Then, equipment costs of the one candidate process which shows best economic performance among the additives and the Selexol process with DEPG are compared. Operating cost of the Selexol process with additives and pure DEPG are calculated. The parameters are obtained by regression tool in simulator using $CO_2$ solubility experimental data. To obtain the amount of $CO_2$ capture using the additives in the simulation, the binary parameters be-tween $CO_2$ and the additives are needed. Perturbed Chain Statistical Association Fluid Theory equation of state (PC-SAFT EOS) model is used for thermodynamics in the simula-tions. The feed gas stream for the 1-stage Selexol process is chosen from syn-gas generated by Integrated Gasification Combined Cycle (IGCC) power plant. The 1-stage Selexol process is developed instead of typical 2-stage Selexol process because only $CO_2$ capture is considered in this research. To estimate their economic feasibility, the Selexol processes with the three candidate additives are simulated using Aspen Plus®. Three compounds, dimethyl carbonate (DMC), diethyl carbonate (DEC), and triacetin (TAT), are chosen as the candidate additives. The additive candidates are selected by comparing solvation energies. The $CO_2$ solubility is can be represented as solvation energy of $CO_2$ in the additive materials. In this work, the compounds are found that have similar $CO_2$ solubility with DEPG as well as cheaper than DEPG. Mixing additive with DEPG is expected to lead lower solvent purchasing cost compared to the Selexol process with pure DEPG while amount of captured $CO_2$ are same. In this study, employing novel additives to the Selexol process are suggested to reduce the economic loss of the Selexol process. Extra cost for constructing and operating of carbon capture process is a main problem for applying it to real industries widely. Dimethyl Ethers of Polyethylene Glycol (DEPG) is used as physical ab-sorbent in this system. Especial-ly, $Selexol^$ process, one of the pre-combustion carbon capture technology, has been commercialized and already adopted to some industries.

Among various candidates for $CO_2$ capture, physical absorption based carbon capture system is relatively mature technology. Various carbon capture technologies have been suggested to capture carbon dioxide such as post-combustion, pre-combustion and oxy-fuel combustion carbon capture system. Therefore, developing technologies about carbon capture and storage has become an active research area. Reducing carbon dioxide emission has become an important social issue due to global warming.

Aspen hysys depg model