Technoeconomic Assessment for the Direct Production of High-value-added Ethanol Fuel from Syngas

[[abstract]]Several common ethanol fuel mixtures (E3-E85) are in use around the world. Ethanol fuel mixtures have “E” numbers which describe the percentage of ethanol fuel in the mixture by volume, for example, E3 is 3% anhydrous ethanol and 97% gasoline. Low-ethanol blends, from E5 to E25, are also known as gasohol. At the present moment, the CPC (Taiwan) sells E3 as partial replacements to the more expensive unleaded gasoline in an attempt to reduce CO2 emission. However, it is still far less than E5 to be regarded as gasohol. In this work, we have presented a new route to producing ethanol fuel directly from syngas derived from IGCC plants. On the basis of 10,000 tonnes per year of ethanol fuel with purity greater than 99.3 vol%, the engineering economic analysis is also assessed. It should be emphasized that the process design on the reactor system is based on the thermodynamic principles. In regard to the separation system design, we used three different methods to purify the aqueous ethanol. The first is the azeotropic distillation process with cyclohexane as the entrainer, the second is the pressure-swing distillation utilizing two distillation columns that operate at varying pressures and the third is the pervaporation process with hydrophilic membrane. It was found that, among the three purification processes, pervaporation is the most economic one with a yearly manufacture cost of US$9.03 x 106 and a per-liter-cost of the ethanol fuel US$0.76. Three kinds of software are used in the research—Aspen Plus, Aspen Custom Modeler (ACM), and SuperTarget. The first and second are applied to implement the process synthesis and design; the third is applied to perform the pinch analysis and the synthesis of heat exchanger network.[[notice]]補正完