An overall thermodynamic view of processes: Comparison of fuel producing processes

Mass, energy and entropy was used to analyze a Methanol and Gas-to-Liquids process. The heat and work flows were calculated using elementary thermodynamic data. This allowed targets to be set for the heat and work flows and from this target operating temperatures and pressures could be calculated. The targets are important as processes operating at these targets have minimum heat and work loads, which in turn corresponds to minimum operating costs of the plant. In addition, processes operating at these targets also have if not minimum, at least reduced capital costs. The simultaneous reduction in both capital and operating costs occurs because as heat and work loads decrease, the process equipment becomes smaller and, in some cases, less complex. Thus, we believe that these targets are useful for synthesis as well as analysis of chemical processes.The analysis of the methanol process revealed that such processes operate far from reversibility (and thus is not work integrated) and require large amount of work. A way the work can be inputted is by operating the synthesis section at high pressure. The technique was also able to estimate the pressure required to put in the work required for current commercial methanol processes. The Gas-to-liquids process was found to operate in the region where work is lost (in both reformer and synthesis sections) and therefore does not require further work and thus there is no need for high pressure operations.