Development of an Integrated Structure of CHP and Heavy Hydrocarbons Liquids Using Fischer-Tropsch Synthesis

Recent developments in gas-to-liquid conversion industry lead to reduction in initial investment, and it is expected by growth in demand for refined products in countries and the need to import these products in the countries. Implementing such projects can prevent currency outflow. In this article an integrated structure is developed for producing liquid fuels from natural gas through Fischer-Tropsch synthesis. This integrated structure consists of steam and gas turbines and HRSG heat exchanger for power and heat recovery. Auto thermal reforming method, due to its high efficiency and exothermic nature is developed here for producing the synthesized gas. The exergy analysis indicates that the highest destruction rate of the equipment is related to the Fischer-Tropsch synthesis unit by 37.34% and the lowest to the gas turbine by 0.3%. The amounts of exergy destruction in compressors and pumps, gas turbine and steam turbine are 2.51%, 0.29% and 3.26%, respectively. The more the rate of exergy destruction in compressors, pumps and turbines, the more the rate of consumed power in the aforementioned equipment; consequently, the exergy destruction in theses equipment should be minimized. The overall thermal efficiency (HHV base) of this Integrated structure is 65.55%, which yields 9 MW power for industrial and residential consumption, and heat with the amount of 21 MW for utilizing in reboilers.