In order to cope with global climate change and improve energy security and supply capacity, it has become a global consensus to vigorously develop green hydrogen energy. According to the International Hydrogen Council's Hydrogen Scaling Up report, hydrogen will cover 18% of the world's energy end-use demand by 2050, of which more than 95% of hydrogen needs to be produced through low-carbon methods. The EU has improved the green hydrogen standards in the Renewable Energy Directive, and the hydrogen produced by the overall low-carbon power mix in the region can also be recognized as green hydrogen, and the certification restrictions on green hydrogen have been gradually relaxed. Japan's "Low-Carbon Hydrogen Certification", Germany's "TUV Green Hydrogen Certification", and the International Green Hydrogen Organization's Green Hydrogen Standard also add the carbon emissions generated in the downstream hydrogen use process to the carbon accounting category.
Compared with the international standards, the mainland green power certification system has not yet required green certificates for power sources for the production of green hydrogen, and has not extended the scope of carbon emission measurement to downstream green hydrogen use, so it is urgent to strengthen the construction of standards in the future to improve the coordination and unification of mainland and international standards.
Framework diagram of China's hydrogen energy standard system
Green electricity can be stored and transported through hydrogen-based energy, and green electricity and green hydrogen-based energy are ideal "process energy" carriers. For example, in the construction of a new power system, hydrogen-based energy can not only achieve cross-seasonal long-term energy storage, but also solve the problem of renewable energy consumption, or in the steel, chemical and other industrial fields, hydrogen-based energy can achieve deep decarbonization of the industry.
How to use renewable energy to obtain "green hydrogen-based energy" is an important research direction in the field of energy in the future. To establish a sound hydrogen-based energy certification system, it is necessary to have a clear definition of green hydrogen-based energy, and at the same time to give clear greenhouse gas quantification standards throughout the production life cycle.
"Green" hydrogen certification standard
欧盟“可再生氢”（Renewable Hydrogen）定义
On February 13, 2023, the European Union passed two enabling acts required by the Renewable Energy Directive. The first enabling act provides for three scenarios that can be counted as "renewable hydrogen": hydrogen produced by a renewable energy production facility directly connected to hydrogen production equipment, hydrogen produced by grid power in areas where the renewable energy content is more than 90%, and hydrogen produced by grid power after entering into a renewable electricity purchase agreement in areas with low CO2 emission limits.
The second enabling act defines a calculation for quantifying renewable hydrogen, i.e., the fuel threshold for renewable hydrogen must be 28.2 grams of CO2e/megajoule (3.4 kg CO2e/kg of hydrogen) to be considered renewable. The approach takes into account greenhouse gas emissions over the entire life cycle of the fuel and clarifies how greenhouse gas emissions should be calculated in the case of co-production of renewable hydrogen or its derivatives in fossil fuel production facilities.
Japan's definition of "low-carbon hydrogen" (low-carbon hydrogen).
On June 6, 2023, Japan's Ministry of Economy, Trade and Industry (METI) released a revised version of the Basic Strategy for Hydrogen Energy, which has been adopted at the Ministerial Meeting on Renewable Energy and Hydrogen. The strategy sets a carbon intensity target for "low-carbon hydrogen", that is, the carbon emission intensity from raw material production to hydrogen production is less than 3.4 kg of CO2/kg hydrogen, and clarifies that the carbon emissions of hydrogen produced abroad should cover the whole life cycle such as long-distance transportation.
美国“清洁氢”（Clean Hydrogen）定义
The U.S. Department of Energy (DOE) has issued the "Guidelines for "Clean Hydrogen" Production Standards, which requires the following requirements to be developed in the United States in connection with "clean hydrogen" standards.
Supporting the production of "clean hydrogen" in a variety of ways, including but not limited to: the use of fossil fuels with carbon capture, utilization, and storage (CCUS), hydrogen carrier fuels (including ethanol and methanol), renewable energy, nuclear energy, etc., and defines the term "clean hydrogen" as no more than 2 kg of CO2 equivalent for every 1 kg of hydrogen produced at the production site, and no more than 4 kg of CO2 equivalent per kg of hydrogen over the life cycle.
国际可再生能源署IRENA“绿氢”（Green Hydrogen）定义
IRENA, the International Renewable Energy Agency, has published the 2020 Policy Development Guide for Green Hydrogen, which defines "green hydrogen", i.e. hydrogen produced from renewable energy. The guide mentions that the most mature green hydrogen production technology is water electrolysis technology based on renewable electricity, and also mentions other renewable energy hydrogen production options, including biomass gasification and cracking, thermochemical water splitting, photocatalysis, biomass supercritical water gasification, etc. The International Renewable Energy Agency (IRENA) does not specify the amount of CO2 equivalent per unit of green hydrogen produced.
Definition of "green hydrogen" in China
The China Hydrogen Energy Association has made a preliminary definition of "green hydrogen", "green hydrogen" refers to the hydrogen obtained by electrolysis of water from renewable energy, it is a clean energy, and the traditional gray hydrogen (through fossil fuels, coal, oil, natural gas, etc., hydrogen produced by combustion) has a clear difference, the electricity used in the production process of "green hydrogen" must come from renewable energy, such as solar energy, wind energy, hydropower, etc.
On December 29, 2020, the China Hydrogen Energy Alliance proposed the "Standards and Evaluation of Low-carbon Hydrogen, Clean Hydrogen and Renewable Energy Hydrogen", which pointed out that in terms of carbon emissions per unit of hydrogen, the threshold for low-carbon hydrogen is 14.51 kg CO2e/kg hydrogen, and the threshold for clean hydrogen and renewable hydrogen is 4.9 kg CO2e/kg hydrogen, and renewable hydrogen requires its hydrogen production energy to be renewable energy.
"Green" ammonia certification standard
EU "Renewable Ammonia" (RFNBO) DefinitionThe EU Renewable Energy Directive defines the renewable fuel product group "RFNBO", and liquid fuels produced based on renewable hydrogen, such as ammonia, methanol or e-fuels, are also considered RFNBO. The EU does not have a clear regulation on the amount of carbon dioxide equivalent per unit of green ammonia produced.
EU "Renewable Ammonia" (RFNBO) definition
The Renewable Fuels product group "RFNBO" is defined in the EU Renewable Energy Directive, and liquid fuels produced from renewable hydrogen, such as ammonia, methanol or e-fuels, are also considered RFNBOs. The EU does not have a clear regulation on the amount of carbon dioxide equivalent per unit of green ammonia produced.
Japan "Low Carbon Ammonia" (Low Carbon Ammonia)
On June 6, 2023, Japan's Ministry of Economy, Trade and Industry (METI) issued a revised version of the "Basic Strategy for Hydrogen Energy", setting a life-cycle carbon emission intensity index for the production of hydrogen and ammonia, and "low-carbon ammonia" (low-carbon ammonia) is defined as the carbon emission intensity of the production chain (including the hydrogen production process) is less than 0.84 kg CO2e/kg ammonia.
Definition of "Green ammonia" by the International Green Hydrogen Organization
On January 14, 2023, the International Green Hydrogen Organization (GH2) announced an update to the green ammonia standard, which stipulates that the greenhouse gas emission intensity standard for green ammonia made from green hydrogen should not exceed 0.3 kg CO2e/kg ammonia.
IRENA“可再生氨”（Renewable Ammonia）定义
In 2022, the International Renewable Energy Agency (IRENA) and the Ammonia Energy Association (AEA) jointly released the Innovation Outlook: Renewable Ammonia, which defines "Renewable Ammonia" as hydrogen produced from renewable electricity and nitrogen purified from the air. All raw materials and energy sources for the production of ammonia from renewable ammonia must be renewable energy sources (biomass, solar, wind, hydroelectric, geothermal, etc.). The International Renewable Energy Agency (IRENA) does not have a clear regulation on the amount of carbon dioxide equivalent per unit of green ammonia produced.
Definition of "green ammonia" in China
At present, there is no unified definition of "green ammonia" in China by official institutions and authoritative organizations. There are relevant voices in the industry, and the definition of green ammonia by domestic companies is mainly concerned with whether its raw material hydrogen is produced from renewable electricity, and there is no clear requirement for carbon emissions in the production process.
CIC consultants proposed that green ammonia refers to ammonia products that obtain raw hydrogen through electrolysis hydrogen production, biomass hydrogen production with carbon capture and other processes, and green ammonia is classified as ammonia with basically zero carbon emissions; Jinlianchuang Fertilizer proposed that green ammonia is produced by electrolysis of water from renewable energy sources such as wind energy and solar energy, and then combined with nitrogen in the air to synthesize ammonia, and green ammonia is prepared from renewable energy as raw materials throughout the process; Zhiyanzhan Industry Research Institute proposed that green ammonia is made by using renewable energy (such as wind energy, solar energy, etc.) to produce hydrogen, and then synthesize hydrogen with nitrogen to obtain ammonia.
"Green" methanol certification standard
国际可再生能源署IRENA“可再生甲醇”Renewable Methanol定义
In 2021, the International Renewable Energy Agency (IRENA) released "Innovation Scenario: Renewable Methanol", which pointed out that the raw material sources required for "Renewable Methanol" must all meet renewable energy standards, and only methanol products in the two ways of biomass recycling and green hydrogen to methanol can be called "renewable methanol".
Bio-methanol: Bio-methanol is produced from biomass. Sustainable biomass feedstocks include forestry and agricultural waste and by-products, biogas from landfills, sewage, municipal solid waste and black liquor from the pulp and paper industry. After the biomass raw material is pretreated, it is pyrolyzed and gasified to produce syngas containing carbon monoxide, carbon dioxide, and hydrogen, and then biomethanol is synthesized by a catalyst. In addition, biomethanol can also be synthesized by directly reforming the biogas produced by anaerobic fermentation of biomass, or separating the carbon dioxide in it, hydroreforming, and reforming.
Green electricity to green hydrogen to methanol: The synthesis of renewable methanol from green hydrogen and renewable carbon dioxide requires the use of "renewable carbon dioxide", that is, carbon dioxide produced from biomass or captured from the air. Green hydrogen and renewable carbon dioxide are synthesized into renewable methanol at high temperature and high pressure, although carbon dioxide will be produced when methanol is burned in the future, but because these carbon emissions are captured through circulation, the carbon emissions of methanol in the whole life cycle are zero.
欧盟“可再生甲醇”Renewable Methanol定义
Based on the renewable fuel product group "RFNBO", the supplementary regulation of the European Union's Renewable Energy Directive (REDII.) proposes that in the short term, methanol prepared from carbon dioxide captured in industry using carbon dioxide captured in the EU ETS can be considered "Renewable Methanol" for the short term, but the carbon emissions throughout the life cycle do not exceed 28.2 grams of carbon dioxide equivalent per megajoule (3.4 kg carbon dioxide equivalent per kilogram of hydrogen).
Definition of "Green Methanol" in the United States
At present, there is no unified standard or definition of green methanol in the United States, and according to online reports, in September 2023, OCI announced that it intends to expand the green methanol (Green Methanol) project, and its green methanol will be produced using a mixture of renewable raw materials, including RNG, green hydrogen and other raw materials. In the above report, the main raw materials of its green methanol are renewable raw materials.
Definition of "green methanol" in China
At present, there is no unified definition of "green methanol" in China by official institutions and authoritative organizations. The Global Methanol Industry Association China mentioned that there is no clear statement on the definition of green methanol in the world, and if methanol can be made from renewable raw materials, and its carbon footprint of the whole life cycle can be low enough, it can be called green methanol.
China's solutions help the world
Green hydrogen-based energy standards are integrated and unified
Green hydrogen-based energy will be driven by both market and policy, so it is necessary to develop its own green hydrogen-based energy standards in China. First of all, the definition of green hydrogen is not uniform in various countries, and there are many similar terms such as "renewable hydrogen", "low-carbon hydrogen", "clean hydrogen" and "green hydrogen", and the standard system of green ammonia and green methanol is more confusing. For example, the United States supports the production of "clean hydrogen" using fossil fuels, biomass, nuclear energy and other non-electrolysis of water to produce hydrogen with carbon capture, utilization and storage (CCUS), while Japan believes that the production method of "low-carbon hydrogen" should be hydrogen production by water electrolysis. Finally, there is no consensus on carbon equivalent emission standards across countries, and the carbon dioxide equivalent thresholds for greenhouse gas emissions in the life cycle of green hydrogen-based energy are not uniform.
At present, China is the only country in the world that has the advantages of the whole industrial chain of green hydrogen-based energy, which can overcome technical problems through large-scale development and application, and solve the core problem of large-scale economic utilization of green hydrogen-based energy.
Clarify the standards for green hydrogen (ammonia and alcohol) and include them in the certification system
In the future, the mainland should have a clear goal of building a hydrogen-based energy certification standard system, and it is necessary to formulate a set of "green hydrogen (ammonia, alcohol) terminology" standards at the national level, clarify the definition of green hydrogen, determine the production scenarios of green hydrogen (ammonia and alcohol), and quantify the greenhouse gas emission threshold. Combined with the development of the domestic hydrogen energy industry, research and formulate green hydrogen-based energy standards that are in line with the national conditions of the mainland and in line with international standards, so as to reduce green trade barriers and international regulatory risks.
Promote the deep integration of the hydrogen market and the carbon market
Promote the green value certification of the whole industrial chain of green hydrogen-based energy, establish and improve the carbon emission accounting system for the life cycle of green hydrogen-based energy, and encourage the large-scale development of the hydrogen-based energy industry with carbon value. Establish hydrogen-based energy carbon footprint certification methods and standards, and create a clean and low-carbon production supply chain. Establish a carbon emission data monitoring system for various hydrogen-based energy projects, and promote international cooperation on hydrogen-based energy in mainland China.
Promote the coupling development of green hydrogen and green certificates
As a symbol of the green attributes of electricity, green certificates have been widely recognized by mainstream economies around the world, which can realize the decoupling of power energy attributes and green attributes, promote the coupling development of green hydrogen-based energy and green certificates, help the large-scale development of green hydrogen-based energy, reduce preparation costs, accelerate the market penetration rate of green hydrogen-based energy, and escort the high-quality development of green hydrogen-based energy.
Source: General Institute of Hydropower and Water Conservancy Planning and Design