Design and assessment of a novel mobile carbon capture system: Energy and exergy analyses

Abstract

In this work, we designed a mobile carbon capture (MCC) system that can effectively capture CO2 from the exhaust gas of diesel engines for applications in commercial vehicles. We present the results of energy and exergy analyses conducted on this system, which includes an energy recovery unit, a cooling unit, CO2 adsorption and desorption units, and a CO2 liquefaction unit. Three processes were considered to capture CO2: temperature vacuum swing adsorption (TVSA), vacuum pressure swing adsorption (VPSA), and vacuum swing adsorption (VSA). Energy is produced using turbines and generators, which supply the necessary power to run the MCC system, thus overcoming the limitation of mobile devices, i.e., lack of energy source. The energy requirement for each process was found to be in the order of VPSA > TVSA > VSA. In terms of specific energy consumption (SEC) and exergy efficiency, VSA was the most suitable process. As an MCC system, the VSA process consumes a small amount of energy in the designed system, and CO2 can be captured, liquefied, and stored by utilizing the energy contained in the exhaust gas. Because the TVSA process is expected to operate with less additional energy input, it can be used as an MCC system to improve the efficiency of each process unit. Our study can serve as a basis for advancing carbon capture technologies that can be implemented in commercial vehicles to reduce the greenhouse effect and help control global warming.