- Open Access
- Article
Developing E-Methane Value Chain and Proper Greenhouse Gas (GHG) Accounting Rules Incentivizing Recycled Carbon Fuels
by Ryota Kuzuki 
, Mitsuhiro Kohara1, Noboru Kizuki1, Satoshi Yoshida1, Yuta Nezasa1 and Yuki Tsuji1
1 Division of Int’l Certification & Standards Harmonization, Planning dept., The Japan Gas Association
* Author to whom correspondence should be addressed.
Journal of Engineering Research and Sciences, Volume 4, Issue 1, Page # 8-15, 2025; DOI: 10.55708/js0401002
Keywords: e-methane, methanation, carbon capture utilization, GHG accounting rules, GHG intensity, recycled carbon fuels, environmental attribute certificates, Clean Gas Certificate
Received: 22 September 2024, Revised: 04 December 2024, Accepted: 05 December 2024, Published Online: 17 January 2025
(This article belongs to the Special Issue Special Issue on Multidisciplinary Sciences and Advanced Technology 2024 & Section Biochemical Research Methods (BRM))
APA Style
Kuzuki, R., Kohara, M., Kizuki, N., Yoshida, S., Nezasa, Y., & Tsuji, Y. (2025). Developing e-methane value chain and proper greenhouse gas (GHG) accounting rules incentivizing recycled carbon fuels. Journal of Engineering Research and Sciences, 4(1), 8–15. https://doi.org/10.55708/js0401002
Chicago/Turabian Style
Kuzuki, Ryota, Mitsuhiro Kohara, Noboru Kizuki, Satoshi Yoshida, Yuta Nezasa, and Yuki Tsuji. “Developing E-Methane Value Chain and Proper Greenhouse Gas (GHG) Accounting Rules Incentivizing Recycled Carbon Fuels.” Journal of Engineering Research and Sciences 4, no. 1 (2025): 8–15. https://doi.org/10.55708/js0401002.
IEEE Style
R. Kuzuki, M. Kohara, N. Kizuki, S. Yoshida, Y. Nezasa, and Y. Tsuji, “Developing e-methane value chain and proper greenhouse gas (GHG) accounting rules incentivizing recycled carbon fuels,” Journal of Engineering Research and Sciences, vol. 4, no. 1, pp. 8–15, 2025, doi: 10.55708/js0401002.
Many countries and industries in the world are aiming to transition to a carbon neutral society. One of the means to achieve this is the use of recycled carbon fuels (RCFs) such as e-methane. Feasibility of an international value chain is being studied in a variety of regions. In particular, with regard to e-methane, demonstration projects are progressing in several regions around the world as well as feasibility studies of cross-border value chain of e-methane. Ideally, e-methane production sites should be located to secure abundant and inexpensive hydrogen and CO2 as feedstocks, besides close to natural gas transmission pipelines, liquefaction facilities, and easily accessible to LNG exporting terminals. In order to stimulate investment in commercialization, development of internationally applicable GHG accounting rules is need at first. It is essential that the CO2 emitted in combustion is recognized under international accounting rules as having environmental value attribute that does not increase CO2 in the atmosphere. As one of the examples, the Japan Gas Association and related organizations have developed a certification scheme called “Clean Gas Certificate” and has applied it to several domestic e-methane production projects in Japan. For the transition period (2030-2050), the use of recycled CO2 captured from factories and thermal power plants emissions are expected to be major feedstock. We propose GHG calculation and accounting method in consideration of avoiding double counting of recycled CO2 in the entire supply chain. A calculation formula of the carbon footprint (CFP) of e-methane was proposed to one of the ISO’s working groups and it was successfully included in the ISO 6338-1:2024. Next, it is necessary to harmonize the proposed methods with internationally common GHG accounting rules.
- R. Kuzuki, et.al., “Promoting Introduction of E-methane for Carbon Neutral City Gas Supply in Japan”, 11th International Conference on Power Science and Engineering (ICPSE), 2022, doi: 10.1109/ICPSE56329.2022.9935370
- IPCC, “The Sixth Assessment Report of the IPCC, Working Group III Report, Climate Change 2022 Mitigation of Climate Change, pp.6-57, 2022 https://www.ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_FullReport.pdf
- IEA, “Net Zero by 2050 A Roadmap for the Global Energy Sector”, 2021, https://iea.blob.core.windows.net/assets/deebef5d-0c34-4539-9d0c-10b13d840027/NetZeroby2050 ARoadmapfortheGlobalEnergySector_CORR.pdf
- G. Molnar, “E-methane: a new gas for a net-zero future?”, Webinar on IEA Low-emissions Gases Work Programme, 2024, https://iea.blob.core.windows.net/assets/9b86ac2a-2055-4eac-9f93-6ab379554d6d/IEA_E-methaneanewgasforanet-zerofuture.pdf
- Y. Vercamen, “eNG’s role for net-zero future”, Webinar on IEA Low-emissions Gases Work Programme, 2024, https://iea.blob.core.windows.net/assets/9b86ac2a-2055-4eac-9f93-6ab379554d6d/TESIEAe-methanewebinar05Sep2024.pdf
- S. Kujara, “E-methane market prospects in Northern Europe”, Webinar on IEA Low-emissions Gases Work Programme, 2024, https://iea.blob.core.windows.net/assets/9b86ac2a-2055-4eac-9f93-6ab379554d6d/Ren_Gas_E-methane_presentation_IEA_2024_0902.pdf
- The Japan Gas Association, Carbon Neutral Challenge 2050 (Press Release), 2020, https://www.gas.or.jp/pdf/en/newsrelease/newsrelease_20211101.pdf
- Europan Biogas Association, “Mapping e-methane plants and technologies – The role of e-methane it the total energy mix”, 2024, https://www.europeanbiogas.eu/wp-content/uploads/2024/09/Mapping-e-methane-plants-and-technologies.pdf
- S. Morimoto et.al., “Scenario assessment of implementing methanation considering economic feasibility and regional characteristics”, 2022, Journal of CO2 Utilization, vol.58, 101935, doi.org/10.1016/j.jcou.2022.101935
- R. Miyake, “Overview of IMO’s guideline of marine fuel life cycle GHG intensity (in Japanese)”, pp.26-28, 2024 Class NK Technical Seminar, 2024, https://www.classnk.or.jp/hp/pdf/research/seminar/2024/seminar_005.pdf
- ISO, “ISO 6338-1:2024 Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain Part 1: General”, 2024, https://www.iso.org/standard/87114.html
- CCR (carbon capture and reuse) Study Group; “A Study on the Carbon Intensity of Synthetic Methane (e-methane)”, 12th Public-Private Council for Promoting Methanation (only Japansese), 2024, https://www.meti.go.jp/shingikai/energy_environment/methanation_suishin/pdf/012_05_01.pdf
- Interim report on CO2 emission accounting in combustion of synthetic methane, Task Force for CO2 Counting Rules of the Public-Private Council for Promoting Methanation (only Japansese) 2022, https://www.meti.go.jp/shingikai/energy_environment/methanation_suishin/co2_tf/pdf/20220322_1.pdf
- G7 (Group of Seven) Climate, Energy and Environment Ministers’ Communiqué Sapporo, 2023, 27, https://www.meti.go.jp/press/2023/04/20230417004/20230417004-1.pdf
- IPCC, Decisions adopted by the Panel, 60th Session of the IPCC, 2024, 9, https://www.ipcc.ch/site/assets/uploads/2024/02/IPCC-60_decisions_adopted_by_the_Panel.pdf
- GHG Protocol, GHG Protocol Corporate Suite of Standards and Guidance Update Process, https://ghgprotocol.org/ghg-protocol-corporate-suite-standards-and-guidance-update-process
- European Union, ANNEX Methodology for determining greenhouse gas emissions savings from renewable liquid and gaseous transport fuels of non-biological origin and from recycled carbon fuels, Official Journal of the European Union, Volume 66, (June 20 2023) 23-33
- European Commision Website, “Voluntary schemes set standards for the production of sustainable fuels and gases” https://energy.ec.europa.eu/topics/renewable energy/bioenergy/voluntary-schemes_en
- ISCC, ISCC PLUS Ver 3.4.2, 2024, 13-15 https://www.iscc-system.org/wp-content/uploads/2024/03/ISCC-PLUS_v3.4.2.pdf
- Cleasn Gas Certificate Committee Website (only in Japanese) https://www.clean-gas-certificate.com/
- Tokyo Gas Co., Ltd., Towards a carbon-neutral, decarbonized society in 2050 – methanation demonstration tests begin (Press Release (in Japanese)) , 2022, https://www.tokyo-gas.co.jp/news/press/20220323-02.html
- Toho Gas Co.,Ltd., Methanation demonstration test using CO2 from Biogas in collaboration with the minicipal government of Chita City (Press Release (in Japanese)), 2022, https://www.tohogas.co.jp/corporate-n/press/1229823_1342.html
- Saibu Gas CO., Ltd., etc.; Start of a methanation demonstration project using local materials (Press Release (in Japanese)) ,2023, https://hd.saibugas.co.jp/news_release/detail/2023/nr040.html
- INPEX Co.,Ltd and Osaka Gas Co.,Ltd, INPEX, Osaka Gas to Commence Technical Development Business on CO2 Emission Reduction and Practical Application of Effective CO2 Use Through One of the World’s Largest Methanation Operations (Joint Press Release), 2021, https://www.osakagas.co.jp/company/press/pr2021/1300478_46443.html
- Osaka Gas Co., Ltd., Contribution to the carbon neutrality of the 2025 Japan International Exposition through the first Clean Gas Certificate (Press Release (in Japanese)), 2024, https://www.osakagas.co.jp/company/press/pr2024/__icsFiles/afieldfile/2024/10/31/241101_1.pdf
- IPCC, “IPCC Expert Meeting Report on Carbon Dioxide Removal Technologies and Carbon Capture, Utilization and Storage”, 2024, https://www.ipcc- nggip.iges.or.jp/public/mtdocs/pdfiles/2407_CDR_CCUS_Report.pdf
- The Japan Gas Association and 17 organizations and companies, “Proposal for Inclusion of Market-Based Accounting in Scope 1 of the GHG Protocol Update” (open letter to the GHG Protocol Secretariat) ,2024, https://www.gas.or.jp/pdf/en/newsrelease/newsrelease_20240131.pdf
- GHG Protocol Website “Event Recording: Reporting Emissions in Carbon Capture and Utilization (CCU) Applications”, 2024, https://www.youtube.com/watch?v=usB47sH-320
- Osaka Gas Co., Ltd., Mitsubishi Heavy Industries, Ltd., IBM Japan, Ltd., Three Partners to Jointly Undertake Proof of Concept (PoC) Applying “CO2NNEX™”, a Digital Platform for CO₂ Accounting across its Supply Chain for Synthetic Methanes (Joint Press Release), 2022, https://www.mhi.com/news/221021.html
