Assessment of Methanol Synthesis Utilizing Exhaust CO₂ for Chemical Storage of Electrical Energy

Abstract

The thermodynamic and operational boundaries to store electrical energy chemically are evaluated in this contribution. Methanol is considered as a candidate for chemical energy storage. The production of methanol from exhaust CO2 could be one way to recyle CO2 and lower the global CO2 emissions. Energetic analysis reveals that exergy losses are most severe in the parts of the system when electrical energy is converted to chemical (electrolysis) and when chemical energy is converted to electrical (power generation). In methanol production, the exergetic efficiency is 83.1%, when the chemical exergy of hydrogen and methanol, the exergy of the power input and the released heat are taken into consideration. The exergetic efficiency of the overall energy conversion-storage system including methanol as storage medium was evaluated to be between 16.2 and 20.0% depending on the applied conversion technology. Methanol is suitable not only as stationary energy storage, but it could also be used as fuel for transportation. The energy storage system with hydrogen as storage medium shows higher exergetic efficiency than the methanol route. However, the storage of hydrogen is clearly more complex and cost-intensive.

Morphology‐Dependent Interactions of ZnO with Cu Nanoparticles at the Materials’ Interface in Selective Hydrogenation of CO2 to CH3OH

“…Particularly, the focus is on the production of methanol, which is a key platform chemical for present fuel and chemical infrastructures. [3] A recent assessment of economic feasibility for this new green process supports the possibility. [4] Today, methanol is produced industrially from syngas containing CO and CO 2 (derived from fossil fuels) over Cu/ ZnO/Al 2 O 3 catalysts.…”

Technoeconomics and Sustainability of Renewable Methanol and Ammonia Productions Using Wind Power-based Hydrogen

“…These processes differ mainly in their reactor designs and the way in which the produced heat is removed from the reactor. To improve their catalytic performance, the CuO/ZnO catalysts have been modified with various metals, such as chromium, zirconium, vanadium, cerium, titanium, and palladium [30][31][32][33]62]. The long-term stability of the catalysts may be improved by adding a small amount of silica to the catalysts at reaction conditions of 5 MPa, 523 K [63].…”

“…However, using the off-peak power could increase plant load factor and improve the economics [49,53]. Electrolytic H 2 may be more attractive for regions without access to natural gas or if H 2 is used as an energy storage medium [33,49].…”

“…Methanol synthesis needs carbon-rich feedstock (natural gas, coal or biomass), hydrogen, and a catalyst, mainly Cu/ZnO/Al 2 O 3 [26][27][28][29][30][31][32][33][34]. Methanol is produced almost exclusively by the ICI, the Lurgi, and the Mitsubishi processes.…”

“…Energy analysis of recycling CO 2 and reaction mechanisms of hydrogenation of CO 2 are some of the efforts toward non-fossil fuel-based methanol as a renewable energy storage and carrier [26][27][28][29][30][31][32]. Rihko-Struckmann et al [33] carried out an energetic evaluation in order to assess the overall efficiency of methanol and hydrogen-based storage systems for renewable electric energy; the efficiency of the system using hydrogen is higher compared with that of using methanol as the storage medium; however, storage and handling of methanol as chemical storage is favorable when compared with H 2 [18][19][20][33][34][35][36].…”