Objective of this research is to Efficieny Enhancement and Polutant Gas Emission Reduction in a Benchmark Turbo-Compressor Gas Engine. Using Heat Recirculation of Flue Gas are studied and using a shell&tube and plate finn heat exchanger for simple gas cycle is considered and optimized. Thermodynamic modeling of the cycle is performed using energy and exergy analysis. Thermo-hydraulic modeling of the recuperators is performed using the modified heat transfer analysis and ε-NTU method in order to estimate the heat exchangers area, effectiveness and pressure drop. Optimization is considered as the multi-objective evolutionary algorithm in which one objective is maximizing the cycle exergetic efficiency, the second is minimizing the capital payback time of the recuperator and the other one is minimizing the Polutant Gas Emission for both of heat exchangers. A set of optimal solutions namely as the Pareto frontier are obtained and a final optimal solution are selected using the Bellman-Zadeh fuzzy decision-making approach, TOPSIS and LINMAP methods and the best solutions are reported. In final by comparing the heat exchangers, The best of heat exchanger was selected. Finally, by comparing optimal shell&tube and plate finn heat exchanger, The best heat exchanger has been chosen for Turbo-Compressor. The final improvement Heat Recirculation, Resulted in a 19.1 percent increase in exergy efficiency and reduce NOx emissions rate is 17.93 percent.