[Haichuan Hydrogen Energy] Current Development Status and Economic Analysis of Hydrogen Production Technologies Using Fossil Feedstocks

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This post was last edited by Desert Fish on 2021-11-22 at 13:47. Title: Current Status and Economic Analysis of Hydrogen Production Using Fossil Fuel Sources. Authors/Source: Written by Huang Geseng, Li Jinshan, Wei Shouxiang, Yang Yanxiang, Zhou Xiaoyang (Petrochemical Research Institute, China National Petroleum Corporation). Date: 2021-11-14. Views: 25. A detailed analysis is provided of the current development status of hydrogen production technologies using fossil fuel sources such as coal, natural gas, methanol, and hydrogen recovered from industrial by-products. The production costs and economic viability of these various technologies are compared, and the future prospects for the development of this industry are discussed. It is generally concluded that coal-based hydrogen production has an advantage in terms of resource costs, making it the preferred technology for large-scale hydrogen production； Natural gas has great potential for hydrogen production, but it currently faces issues such as resource constraints and high costs ； Recycling hydrogen from industrial by-products is a hydrogen production method with great potential for development in the future ； The scale of hydrogen production from methanol is flexible, but it has drawbacks such as high equipment costs and poor stability. Under the current circumstances where technologies for producing hydrogen from new energy sources such as solar power are not yet mature, hydrogen production from fossil fuels will inevitably play a major role. In the future, the hydrogen industry will feature a supply structure characterized by multiple approaches to hydrogen production, including that from fossil fuels, water electrolysis, and new energy sources, all coexisting and developing in a diversified manner. In recent years, as environmental regulations around the world have become increasingly strict and there is a growing emphasis on clean and renewable energy sources, the new energy vehicle industry has seen rapid development. In particular, hydrogen fuel cell vehicles are considered to have better prospects for development compared to electric vehicles, thanks to their advantages such as using hydrogen as a fuel source, high energy density, high energy conversion efficiency, long driving range, and no emissions of CO2 or pollutants. At present, looking at the development progress of the entire industry chain—from hydrogen production, storage and transportation, fuel cell development, vehicle development to the construction of hydrogen refueling stations—the development of hydrogen energy has generally entered the initial stage of industrialization. Hydrogen is a clean secondary energy source. In the development of hydrogen fuel cell vehicles, the source of hydrogen is the primary issue for industrial progress; therefore, hydrogen production technology attracts significant attention from the industry. Currently, numerous hydrogen production methods have been proposed in the industry, including those that use fossil resources (coal, oil, natural gas) as well as renewable resources (water, biomass, solar energy, etc.) to produce hydrogen. However, in industrial applications, fossil resources such as coal and natural gas remain the dominant materials for hydrogen production due to their scalability, economic viability. It is therefore of great practical significance to utilize China’s existing fossil resource capabilities to develop practical hydrogen production technologies, thereby providing a sufficient supply of fuel for the development of hydrogen fuel cell vehicles. 1 Current Development Status of Hydrogen Production Technologies Using Fossil Fuel Raw Materials Industrial hydrogen production technologies include coal gasification, methane steam reforming, partial oxidation of heavy oil, methanol steam reforming, water electrolysis, recovery of hydrogen-containing by-products, and hydrogen production via biomass gasification. At present, large-scale hydrogen production still relies primarily on coal and natural gas; 92% of global hydrogen production comes from coal and natural gas, about 7% comes from industrial by-products, and only 1% comes from water electrolysis. In recent years, due to the widespread use of coal-based and natural gas-based hydrogen production technologies, the technology for producing hydrogen through the partial oxidation of heavy oils (such as normal and vacuum residue oils, as well as fuel oils) has been rarely used in industry, owing to reasons related to oil substitution and cost-effectiveness. Details on the raw materials, technical maturity, and industrial application of various hydrogen production processes are shown in Table 1. 1.1 Hydrogen production from coal Gasification is one of the preferred methods for large-scale industrial hydrogen production. The specific process involves gasifying coal at high temperatures to produce syngas (H2+CO), converting CO and water vapor through shift reaction into H2+CO2, removing acidic gases (CO2+SO2), and purifying hydrogen – all of which enable the production of hydrogen at different purity levels. The typical coal-to-hydrogen process flow is shown in Figure 1. The traditional gasification hydrogen production process features mature technology, low raw material costs, and large plant scale. However, it has a complex equipment structure, a relatively short operation cycle, numerous supporting systems, high investment costs for the plants, high costs for gas separation, low hydrogen production efficiency, and significant CO2 emissions. Similar to the gasification process, petroleum coke produced in refineries can also be used as a feedstock for hydrogen production via gasification, which is one of the important ways to utilize petroleum coke with high added value. The coal/petcoke hydrogen production process can also be effectively combined with the integrated gasification combined cycle (IGCC) process, enabling the integrated production of hydrogen, steam, and electricity and thereby improving the efficiency of refineries. Gasification hydrogen production technology has a history of over a hundred years and can be divided into three generations of technologies. The first generation consists of the atmospheric pressure gasification processes developed in Germany during the 1920s and 1930s. Typical processes include the fixed-bed process of the Lurgi furnace for coal pulverization under pressure, the fluidized-bed process of the atmospheric pressure Winkler furnace, and the gas-flow bed process of the atmospheric pressure KT furnace. All these processes use oxygen as the gasifying agent and operate on a continuous basis, resulting in a significant increase in gasification efficiency and cold gas yield. The second-generation technology is a pressurized gasification process developed in the 1970s by countries such as Germany and the United States on the basis of the first-generation technology; typical processes include the Shell, Texaco, BGL, HTW, and KRW gasification processes. In our country, the gasification process for hydrogen production is primarily used in the manufacture of ammonia. Over the years, a number of advanced gasification technologies with independent intellectual property rights have been developed, such as the multi-nozzle water-coal slurry gasification technology, the space furnace technology, and the Tsinghua furnace technology. The third-generation technologies mainly include coal catalytic gasification, coal plasma gasification, coal solar gasification, and coal nuclear waste heat gasification, etc., and they are still in the laboratory research stage at present. In recent years, as the pace of upgrading the quality of refined oil in China has accelerated, most newly built refineries in the country have chosen the full hydrogenation process to meet key technical and economic requirements such as the yield of light oils, product quality, and overall yield. This has greatly increased the demand for hydrogen in the refining industry as well as spurred the development of hydrogen production technologies. According to preliminary estimates, among the 15 integrated refining and chemical projects currently under construction or planned in China, 11 have decided to use coal-based hydrogen production (including petroleum coke) for this purpose. These include new oil refining projects such as Hengli Petrochemical’s project with a capacity of 20 million tons per year, Zhejiang Petrochemical’s project with a capacity of 40 million tons per year, Shenghong Petrochemical’s project with a capacity of 26 million tons per year, and CNPC’s Guangdong Petrochemical project with a capacity of 20 million tons per year. Additionally, Huizhou Refining and Chemical Company under CNOOC has a capacity of 22 million tons per year, Yanshan Petrochemical Company under Sinopec has a capacity of 12 million tons per year, and Luoyang Petrochemical Company has a capacity of 18 million tons per year – all of these use coal-based hydrogen production to generate hydrogen. The only facility that uses natural gas to produce hydrogen is the 13 million tons per year refining project of Yunnan Petrochemical Company, under China National Petroleum and Natural Gas Group Corporation. 1.2 Hydrogen production via natural gas steam reforming: Natural gas-based hydrogen production is a commonly used method in regions such as North America and the Middle East. The main industrial technologies for producing hydrogen from natural gas include steam reforming, partial oxidation, and catalytic cracking of natural gas. 1.2.1 Hydrogen production by steam reforming of natural gas
The steam reforming process involves the reforming reaction of hydrocarbons such as methane with water vapor in the presence of a catalyst and at high temperatures, resulting in a mixture of gases including H2 and CO. This is a highly endothermic reaction that requires external heat supply (via natural gas combustion). The main reaction is shown in Equation (1). CH4 + H2O = CO + 3H2 ΔH = 206kJ/mol (1) The technology for producing hydrogen through the reformation of natural gas with water vapor is well-developed; it is widely used in the production of syngas, pure hydrogen, and raw materials for ammonia synthesis, and it represents the most common method for hydrogen production in industry. The natural gas steam reforming reaction requires high temperatures of 750–920°C and a reaction pressure of 2–3 MPa, with Ni/Al2O3 typically being used as the catalyst. In industrial production processes, the molar ratio of water vapor to methane is generally 3–5, resulting in an H2/CO ratio of approximately 3. The syngas produced via steam methane reforming enters a water-gas shift reactor, where high- and low-temperature shift reactions convert CO into CO2 and additional hydrogen, thereby increasing the hydrogen yield. The basic process flow diagram is shown in Figure 2. Early methane steam reforming processes were carried out at atmospheric pressure, but increasing the reaction pressure can improve thermal efficiency and the production capacity of the equipment. Raw gas is produced by the steam reforming of methane; through a shift reaction, CO is converted into CO2 and hydrogen. To prevent carbon deposition during the steam reforming process, an excess of water vapor is often added to the reaction feed, with a water-to-carbon ratio of 3–5 in industrial applications. The main providers of global methane steam reforming process technologies include French companies such as Technip, Linde, and Uhde, as well as the British company Foster Wheeler. 1.2.2 Hydrogen production by partial oxidation of methane The partial oxidation method involves the incomplete oxidation of hydrocarbons such as methane with oxygen to produce syngas, as shown in Equation (2). CH4 + 1/2O2 = CO + 2H2 ΔH= -35.7kJ/mol (2) This process can proceed spontaneously without external heat supply, and it has a high thermal efficiency. However, if oxygen is produced using the traditional air liquefaction and separation method, the energy consumption is too high. In recent years, foreign countries have developed a process that uses oxygen-enriched air instead of pure oxygen; the process flow is shown in Figure 3. As shown in Figure 3, after compression and desulfurization, the natural gas is first mixed with steam to be preheated to about 500°C, and then it enters the reactor from the top together with oxygen or oxygen-enriched air (also preheated to about 500°C), in two separate streams, to undergo partial oxidation. The converted gas exits from the lower part of the reactor at a temperature of 900–1000°C, with a hydrogen content of 50%–60%. This process utilizes the heat within the reactor for the steam conversion of hydrocarbons; as a result, a wide range of hydrocarbon feedstocks can be used and a higher level of impurities is tolerated (partial oxidation is commonly employed for the conversion of heavy oil and residue). However, it requires an air separation unit or a pressure swing adsorption oxygen generation system, resulting in higher investment costs compared to the natural gas steam conversion method. The reactor used for the partial oxidation of natural gas to produce hydrogen employs high-temperature inorganic ceramic oxygen-permeable membranes, which can separate pure oxygen from air at high temperatures and prevent nitrogen from entering the syngas. Compared with traditional steam reforming for hydrogen production, this approach results in significantly lower energy consumption during the process, thereby reducing investment costs to a certain extent. 1.2.3 Hydrogen production via catalytic cracking of natural gas: Hydrogen production through catalytic cracking of natural gas involves using natural gas as a raw material; after dehydration, desulfurization, and preheating, the gas is fed into a moving-bed reactor from the bottom, where it comes into counterflow contact with nickel-based catalysts that descend from the top of the reactor. Within the catalyst surface, catalytic cracking reactions occur, producing hydrogen and carbon. Since this is an endothermic process, in addition to preheating the raw material, external heating is also required to supply the necessary heat. The mixture of hydrogen and methane exiting from the top of the reactor is passed through a cyclone separator to separate carbon and catalyst dust, after which the heat is recovered. The resulting gas is then subjected to pressure swing adsorption (PSA) for separation and purification, yielding pure hydrogen as the final product. Some of the unreacted products such as methane and ethane are reused as fuel. The other main product of the reaction, carbon, flows out of the reactor along with the catalyst from the bottom. After heat exchange, it enters a gas-solid separator to remove residual methane and hydrogen; thereafter, it passes through a mechanical vibration sieve to separate the catalyst from the carbon. The catalyst is regenerated and reused, while the separated carbon can be used to produce high-value products such as carbon nanofibers. From a theoretical perspective, the hydrogen production process via natural gas catalytic cracking does not generate any CO2. While hydrogen is produced, the main product, carbon, can be processed into high-quality carbon materials. Compared to hydrogen production from coal and natural gas steam reforming, this process results in lower costs and less CO2 emissions; it thus offers significant economic and social benefits, with promising market prospects. At present, this technology is still in the research and development stage. 1.3 Hydrogen production from methanol: Industrially, methanol is typically produced by the carbonylation of CO and hydrogen. The technology for producing hydrogen from methanol is the reverse process of methanol synthesis, and it can be used to generate hydrogen on-site, addressing the drawbacks associated with current high-pressure and liquid hydrogen storage methods, such as low hydrogen storage density, high compression energy costs, high transportation expenses, and poor safety. Classified by process technology, methanol-to-hydrogen production methods include three types: methanol cracking for hydrogen production, methanol steam reforming for hydrogen production, and methanol partial oxidation for hydrogen production. (1) Hydrogen production by methanol pyrolysis: Methanol pyrolysis is the gas-phase catalytic decomposition of methanol at around 300°C in the presence of a catalyst; it is typically used for the production of syngas, or to obtain high-purity CO and hydrogen through further separation, with the hydrogen purity reaching 99.999%. This technology is mature and suitable for small-scale hydrogen production in scientific research experiments. (2) Hydrogen production by methanol steam reforming: At temperatures of 220–280°C and pressures of 0.8–2.5 MPa, in the presence of a catalyst, methanol and water are converted into approximately 75% hydrogen, 24% CO2, and trace amounts of CO and CH4. All the hydrogen contained in methanol and water can be transformed into hydrogen; the amount of methanol required is 0.5–0.65 kg per m3 of hydrogen produced, with the mass fraction of hydrogen stored in methanol reaching 18.75%. The process is shown in Figure 4. This technology requires mild operating conditions, produces few components that are easy to separate. Hydrogen production can be achieved at rates ranging from 10 to 10,000 m3/h, and the production capacity can be adjusted flexibly, making it suitable for small and medium-sized hydrogen users who need on-demand production. The drawback is the use of a Cu/Zn/Al catalyst, which is prone to deactivation; thus, there is a need to develop new catalysts with high activity and good stability. Industrial facilities for hydrogen production via methanol steam reforming have already been built in China. In July 2018, the 60,000 m3/h methanol-to-hydrogen plant operated by Shandong Shouguang Luqing Petrochemical Co., Ltd. came online. It is the largest methanol-to-hydrogen plant in China, utilizing advanced methanol-to-hydrogen technology and PSA technology provided by Huaxi Chemical Technology Co., Ltd., as well as catalysts from Sichuan Shutai Chemical. Anhui Huadong Chemical Pharmaceutical Engineering Co., Ltd. was responsible for the detailed design of this plant. In January 2019, the groundbreaking ceremony for Shanghai Bohydro New Energy Technology Co., Ltd.’s production facility capable of manufacturing 200,000 sets of methanol hydrogen fuel cells per year was held in Cixi, Ningbo, Zhejiang. The total investment in this project is approximately 3 billion yuan, and it will be constructed in phases. Phase 1 of the project will have an annual production capacity of 50,000 units, with operations set to begin in the third quarter of 2019; the entire project is expected to be completed and put into operation by 2020. Currently, methanol hydrogen fuel cell vehicles have been applied in various transportation sectors, including buses, logistics vehicles, coaches, and cold chain transport vehicles. (3) Hydrogen production via partial oxidation of methanol: Through the partial oxidation of methanol (where 1 molecule of methanol reacts with 0.5 molecules of oxygen to produce 2 molecules of hydrogen and 1 molecule of CO2), the system can generate its own heat, significantly improving energy utilization efficiency. This, in turn, is expected to further reduce the cost of hydrogen production. This technology is still in the research and development stage. 1.4 Hydrogen produced as an industrial by-product Hydrogen produced as an industrial by-product is hydrogen that emerges as a side product during industrial production processes, including that generated in refinery catalytic reforming, propane dehydrogenation, coke oven gas production, and chlor-alkali industries. Among this, only the hydrogen produced in refinery catalytic reforming processes is used in oil refining hydrogenation and hydrocracking units; most of the hydrogen generated as a by-product in other industrial processes is used as fuel or released into the atmosphere, with little to no effective utilization. This type of industrially produced hydrogen holds great potential for recycling and utilization in the development of hydrogen fuel cell vehicles. The production principles and applications of hydrogen derived from various industrial by-products are detailed in Table 2. As can be seen from Table 2, China has great potential in terms of industrial by-product hydrogen resources, with an annual production of around 10.48 million tons. Among these, the largest amount of hydrogen is produced through refinery reforming (1.36 million tons per year), and this hydrogen is entirely used for oil refining processes. The hydrogen produced by propane dehydrogenation units is less in quantity (180,000 tons per year) and its sources are scattered. In the steel industry and the coking sector, coke oven gas contains a high amount of hydrogen, with an annual production of 7.21 million tons. Together, coke oven gas and the chlor-alkali industry generate 8.02 million tons of hydrogen per year, accounting for 76.5% of the total amount of by-product hydrogen. If 30% of the currently produced by-product hydrogen (8.02 million tons/year), 40% in the medium term (3.2 million tons/year), and 50% in the long term (4 million tons/year) were to be used for hydrogen refueling stations, then, based on the assumption that each fuel cell passenger car travels 20,000 km per year and consumes 224 kg of hydrogen, this would be sufficient to supply 10.71 million, 14.28 million, and 17.85 million fuel cell passenger cars respectively. Based on an annual driving distance of 14,400 km per fuel cell bus and a hydrogen consumption of 882.32 kg, this amount of hydrogen can supply 2.72 million, 3.62 million, and 4.53 million fuel cell buses respectively. If most of the by-produced hydrogen is used to supply fuel to hydrogen fuel cell vehicles at hydrogen refueling stations, it can support China’s hydrogen transportation industry by 2040. 2 Current status of hydrogen production in China and economic analysis of hydrogen production from fossil fuels 2.1 Analysis of the current status of hydrogen production in China and its potential for hydrogen production In 2015, China’s annual hydrogen production was 18 million tons; by 2018 it had increased to 19.8 million tons, ranking first in the world. It is predicted that the figures will reach 20.5 million tons and 21 million tons in 2019 and 2020 respectively, with average annual growth rates of 3.5% and 4.8% respectively, as shown in Figure 5. In 2016, within China’s hydrogen production structure, hydrogen produced from coal accounted for 62%, hydrogen produced from natural gas accounted for 19%, hydrogen produced through water electrolysis accounted for 1%, while hydrogen produced from other sources such as refinery off-gases, coke oven gas, methanol, and vent gases accounted for 18%. Due to the economic limitations of current hydrogen production technologies, about 97% of the hydrogen used in industry in China is produced directly from coal and natural gas, as well as as a by-product of industrial processes. The raw materials used for producing hydrogen as a by-product are also the three fossil fuels: coal, oil, and natural gas. Hydrogen produced through water electrolysis and other methods accounts for less than 3%. According to the results of coal field geological surveys in our country, the total proven reserves of coal resources nationwide amount to 2.01 trillion tons, while the resources available for exploitation amount to 1.95 trillion tons ； If 1% of the existing resource reserves are allocated to coal gasification for hydrogen production, and assuming a coal consumption of 8 kg per kg of hydrogen produced, China’s potential for hydrogen production from coal is approximately 2.438 billion tons. According to statistics from the Ministry of Land and Resources’ “National Dynamic Assessment of Oil and Gas Resources (2015)”, China’s geological reserves of natural gas (including both conventional and unconventional natural gas) amount to 90.3 trillion cubic meters, while its recoverable reserves total 50.1 trillion cubic meters. If 1% of these recoverable reserves were used for hydrogen production via steam methane reforming, and given that the consumption rate is 5 cubic meters of natural gas per kilogram of hydrogen produced, China’s potential for natural gas-based hydrogen production would be approximately 100 million tons. In 2018, China’s apparent methanol consumption was 54.6 million tons. If 1% of this amount were used for methanol reformation to produce hydrogen, and considering that 7.2 kg of methanol is required per kg of hydrogen produced, China’s potential for producing hydrogen from methanol is approximately 75,800 tons per year. Overall, China is rich in coal and natural gas resources (including unconventional natural gas); thus, there is great potential for their development in hydrogen production. Hydrogen can be used as both a chemical raw material and an industrial gas, as well as an energy carrier. Different applications have varying requirements regarding the purity and impurity content of hydrogen. For example, GB/T 3634.1-2006 “Hydrogen – Part 1: Industrial hydrogen” stipulates the purity requirements for hydrogen as follows: premium grade ≥99.95%, first-grade ≥99.5%, and qualified grade ≥99%. GB/T 3634.2-2011 “Hydrogen – Part 2: Pure hydrogen, high-purity hydrogen and ultra-high-purity hydrogen” specifies the purity requirements for hydrogen as follows: pure hydrogen ≥99.99%, high-purity hydrogen ≥99.999%, and ultra-high-purity hydrogen ≥99.9999%. Industrial hydrogen cannot be used directly as hydrogen for fuel cells; it must be separated and purified to further remove impurities and increase its purity. On July 1, 2019, China officially implemented the standard GB/T 37244-2018 \"Fuel Hydrogen for Proton Exchange Membrane Fuel Cell Vehicles\", which requires a hydrogen purity (mole fraction) of 99.97%. However, the requirements for impurities such as total sulfur, formaldehyde, formic acid, ammonia, and halides are very strict, at 0.004 μmol/mol, 0.001 μmol/mol, 0.2 μmol/mol, 0.1 μmol/mol, and 0.5 μmol/mol respectively. This imposes higher demands on the development of cost-effective industrial hydrogen purification technologies. 2.2 Economic analysis of hydrogen production from fossil fuel raw materials: Based on industry-specific models for hydrogen costs, the authors of this paper used extrapolation to plot graphs showing the hydrogen costs under different coal and natural gas price levels; the results are shown in Figure 6. As can be seen from Figure 6, as the natural gas price rises from 1.24 CNY/m3 (corresponding to a coal price of 250 CNY/t) to 2.95 CNY/m3 (corresponding to a coal price of 1050 CNY/t), the cost of hydrogen increases from 0.73 CNY/m3 (equivalent to 8119 CNY/t) to 1.29 CNY/m3 (equivalent to 14349 CNY/t). According to the Beijing Municipal Notice on Adjusting the Sales Prices of Natural Gas for Non-residential Use issued in July 2018, the price of natural gas for industrial use in districts and counties outside Beijing’s six core urban areas is 2.75 CNY/m3. Based on this figure, the cost of producing hydrogen from natural gas is 1.24 CNY/m3, which equates to 12,796 CNY per ton; this is comparable to the cost of producing hydrogen from coal, which is 950 CNY per ton. Based on the current price of 2.3×104 kJ/t for thermal coal in Qinhuangdao (around 580 CNY/t), the cost of producing hydrogen from coal is 0.92 CNY/m3, which is equivalent to 10,233 CNY/t. This is comparable to the cost of producing hydrogen from natural gas, whose price is around 1.8 CNY/m3. It is clear that, given the current prices of natural gas and coal, the cost of producing hydrogen from coal is significantly lower than that of producing it from natural gas. After comparing the costs of hydrogen production from coal, natural gas, methanol, and water electrolysis, the calculations were carried out using coal prices of 580 CNY/t, natural gas prices of 2.75 CNY/m3, methanol prices of 2280 CNY/t, and electricity prices of 0.55 CNY/(kW·h); the results are shown in Figure 7. As can be seen from Figure 7, the cost of producing hydrogen through coal gasification is the lowest (10,233 CNY/t, or 0.92 CNY/m3). Hydrogen production from natural gas is the next cheapest option (12,796 CNY/t, or 1.15 CNY/m3). Hydrogen production via methanol cracking ranks third (26,900 CNY/t, or 2.42 CNY/m3). The cost of producing hydrogen through water electrolysis is the highest (35,900 CNY/t, or 3.23 CNY/m3). The cost of hydrogen production via methanol cracking is 2.6 times that of coal-based hydrogen production, and 2.1 times that of natural gas-based hydrogen production. Meanwhile, the cost of water electrolysis for hydrogen production is 3.5 times that of coal-based hydrogen production and 2.8 times that of natural gas-based hydrogen production. The cost of hydrogen production is closely related to the types and prices of raw materials used. Different raw materials, varying prices, as well as different electricity and water prices all have a direct impact on the cost of hydrogen production. Taking coal-based hydrogen production as an example, by employing the pulverized coal pressurized gasification technology using space-grade gasifiers, it is estimated that when the coal price is 470 CNY/ton and 600 CNY/ton respectively, the electricity price is 0.42 CNY/(kW·h), and the cost of fresh water consumption is 4 CNY/ton, the corresponding hydrogen production costs are 0.728 CNY/ton and 0.9 CNY/m³ (equivalent to 8,100 CNY/ton and 10,014 CNY/ton) ； If building carbon capture, utilization, and storage facilities (CCUS) is considered, the cost of hydrogen production will inevitably rise accordingly. Another example is the cost of producing hydrogen through water electrolysis, which is highly dependent on the source of electricity and its price. When using electricity from sources such as wind, hydro, or surplus power, the electricity cost can be as low as 0.1 CNY/(kW·h), resulting in a hydrogen cost of only 1.16 CNY/m3 (equivalent to 13,000 CNY per ton) ； When the electricity price is 0.65 CNY/(kW·h), the cost of hydrogen reaches 4.13 CNY/m3 (equivalent to 46,000 CNY/t). In short, the cost of hydrogen production is most closely related to the price of raw materials; to control the price of hydrogen energy, it is first necessary to control the price of these raw materials. Currently, large-scale production of hydrogen in refineries has been achieved; there is limited room for cost reduction through technological improvements. By adapting to local conditions and selecting appropriate raw materials, the cost of hydrogen can be kept below 1.35 CNY/m³ (equivalent to 15,000 CNY/ton). 3. Reflections on the development prospects of the hydrogen production industry from fossil raw materials. Through an analysis of the technological routes and economic viability of hydrogen production from fossil raw materials, it can be seen that each route has its own advantages and disadvantages; it is impossible to simply declare one as superior to the others. The author of this article has the following thoughts and views on the prospects for the development of the hydrogen production industry using fossil feedstocks. Coal-to-hydrogen is the preferred technology for leveraging the advantages of coal resources to produce hydrogen on a large scale. China’s relatively abundant coal resources provide a guarantee of hydrogen production materials for the development of hydrogen energy. As mentioned earlier, in the petrochemical integration projects that are under construction or planned in our country in recent years, coal-based hydrogen is used in most of them. There are four main reasons why the coal-to-hydrogen process is favored by domestic refineries: ① Due to the high demand for hydrogen in refineries, this process enables large-scale hydrogen production to meet their hydrogen needs ； ②Coal-based hydrogen production has low costs, making it the preferred process for refineries to reduce expenses and improve efficiency while achieving a balance in hydrogen supply ； ③By using coal-based hydrogen, refineries can replace existing hydrogen production materials such as natural gas and dry gas, thereby creating conditions for the comprehensive utilization of dry gas resources in refineries ； ④With the widespread use of fluidized-bed pressurized gasification technology in recent years and the improvement in the treatment technologies for the \"three wastes\" in coal chemical industries, coal-to-hydrogen production processes can achieve compliant emissions. In recent years, large domestic coal energy companies have also been actively involved in developing the hydrogen energy industry chain. In February 2018, the China Hydrogen Energy and Fuel Cell Industry Innovation Strategic Alliance was established under the leadership of an **Energy Group, with the participation of 17 other large domestic enterprises, universities, and research institutions; since then, the number of members has increased to 54. This alliance aims to integrate resources from all parties and attract private investment in order to promote industrial technological innovation, with coal-based hydrogen production as a key focus. Overall, coal chemical enterprises possess inherent resource and technological advantages for developing coal-to-hydrogen production, and coal-to-hydrogen is the most viable technology for large-scale hydrogen production at present. Natural gas has great potential for hydrogen production, but it currently faces issues such as resource constraints and high costs. Compared to coal-based hydrogen production facilities, natural gas-based hydrogen production requires lower investment, results in less CO2 emissions and water consumption, and achieves a higher hydrogen yield; it is thus an ideal method for producing hydrogen from fossil fuels. However, China’s fossil fuel resources are characterized by an abundance of coal but a shortage of oil and gas. In 2018, the country’s dependence on imported crude oil exceeded 70.5%, while its dependence on imported natural gas exceeded 40%. Under such circumstances regarding energy supply, it is no longer economical to use heavy oil as a source for hydrogen production; in practice, this method is rarely employed ； Using natural gas to produce hydrogen faces practical challenges such as unreliable supply of gas sources and high prices for natural gas. However, in the long term, given China’s abundant reserves of unconventional natural gas resources (such as shale gas, coalbed methane, and methane clathrates), and as extraction technologies improve and costs decrease, there will be a period of significant development for natural gas use. At that time, producing hydrogen from natural gas is expected to be more advantageous than using coal. Recycling hydrogen from industrial by-products is a hydrogen production method with great potential for development in the future. China is rich in hydrogen-containing industrial waste gas resources. From the perspective of the petrochemical industry, there are various ways to produce hydrogen, such as hydrogen generated as a by-product of catalytic reforming, hydrogen produced from refinery dry gas, hydrogen obtained as a by-product of naphtha and ethane cracking, and hydrogen generated through propane dehydrogenation. Some of these hydrogen resources are utilized (such as hydrogen produced via catalytic reforming and dry gas processing), while others are used as fuel at low value or simply released into the atmosphere. If this hydrogen can be recovered using separation techniques such as pressure swing adsorption, it not only enables higher-value utilization of these resources but also helps reduce carbon emission levels – achieving two benefits at once. In recent years, thanks to the development of hydrogen energy, there has been significant attention within the industry to the utilization of hydrogen produced as a by-product of industrial processes. Many energy and chemical companies are working closely with investors in hydrogen energy development to find ways to make efficient use of this industrial by-product for the advancement of hydrogen energy, and the future for its utilization looks promising. The scale of hydrogen production from methanol is flexible, but it has drawbacks such as high equipment costs and poor stability. Although the cost of producing hydrogen from methanol is higher than that of producing hydrogen from oil, natural gas, or coal, the investment required for methanol-based hydrogen production facilities is low, the construction period is short, the scale of such facilities can be adjusted as needed, and the raw materials are readily available. Additionally, approval processes for methanol-based hydrogen production projects are straightforward. For users who can tolerate higher hydrogen prices, this method of hydrogen production is an acceptable option. Looking at the current development of the hydrogen energy industry chain, there are numerous technical and economic challenges that need to be addressed in areas such as hydrogen storage, transportation, and refueling. Hydrogen production from methanol allows for on-site hydrogen generation around hydrogen refueling stations; in this process, methanol, which is easy to store and transport, acts as a carrier for hydrogen. This approach avoids the problems associated with high-pressure hydrogen or liquid hydrogen, such as the high technical requirements for storage and transportation materials, significant safety risks, and high costs. Nevertheless, it cannot be denied that power systems that combine on-site methanol-based hydrogen production with fuel cell generation still face drawbacks in terms of high equipment costs, as well as poor stability and reliability. Therefore, developing efficient and reliable methanol-to-hydrogen systems that can meet user needs is the technical key to promoting the development of hydrogen-related industries that use methanol as a hydrogen carrier. Electrolytic water splitting to produce hydrogen is also expected to become one of the methods for large-scale hydrogen production in the future. Hydrogen production by water electrolysis involves generating hydrogen through the electrolysis of water, with oxygen being produced as a by-product. Depending on the type of electrolyzer, hydrogen production through water electrolysis can be carried out using three different methods: alkaline electrolyzers (which use KOH or NaOH as electrolytes), proton exchange membrane (PEM) electrolyzers (which use pure water as an electrolyte), and solid oxide (SOE) electrolyzers. In comparison, alkaline electrolysis technology is currently the most commercially developed and mature water electrolysis technique. The leading foreign companies in this field include France’s McPhy, the United States’ Teledyne, and Norway’s Nel. In China, key companies in this sector include Suzhou Jingli Hydrogen Production, Tianjin Daliu Hydrogen Production, and CSIC Institute 718. PEM pure water electrolysis has been commercialized abroad, with major technology providers including Proton Company and Hydrogenics Company. In China, research on PEM pure water electrolysis technology is primarily carried out by institutions such as the 718 Research Institute of CSSC, CEFC Fengye, and the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences. The PEM pure-water hydrogen production process involves no corrosive liquids, is simple to operate and maintain, and has low costs; it represents a hydrogen production technology via pure-water electrolysis that needs to be prioritized for development in China in the future. The current drawback of water electrolysis for hydrogen production is the high cost of hydrogen generation and its poor economic viability. In the future, as this technology improves and costs decrease, it is expected to become an important alternative to hydrogen production from fossil fuels. In the past two or three years, by drawing on international experience, China has adopted a approach that combines the excess electricity generated from renewable energy sources (such as wind power, photovoltaic power, hydroelectric power, and geothermal power) with traditional water electrolysis for hydrogen production – an approach also known as the \"green hydrogen\" route. This approach has opened up an innovative path for the development of hydrogen fuel cell vehicles, enabling large-scale and cost-effective hydrogen production. Finally, it should be noted that regardless of the raw material used for hydrogen production, the hydrogen production facility generally needs to be installed in a location where the raw materials are readily available. Since hydrogen production facilities (especially those that produce hydrogen from fossil fuels) generally require a large amount of space, in order to save land and reduce carbon emissions, as well as for the safe operation of hydrogen refueling stations, on-site hydrogen production is usually not permitted. On-site hydrogen production eliminates the need for hydrogen transportation, but it is only suitable for certain applications where the demand for hydrogen is low. It requires flexible scale adjustment, advanced control systems, reliable operation, as well as safety and environmental protection features. 4 Conclusion As the hydrogen energy industry matures and hydrogen fuel cell vehicles begin to be produced on a larger scale, demand for hydrogen is set to grow rapidly, with continuous advancements in hydrogen production technologies. Hydrogen production from traditional fossil fuels such as coal and natural gas (including the recovery of hydrogen from industrial by-products) relies on mature technologies and will continue to enjoy good prospects for development. New hydrogen production technologies such as solar hydrogen production (including photocatalysis and photothermal decomposition) and biomass hydrogen production (biomass pyrolysis and gasification) can enable clean hydrogen production, and they have promising development prospects. However, due to issues such as low conversion efficiency and high hydrogen production costs, large-scale implementation is expected to be difficult in the short term. Producing hydrogen through water electrolysis can effectively utilize unstable power sources such as wind and solar power, as well as other excess power generated during off-peak times; it is expected to become one of the main sources of industrial hydrogen in the future. Given the current reality that technologies for producing hydrogen from new energy sources such as solar power are not yet mature, hydrogen production from fossil fuels will inevitably play a major role. In the future, the hydrogen industry will feature a supply structure characterized by diversified development, with hydrogen produced from fossil fuels, through water electrolysis, and from new energy sources all coexisting. At present, in addition to making significant efforts to develop low-cost hydrogen production technologies, China’s hydrogen industry also needs to focus on addressing key challenges such as developing safe and efficient methods for storing and transporting hydrogen, reducing the costs associated with building hydrogen refueling stations, and lowering the production costs of hydrogen fuel cell vehicles. It is believed that, under the unified planning and strong promotion of our country, and through the collaborative efforts of research institutions, energy companies, automobile manufacturers, battery producers, and others, the hydrogen energy industry will soon move past its initial development stage and enter a phase of genuine industrialization. Thus, China’s goal of building a \"hydrogen energy society\" will soon become a reality.