| dc.description.abstract | Transitioning industries away from fossil fuels is imperative due to both
climate change and geopolitical considerations. Electrochemistry presents an op-
portunity to convert captured CO2 into a de-fossilized carbon feedstock for the
chemical industry. In this Thesis an industrial scale electrochemical formic acid
production plant was simulated based on a pilot electrolyser. The obtained mass
and energy balances, evaluated under three operational scenarios and utilizing four
alternative downstream methods, were subject to an ex-ante life cycle assessment,
with a scope of present and 2050 Germany. Additionally, scenarios for the real-
ization and environmental implications of electrolyzer operation based on excess
renewable electricity were explored.
Compared to conventional formic acid production, electrolytic production
has a substantially higher energy demand, which contributes most impacts in the
assessed categories. Scenarios minimizing energy use demonstrated reduced envi-
ronmental impacts. The change in the environmental impacts of energy towards
2050 (reduced climate impacts and non-renewable energy use, and increased re-
newable energy use, abiotic depletion potential of materials, and water scarcity)
is reflected in the production impacts of formic acid. At present, energy use
(non-renewable and renewable) and climate impacts of electrolytic formic acid
production are higher than of conventional production. In 2050, the comparison
between production methods becomes less clear-cut; while electrolytic production
reduces fossil fuel dependence, its climate advantages hinge on the efficiency of the
electrolyzer. Notwithstanding, electrolytic formic acid production demonstrates
a reduction in water scarcity impacts compared to conventional methods across
both temporal scopes.
Electrolyzer materials have a minor contribution to the overall impacts. Con-
sequently, intermittent electrolyzer operation, enabled by increasing the cell size to
process more CO2 during periods of excess renewable energy supply, could achieve
impacts reductions in all environmental categories, specifically, ranging from -41%
of water scarcity to an impressive -81% of climate impacts. In electrolyzer devel-
opment, priority should be given to minimizing electricity consumption, even if it
entails enlarging the cell area. Additionally, the ability to operate intermittently
stands out as a crucial feature for maximizing environmental merits. To facili-
tate industrial realization, the development of a viable and efficient technology for
purifying the CO2 recycle stream is required. | |
