XNUMX. XNUMX.Search background

　Aiming to achieve carbon neutrality by 2050, various efforts are being made in all fields and industries under the "Green Growth Strategy" formulated by the Ministry of Economy, Trade and Industry at the end of 2020.In the automotive industry, the development of synthetic fuels is underway to move toward decarbonization using existing engine vehicles.※ 1.
　Synthetic fuels are fuels produced by synthesizing CO2 (carbon dioxide) and H2 (hydrogen).By combining CO2 emitted from refineries and factories with hydrogen and electricity derived from renewable energy (renewable energy) and synthesis technology, it is possible to create a carbon-neutral fuel. Synthetic fuel using hydrogen is called “e-fuel”.
　NEDO (New Energy and Industrial Technology Development Organization) is also working to establish a technology for integrated production of liquid synthetic fuel for engines.※ 2, the future development of e-fuel is desired.Therefore, we investigated patent applications related to e-fuel.

*1:From the Ministry of Economy, Trade and Industry Agency for Natural Resources and Energy HP
*2:From the website of NEDO (New Energy and Industrial Technology Development Organization)

XNUMX. XNUMX.Technical overview

　E-fuel is one method of storing and using surplus electricity generated by renewable energy. Hydrogen produced from surplus electricity, carbon dioxide concentrated and recovered from that hydrogen, and carbon dioxide in biogas are used as raw materials. Synthesized and manufactured carbon-neutral fuel.Among them, the method of storing and using gaseous fuel such as hydrogen produced by water electrolysis and methane synthesized from hydrogen and carbon dioxide by methanation is also called Power to Gas (PtG, P2G).
　Also, a method (Power to Liquids, Power to Fuel) of synthesizing hydrocarbon liquid fuel equivalent to gasoline or light oil, methanol, etc. directly or via synthetic gas from hydrogen and carbon dioxide is being studied.※ 3

*3:From the Encyclopedia of Mechanical Engineering

XNUMX. XNUMX.Search strategy (overview)

　In this search, a patent population was created under the following search strategy.

・For the purpose of mainly grasping domestic trends, only Japanese applications were targeted.
　(Publication types include published patents, patents, published practical applications, and practical applications)
・We focused on the FT (Fischer-Tropsch) reaction used to generate e-fuel, and used the following patent classification (F term) from the viewpoint of FT synthesis.
・Keywords (KW) are those related to alternative/next-generation fuels and carbon-neutral, which are set for the full text and multiplied by the patent classification.

　The group created by the above strategy, about 100 cases, was used as the population.

<Patent classification>
4H129-BB07 ･･FT Synthesis
4H129-BB06 ･Chemical Synthesis
4H129-BB00 Types of liquid hydrocarbon manufacturing processes
4H129-. 石油精製,液体炭化水素混合物の製造 (C10G1/00-99/00) [リスト再作成旧4H029、解析要否変更(H20)、1976年以降に発行された文献を解析対象としている]
----------------------
4H129-BC43 ･･FT synthesis method
4H129-BC41 ･Chemical synthesis method and apparatus
4H129-BC00 Processing method, device details
4H129-. 石油精製,液体炭化水素混合物の製造 (C10G1/00-99/00) [リスト再作成旧4H029、解析要否変更(H20)、1976年以降に発行された文献を解析対象としている]
----------------------
4H129-BC46 ･･FT synthesizer
4H129-BC41 ･Chemical synthesis method and apparatus
4H129-BC00 Processing method, device details
4H129-. 石油精製,液体炭化水素混合物の製造 (C10G1/00-99/00) [リスト再作成旧4H029、解析要否変更(H20)、1976年以降に発行された文献を解析対象としている]

XNUMX.Introduction of related applications

　Here are some e-fuel applications.

* Some contents have been revised and added from the original publication.

Patent No. 5155147
[Filing date] 2006/03/16
Title of Invention: Systems, methods and compositions for producing synthetic hydrocarbon compounds
[Applicant] Fuel Core LLC
There is a long felt need for a production system that recycles the products of combustion into hydrocarbon compound fuels, and there is a need for such a system with an emphasis on energy efficiency.
A process and system for refining a hydrocarbon compound or fuel that recycles the products of combustion of the hydrocarbon compound (carbon dioxide gas or carbon monoxide gas, or both, and water).The energy for recycling is preferably electricity derived from nuclear fuels or renewable energy rather than fossil fuels.Water is electrolyzed and hydrogen is used to reduce externally supplied carbon dioxide gas to carbon monoxide gas.The carbon monoxide produced is used in a Fischer-Tropsch reactor with externally supplied carbon monoxide and hydrogen and upgraded upstream to gasoline, jet fuel, kerosene, diesel fuel and other fuels. do.
Effect: A single facility can produce approximately 500,000 gallons or more of fuel per day if sufficient electrical energy, carbon monoxide and/or carbon dioxide are available.

Patent No. 5155147 (J-PlatPat publication link)

* Some contents have been revised and added from the original publication.

Patent No. 6999213
[Filing date] 2021/9/9
[Title of Invention] Carbon Neutral Liquid Fuel Manufacturing System
[Applicant] Eureka Engineering Co., Ltd.
[PROBLEMS] To produce a carbon-neutral liquid fuel with high thermal efficiency at low cost.
SOLUTION: Using carbon-neutral power from biomass-derived fuel and renewable energy-derived power supplied from a power grid, synthesis gas is generated using high-temperature steam heated by a reheater, and the synthesis gas is generated. FT crude oil or crude methanol is synthesized by reacting with a catalyst in a predetermined temperature and pressure environment.
[Effect] Carbon-neutral electricity can be used to emit carbon dioxide-rich exhaust gas, and carbon dioxide can be separated efficiently and at low cost. can be manufactured at relatively low cost.

Patent No. 6999213 (J-PlatPat publication link)

* Some contents have been revised and added from the original publication.

Patent No. 7036853
[Filing date] 2020/3/19
[Title of Invention] Fuel production system
[Applicant] Honda Motor Co., Ltd.
[Problem] Renewable energy is not always generated in a constant amount, so the remaining amount of hydrogen in the hydrogen tank fluctuates greatly according to environmental conditions, making it difficult to fully utilize renewable energy. rice field.
SOLUTION: A liquid fuel manufacturing device that gasifies biomass raw materials and manufactures liquid fuel from the synthesis gas generated by the gasification, and hydrogen is generated from water by electric power generated using renewable energy, and the hydrogen is stored. The amount of hydrogen remaining in the hydrogen tank is controlled by controlling the amount of hydrogen used and the amount of hydrogen produced.
[Effect] By storing the hydrogen generated by the electrolyzer in the hydrogen tank, it is possible to generate hydrogen by fully utilizing renewable energy regardless of changes in environmental conditions, and to replenish the hydrogen in the hydrogen tank as needed. Since it can be supplied to a gasifier, it is possible to produce liquid fuel while making full use of renewable energy.

Patent No. 7036853 (J-PlatPat publication link)

XNUMX.Summary

　Regarding e-fuel, we were able to confirm applications from multiple companies.As issues to be resolved, it can be seen that development for practical use is being carried out, such as efficiency improvement, cost reduction, and countermeasures against fluctuations in renewable energy.Toward the realization of carbon neutrality, future e-fuel development and promotion are expected.

Research Division Yamashita