carbon dioxide (C02) emission to atmosphere (due to fossil fuel fired energy consumption) is a major contributor to greenhouse effect which is causing climate change. Integrated Gasification Combined Cycle (IGCe) power plants have greater adaptability to C02 capture in comparison to the state of the art technology (for Greenhouse gas mitigation). Economic infeasibility, Techno-Economic uncertainty and lack of operational experience are some of the major hurdle preventing further penetration of this technology. As a result, larger amount of contingency is applied to the project cost (for various equipment and sUb-systems of the plant). The aim of this research is to develop a significantly detailed process model (of Hydrogen sulphide and Carbon Dioxide capture from syngas) and to develop a realistic estimate of the size of the plant (to conduct the economic assessment). Detailed process design is developed for H2S and C02 capture from syngas using physical solvent. The physical solvent chosen for this research is a blend of various di-methyl ether of poly ethylene glycol (DMEPEG). Rate based simulations are conducted (using Pro-Treat software) to determine the equipment size, the operating condition and the process performance parameters. Various unit operations (within the process) have been optimized using sensitivity study of various process parameters. Several energy saving features have been introduced in the process which finally result in Reboiler Duty (for H2S capture) as low as 30.67 GJ/Ton (which is 99.5 % of feed) and Energy consumption (for C02 capture) as low as 52.422 kW-Hr/Ton (which is 88 % of feed). Suppliers have been identified for various process equipment and their suggestions have been incorporated to develop the process model, to evaluate the process performance and to estimate the cost of the plant.