Thermodynamic Fundamentals and Energy Efficiency for the Separation and Highly Valued Utilization of Light Naphtha from Fischer–Tropsch Synthesis

To improve the economic potential of Fischer–Tropsch (F–T) products, the low-cost separation of linear α-olefins is a flexible technology. However, the scarcity of thermodynamic data and high production cost were the key R&D issues essential to commercialization. In this article, the isobaric vapor–liquid equilibria (VLE) data of five binary systems composed of 1-hexene, 2-hexene, 2-methylpentane, 1-octene, and 2-octene were measured and regressed by the activity coefficient models. With the binary interaction parameters regressed by experimental data, two separation processes for obtained α-olefins fraction products C6 (1-hexene) and C8 (1-octene) were simulated by comparing with a traditional sequence distillation route and a dividing wall column (DWC) route. A practical configuration of the heat-integrated distillation process was proposed to reduce the energy consumption for the separation of olefins and alkanes. The energy consumption and total annual costs (TACs) of the separation technology were estimated and compared, which indicated that an advanced separation technology could reduce the energy consumption and TAC of the production of α-olefins from F–T products.