Optimizing Emissions Reduction in Ammonia–Ethylene Chemical Clusters: Synergistic Integration of Electrification, Carbon Capture, and Hydrogen

The transition of
the chemical industry to net-zero CO2 emissions presents
several significant challenges, due to the presence
of carbon as material feedstock, the capital-intensive nature of plants,
the interdependence of multiple processes within industrial clusters,
and the availability of low-carbon electricity, hydrogen, and CO2 transport and storage. To obtain an effective plan for reducing
emissions, a comprehensive modeling approach that accounts for the
dynamics of clusters and their interactions with the broader energy
system is needed. In light of the aforementioned considerations, the
present study develops and applies a mixed-integer linear programming
(MILP) model with a one-year hourly resolution to optimize technology
selection and operation in two existing ammonia-ethylene clusters.
The findings show that significant emission reduction is possible
with close-to-market technologies that bridge electrification, green
hydrogen, and carbon capture and storage, yet reaching zero emission
is not possible. Moreover, the optimal CO2 reduction strategies
are highly cluster-specific and contingent upon the availability of
a critical infrastructure. For instance, emissions can increase by
up to 118% in the absence of a CO2 transport and storage
infrastructure, because separated CO2 from reformer syngas
cannot be stored or further utilized. While process integration can
improve cost-effective CO2 mitigation, reducing costs by
9–?% and emissions by 29%–54%, it also limits operational
flexibility. The developed framework offers a valuable tool for identifying
cluster designs and robust CO2 emission reduction strategies.