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How Can Coal-Based Hydrogen Shed Its “High-Carbon” Label? Author/Source: Gasification World Date: 2021-04-02 Clicks: 45 Based on the source of hydrogen, the World Energy Council classifies hydrogen into gray hydrogen, blue hydrogen, and green hydrogen – referring respectively to hydrogen produced from carbon-based fuels, hydrogen produced from fossil fuels with carbon capture and storage, and hydrogen produced through electrolysis using renewable energy. “Grey hydrogen is not advisable; blue hydrogen can be used. Waste hydrogen is recyclable, and green hydrogen is the way forward. ”Li Yizhong, former minister of the Ministry of Industry and Information Technology and president of the China Industrial Economic Federation, said. With advantages such as raw material enrichment, low costs, and mature technology, the merits of hydrogen produced from coal are widely recognized. Many coal companies have even adopted this as one of their directions for transformation, increasing their investment in it. Faced with its \"weakness\" of high carbon emissions, can coal-based hydrogen make use of its strengths to overcome these weaknesses? The current cheapest method for hydrogen production is indicated in the \"White Paper on China’s Hydrogen Energy and Fuel Cell Industry\" published by the China Hydrogen Energy Alliance (hereinafter referred to as the \"White Paper\"). China is already the world’s largest producer of hydrogen, with an estimated industrial hydrogen production capacity of 25 million tons per year. Among them, “the coal-to-hydrogen technology is mature and efficient, enabling large-scale and stable production; it represents the lowest-cost method for hydrogen production at present.” Taking the coal gasification hydrogen production technology as an example, with a coal price of 600 yuan per ton, the cost of producing hydrogen is approximately 8.85 yuan per kilogram. “The greatest advantage of hydrogen produced from coal lies in its cost. Based on conversions for different types of coal, the cost of large-scale hydrogen production can be kept at around 0.8 yuan per cubic meter; in some projects, it is even as low as 0.4–0.5 yuan per cubic meter. Compared to methods such as natural gas and water electrolysis, coal-based hydrogen production offers superior economic efficiency. ”Peng Suping, an academician of the Chinese Academy of Engineering, said. In terms of energy efficiency, coal-based hydrogen production also has a certain level of competitiveness. Han Hongmei, deputy chief engineer of the Energy and Chemicals Division at the Petroleum and Chemical Industry Planning Institute, explained that the energy utilization efficiency of hydrogen production from coal is 50%-60%, while the efficiency of water electrolysis is currently only around 30%. In addition, coal-based hydrogen production has scalability potential. “The abundant availability of hydrogen sources is one of the advantages for China in developing hydrogen energy. ”Peng Suping said that China’s coal reserves amount to approximately 1.95 trillion tons, and assuming that 10% of this is used for gasification to produce hydrogen, the potential for hydrogen production is around 24.38 billion tons. According to the White Paper, by 2050, China’s demand for hydrogen is expected to reach nearly 60 million tons. In China’s hydrogen source structure, coal accounts for 62%, while natural gas, electrolyzed water, hydrocarbons, and alcohols each account for 19%, 1%, and 18% respectively. “On a global average, coal-based hydrogen accounts for about 18% ； In Japan, a country strong in hydrogen energy, only about 6% of its hydrogen comes from coal. ”Fu Guanyun, a researcher at the Energy Research Institute of the China Academy of Macroeconomic Research, said that currently, coal remains the primary source of hydrogen in China. The issue of high carbon emissions cannot be ignored. Coal-based hydrogen production has distinct advantages, but in Li Yizhong’s view, the carbon dioxide emissions associated with this method are \"unacceptable\". Especially given the urgent need for carbon emission reduction, producing 1 kilogram of hydrogen from coal generates approximately 11 kilograms of carbon dioxide. Only by capturing and storing carbon dioxide can \"gray hydrogen\" be turned into \"blue hydrogen\" to be used. On this matter, Li Can, an academician of the Chinese Academy of Sciences, also takes a stance of “not advocating” it. He believes that the hydrogen industry is still in its early stages of development, and at this point a small amount of fossil fuels must be used to produce hydrogen as a catalyst for its growth. However, the rush to embark on coal-based hydrogen production is neither rational nor the right direction. “One of the original intentions behind developing hydrogen energy is to reduce pollutants and carbon dioxide emissions. Looking at the entire process of coal-to-hydrogen production, storage, transportation, and utilization, carbon emissions are not reduced; rather, the emissions are shifted from the end stage to the earlier stages. At the same time, from the perspective of optimal utilization, coal, as a valuable raw material resource, is more appropriately used to produce more important chemicals and materials. ” Is there any way to resolve the above contradiction? The White Paper holds that carbon dioxide capture and storage technology (CCS) is a new technology with the potential to enable the large-scale, low-carbon use of fossil fuels. Currently, the cost of CCS technology in our country is between 350 and 400 yuan per ton; by 2030 and 2050, it is expected to drop to around 210 yuan per ton and 150 yuan per ton respectively. Taking into account the average proportion of carbon dioxide generated per unit of hydrogen produced via the coal-to-hydrogen route, and together with CCS technology, the cost of hydrogen production rises to around 15.85 yuan per kilogram. However, since the technology is still in the exploration and demonstration phase, further development is needed to reduce costs and energy consumption. Schematic diagram of carbon capture and storage (CCS) “From a technical standpoint, there is no problem with using CCS.” Especially in coal chemical projects, more than 98% of carbon dioxide can be captured through the mature low-temperature methanol washing process. The key issue is that there is no place to store the captured carbon dioxide; currently, there are no ideal conditions for its sequestration. ”Wang Shudong, head of the Energy Conservation and Environment Research Department at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, believes that there is still a long way to go in order to expand the channels for carbon dioxide sequestration and utilization, while also taking into account technical and economic considerations.