Renewable methanol production from green hydrogen and captured CO2: A techno-economic assessment

This paper aims to present a pre-feasibility study of a power-to-fuel plant configuration designed for the production of 500 kg/h of renewable methanol (e-methanol) from green hydrogen and captured carbon dioxide. Hydrogen is obtained by water electrolysis employing the overproduction of renewable electricity. Carbon dioxide is assumed to be separated from the flue gas of a conventional power station by means of an amine-based CO2 absorption system. A comprehensive process model has been developed with the support of Aspen Plus tool to simulate all the plant sections and the overall system. After the process optimization, a detailed economic analysis – based on capital and operating costs derived from commercial-scale experience and assuming a 20-year lifetime – has been performed to calculate a levelized cost of methanol (LCoM) of 960 €/t (about 175 €/MWh). The analysis confirms that, today, the technology is still not competitive from the economic point of view, being LCoM more than double than the current methanol price in the international market (450 €/t). However, it indicates that the process is expected to become competitive in a mid-term future, as a consequence of the new European policies. The study also reveals that LCoM is mainly affected by the electricity price and the electrolyser capital cost, as well as the capacity factor of the plant.