Butadiene Purification Using Polar Solvents. Analysis of Solution Nonideality Using Data and Estimation Methods

• Published in: Industrial & engineering chemistry research 2008-08, Vol.47 (15), p.4996-5004
• Main Authors: Mathias, Paul M, Richard Elliott, J, Klamt, Andreas
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical engineering; Exact sciences and technology
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie070774p

The classical problem of 1,3-butadiene recovery from steam cracker C4 hydrocarbons is reconsidered using modern tools of quantum mechanics and molecular simulation. The effectiveness of N,N-dimethylformamide (DMF) and acetonitrile (ACN) to act as extractive-distillation solvents is explored with an emphasis on the predictive capability of various models. The quantum mechanical method of interest is the COSMO-RS method. The chosen molecular simulation method is the SPEADMD model. These methods are compared to conventional methods such as UNIFAC and “thermodynamic intuition”. The COSMO-RS method is found to predict the trends of infinite-dilution activity coefficients quantitatively, but requires a systematic empirical correction to provide accuracy comparable to UNIFAC. It is noted that the COSMO-RS method has a special capability to predict subtle trends. The SPEADMD model is found to provide unique qualitative insights, but requires empirical refinement of the interaction-potential models that is similar to the regression of UNIFAC parameters. This work is intended to serve as an objective framework to evaluate toolstraditional and modernto predict solution nonideality.