CO₂ adsorption and conversion to ethylene urea using Zr-doped Mg-Al layered double hydroxides.

Abstract

With the progression of global warming, Carbon Capture and Utilization (CCU) technology, which involves separating and recovering CO₂ and converting it into other compounds for beneficial use, has been gaining attention in recent years. The reaction of CO₂ and Ethylenediamine (EDA) in the presence of a catalyst produces Ethylene Urea (EU), which is used as a raw material for chemicals. However, a major challenge is the requirement for high-pressure and high-purity CO₂, which involves energy-intensive compression and purification processes. To overcome this, the use of inorganic materials capable of adsorbing CO₂ to capture and then reacting the adsorbed CO₂ with an amine eliminates the need for high-pressure CO₂. Therefore, attention has been given to Mg-Al Layered Double Hydroxide (Mg-Al LDH) as a CO2 adsorbent. Mg-Al LDH has the ability to adsorb CO2 and shows potential for application in CCU technology. Additionally, research on CO₂ capture and EU synthesis using Ti_xZr_(1-x)O₂ has confirmed that an increase in the Zr content leads to an increase in EU production. In this study, Zr-doped LDH was synthesized and utilized as a source of CO₂ and a reaction promoter to explore the synthesis of EU without the need for high-pressure and high-purity CO₂.