is denoted as oxygen-enriched flue gas-260°C→N2-800°C.
[0040] The gas product compositions after gasification in Example 1 and Comparative Examples 1-3 are shown in Table 1. Figure 2 As can be seen from Table 1, both Example 1 and Comparative Example 1 show that CO2 is the main component (66.4-68.1%), and the volume fractions of CO and H2 are relatively high (CO is 16.5-17.2%, H2 is 9.4-10.2%), and CH4 is about 6.0-6.2%; this component structure is suitable for subsequent transformation or synthesis (especially obtaining a suitable H2 / CO ratio in the case of CO2 enrichment but sufficient CO / H2). Figure 2 Direct comparison of Example 1 and Comparative Example 1 shows that the H2 proportion (about 10.2%) produced by the CO2-baked sample of the present application in oxygen-enriched flue gas gasification is higher than that in N2 baking (about 9.4%), and the CO is also slightly higher (17.2% vs 16.5%), indicating that oxygen-enriched flue gas baking is beneficial to subsequent oxygen-enriched flue gas gasification.
[0041]
[0042] The product gas composition shows significant difference under different combinations of torrefaction and gasification atmosphere. The content of H2 and CO of the method H2 of Comparative Example 1 is 9.4% and 16.5% respectively; while the content of H2 and CO of the method of Example 1 is significantly increased to 10.2% and 17.2%, reaching the highest level. In contrast, under the conditions of Comparative Example 2, the content of H2 and CO is only 7.3% and 8.8% respectively, and the quality of the synthesis gas is the worst. This shows that the combination of torrefaction and gasification under the oxygen-enriched flue gas atmosphere can produce a significant synergistic effect, thereby significantly enhancing the generation efficiency of hydrogen and synthesis gas.
[0043] Comparative Example 4
[0044] This comparative example provides a method for preparing hydrogen by torrefaction of reed canary grass, which specifically refers to Example 1, except that only torrefaction is performed without gasification.
[0045] The method of this comparative example is recorded as oxygen-enriched flue gas-260℃.
[0046] Comparative Example 5
[0047] This comparative example provides a method for preparing hydrogen by torrefaction of reed canary grass, which specifically refers to Example 1, except that only torrefaction is performed without gasification, and the atmosphere for torrefaction is nitrogen atmosphere.
[0048] The method of this comparative example is recorded as N2-260℃.
[0049] Comparative Example 6
[0050] This comparative example provides a method for preparing hydrogen by gasification of reed canary grass, which specifically refers to Example 1, except that only gasification is performed without torrefaction.
[0051] The method of this comparative example is recorded as oxygen-enriched flue gas-800℃.
[0052] Comparative Example 7
[0053] This comparative example provides a method for preparing hydrogen by gasification of reed canary grass, which specifically refers to Example 1, except that only gasification is performed without torrefaction, and the atmosphere for gasification is nitrogen atmosphere.
[0054] The method of this comparative example is recorded as N2-800℃.
[0055] The preparation conditions corresponding to Example 1 and Comparative Examples 1-7 are shown in Table 1.
[0056] Table 1 Preparation conditions corresponding to Example 1 and Comparative Examples 1-7
[0057] The basic properties of the raw material (reed canary grass) and the solid products after torrefaction and / or gasification under different conditions are shown in Table 2.
[0058] Table 2. Basic properties of feedstock (cattail) and solid products under different conditions
[0059] From Table 2, it can be seen that the oxygen-enriched flue gas torrefaction + oxygen-enriched flue gas gasification route of the present application is superior to other control routes in general. The oxygen-enriched flue gas torrefaction improves the flue ratio of the torrefaction product; the oxygen-enriched flue gas gasification improves carbon conversion, and the product gas quality is better.
[0060] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.
Claims
1. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification, characterized by, The method comprises the following steps: pretreatment: crushing and drying the Arundo donax to obtain pretreated Arundo donax; oxygen-enriched flue gas roasting: roasting the pretreated Arundo donax in a first oxygen-enriched flue gas atmosphere to obtain roasted material; gasification: gasifying the roasted material in a second oxygen-enriched flue gas atmosphere to collect a gas product, i.e. completing the preparation of high-quality hydrogen by oxygen-enriched flue gas roasting coupled gasification of Arundo donax.
2. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification as claimed in claim 1 wherein, The moisture content of the pretreated Arundo donax is ≤3%.
3. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification as claimed in claim 2 wherein, The roasting temperature is 220-300 ℃, and the roasting time is 15-45 min.
4. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification as claimed in claim 3 wherein, The first oxygen-enriched flue gas comprises CO2 and O2, the volume fraction of CO2 in the first oxygen-enriched flue gas is 88-95%, and the volume fraction of O2 in the first oxygen-enriched flue gas is 5-12%.
5. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification as claimed in claim 4 wherein, The gasification temperature is 700-900 ℃.
6. A process for the production of high quality hydrogen from bamboo by oxygen-enriched flue gas baking coupled gasification as claimed in claim 5 wherein, The second oxygen-enriched flue gas comprises CO2 and O2, the volume fraction of CO2 in the second oxygen-enriched flue gas is 88-95%, and the volume fraction of O2 in the second oxygen-enriched flue gas is 5-12%.
7. A process for the production of high quality hydrogen from bamboo by oxygen enriched flue gas baking coupled gasification as claimed in claim 1 wherein, The gas product is used for preparing hydrogen-rich synthesis gas.