posted on 2024-01-30, 04:07authored byFabio Cameli, Evangelos Delikonstantis, Afroditi Kourou, Victor Rosa, Kevin M. Van Geem, Georgios D. Stefanidis
Carbon-negative electrified production of methanol (e-MeOH) can
play a central role in sustainable chemical manufacturing in the coming
years. In this context, CO2-based methanol synthesis routes
solely based on renewable electricity have been proposed. However,
the production route via direct air-captured (DAC) CO2 and
green H2 from water electrolysis (WE) is not industrially
available, and in-depth feasibility studies are needed to determine
its viability. By designing a 50 kt y–1 e-MeOH production
plant based on DAC-CO2 and electrolytic H2,
we assess the plant’s performance and economic feasibility
against the state-of-the-art industrial manufacturing based on natural
gas steam reforming. Absorption-based DAC accounts for the highest
capital expenditure (CAPEX) of the plant, whereas the proton-exchange
membrane WE drives electricity consumption. The adiabatic reactor
for the catalytic CO2–H2 reaction is
the least cost-intensive section. Thus, the levelized cost of product
of e-MeOH in 2050 is expected to be still 3 times that of the current
fossil-based MeOH. However, the overall electrified process is carbon
negative by consuming 0.64 kgCO2‑eq kgMeOH–1, whereas the conventional process releases a
significant amount of greenhouse gases. Technological improvement
of the DAC unit could increase the competitiveness of the e-process,
together with lower electricity prices. Furthermore, sourcing CO2 from concentrated streams would cut production costs up to
equaling a conventional process penalized with a 183 $ tCO2–1 carbon tax.