Abstract
e-methane, which is produced from CO2 and hydrogen using renewable energy, etc., can be utilized in city gas facilities for import/export, pipeline network and equipment for use, and other hydrogen carriers such as liquefied hydrogen and LOHC do not have these features. In this analysis, we analyzed the carbon intensity of the e-methane supply chains which are (I) overseas methanation, (I’) overseas methanation with CO2 transport chains, and (II) domestic methanation. It was found that CI of the e-methane supply chains is about half the reference value in the REDII, if the value of the raw material hydrogen is set at 3.4 kg-CO2/kg-H2. As a result of the sensitivity analysis, the most sensitive assumption was CI of hydrogen. Toward more contribution to carbon neutrality, CI of e-methane supply chain can be reduced by applying the reduction measures though some of them may accompany additional facilities and costs. Therefore, these measures will be applied considering the trade-off the CI criteria required from standards or legislation in the production and utilization regions and countries and cost competition to other alternative technologies.
