Mitigation Measures to Reduce CO2 Emissions as a Greenhouse Gas and Enhance its Utilization in Petrolchemical Industries.

Abstract

The removal and use of the greenhouse gas, carbon dioxide (CO2), which contributes significantly to global warming, from flue gas was investigated using the absorption method in this study. To investigate its utilisation, the captured CO2 was used as a feedstock for an urea synthesis process. The absorption model was simulated using the ASPEN HYSYS software and the urea synthesis section was modelled using the ASPEN Plus. For the CO2 absorption, Methydiethanolamine (MDEA) was used as the solvent serving to be the absorbent medium. The effect of operating parameters such as flue gas inlet temperature, absorber column number of stages, and absorbent circulation rate on absorption capacity were examined. A flue gas stream containing about 128.2ton/h fractional mass rate of CO2 was treated to capture 109.8ton/h of CO2 which means 85.67% of CO2 recovered. The outlet clean flue gas stream was concluded to be relatively safe to be vented to the atmosphere with about 8.7ton/h (6.8%) of CO2 in it and the remnant was recircled in the loop as slippage into the absorbent solution. Captured CO2 was used as a feed to urea synthesis where 32.9ton/h of CO2 was used to give a wet urea flow of 42.6ton/h. The two models simulated showed that global warming could be greatly reduced by curtailing CO2 emissions from industrial activities. It also shows that the ASPENTECH software is a promising software for simulating carbon capture for utilisation in urea production.