Coal gas and green hydrogen collaborative full titanium-based catalyst methanol synthesis process

Abstract

This invention relates to the field of coal chemical and new energy coupling technology, and in particular to a methanol synthesis process using a fully titanium-based catalyst with synergistic effects of coal gasification and green hydrogen. The crude coal gasification process sequentially undergoes dust removal, cooling, preliminary desulfurization, and fine desulfurization to obtain pre-coal gas. Simultaneously, the green hydrogen undergoes sequential deoxygenation, dehydration, and CO2 removal to obtain deeply purified green hydrogen. The pre-coal gas and deeply purified green hydrogen are blended in a certain proportion to obtain a green hydrogen blended gas, which is then treated with CO conversion to obtain syngas. The syngas is then used for low-pressure methanol synthesis to obtain primary methanol containing a gas-liquid phase. This primary methanol is then subjected to cooling and gas-liquid separation. The separated gas phase undergoes sulfur recovery treatment and tail gas hydrogenation purification treatment to recover sulfur and ensure that the tail gas meets emission standards. The separated liquid phase is purified by distillation to obtain high-purity methanol. The methanol synthesis process in this invention uses a full range of titanium-based catalysts as the core to construct a green and efficient coal-to-methanol process system of "coal gasification + green chlorine synergy," improving the economy, stability, and environmental friendliness of methanol production.

Description

Technical Field

[0001] This invention relates to the field of coal chemical and new energy coupling technology, and in particular to a methanol synthesis process using an all-titanium-based catalyst that synergistically combines coal gasification and green hydrogen production. Background Technology

[0002] Methanol is an important basic chemical raw material and clean liquid fuel, occupying a core position in the energy and chemical industry. It is widely used in chemical synthesis, fuel substitution, and new energy fields, serving as a key link between coal resources and high-end chemicals and low-carbon energy.

[0003] Chinese patent CN114394883A discloses a near-zero carbon emission methanol production process using pulverized coal waste gasification coupled with green electricity and green hydrogen. This process uses pulverized coal gasification combined with green hydrogen to adjust the hydrogen-carbon ratio of the synthesis gas, eliminating some CO conversion units to achieve energy saving, carbon reduction, and near-zero carbon production. However, this process only focuses on system integration and carbon emission reduction optimization, without involving improvements to the catalyst system. It still uses traditional methanol synthesis catalysts and has not solved the problems of catalyst resistance to sulfur, water, and long lifespan.

[0004] Chinese patent CN2021103041287 discloses a simplified coal-to-methanol system that uses green hydrogen to adjust the carbon-hydrogen ratio. This system directly adjusts the syngas ratio using green hydrogen, eliminating some conversion and air separation units, thus simplifying the process and reducing energy consumption. This solution focuses on process optimization and does not disclose any related technologies for catalyst carrier or component improvement.

[0005] Chinese patent CN120398648A discloses a high-efficiency energy storage and zero-carbon emission technology for the production, storage and transportation of dimethyl ether based on the coupling of green hydrogen and coal gasification, realizing the conversion of syngas into methanol and dimethyl ether. However, its core technology is the co-production of downstream products and zero-carbon energy storage. It does not innovate the methanol synthesis catalyst and still uses conventional copper-zinc-aluminum catalysts, which have common industry problems such as poor low-temperature activity, easy poisoning and short service life.

[0006] In summary, traditional industrial methanol production primarily uses coal gasification as a raw material, producing syngas through coal gasification, which is then synthesized into methanol via catalytic hydrogenation. However, traditional coal-to-methanol processes suffer from problems such as an imbalanced hydrogen-to-carbon ratio in the syngas, high carbon emissions, limited catalyst performance, and a difficulty in simultaneously achieving low carbon emissions and high efficiency. There is an urgent need for an innovative process that can achieve synergistic effects between green hydrogen and coal gasification, possess excellent catalyst performance, and achieve low carbon emissions and high efficiency, thereby driving the transformation and upgrading of the coal chemical industry.

[0007] With the advancement of the "dual carbon" goal, the synergistic production of methanol from green hydrogen and coal-to-gas has become a core technological direction for the low-carbon transformation of coal chemical industry. This approach optimizes the hydrogen-to-carbon ratio and reduces carbon emissions, demonstrating significant industrial value. To this end, the inventors have provided a methanol synthesis process using an all-titanium-based catalyst in synergistic coal-to-gas and green hydrogen production. Summary of the Invention

[0008] To address the problems of imbalanced hydrogen-to-carbon ratio in syngas, high carbon emissions, limited catalyst performance, and difficulty in balancing low carbon emissions and high efficiency in traditional coal-to-methanol processes, this invention provides a methanol synthesis process using a fully titanium-based catalyst that synergizes coal gasification and green hydrogen. Based on the demand for integrated development of green hydrogen, this invention uses a full range of titanium-based catalysts as the core to construct a green and efficient coal-to-methanol process system that combines coal gasification and green chlorine synergy. This improves the economic efficiency, stability, and environmental friendliness of methanol production and fills the technological gap in the field of methanol production through the synergistic use of green hydrogen and coal gasification.

[0009] The present invention provides a methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, which is achieved through the following technical solution: Step 1, Coal gasification pretreatment: The crude coal gasification process involves dust removal, cooling, and preliminary desulfurization to obtain primary crude coal gasification. The crude coal gasification is then subjected to fine desulfurization treatment using a titanium-based fine desulfurization catalyst to obtain pre-processed coal gasification with a COS conversion rate ≥95% and an O2 content ≤10ppm. Simultaneously, deep purification of green hydrogen is carried out, sequentially passing the green hydrogen through a titanium-based low-temperature deoxygenation catalyst for deoxygenation, a deep dehydration adsorbent for dehydration, and a titanium-based CO2 removal adsorption and conversion agent for CO2 removal. The treatment conditions are: temperature 20-80℃, pressure 2.0-5.0 MPa, and space velocity 1000-3000 h⁻¹. -1 The green hydrogen processing capacity is 1000-5000 Nm³. 3 / h, to obtain deeply purified green hydrogen with O2<0.1ppm, H2O<10ppm, and CO2<50ppm; Step 2, Syngas Blending: The pre-produced coal gas from Step 1 is blended with deeply purified green hydrogen in a certain proportion to obtain green hydrogen blended gas. The green hydrogen blending ratio in the green hydrogen blended gas is 5-20%. The green hydrogen blended gas is treated with a titanium-based sulfur-resistant conversion catalyst to obtain syngas through CO conversion. The hydrogen-to-carbon ratio of the syngas is adjusted to 2.0-2.2 to obtain qualified syngas. Step 3, low-pressure catalytic synthesis of methanol: The qualified synthesis gas obtained in step 2 is passed through a titanium-based low-pressure methanol synthesis catalyst to carry out a methanol synthesis reaction to obtain primary methanol. Step 4, methanol separation and purification: The reaction products from Step 3 are sequentially cooled and separated into gas and liquid phases. The separated gas phase is sequentially treated with a titanium-based sulfur recovery catalyst for sulfur recovery and a titanium-based Claus tail gas hydrogenation catalyst for tail gas purification, recovering sulfur and achieving a tail gas SO2 conversion rate of >99% to meet emission standards. The separated liquid phase is purified by distillation to obtain high-purity methanol with a purity of ≥99.9%.

[0010] In step one of this invention, the coal gasification pretreatment involves gasifying coal to obtain crude coal gas. This crude coal gas contains impurities such as dust, tar, COS, H2S, O2, and CO2. First, it undergoes dust removal and cooling to remove dust and tar. Then, it enters a preliminary desulfurization unit to remove most of the H2S. Next, it enters a titanium-based fine desulfurization catalyst bed. The reaction temperature is controlled at 80℃±5℃ and the pressure at 2.0-3.0MPa. Through the low-temperature COS hydrolysis and deep desulfurization effect of the titanium-based fine desulfurization catalyst, COS and trace amounts of O2 and CO2 in the crude coal gas are removed, ensuring a COS conversion rate ≥95% and an O2 content ≤10ppm, providing qualified coal gasification feedstock for subsequent reactions. The titanium-based fine desulfurization catalyst has resistance to hydrothermal deactivation and potassium escape, with a service life >8000h, effectively protecting downstream catalysts from impurity poisoning.

[0011] In step one of this invention, the green hydrogen undergoes deep purification: As a supplementary hydrogen source, the purity of green hydrogen directly affects the efficiency and catalyst lifespan of the subsequent methanol synthesis reaction, thus requiring deep purification. The green hydrogen is sequentially passed through a titanium-based low-temperature deoxygenation catalyst bed, a deep dehydration adsorbent bed, and a titanium-based CO2 removal adsorption and conversion agent bed. The titanium-based low-temperature deoxygenation catalyst is CuO–MnO. x The CeO2 / TiO2 system exhibits excellent low-temperature activity, achieving deep O2 removal without additional heating, reducing the O2 content in green hydrogen to <0.1ppm. The deep dehydration adsorbent has a large adsorption capacity and good regenerability, reducing the H2O content in green hydrogen to <10ppm and can be repeatedly regenerated, reducing operating costs. The titanium-based CO2 removal adsorbent can achieve CO2 removal and partial conversion, reducing the CO2 content in green hydrogen to <50ppm, while converting some CO2 into a usable carbon source, further optimizing the hydrogen-carbon ratio of the synthesis gas, and obtaining purified green hydrogen.

[0012] In step two of this invention, the syngas is blended as follows: the pretreated coal gas from step one is mixed with the purified green hydrogen in a certain proportion, with the green hydrogen blending ratio being 5-20%, preferably 10% (suitable for a 600,000-ton / year coal-to-methanol plant, approximately 180 million Nm³). 3 ( / year of green hydrogen); the mixed gas is then fed into a titanium-based sulfur-resistant shift catalyst bed (K / T205-1 series), with the reaction temperature controlled at 180-220℃ and the pressure at 4.0-6.0MPa, to carry out the CO shift reaction, achieving a CO conversion rate of ≥98%. Simultaneously, the hydrogen-to-carbon ratio of the syngas is adjusted to 2.0-2.2 to obtain qualified syngas. This titanium-based sulfur-resistant shift catalyst can withstand a high pressure of 6.0MPa, is adaptable to fluctuations in the hydrogen-to-carbon ratio of ±5% after green hydrogen blending, has high operational flexibility, can reduce steam consumption, and achieve energy saving and carbon reduction.

[0013] In step three of this invention, methanol is synthesized under low pressure via catalytic oxidation: the qualified synthesis gas obtained in step two is introduced into a titanium-based low-pressure methanol synthesis catalyst bed, and the reaction temperature is controlled at 220-280℃ and the pressure at 5.0MPa to carry out the methanol synthesis reaction. This titanium-based low-pressure methanol synthesis catalyst does not require an additional protective layer, is resistant to poisoning by trace amounts of O2 and H2O impurities in green hydrogen, and shows no significant decrease in methanol conversion rate under the condition of 5-20% green hydrogen mixing. The space-time yield is increased by 10-15% compared with traditional copper-zinc-aluminum catalysts, and the service life is ≥4 years, which greatly reduces the frequency of catalyst replacement and shutdown losses.

[0014] In step four of this invention, methanol separation and purification involves sequentially cooling and gas-liquid separation of the reaction products from step three. The separated gas phase (mainly containing unreacted H2, CO, CO2, and trace amounts of SO2 and organic sulfur) is passed into a titanium-based sulfur recovery catalyst bed (SL-K01 / K02 / K03). The Claus sulfur recovery reaction is carried out using residual heat from green hydrogen at 80-100℃, adapting to temperature fluctuations of ±20℃. The total sulfur recovery rate is >98.5%, and the organic sulfur hydrolysis rate is 100%. The sulfur-treated tail gas is fed into a titanium-based Claus tail gas hydrogenation catalyst bed (SL-S01 / S02) to carry out SO2 hydrogenation reaction at around 220℃, achieving an SO2 conversion rate of >99% and ensuring that the tail gas meets emission standards. This catalyst is resistant to sulfation and high-temperature hydrothermal processes, adaptable to H2 fluctuations of ±5%, and can use green hydrogen as a supplementary hydrogen source to further reduce carbon emissions. The separated liquid phase (mainly containing methanol, water, and a small amount of impurities) is purified by distillation to obtain methanol product with a purity of ≥99.9%.

[0015] Preferably, the fine desulfurization treatment conditions of the titanium-based fine desulfurization catalyst are: 80℃±5℃, pressure 2.0-3.0MPa, and space velocity 4000-8000h⁻¹. -1 Fine desulfurization treatment under certain conditions.

[0016] Preferably, the titanium-based desulfurization catalyst has a COS conversion rate of ≥95% at 80-90℃, a lifespan of >8000h, and a total sulfur removal accuracy of <0.1ppm.

[0017] Preferably, the titanium-based desulfurization catalyst is a ZnO–Fe2O3–CeO2@TiO2 system, with the following mass fractions: ZnO 7-10%, Fe2O3 3-5%, CeO2 1-3%, and anatase TiO2 support 82-89%.

[0018] Preferably, the preparation method of the titanium-based fine desulfurization catalyst includes the following steps: pulverizing anatase TiO2 support, adding guar gum powder binder, and extruding to obtain a catalyst support precursor; dissolving Zn(NO3)2, Fe(NO3)3, and Ce(NO3)3 in deionized water according to the following mass fractions: ZnO 7-10%, Fe2O3 3-5%, CeO2 1-3%, and anatase TiO2 support 82-89% to prepare a mixed impregnation solution; impregnating the catalyst support precursor in the mixed solution for 2-6 hours, followed by drying and calcination treatment at a drying temperature of 110-130℃ for 4-6 hours; and calcining at a calcination temperature of 450-550℃ for 3-5 hours to obtain the titanium-based fine desulfurization catalyst.

[0019] Preferably, the titanium-based low-temperature deoxidation catalyst is CuO–MnO. x –CeO2@TiO2 system, the mass fractions of each component are: CuO 10-15%, MnO x With a composition of 8-12%, CeO2 of 5-8%, and TiO2 support of 65-77%, it can remove O2 to <0.1ppm, and can remove O2 to <0.1ppm at room temperature -50℃. It has a specific surface area >100m². 2 / g, with an activity retention rate of ≥95% after continuous operation for 8000h.

[0020] Preferably, the preparation method of the titanium-based low-temperature deoxidation catalyst includes the following steps: pulverizing the TiO2 support, adding guar gum powder binder, and extruding it into a catalyst support precursor; according to the following mass fractions: CuO 10-15%, MnO x The catalyst precursor is prepared by dissolving Cu(NO3)3, Mn(NO3)2, and Ce(NO3)3 in deionized water to form a mixed impregnation solution. The catalyst support precursor is impregnated in the mixed solution for 2-6 hours, followed by drying and calcination. The drying temperature is 110-130℃ and the drying time is 4-6 hours. The calcination temperature is 450-550℃ and the calcination time is 3-5 hours to obtain a titanium-based low-temperature deoxidation catalyst.

[0021] By using titanium-based fine desulfurization catalysts for low-temperature COS hydrolysis and deep desulfurization, COS and trace amounts of O2 and CO2 are removed from crude coal gasification, ensuring a COS conversion rate of ≥95% and an O2 content of ≤10ppm, thus providing qualified coal gasification feedstock for subsequent reactions.

[0022] Preferably, the deep dehydration adsorbent is a composite adsorbent of molecular sieve and alumina, which can remove H2O to <10ppm.

[0023] Preferably, the deep dehydration adsorbent is a titanium-based modified adsorbent, wherein the titanium-based modified adsorbent uses TiO2 as a carrier and is loaded with 5-10% Al2O3, and the specific surface area of ​​the titanium-based modified adsorbent is 300-400 m². 2 / g.

[0024] Preferably, the preparation method of the deep dehydration adsorbent is as follows: TiO2 and Al2O3 are mixed in a certain proportion, and a binder and an extrusion aid are added. The binder is guar gum powder, and the extrusion aid is nitric acid. The mass ratio of the binder to the mass of the mixture is (4-8):100, and the mass ratio of the nitric acid extrusion aid to the mass of the mixture is (2-3):100. After thorough mixing, the mixture is extruded into strips to obtain a catalyst support precursor. Subsequently, the catalyst support precursor is dried and calcined. The drying temperature is 100-120℃, and the drying time is 3-5h. The calcination temperature is 500-600℃, and the calcination time is 4-6h to obtain the deep dehydration adsorbent.

[0025] Preferably, the titanium-based CO2 removal adsorption converter is a CaO-TiO2 composite system, which can remove CO2 to <50ppm and further optimize the hydrogen-to-carbon ratio.

[0026] Preferably, the titanium-based CO2 removal adsorbent is a titanium-based supported adsorbent, wherein the titanium-based supported adsorbent uses TiO2 as a carrier and is loaded with 8-15% ZrO2 and 3-5% MgO, and the specific surface area of ​​the titanium-based supported adsorbent is 250-350 m². 2 / g.

[0027] Preferably, the preparation method of the titanium-based CO2 removal adsorption converter is as follows: TiO2 support is pulverized, and guar gum powder binder is added and extruded to obtain a catalyst support precursor; according to the mass fraction of each component: ZrO2 is 8-15%, MgO is 3-5%, and TiO2 support is 80-89%, Mg(NO3)2 and Zr(NO3)4 are dissolved in deionized water to prepare a mixed impregnation solution; the catalyst support precursor is impregnated in the mixed impregnation solution for 2-6 hours, then dried and calcined at a drying temperature of 120-140℃ for 5-7 hours; the calcination temperature is 480-580℃ for 3-5 hours to obtain the titanium-based CO2 removal adsorption converter.

[0028] The aforementioned titanium-based low-temperature deoxygenation catalyst, deep dehydration adsorbent, and titanium-based CO2 removal adsorption and conversion agent constitute a green hydrogen purification combined catalyst. In synergy with the all-titanium-based catalyst, it solves the problem of catalyst poisoning caused by trace amounts of O2 / H2O / CO2 in green hydrogen.

[0029] Preferably, the titanium-based low-pressure methanol synthesis catalyst is a Cu-Zn active component supported on TiO2, with the addition of a Ce / La composite additive, wherein the CeO2 loading is 2-5 wt%, the La2O3 loading is 1-3 wt%, and the specific surface area is >120 m². 2 / g, copper grain size <6nm, bulk density 0.8-1.0g / cm³ 3 The compressive strength is ≥150 N / cm; the methanol selectivity is ≥99% under operating conditions of 5.2-5.8 MPa and 220-240℃; the titanium-based low-pressure methanol synthesis catalyst has excellent tolerance to trace O2 / H2O impurities in green hydrogen, requires no additional protective layer, and has a lifespan of ≥4 years.

[0030] Preferably, the titanium-based low-pressure methanol synthesis catalyst uses TiO2 as a support and supports active components CuO and ZnO and co-catalysts La2O3 and ZrO2, with the following mass fractions: CuO 20-25%, ZnO 10-15%, La2O3 3-5%, ZrO2 2-4%, and TiO2 51-65%.

[0031] Preferably, the preparation method of the titanium-based low-pressure methanol synthesis catalyst includes the following steps: S1. After crushing the TiO2 support, add a binder and an extrusion aid. The binder is guar gum powder and the extrusion aid is nitric acid. The mass ratio of the binder to the mass of the mixture is (4-8):100, and the mass ratio of the nitric acid extrusion aid to the mass of the mixture is (2-3):100. After thorough mixing, extrude the mixture into strips to obtain the catalyst support precursor. S2, according to the following mass fractions of each component: CuO 20-25%, ZnO 10-15%, La2O3 3-5%, ZrO2 2-4%, TiO2 51-65%, Cu(NO3)2, Zn(NO3)2, La(NO3)3, and Zr(NO3)4 are dissolved in deionized water in proportion to prepare a mixed impregnation solution; S3. The catalyst support precursor is immersed in a mixed impregnation solution for an equal volume impregnation time of 4-6 h. The impregnated precursor is dried at 120-140℃ for 6-8 h and then calcined at 480-580℃ for 4-6 h to obtain a titanium-based low-pressure methanol synthesis catalyst.

[0032] Preferably, the methanol synthesis reaction conditions for the titanium-based low-pressure methanol synthesis catalyst are: 220-280℃, pressure 5.0±0.5MPa, and space velocity 4000-8000h⁻¹. -1 Methanol synthesis reaction is carried out under the following conditions.

[0033] Titanium-based catalysts possess excellent chemical stability and corrosion resistance, eliminating the need for an additional catalyst protective layer, significantly simplifying the process and reducing equipment investment and maintenance costs. Experimental verification shows that the titanium-based low-pressure methanol synthesis catalyst in this invention has a lifespan of up to 4 years, superior to imported catalysts with a lifespan of 2 years and superior to domestically produced traditional catalysts with a lifespan of 2.5 years, demonstrating significantly improved resistance to impurities.

[0034] Preferably, the titanium-based sulfur-resistant shift catalyst is titanium-based sulfur-resistant shift catalyst K / T205-1; the CO conversion treatment conditions of the titanium-based sulfur-resistant shift catalyst are: 180-280℃, pressure 4.0-6.0MPa, and space velocity 4000-8000h⁻¹. -1 The CO conversion reaction is carried out under the specified conditions.

[0035] Preferably, the titanium-based sulfur-resistant shift catalyst K / T205-1 uses anatase TiO2 as a support, loaded with 8-12 wt% MoO3, 2-4 wt% CoO, and 3-5 wt% K2O, with a specific surface area >80 m². 2 / g, pore volume 0.3-0.5cm³ / g, bulk density 0.8-1.0g / cm³, compressive strength ≥150N / cm, wear rate ≤1.0%.

[0036] Preferably, the titanium-based sulfur recovery catalyst is any one of titanium-based sulfur recovery catalyst SL-K01, titanium-based sulfur recovery catalyst SL-K02, and titanium-based sulfur recovery catalyst SL-K03.

[0037] Preferably, the titanium-based sulfur recovery catalyst uses TiO2 as a carrier to load active components and additives, with a total sulfur recovery rate of >98.5%, and can utilize the waste heat of green hydrogen at 80-100℃ to heat the feed, and can withstand temperature fluctuations of ±20℃.

[0038] Preferably, the titanium-based Claus tail gas hydrogenation catalyst is either titanium-based Claus tail gas hydrogenation catalyst SL-S01 or titanium-based Claus tail gas hydrogenation catalyst SL-S02.

[0039] Preferably, the titanium-based Claus tail gas hydrogenation catalyst uses TiO2 as a support, achieves an SO2 conversion rate of >99% at 220-260℃, uses green hydrogen as a supplementary hydrogen source, and has a hydrogen-to-oil ratio of 3-8:1.

[0040] Preferably, the titanium-based sulfur recovery catalyst is adaptable to temperature fluctuations within a range of ±20℃, utilizes residual heat from green hydrogen at 80-100℃ for the reaction, and has a space velocity of 4000-8000 h⁻¹. -1 Total sulfur recovery rate >98.5%, organic sulfur hydrolysis rate 100%.

[0041] Preferably, the titanium-based Claus tail gas hydrogenation catalyst can adapt to H2 fluctuations within a range of ±5%, uses green hydrogen as a supplementary hydrogen source, has a hydrogen-to-oil ratio of 3-8:1, and operates under catalytic conditions of 220-260°C and a space velocity of 4000-8000 h⁻¹. -1 .

[0042] In summary, the present invention has the following advantages: 1. This invention adopts an all-titanium-based catalyst system, completely eliminating the dependence on traditional copper-zinc-aluminum catalysts. It solves the problems of insufficient low-temperature activity, poor sulfur and water resistance, easy poisoning and deactivation, and short service life of traditional catalysts. The all-titanium-based catalyst system has a long service life, with the fine desulfurization catalyst having a service life of >8000h and the methanol synthesis catalyst having a service life of ≥4 years, which greatly reduces catalyst replacement costs and shutdown losses.

[0043] 2. This invention achieves the integrated application of coal-to-gas, green hydrogen synergy, and all-titanium-based catalysis technology. It has strong process adaptability, and the green hydrogen blending ratio can be flexibly adjusted (5-20%), making it suitable for coal-to-methanol plants of different scales, especially for plants with a scale of 600,000 tons / year and above. The green hydrogen purification and coal-to-gas pretreatment are synergistically optimized to ensure the purity of syngas and improve the methanol conversion rate and selectivity.

[0044] 3. Significant energy saving and carbon reduction effects: The titanium-based catalyst exhibits excellent low-temperature activity and can utilize the waste heat of green hydrogen for the reaction, reducing steam consumption and energy waste; the titanium-based Claus tail gas hydrogenation catalyst can use green hydrogen as a supplementary hydrogen source, further reducing carbon emissions and meeting the dual carbon target requirements.

[0045] 4. Significant economic advantages: The investment in catalysts throughout the entire process is 30-40% lower than that of imported catalysts. Although it is 5-15% higher than that of domestic general-purpose catalysts, the overall cost over the entire life cycle is the best. The average annual catalyst consumption cost of a 600,000-ton / year unit is ≤7.2 million yuan, which is far lower than that of imported catalysts (about 18 million yuan / year under green hydrogen conditions) and domestic general-purpose catalysts (about 10 million yuan / year under green hydrogen conditions).

[0046] 5. The process is highly stable, and the catalyst has strong resistance to impurities and fluctuations. No additional catalyst protection layer is required. It can be directly adapted to green hydrogen blending conditions, avoiding the poisoning and deactivation problems caused by green hydrogen impurities in traditional catalysts. This ensures long-term stable operation of the device, has significant industrial application value and environmental benefits, and meets the substantive conditions for patent authorization. Attached Figure Description

[0047] Figure 1 This is an SEM image of the titanium-based fine desulfurization catalyst in Preparation Example 1 of this invention. Detailed Implementation

[0048] To further understand the inventiveness and technical advancements of this invention, the preferred embodiments of this invention will be discussed in detail below with reference to examples and comparative examples.

[0049] Preparation Example 1: The titanium-based fine desulfurization catalyst is a ZnO–Fe2O3–CeO2@TiO2 system, with the following mass fractions: ZnO 8%, Fe2O3 4%, CeO2 2%, and anatase TiO2 support 86%.

[0050] The preparation method of titanium-based fine desulfurization catalyst includes the following steps: S1, crush the anatase TiO2 carrier, add guar gum powder binder and water to knead into a plastic mud, and extrude the plastic mud into a honeycomb structure catalyst carrier precursor. The mass ratio of guar gum powder binder to TiO2 carrier powder is 19:1. S2, according to the following mass fractions of each component: ZnO 8%, Fe2O3 4%, CeO2 2%, and anatase TiO2 support 86%, Zn(NO3)2, Fe(NO3)3, and Ce(NO3)3 are dissolved in deionized water to prepare a mixed impregnation solution; S1, the catalyst support precursor was immersed in a mixed solution for 3 hours, followed by drying and calcination. The drying temperature was 120℃ and the drying time was 5 hours. Then, the catalyst was calcined by raising the temperature to 500℃ at 10℃ / min and calcining at 500℃ for 4 hours. After calcination, the temperature was lowered from 500℃ to 200℃ at 20℃ / min. The furnace was then opened and allowed to cool naturally to room temperature to obtain the titanium-based fine desulfurization catalyst.

[0051] Preparation Example 2: A method for preparing a titanium-based low-temperature deoxidation catalyst, comprising the following steps: S1. The anatase TiO2 carrier is crushed to 90 mesh, and guar gum powder binder and water are added to knead into a plastic mud. The plastic mud is extruded into strips to obtain a honeycomb structure catalyst carrier precursor. The mass ratio of guar gum powder binder to TiO2 carrier powder is 19:1. S2, with a mass fraction of CuO of 12% and MnO x The components are Cu(NO3)2, Mn(NO3)2, and Ce(NO3)3, with a content of 10%, CeO2 of 6%, and TiO2 of 72%. Cu(NO3)2, Mn(NO3)2, and Ce(NO3)3 are dissolved in deionized water to prepare a mixed impregnation solution. In step S3, the catalyst precursor prepared in step S1 is immersed in the mixed impregnation solution prepared in step S2 for 3 hours. After impregnation, it is placed in an oven and dried at 120°C for 5 hours, followed by calcination. The temperature is increased to 500°C at a rate of 10°C / min, and calcined at 500°C for 4 hours. After calcination, the temperature is decreased from 500°C to 200°C at a rate of 20°C / min, and the furnace is opened and allowed to cool naturally to room temperature to obtain a titanium-based low-temperature deoxidation catalyst with a bulk density of 1.3 g / cm³. 3 Compressive strength 160 N / cm.

[0052] Preparation Example 3: A method for preparing a deep dehydration adsorbent, comprising the following steps: S1. Anatase TiO2 / Al2O3 is mixed evenly at a mass ratio of 9:1. Then, guar gum binder and nitric acid extrusion aid are added to the mixture. The mass ratio of guar gum binder to the mass of the mixture is 6:100, and the mass ratio of nitric acid extrusion aid to the mass of the mixture is 2.5:100. Deionized water is added, and the mixture is thoroughly mixed and kneaded into a plastic slurry. The slurry is then extruded into strips to obtain a honeycomb structure catalyst carrier precursor. S2, the catalyst support precursor was dried in an oven at 110℃ for 4.0 h, followed by calcination. The temperature was increased to 550℃ at a rate of 10℃ / min, and calcined at 550℃ for 5.0 h. After calcination, the temperature was decreased from 550℃ to 200℃ at a rate of 20℃ / min, and the furnace was opened and allowed to cool naturally to room temperature to obtain a deeply dehydrated adsorbent with a specific surface area of ​​350 m². 2 / g, bulk density 1.2g / cm³ 3 Compressive strength 150 N / cm.

[0053] Preparation Example 4: A method for preparing a titanium-based CO2 removal adsorption converter, comprising the following steps: S1. The anatase TiO2 carrier is crushed to 90 mesh, and guar gum powder binder and water are added to knead into a plastic mud. The plastic mud is extruded into strips to obtain a honeycomb structure catalyst carrier precursor. The mass ratio of guar gum powder binder to TiO2 carrier powder is 19:1. S2, with a mass fraction of ZrO2 of 12%, MgO of 4%, and TiO2 of 82%, Mg(NO3)2 and Zr(NO3)4 are dissolved in deionized water to prepare a mixed impregnation solution; In step S3, the catalyst precursor prepared in step S1 is immersed in the mixed impregnation solution prepared in step S2 for 4.0 h. After impregnation, it is placed in an oven and dried at 130 °C for 6.0 h, followed by calcination. The temperature is increased to 530 °C at a rate of 10 °C / min, and calcined at 530 °C for 4.0 h. After calcination, the temperature is decreased from 530 °C to 200 °C at a rate of 20 °C / min, and the furnace is opened and allowed to cool naturally to room temperature to obtain a titanium-based CO2 removal adsorption converter. The obtained titanium-based CO2 removal adsorption converter has a bulk density of 1.4 g / cm³, a compressive strength of 170 N / cm, and a specific surface area of ​​300 m². 2 / g.

[0054] Preparation Example 5: A method for preparing a titanium-based low-pressure methanol synthesis catalyst, comprising the following steps: S1, Carrier Pretreatment and Molding: Take anatase TiO2 carrier, crush it to 110 mesh, add guar gum binder and nitric acid extrusion aid. The mass ratio of guar gum binder to the mass of the mixture is 6:100, and the mass ratio of nitric acid extrusion aid to the mass of the mixture is 2.5:100. Add deionized water, mix and knead thoroughly to form a plastic slurry, and extrude it into strips to obtain a honeycomb structure catalyst carrier precursor. S2, Preparation of mixed impregnation solution: Weigh out the corresponding masses of Cu(NO3)2, Zn(NO3)2, La(NO3)3, and Zr(NO3)4 according to the mass fractions of CuO 22%, ZnO 12%, La2O3 4%, ZrO2 3%, and TiO2 59%, dissolve them in deionized water, stir evenly, and prepare the mixed impregnation solution; S3, Equal volume impregnation: The catalyst precursor prepared in S1 is immersed in the mixed impregnation solution prepared in S2 for 5.0 h to ensure that the impregnation solution is completely adsorbed by the catalyst precursor. S4, after impregnation, was placed in an oven and dried at 130℃ for 7.0h, followed by calcination. The temperature was increased to 530℃ at 10℃ / min and calcined at 530℃ for 5.0h. After calcination, the temperature was decreased from 530℃ to 200℃ at 20℃ / min, and the furnace was opened and allowed to cool naturally to room temperature to obtain a titanium-based low-pressure methanol synthesis catalyst. The bulk density of the obtained titanium-based low-pressure methanol synthesis catalyst was 1.5 g / cm³. 3 Compressive strength 220 N / cm², specific surface area 250 m² 2 / g, pore size 7nm.

[0055] Example: A methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, comprising the following steps: Step 1, Coal Gasification Pretreatment: The crude coal gasification process involves dust removal, cooling, and preliminary desulfurization to obtain primary crude coal gas. This primary crude coal gas is then subjected to fine desulfurization treatment using a titanium-based sulfur-resistant shift catalyst, K / T205-1. The CO shift treatment conditions for this titanium-based sulfur-resistant shift catalyst are: 220-280℃, pressure 5.0±0.5MPa, and space velocity 4000-8000h⁻¹. -1 Methanol synthesis reaction was carried out under certain conditions to obtain pre-coal gasification with COS conversion rate ≥95% and O2 content ≤10ppm; Simultaneously, deep purification of green hydrogen is carried out, sequentially passing it through a titanium-based low-temperature deoxygenation catalyst for deoxygenation, a deep dehydration adsorbent for dehydration, and a titanium-based CO2 removal adsorption and conversion agent for CO2 removal. Treatment conditions: temperature 20-80℃, pressure 2.0-5.0 MPa (pressure can be adjusted according to process requirements to match subsequent syngas synthesis processes), and space velocity 1000-3000 h⁻¹. -1 The green hydrogen processing capacity is 1000-5000N. 3 / h, to obtain deeply purified green hydrogen with O2<0.1ppm, H2O<10ppm, and CO2<50ppm; Step 2, Syngas Blending: The pre-generated coal gas from Step 1 is blended with deeply purified green hydrogen in a certain proportion to obtain green hydrogen blended gas. The green hydrogen blending ratio in the green hydrogen blended gas is 5-20%, preferably 10±0.5%. The green hydrogen blended gas is then subjected to CO conversion treatment using a titanium-based sulfur-resistant shift catalyst to obtain syngas. The titanium-based sulfur-resistant shift catalyst is K / T205-1. The CO conversion treatment conditions of the titanium-based sulfur-resistant shift catalyst are: 180-280℃, pressure 4.0-6.0MPa, and space velocity 4000-8000h⁻¹. -1 Adjust the hydrogen-to-carbon ratio of the syngas to 2.0-2.2 to obtain qualified syngas; Step 3, Low-pressure catalytic synthesis of methanol: The qualified synthesis gas obtained in Step 2 is passed through a titanium-based low-pressure methanol synthesis catalyst to carry out the methanol synthesis reaction. The methanol synthesis reaction conditions are: 220-280℃, pressure 5.0±0.5MPa, and space velocity 4000-8000h. -1 Under certain conditions, a methanol synthesis reaction is carried out to obtain primary methanol; Step 4, Methanol Separation and Purification: The reaction products from Step 3 are sequentially cooled and subjected to gas-liquid separation. The separated gas phase is then sequentially treated with a titanium-based sulfur recovery catalyst for sulfur recovery and a titanium-based Claus tail gas hydrogenation catalyst for tail gas purification. The titanium-based sulfur recovery catalyst is any one of titanium-based sulfur recovery catalysts SL-K01, SL-K02, and SL-K03. The titanium-based Claus tail gas hydrogenation catalyst is any one of titanium-based Claus tail gas hydrogenation catalysts SL-S01 and SL-S02. The titanium-based sulfur recovery catalyst can adapt to temperature fluctuations within ±20℃. The reaction is carried out using residual heat from green hydrogen at 80-100℃, with a space velocity of 4000-8000 h⁻¹. -1 Total sulfur recovery rate >98.5%, organic sulfur hydrolysis rate 100%, titanium-based Claus tail gas hydrogenation catalyst adaptable to H2 fluctuations within ±5%, using green hydrogen as supplementary hydrogen source, hydrogen-to-oil ratio 3-8:1, catalytic conditions 220-260℃, space velocity 4000-8000 h⁻¹ -1 The process involves recovering sulfur and achieving a SO2 conversion rate of >99% in the tail gas, ensuring compliance with emission standards. The separated liquid phase is purified by distillation to obtain high-purity methanol with a purity of ≥99.9%.

[0056] Example 1: A methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, the steps of which are as follows: Step 1, Coal Gasification Pretreatment: Raw coal is gasified to obtain crude coal gas. After dust removal and cooling to 80℃, the crude coal gas is initially desulfurized and then passed through a fixed-bed reactor loaded with the titanium-based fine desulfurization catalyst obtained in Example 1. The gas is then subjected to a pressure of 2.5 MPa, a temperature of 80℃, and a space velocity of 8000 h⁻¹. -1 Under these conditions, fine desulfurization treatment was carried out to obtain pretreated coal gas with a COS conversion rate of 96% and an O2 content of 8ppm. Simultaneously, deep purification of green hydrogen was carried out. Green hydrogen (purity 99.5%, O2 content 0.5ppm, H2O content 50ppm, CO2 content 200ppm) was sequentially passed through a fixed-bed reactor with the titanium-based low-temperature deoxygenation catalyst obtained in Example 2, a fixed-bed reactor with the deep dehydration adsorbent obtained in Example 3, and a fixed-bed reactor with the titanium-based CO2 removal adsorption converter obtained in Example 4 for purification. The treatment conditions were: temperature 50℃, pressure 3.5MPa, and space velocity 2000h. -1 The green hydrogen processing capacity is 3000 Nm³. 3 / h, to obtain deeply purified green hydrogen with O2 content of 0.07ppm, H2O content of 7ppm and CO2 content of 42ppm; Step 2, Syngas Blending: The pre-processed coal gas obtained in Step 1 is blended with deeply purified green hydrogen in a specific ratio, controlling the green hydrogen blending ratio to be 10%. The mixed gas is then subjected to CO conversion treatment in a fixed-bed reactor supported on a titanium-based sulfur-resistant shift catalyst K / T205-1 at a reaction temperature of 220℃, a pressure of 5.0MPa, and a space velocity of 8000h⁻¹. -1 This yielded qualified syngas with a CO conversion rate of 98.5% and a hydrogen-to-carbon ratio of 2.1. Step 3, Low-pressure catalytic synthesis of methanol: The qualified synthesis gas obtained in Step 2 is passed through a fixed-bed reactor loaded with the titanium-based low-pressure methanol synthesis catalyst obtained in Example 5 to carry out the methanol synthesis reaction. The reaction temperature is 250℃, the pressure is 5.0MPa, and the space velocity is 8000h. -1 The methanol single-pass conversion rate was 88%, the methanol selectivity was 98.5%, and the methanol space-time yield was 1.9 g / (mL·h). Step 4, Methanol Separation and Purification: The reaction product is cooled to 40℃ for gas-liquid separation. The separated gas phase is then subjected to sulfur recovery treatment in a fixed-bed reactor supported on a titanium-based sulfur recovery catalyst SL-K02, utilizing the residual heat from 90℃ green hydrogen and a space velocity of 8000 h⁻¹. -1 The total sulfur recovery rate was 98.8%; the tail gas entered the titanium-based Claus tail gas hydrogenation catalyst SL-S01 bed and was heated at 220℃ and a space velocity of 8000 h⁻¹. -1 Using a portion of green hydrogen as the hydrogen source (hydrogen-to-oil ratio 5:1), the SO2 conversion rate is 99.2%, achieving emission standards. The separated liquid phase is purified by distillation to obtain high-purity methanol with a purity of 99.92%.

[0057] The methanol synthesis process in Example 1 is a 600,000-ton / year coal-to-gas and green hydrogen co-synthesis process for methanol synthesis. The total catalyst investment for the entire process is approximately RMB 24.9 million. The methanol synthesis catalyst has a lifespan of 4 years, and the pre-treatment / purification catalyst has a lifespan of more than 3 years. The average annual catalyst consumption cost is RMB 7.2 million. Steam consumption is reduced by 15% compared to traditional processes, carbon emissions are reduced by 20%, and the unit has been running continuously and stably for more than 8,000 hours without catalyst poisoning or deactivation, fully meeting the design requirements.

[0058] Example 2: A methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, the steps of which are as follows: Step 1, Coal Gasification Pretreatment: Raw coal is gasified to obtain crude coal gas. After dust removal and cooling to 75°C, the crude coal gas undergoes preliminary desulfurization and is then subjected to fine desulfurization treatment in a fixed-bed reactor loaded with the titanium-based fine desulfurization catalyst obtained in Example 1, under conditions of 2.0 MPa pressure, 75°C temperature, and 8000 h⁻¹ space velocity. -1 Under these conditions, pretreated coal gasification with a COS conversion rate of 95.5% and an O2 content of 9 ppm was obtained; Simultaneously, deep purification of green hydrogen was carried out by sequentially passing the green hydrogen through a fixed-bed reactor containing the catalysts obtained in Preparation Example 2, Preparation Example 3, and Preparation Example 4. The treatment conditions were: temperature 50°C, pressure 3.5 MPa, and space velocity 2500 h⁻¹. -1 A deeply purified green hydrogen with an O2 content of 0.09ppm, an H2O content of 9ppm, and a CO2 content of 48ppm was obtained. Step 2, Syngas Blending: The pre-generated coal gas obtained in Step 1 is blended with deeply purified green hydrogen in a certain proportion, controlling the green hydrogen blending ratio to be 15%. The mixed gas is then subjected to CO conversion treatment in a fixed-bed reactor supported on titanium-based sulfur-resistant shift catalyst K / T205-1, with a reaction temperature of 220℃, a pressure of 4.0MPa, and a space velocity of 8000h⁻¹. -1 This yielded qualified syngas with a CO conversion rate of 98.0% and a hydrogen-to-carbon ratio of 2.0. Step 3, Low-pressure catalytic synthesis: The qualified synthesis gas obtained in Step 2 is passed through a fixed-bed reactor loaded with the titanium-based low-pressure methanol synthesis catalyst obtained in Example 5 to carry out methanol synthesis reaction. The reaction temperature is 250℃, the pressure is 5.0MPa, and the space velocity is 8000h. -1 The methanol single-pass conversion rate was 86%, the methanol selectivity was 98.2%, and the methanol space-time yield was 1.82 g / (mL·h). Step 4, Methanol Separation and Purification: The reaction product is cooled to 40℃ for gas-liquid separation. The separated gas phase is treated for sulfur recovery in a fixed-bed reactor supported on a titanium-based sulfur recovery catalyst SL-K02, utilizing the residual heat of green hydrogen at 90℃, with a space velocity of 8000 h⁻¹, achieving a total sulfur recovery rate of 98.6%. The tail gas enters a titanium-based Claus tail gas hydrogenation catalyst bed SL-S01, and is treated at 220℃ and a space velocity of 8000 h⁻¹. -1 Hydrogenation purification was carried out using a portion of green hydrogen as the hydrogen source (hydrogen-to-oil ratio 5:1), achieving a SO2 conversion rate of 99.1% and meeting emission standards. The separated liquid phase was purified by distillation to obtain high-purity methanol with a purity of 99.90%.

[0059] The methanol synthesis process in Example 2 is a 400,000-ton / year coal-to-gas and green hydrogen co-synthesis process for methanol synthesis. The total catalyst investment for the entire process is approximately RMB 16.6 million. The methanol synthesis catalyst has a lifespan of 4 years, and the pre-treatment / purification catalyst has a lifespan of more than 3 years. The average annual catalyst consumption cost is RMB 4.8 million. Steam consumption is reduced by 14% compared to traditional processes, carbon emissions are reduced by 18%, and the unit has been running continuously and stably for more than 8,000 hours without catalyst poisoning or deactivation, fully meeting the design requirements.

[0060] The difference between Comparative Example 1 and Example 1 is that the titanium-based low-pressure methanol synthesis catalyst bed in step 3 was replaced with a catalyst bed prepared by the imported brand Johnson Matthey KATALCO 51-9 catalyst. After 18 months of operation under green hydrogen conditions, the activity significantly decreased to below 75%, the catalyst life was estimated to be <2 years, the average annual amortization cost was about RMB18 million / year, and an additional impurity protection bed was required, increasing the investment by RMB5 million.

[0061] The difference between Comparative Example 2 and Example 1 is that the titanium-based low-pressure methanol synthesis catalyst bed in step 3 is replaced with a catalyst bed prepared by the mainstream domestic copper-zinc-aluminum catalyst (Nanjing Chemical Research Institute C307-M), and the titanium-based sulfur-resistant shift catalyst K / T205-1 is replaced with an Al2O3 supported catalyst. An additional protective bed is required (investment of about RMB 5 million), and the annual catalyst amortization cost is about RMB 10 million / year, which is 38.9% higher than the cost of Example 1. Moreover, the catalyst life is only 2.5 years and needs to be replaced frequently. The CO conversion rate of the sulfur-resistant shift section is only 85.3%, and the steam consumption is 35% higher than the steam consumption of Example 1.

[0062] Performance comparison of all-titanium-based catalyst assemblies for green hydrogen purification: The dedicated titanium-based catalyst combination for green hydrogen purification comprises the titanium-based low-temperature deoxygenation catalyst from Preparation Example 2, the deep dehydration adsorbent from Preparation Example 3, and the titanium-based CO2 removal adsorption and conversion agent from Preparation Example 4. The performance of this catalyst combination was compared with that of a traditional general-purpose catalyst combination (copper-based deoxygenation catalyst + molecular sieve dehydration adsorbent + alkaline CO2 removal catalyst) under the same experimental conditions: temperature 50℃, pressure 3.5MPa, and space velocity 2000h⁻¹. -1 Green hydrogen processing capacity 3000 Nm 3 The raw material, green hydrogen, has a purity of 99.5%, an O2 content of 0.5 ppm, an H2O content of 50 ppm, and a CO2 content of 200 ppm per hour. The test results are shown in Table 1 below. Table 1: Performance Comparison of All-Titanium-Based Catalyst Assemblies for Green Hydrogen Purification and Traditional General-Purpose Catalyst Assemblies

[0063] As shown in Table 1, the purification precision, energy consumption and lifespan of the catalyst combination of the present invention are superior to those of traditional general-purpose catalyst combinations, and it has significant performance advantages. It can effectively meet the needs of deep purification of green hydrogen and is suitable for the process of coal gasification and green hydrogen co-synthesis of methanol.

[0064] Catalyst performance comparison test: The performance of titanium-based low-pressure methanol synthesis catalyst was compared with that of traditional copper-zinc-aluminum methanol synthesis catalyst and conventional titanium-based methanol synthesis catalyst. The test conditions were the same: temperature 250℃, pressure 5.0MPa, space velocity 8000h. -1The experiment involved blending 10% green hydrogen (containing 0.07 ppm O2, 7 ppm H2O, and 42 ppm CO2). The results are shown in Table 2 below. Table 2: Performance comparison of the catalyst of this invention with traditional copper-zinc-aluminum methanol synthesis catalysts and conventional titanium-based methanol synthesis catalysts.

[0065] As shown in Table 2, the catalyst of this invention is significantly superior to traditional copper-zinc-aluminum catalysts and conventional titanium-based catalysts in terms of catalytic efficiency, impurity resistance, and service life. It has outstanding performance advantages and can effectively meet the needs of the coal gasification and green hydrogen co-synthesis of methanol process. It also shows excellent adaptability and economy.

[0066] Catalyst performance testing under different green hydrogen blending ratios: Based on the methanol synthesis conditions of Example 1, the titanium-based low-pressure methanol synthesis catalyst from Preparation Example 5 was used to test the catalyst under different green hydrogen blending ratios (5%, 10%, 15%, 20%) while maintaining the reaction conditions (temperature 250℃, pressure 5.0 MPa, space velocity 8000 h⁻¹). -1 With the catalyst unchanged, its performance was tested, and the results are shown in Table 3: Table 3: Catalytic performance of titanium-based low-pressure methanol synthesis catalysts with different green hydrogen blending ratios (5%, 10%, 15%, 20%)

[0067] As shown in Table 3, the catalyst of the present invention can maintain stable catalytic performance in the range of 5-20% green hydrogen blending, with no significant decrease in methanol conversion rate. It has strong adaptability and can meet the requirements of coal gasification and green hydrogen co-synthesis methanol processes of different scales and different green hydrogen blending ratios.

[0068] This invention is the first to comprehensively apply titanium-based catalysts to the entire process of methanol production from coal gasification and green hydrogen synergy, covering six major stages: green hydrogen purification, sulfur-resistant conversion, sulfur recovery, tail gas hydrogenation, fine desulfurization, and methanol synthesis, forming a complete technical closed loop and filling a gap in the field. The synergistic effect of each catalyst solves the problems of poor compatibility and insufficient performance when using a single catalyst, achieving deep compatibility between the catalyst system and the process. At the same time, it constructs a dual protection of "process + materials", significantly increasing the difficulty for competitors to circumvent it.

[0069] This invention has significant energy-saving and carbon-reducing effects: the titanium-based catalyst has excellent low-temperature activity (80-220℃), and the sulfur-resistant conversion section can reduce steam consumption by 30-40% (based on a 600,000-ton / year plant, saving approximately 120,000 tons of steam annually); the sulfur recovery unit utilizes the waste heat of green hydrogen at 80-100℃ to replace traditional heating devices, reducing energy consumption by approximately 15%; the tail gas hydrogenation uses green hydrogen as a supplementary hydrogen source to replace traditional fossil hydrogen sources, reducing carbon emissions by approximately 8-12% (based on a 600,000-ton / year plant, reducing carbon emissions by approximately 50,000 tons annually).

[0070] This invention boasts the most favorable life-cycle cost and outstanding commercial value: taking a 600,000-ton / year plant with 10% green hydrogen blending as an example, the total catalyst investment for this invention is approximately RMB 24.9 million (including all catalyst loading), with an average annual amortization of approximately RMB 7.2 million (based on 10-year depreciation), lower than the RMB 18 million / year of imported solutions (green hydrogen operating conditions). It offers superior overall cost-effectiveness and shortens the investment payback period by 3-4 years. Furthermore, the catalyst can be regenerated through an oxidation-reduction process, restoring its activity to over 95% of its initial activity, further reducing operating costs and enhancing commercial value and patent competitiveness.

[0071] This invention has strong adaptability and broad prospects for promotion: The process route of this invention is clear, the catalyst system is complete, and the operating parameters are stable. It can be directly applied to the green hydrogen coupling retrofit of existing coal-to-methanol plants (retrofit investment of about RMB 80-100 million) or new projects. The retrofit cycle is short (3-6 months), and there is no need for large-scale adjustment of existing equipment. It is in line with the "dual carbon" strategic direction and has significant industrial value and promotion prospects.

[0072] In summary, the methanol synthesis process in this invention uses a full range of titanium-based catalysts as the core to construct a green and efficient coal-to-methanol process system of "coal-to-gas + green chlorine synergy", thereby improving the economy, stability and environmental friendliness of methanol production.

[0073] It should be noted that this specific embodiment is merely an explanation of the technical solution of the present invention and is not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, characterized in that: Includes the following steps: Step 1, Coal gasification pretreatment: The crude coal gasification process involves dust removal, cooling, and preliminary desulfurization to obtain primary crude coal gasification. The crude coal gasification is then subjected to fine desulfurization treatment using a titanium-based fine desulfurization catalyst to obtain pre-processed coal gasification with a COS conversion rate ≥95% and an O2 content ≤10ppm. Meanwhile, the green hydrogen is subjected to deep purification treatment, and the green hydrogen is sequentially subjected to deoxidation treatment of a titanium-based low-temperature deoxidation catalyst, dehydration treatment of a deep dehydration adsorbent and CO2 removal treatment of a titanium-based CO2 removal adsorption conversion agent, and the treatment conditions are as follows: temperature 20-80℃, pressure 2.0-5.0MPa, space velocity 1000-3000h -1 , and the green hydrogen treatment amount is 1000-5000Nm 3 / h, and deep purified green hydrogen with O2<0.1ppm, H2O<10ppm and CO2<50ppm is obtained. Step 2, Syngas Blending: The pre-produced coal gas from Step 1 is blended with deeply purified green hydrogen in a certain proportion to obtain green hydrogen blended gas. The green hydrogen blending ratio in the green hydrogen blended gas is 5-20%. The green hydrogen blended gas is treated with a titanium-based sulfur-resistant conversion catalyst to obtain syngas through CO conversion. The hydrogen-to-carbon ratio of the syngas is adjusted to 2.0-2.2 to obtain qualified syngas. Step 3, low-pressure catalytic synthesis of methanol: The qualified synthesis gas obtained in step 2 is passed through a titanium-based low-pressure methanol synthesis catalyst to carry out a methanol synthesis reaction to obtain primary methanol. Step 4, methanol separation and purification: The reaction products from Step 3 are sequentially cooled and separated into gas and liquid phases. The separated gas phase is sequentially treated with a titanium-based sulfur recovery catalyst for sulfur recovery and a titanium-based Claus tail gas hydrogenation catalyst for tail gas purification, recovering sulfur and achieving a tail gas SO2 conversion rate of >99% to meet emission standards. The separated liquid phase is purified by distillation to obtain high-purity methanol with a purity of ≥99.9%.

2. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The fine desulfurization treatment conditions of the titanium-based fine desulfurization catalyst are: 80℃±5℃, pressure 2.0-3.0MPa, and space velocity 4000-8000h⁻¹. -1 Fine desulfurization treatment under certain conditions.

3. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 2, is characterized in that: The titanium-based fine desulfurization catalyst is a ZnO–Fe2O3–CeO2@TiO2 system, with the following mass fractions: ZnO 7-10%, Fe2O3 3-5%, CeO2 1-3%, and anatase TiO2 support 82-89%; the preparation method of the titanium-based fine desulfurization catalyst includes the following steps: pulverizing the anatase TiO2 support, adding guar gum powder binder, and extruding to obtain a catalyst support precursor; according to the following mass fractions: ZnO 7-10%, Fe2O3 3-5%, CeO2 1-3%, and anatase TiO2 support 82-89%; The catalyst precursor is prepared by dissolving Zn(NO3)2, Fe(NO3)3, and Ce(NO3)3 in deionized water to form a mixed impregnation solution. The catalyst support precursor is impregnated in the mixed solution for 2-6 hours, followed by drying and calcination. The drying temperature is 110-130℃ and the drying time is 4-6 hours. The calcination temperature is 450-550℃ and the calcination time is 3-5 hours to obtain a titanium-based fine desulfurization catalyst.

4. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The titanium-based low-temperature deoxidation catalyst is CuO–MnO. x –CeO2@TiO2 system, the mass fractions of each component are: CuO 10-15%, MnO x The titanium-based low-temperature deoxidation catalyst is prepared as follows: The TiO2 support is pulverized, and guar gum powder binder is added and extruded to obtain a catalyst support precursor; the mass fraction of each component is: CuO 10-15%, MnO 8-12%, CeO2 5-8%, and TiO2 support 65-77%; the preparation method of the titanium-based low-temperature deoxidation catalyst is as follows: the TiO2 support is pulverized, and guar gum powder binder is added and extruded to obtain a catalyst support precursor; the mass fraction of each component is: CuO 10-15%, CeO 5-8%, and TiO2 support 65-77%; x The catalyst precursor is prepared by dissolving Cu(NO3)3, Mn(NO3)2, and Ce(NO3)3 in deionized water to form a mixed impregnation solution. The catalyst support precursor is impregnated in the mixed solution for 2-6 hours, followed by drying and calcination. The drying temperature is 110-130℃ and the drying time is 4-6 hours. The calcination temperature is 450-550℃ and the calcination time is 3-5 hours to obtain a titanium-based low-temperature deoxidation catalyst.

5. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The deep dehydration adsorbent is a titanium-based modified adsorbent, which uses TiO2 as a carrier and loads 5-10% Al2O3. The specific surface area of ​​the titanium-based modified adsorbent is 300-400 m² / g. The preparation method of the deep dehydration adsorbent is as follows: TiO2 and Al2O3 are mixed in a certain proportion, and a binder and an extrusion aid are added. The binder is guar gum powder, and the extrusion aid is nitric acid. The mass ratio of the binder to the mass of the mixture is (4-8):100, and the mass ratio of the nitric acid extrusion aid to the mass of the mixture is (2-3):

100. After thorough mixing, the mixture is extruded into a catalyst carrier precursor. The catalyst carrier precursor is then dried and calcined. The drying temperature is 100-120℃, and the drying time is 3-5 h. The calcination temperature is 500-600℃, and the calcination time is 4-6 h to obtain the deep dehydration adsorbent.

6. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The titanium-based CO2 removal adsorption converter is a titanium-based supported adsorption converter. The titanium-based supported adsorption converter uses TiO2 as a support and is loaded with 8-15% ZrO2 and 3-5% MgO. The specific surface area of ​​the titanium-based supported adsorption converter is 250-350 m² / g. The preparation method of the titanium-based CO2 removal adsorption converter is as follows: the TiO2 support is pulverized, and guar gum powder binder is added and extruded to obtain a catalyst support precursor; according to the mass fraction of each component... The catalyst precursor is prepared by dissolving Mg(NO3)2 and Zr(NO3)4 in deionized water to form a mixed impregnation solution. The catalyst support precursor is impregnated in the mixed impregnation solution for 2-6 hours, then dried and calcined. The drying temperature is 120-140℃ and the drying time is 5-7 hours. The calcination temperature is 480-580℃ and the calcination time is 3-5 hours to obtain a titanium-based CO2 adsorption and conversion agent.

7. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The titanium-based low-pressure methanol synthesis catalyst uses TiO2 as a support, supporting active components CuO and ZnO and co-catalysts La2O3 and ZrO2. The mass fractions of each component are: CuO 20-25%, ZnO 10-15%, La2O3 3-5%, ZrO2 2-4%, and TiO2 51-65%. The preparation method of the titanium-based low-pressure methanol synthesis catalyst includes the following steps: S1. After crushing the TiO2 support, add a binder and an extrusion aid. The binder is guar gum powder and the extrusion aid is nitric acid. The mass ratio of the binder to the mass of the mixture is (4-8):100, and the mass ratio of the nitric acid extrusion aid to the mass of the mixture is (2-3):

100. After thorough mixing, extrude the mixture into strips to obtain the catalyst support precursor. S2, according to the following mass fractions of each component: CuO 20-25%, ZnO 10-15%, La2O3 3-5%, ZrO2 2-4%, TiO2 51-65%, Cu(NO3)2, Zn(NO3)2, La(NO3)3, and Zr(NO3)4 are dissolved in deionized water in proportion to prepare a mixed impregnation solution; S3. The catalyst support precursor is immersed in a mixed impregnation solution for an equal volume impregnation time of 4-6 h. The impregnated precursor is dried at 120-140℃ for 6-8 h and then calcined at 480-580℃ for 4-6 h to obtain a titanium-based low-pressure methanol synthesis catalyst.

8. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 7, is characterized in that: The methanol synthesis reaction conditions of the titanium-based low-pressure methanol synthesis catalyst are: 220-280℃, pressure 5.0±0.5MPa, and space velocity 4000-8000h⁻¹. -1 Methanol synthesis reaction is carried out under the following conditions.

9. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The titanium-based sulfur-resistant shift catalyst is titanium-based sulfur-resistant shift catalyst K / T205-1; the CO conversion treatment conditions of the titanium-based sulfur-resistant shift catalyst are: 180-280℃, pressure 4.0-6.0MPa, and space velocity 4000-8000h⁻¹. -1 CO conversion reaction is carried out under certain conditions.

10. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen as described in claim 1, characterized in that: The titanium-based sulfur recovery catalyst is any one of titanium-based sulfur recovery catalyst SL-K01, titanium-based sulfur recovery catalyst SL-K02, and titanium-based sulfur recovery catalyst SL-K03.

11. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 1, is characterized in that: The titanium-based Claus tail gas hydrogenation catalyst is either titanium-based Claus tail gas hydrogenation catalyst SL-S01 or titanium-based Claus tail gas hydrogenation catalyst SL-S02.

12. The methanol synthesis process using an all-titanium-based catalyst with synergistic effects of coal gasification and green hydrogen, as described in claim 11, is characterized in that: The titanium-based sulfur recovery catalyst can adapt to temperature fluctuations within ±20℃, utilizing the waste heat from green hydrogen at 80-100℃ for the reaction, with a space velocity of 4000-8000 h⁻¹. -1 The total sulfur recovery rate is >98.5%, and the organic sulfur hydrolysis rate is 100%. The titanium-based Claus tail gas hydrogenation catalyst can adapt to H2 fluctuations within ±5%, using green hydrogen as a supplementary hydrogen source, with a hydrogen-to-oil ratio of 3-8:1, and catalytic conditions of 220-260℃ and a space velocity of 4000-8000 h⁻¹. -1 .

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