Performance analysis of bio-methanol production through bi and tri-reforming processes integrated into a Carnot battery

It is expected that methanol will play a key role in the future as its global demand has been increasing over the years. Moreover, bio-methanol can facilitate the changeover from fossil fuels to renewable energies, ensuring the so-called energy transition, but its production process still relies on conventional sources such as grid energy and methane for the energy supply. In this contest, to allow a more sustainable methanol production, an innovative process scheme is here proposed: a Carnot battery, powered by renewable electricity and providing both electrical and thermal energies, is integrated into a bi-reforming and tri-reforming process for methanol production from biogas. While the chemical process is modeled in Aspen Plus, the Carnot battery and the integration of the system are modeled in MATLAB to evaluate efficiency, total production cost, and carbon dioxide emissions. Results show that even though both integrated systems have a total methanol production cost (300–600 $/tonMeOH) higher when compared to the base case study (170–260 $/tonMeOH), the economy remains competitive with the current market. Moreover, the proposed process scheme can reduce the CO2 emissions up to 84 % compared to the non-integrated scheme. A sensitivity analysis is also carried out to find the effect of the main operating parameters on system performance. Overall, it is found that the tri-reforming route has higher efficiencies for methanol production and the integration of an energy storage system like that of Carnot battery allows to have the saving of emissions at a methanol production cost in line with those of the market.