Molecular Modeling of Environmentally Benign Solute-Solvent Systems

Colorado School Of Mines, Golden CO

Investigators

Abstract

McCabe, Clare M Colorado School of Mines "Molecular Modeling of Environmentally Benign Solute-Solvent Systems" As current solvents have become banned or discouraged from use, solvent replacement - i.e., replacing a hazardous and/or carcinogenic solvent in reaction, separation, and dissolution/cleaning operations with an environmentally acceptable one - is one of the key methods for turning an existing process into an environmentally benign one. In the pursuit of environmentally benign processes, the application of neoteric solvents, including supercritical carbon dioxide and ionic liquids, show enormous potential for industrial application and it is these fluids that we focus our proposed research on. The future focus on the design of environmentally benign processes - whether achieved by solvent replacement or by the development of fundamentally new environmentally benign chemical processes - parallels a crucial emerging need for an accurate comprehensive methodology for calculating the thermodynamic properties (especially phase equilibria) of mixtures containing novel solvents at operating conditions relevant to the application of these solvents. For the wide range of conditions and systems expected to be encountered in environmentally benign processes, the method for predicting thermodynamic properties (including phase equilibria) should be robust, rapid and versatile. The PI proposes to address this need by undertaking a sustained research program whose goal is to apply molecular theory and simulation to the development, modification and deployment of a predictive molecular-based methodology based on the molecular-level statistical associating fluid theory (SAFT) integrated with other molecular modeling techniques. The PI believes that the resulting methodology will be the modeling platform of choice for the design of environmentally benign processes. A combination of theoretical developments to enhance the predictive capabilities of SAFT in key areas relevant to EB systems - ab initio methods to facilitate potential model development and testing, and computer simulations to provide both a rigorous test of the theory and aid in potential model development - will enable a true predictive platform to be realized. In pursuit of this goal two broad application areas relevant to EB processes will be the long-term focus of the PI's research activities. The first area is the accurate modeling of polar polymer-solvent, and co-polymer-solvent systems through the incorporation of the underlying molecular interactions in these systems into the theoretical approach. Secondly the PI will concentrate efforts on developing much need models and molecular theory for describing the thermodynamic properties of ionic liquids and their mixtures. In this proposal, the PI will focus on the first of these two areas. The proposed research is the first step towards achieving the PI's long-term goals. The lessons learned from this project will facilitate similar advances in other application areas. Strong ties with industry and experimental groups will be maintained throughout the project which will provide students with the opportunity to experience both the theoretical and experimental sides of research, a means to validate our methods and models, and provide guidance towards key problems faced by industry in adopting environmentally benign alternatives to existing, and new processes. The results of this research will be incorporated into an active-learning-based molecular modeling course, under development by the PI. The course will be suitable for both graduates and undergraduate students, which will ensure that students at CSM will be exposed to and participate in the frontiers of molecular modeling and the molecular thermodynamics of EB processes. Undergraduate participation in the project will be strongly encouraged through research projects and women and minorities actively recruited through the PI's participation in the Science Related Degrees project at CSM, which offers mentored research projects for undergraduate students in these underrepresented groups.