The Solid Oxide Fuel Cells are mainly distinguished from other fuel cells, such as proton exchange membrane fuel cells, because of the intermediate and high operating temperatures causing the cogeneration opportunities same as combined cycle and freshwater production via thermal desalination unit (Multi effect distillation). The generated syngas from heavy fuel oil gasification process can be used as the inlet feedstock of solid oxide fuel cell or other power generation systems. In this article, the integration of heavy fuel oil gasification process, different combinations of high efficiency power generation (Solid Oxide Fuel Cell-Gas Turbine-Steam Turbine) and freshwater generation are considered from technical and economic points of view. Extra power generation (in Steam Turbine) or producing the freshwater (in Multi Effect Distillation) in the integrated gasification combined cycle-Solid Oxide fuel cell is investigated from technical and economic aspects. Finally the thermodynamic and economic optimizations are performed using GA algorithm. Results show that the optimum number of cell in fuel cell are 2300, 1700 and 600 for SOFC-GT, SOFC-GT-ST and SOFC-GT-MED respectively. It also shows that in the second objective function (Period of Return) the calculated improvement of SOFC-GT, SOFC-GT-ST and SOFC-GT-MED are 9.88, 6.78 and 31.86 percent respectively. (C) 2016 Elsevier Ltd. All rights reserved.