水-乙酸-糠醛三元体系相平衡数据关联与共沸精馏过程模拟

VLE correlation and azeotropic distillation simulation for water-acetic acid-furfural ternary system

通过最大似然法,采用NRTL-HOC和UNIQUAC-HOC模型对水-乙酸、水-糠醛、乙酸-糠醛二元体系相平衡进行回归模拟,发现NRTL-HOC模型较适合于水-乙酸二元体系,UNIQUAC-HOC模型较适合于水-糠醛、乙酸-糠醛二元体系;选择UNIQUAC-HOC模型,根据二元相互作用参数推算出水-乙酸-糠醛三元体系的汽液相平衡数据,其结果与文献值吻合较好;根据二元相互作用参数,绘出了水-乙酸-糠醛三元体系的剩余曲线图,结合剩余曲线图,对该三元非均相共沸体系进行了精馏过程模拟,结果表明剩余曲线图对该三元非均相共沸精馏过程的设计和操作都有重要的指导作用。

Phase equilibria for three binary systems,water-acetic acid,water-furfural,and acetic acid-furfural,at various pressures were simulated by NRTL-HOC（Hayden-O′Connell equations）and UNIQUAC-HOC models.The association of acetic acid in vapor phase was considered and the nonideality of vapor phase was corrected by Virial and Hayden-O′Connell equations.Considering the non-ideal behavior of the liquid phase,the NRTL and UNIQUAC models were employed to account for nonidealities in the liquid phase.The data regression option was used with a generalized least-squares method based on the maximum likelihood principle.The results show that the NRTL-HOC model that describes binary vapor-liquid equilibrium for the water-acetic acid system is better than the UNIQUAC-HOC model,whereas the UNIQUAC-HOC model is more effective to describe the water-furfural and acetic acid-furfural binary systems.In addition,the UNIQUAC-HOC model presents a very good prediction to the phase equilibrium of the water-acetic acid-furfural ternary system at 101.33 kPa using the pertinent parameters of the binary systems,and the rectification process of water-acetic acid-furfural ternary system was simulated with the residue curve maps of the ternary system.The results indicate that the binary interaction parameters obtained are accurate and reliable.The residue curve maps are important for the design and operation of heterogeneous azeotrope rectification process of water-acetic acid-furfural ternary system.