Optimization of CaO–Ni Blends for Enhanced CO2 Adsorption: Aspen Plus Simulation Study

Abstract

Carbon capture and storage (CCS) technologies are essential for mitigating global CO2 emissions, yet challenges such as high energy consumption and material degradation hinder their widespread adoption. This study investigates the integration of nickel (Ni) into calcium oxide (CaO) sorbents to enhance CO2 capture efficiency by leveraging Ni's catalytic properties to optimize carbonation kinetics. Aspen Plus simulations were employed to evaluate the effects of varying Ni concentrations (5–25 wt%) on reaction rates, activation energy, and carbonation efficiency. The results revealed that adding Ni considerably reduced the activation energy from 178 kJ/mol (pure CaO) to 70–90 kJ/mol. The maximum catalytic efficiency was achieved at 20 wt% Ni. At this concentration, the rate of the carbonation reaction increased exponentially, leading to considerable improvements in CO2 collection and CaCO3 formation rates. Sensitivity analysis identified key operational parameters, such as temperature, CO2 partial pressure, and flow rates, for improving process optimization in industrial settings. In comparison to typical CaO-based sorbents, Ni–CaO blends demonstrated higher catalytic efficiency and lower energy needs, addressing key challenges in CCS systems. This work distinguishes itself from previous CaO stability studies by integrating process optimization and kinetic modeling, resulting in practical insights for the development of energy-efficient CO2 capture technologies. Future research ought to explore the long-term stability of Ni–CaO sorbents and incorporate renewable energy sources to increase the sustainability and economic feasibility of CCS systems.