Techno-economic analysis of renewable methanol production at gigawatt scale - Utilizing green hydrogen for direct CO2 hydrogenation

As part of the European project Hy2Market, the use of green hydrogen in refineries will be investigated.
One possible use case of green hydrogen is the production of renewable methanol by means of direct CO2 hydrogenation, which will be examined in this paper. In the course of this work, a techno-economic analysis of renewable methanol production at gigawatt scale was carried out. Such scales have an impact on a country's infrastructure and have not been realized yet. Throughout this study efficiencies and energy balances of a base case scenario are investigated and visualized in a sankey diagram. Renewable electricity is produced either with wind, solar or a combination of it. The dynamics of the electrolyzer are taken into account to reflect the fluctuation of renewables. At this scale, large storage quantities are necessary. The aim of this work is to examine the required storage capacities for hydrogen including large scale storages (underground) as well as intermediate and short-term storages (pressure, liquid, metal hydrides, liquid organic hydrogen carrier) to identify the most suitable solution for renewable methanol production. The system simulations were done in Modelica/Dymola, which enables a dynamic view of the system. Furthermore, the conducted techno-economic analysis shows that renewable methanol can be produced for less than 1000 €/t.