Rough Assessment on Conversion and Transportation Model of Fuel Produced by Methanation of Carbon Dioxide and Hydrogen Produced by Water Electrolysis Using Electric Power of Large Scale Wind Power

摘要

大規模風力発電電力利用水電解水素とCO_2のメタネーシヨンで製造した燃料の変換•輸送モデルの概算評価優れた風況が得られるアルゼンチンのバタゴニァ地方に大規模に風力発電を設置し得られた電力を水電解装置にて変換した水素を用いCO_2をメタネーシヨンでメタンに変換し，それを液ィ匕してタンカーで日本まで輸送するモデルのエネルギー生産性•収支， CO_2循環可能性，投資回収を概算した。メタネーシヨンで使用するCO_2は日本でメタン利用により生成した分をパタゴヒア地方に運 ぶとともに不足分は南米カゝら調達することとした。3000 kW級風車をパ夕ゴニァ地方のチュプット州とサンタクルス州に合計7.81x10~5 台設置することを想定したところ，日本へ輸送可能な液化メタン量は熱量ベースで国内LNG輸入量の2.2倍であり.パタゴニァ地方 に大規模に風力発電を導入し，水素製造• メタン化して日本に輸送するモデルは十分にエネルギー生産性のあることが確認された。 またその際のエネルギー損失は64.7%となった。バタゴニァ地方カゝら日本まで輸送した液化メタン利用によるCO_2排出量はパタゴ ニァ地方でのメタネーシヨンに要するCO_2量の49.1%に留まり，不足するため，南米から別途調達するシステムが必要である。なお 本試算はー部大胆な仮定に基づくため，今後さらなる精査が必要である。%This study conducted the rough assessment on the model transporting liquid methane converted by methanation of carbon dioxide with hydrogen produced by water electrolysis using electric power of large scale wind power assumed to be installed in Patagonia region in Argentina from the viewpoint of energy productivity, energy balance, carbon dioxide circulation possibility and investment recovery. It was assumed that the CO_2 for methanation was transported from both Japan where CO2 was produced by using the methane and South America. As a result, when wind turbines in 3000 kW class of 7.81x10~5 units were assumed to be installed, the amount of liquid methane which could be transported to Japan was 2.2 times as large as the import volume of LNG in Japan, indicating that the model had the adequate energy productivity. The energy loss of the model was 64.7%. The amount of carbon dioxide emission from liquid methane transported from Patagonia region to Japan was equal to 49.1% of the amount of carbon dioxide which was necessary for methanation in Patagonia region, which was short. Consequently, the CO_2 which is short for methanation should be procured from the other system in South America. Since this assessment was carried out based on some bold assumptions, the further investigation should be necessary in the future.