XTL (Anything to Liquid) is recently emerging phrase that represented all of technologies intended to convert any source of carbon to liquid hydrocarbons. These processes have at least three main steps: syngas production, Fischer Tropsch Synthesis (FTS) and product finalizing. Syngas production might be different from feed and technology point of view and these differences affect all downstream units partially. In this step, source of carbon converted to syngas which is a mixture of hydrogen and carbon monoxide. Origin of the letter X in the XTL phrase depends on this carbon source since B stands for Biomass, C for Coal (bituminous or non-bituminous), G for (natural) Gas and W for Waste (petrochemical wastes, worn automobile tires and …)…show more content… Also it is comprehended by review of academic literatures such as articles and dissertations that GTL is more attractive than any other XTL technologies. Although pipeline is a routine method for transmission of natural gas in countries with huge amount of this wealth  but GTL also have its own value in monetizing natural gas source to easily vendible liquid hydrocarbons. So many of researches devoted to different fields of GTL process merely, beside those investigations on the common part of all XTL technologies such as FTS and syngas production. Amongst these fields, catalyst is the most attractive issue in different fields such as promoters and formulation [11, 12], support , preparation …, and both cobalt and iron catalysts are matter of investigation as well as other new catalysts.
Beside catalyst, reactor design is of high importance. There are different types of reactors for performing FTS such as multi-tubular fixed bed reactors (also named trickle bed reactor, developed by Shell), Slurry Bubble Column Reactors (or SBCR, developed by Sasol), Fluidized bed and circulating fluidized bed reactors (namely Synthol, invented by Kellogg and developed by Sasol) [9, 14, 15]. Although each reactor has it's own advantages, but ease of