In the present paper, a gas turbine (GT) unit with nominal capacity of 26.8 MWe, which is used for continuous production of electricity in Ilam Gas Refinery Company, has been investigated for combined production of cooling, heating, power and process (CCHPP). Critical parameters are measured and the potentials of transforming the GT unit to CCHPP are investigated from technical, economic, and environmental point of views. A heat recovery steam generator (HRSG) converts the exhaust energy to steam that can be used for three purposes of cooling, heating and process. The cycle is first evaluated thermodynamically, and to be certain about the HRSG, its operation is studied by using the pinch technology. Economical evaluation is carried out by calculating initial investment, payback period, net present value (NPV) and internal rate of return. In addition the impact of using CCHPP on reduction of environment pollutant gases such as CO, CO2, and NOx is studied. The results reveal that, the fuel energy saving ratio of 36% is achieved for the minimum pinch point temperature of 19 ̊ C in the HRSG unit. The payback period is only 5.2 year, and the NPV during the project lifetime is 1.87 M$. In addition the CO2, CO, and NOx reduction is about 32000, 22 and 27 tons/year respectively.