Japan, the US and Australia: to cooperate with ASEAN on CO2 underground storage: to achieve virtually zero emission

Recently Nihon Keizai Shimbun electronic version reported the following:

日米豪とASEAN、CO2の地下貯留で連携　実質ゼロへ

【イブニングスクープ】

経済 環境エネ・素材

2020/11/17 18:00日本経済新聞　電子版

日米豪と東南アジア諸国連合（ASEAN）各国が、温暖化ガス削減に向けた新たな手法で連携する。二酸化炭素（CO2）を地下に埋め大気中への排出を減らす事業で協力する。アジアで排出されたCO2を現地で貯留した分は、日本での排出分と相殺できる。日本は温暖化ガス排出「実質ゼロ」を実現する有力手段になるとみて推進する。

欧州などで温暖化ガス排出を実質ゼロにする「カーボンニュートラル」を目標にする動きが広がっている。日本も菅義偉首相が10月、2050年の実現を表明した。

実質ゼロの実現にはCO2の排出量を森林が吸収する量などと同等に抑える必要がある。再生可能エネルギーの拡大や水素の活用を進めても、鉄鋼や化学など産業によっては排出が続き完全に均衡させるのは難しい。

「実質ゼロ」の取り組みの広がりに伴い、CO2を地下に埋める技術に注目が高まっている。CCUS（CO2の回収・利用・貯留）と呼ばれる技術で、例えば火力発電所から出てきたCO2を圧縮したり液体に吸収させたりして、井戸を通して地下に封入する。油田やガス田などの地層を利用しCO2が外に漏れ出さないようにする。

北米ではすでに一部で実用化されており、欧州では各国から集めたCO2を北海に埋める実証実験が始まっている。

日本のエネルギー政策は再生エネの拡大を進める一方、一定割合で火力発電も使い続ける方針だ。アジアでも火力発電などに頼る国が多い。現地で排出されたCO2の地下貯留に協力すれば、その分を自国で排出した量と相殺できる排出権取引の国際ルールがあり、実質的に日本のCO2排出量を削減できる。

月内に開く東アジア首脳会議（EAS）のエネルギー相会合で新たな枠組みの方向性を確認する。21年からまずアジアでCO2を貯留できる候補地の一覧をつくる。油田やガス田が多いアジアは地下貯留の候補地も多いとされる。

経済産業省によると少なくとも現在の日本の年間排出量の10年分にあたる100億トン以上のCO2を貯留でき、油田やガス田などの利用を増やせばさらに広がる可能性がある。国際エネルギー機関（IEA）は2070年に世界のCO2排出削減量の15%をCCUSが占めると予測する。

貯留量やコスト、環境への影響などを調査し、各国と民間企業で2030年から商業利用の開始をめざす。日本は国際石油開発帝石が地質的に安定しているオーストラリアなどで検討を始めている。米国はアジアで実用化した技術を米国で応用することも見込む。

国境を越えて地域全体でCO2貯留量を取引することも検討する。CO2を船やパイプラインで貯留場所まで運搬したり、技術協力した分を自国の排出分と相殺したりする仕組みを想定する。

日本企業も技術開発を進めている。北海道苫小牧沖では約30社が連携し地下貯留の実証実験を実施中だ。日揮が地上設備の設計や運転技術を担い、石油資源開発（JAPEX）は井戸の掘削などを担当した。

東芝子会社は10月末から福岡県の火力発電所で排ガスを特殊な溶液に通しCO2を分離・回収する実証を始めた。川崎重工業は関西電力の舞鶴発電所（京都府）でCO2回収設備を設置する。三菱重工業は米国でCO2回収設備を納入した実績があり、東レはCO2を効率的に回収する高機能膜の開発を進める。

実用化では回収や貯留の効率を高める技術開発に加え、コスト低減が課題になる。現行の技術では1トンあたり約7千円かかるとみられる。国内は大規模な地下貯留の候補地が少なくアジアで事業を拡大してコストを下げられるかがカギになる。

Translation

Japan, the United States and Australia together with the Association of Southeast Asian Nations (ASEAN) would collaborate on new methods to reduce warming gas. They would cooperate in a project to bury carbon dioxide (CO2) underground to reduce emissions into the atmosphere. The amount of CO2 emitted in Asia and stored locally could be offset by the amount emitted in Japan. Japan would promote it as a powerful means to achieve "virtually zero" warming gas emissions.

In Europe and elsewhere, there was a growing movement to aim for "carbon neutral", which could reduce warming gas emissions to virtually zero. In Japan, Prime Minister Yoshihide Suga announced in October that this could be realized in 2050.

In order to achieve virtually zero, it was necessary to reduce CO2 emissions to the same level as the amount absorbed by forests. Even with the expansion of renewable energy and the utilization of hydrogen, it would be difficult to achieve a perfect balance due to continued emissions in some industries such as steel and chemicals.

With the spread of "substantially zero" initiatives, attention had been increasingly given to technology in burying CO2 underground. It was a technology called CCUS (CO2 capture, utilization, and storage). For example, CO2 emitted from a thermal power plant would be compressed, or absorbed into a liquid and sealed underground through a well. In oil fields and gas fields, by making use of the geological formations, the leaking out of CO2 was prevented.

This had already been put to practical use in some parts of North America; and in Europe, demonstrative experiments had begun to bury CO2 collected from each country in the North Sea.

Japan's energy policy was to expand renewable energy while continuing to use thermal power generation at a certain rate. In Asia many countries still relied on thermal power generation. If cooperation could be arranged to store underground the CO2 emitted locally, and as there were international rules for emissions trading that could allow the offsetting of the amount of emission in the home country, then Japan's CO2 emissions could be substantially reduced.

The direction of the new framework would be confirmed at the Energy Ministers' Meeting of the East Asia Summit (EAS) held within this month. From 2021, a list of candidate sites that could store CO2 in Asia would first be made. In Asia there were many oil and gas fields, it was said that there were many candidate sites for underground storage.

According to the Ministry of Economy, Trade and Industry, these sites had the capability to store at least 10 billion tons of CO2, which was equivalent to 10 years of Japan's current annual emissions. There was a possibility that it could be expanded further if the use of oil and gas fields was increased. The International Energy Agency (IEA) predicted that CCUS might account for 15% of global CO2 emission reductions in 2070.

Investigation on the storage capacity, cost, environmental impact, etc. were being done by individual countries and private companies with an aim to start commercial use in 2030. For Japan, INPEX had begun studying in Australia where it was geologically stable. For the United States, it was also expected that the technology practically used in Asia would be used in America.

Trading CO2 storage crossing borders into region was under consideration. A system was being envisioned in which CO2 was transported to a storage location by ship or pipeline, and the amount dealt with through technical cooperation could be offset against the amount of emissions by a home country.

Japanese companies were also developing the technology. Off the coast of Tomakomai, Hokkaido, about 30 companies were collaborating to conduct a demonstration experiment about underground storage. JGC was in charge of the design and the operation technology related to ground equipment; Petroleum Resources Development (JAPEX) was in charge of wells drilling.

Starting from the end of October, a Toshiba subsidiary had began demonstrating the separation and recovery of CO2 by passing exhaust gas through a special solution at a thermal power plant in Fukuoka Prefecture. Kawasaki Heavy Industries would install a CO2 capture facility at the Maizuru Power Station (Kyoto Prefecture) of Kansai Electric Power Company. Mitsubishi Heavy Industries had a track record of delivering CO2 capturing equipment in the United States, and Toray Industries would proceed with the development of high-performance membranes that could efficiently capture CO2.

In addition to practical use, the technological development to improve efficiency in respect of collection and storage, cost reduction could also be an issue. The current technology was estimated to cost about 7,000 yen per ton. In Japan, there were few potential sites for large-scale underground storage, and the key would be to expand the business in Asia to reduce costs.

              So, INPEX​ a Japanese petroleum company together with others are trying to reduce CO2 emissions in co-operation with the ASEAN countries. To develop the knowhow on the collection and storage of CO2 would be a new business opportunity for some companies.

[Note: INPEX​ is the short name for INternational PEtroleum EXploration Corporation. It is a Japanese oil company formed by the merging of Teikoku Oil (founded in 1941) and International Petroleum Development (founded in 1966)]