GOALI: Combining Discontinuous Molecular Dynamics and Chemical Process Simulation

J. Richard Elliott，阿克伦大学“GOALI：将不连续分子动力学与化学过程模拟相结合“分子建模将与化学过程模拟软件包相结合，为物理性质预测和关联提供完整、严格和准确的框架。化工过程模拟器正在成为工业化学知识的主要接口。PI最近发现微扰理论比以前认识到的要精确得多，特别是对于多原子分子。不连续分子动力学（DMD）模拟结合微扰理论和维里展开，为分子建模的各个方面提供了高度杠杆化的计算工作的基础。现有的DMD程序将在低成本微处理器上以合理的速度运行所需的最小数量的模拟。所得的链段势模型将作为分子尺度的基团贡献，类似于传统的工程基团贡献模型。PI实现了计算输运性质的方法，如粘度，热导率和扩散率，以及他过去计算的平衡和共存性质。这项研究将使用参考流体的基本模拟数据的预列表，在以后的时间进行高效率的详细扰动计算。通过与实验值的大型数据库进行比较，与现有的半经验方法相比，将评估这种基本方法的准确性。PI将确定扰动视角在估计传输属性以及平衡属性时可以提供类似杠杆作用的程度。这项工作将与阿克伦大学和ChemStations，Inc.的技术人员合作进行。由此产生的产品将是一个互联网网站，客户可以访问零成本的前面和相对较低的每小时费用根据强度的服务器端计算要求。所提供的服务将包括运输和平衡性质的分子建模，如蒸汽压，活性，水溶性，辛醇分配系数，粘度，以及通过共同的分子模型从其他性质的测量中推断一种性质的能力。在选项范围内将是一个全面的收集半经验的方法与估计的准确性，每一个属性。该项目的范围包括半经验模型和基于分子的模型对大约1800种化合物的数据库的准确性进行全面评估。还将包括流程和工艺模拟的基础上，快捷单元操作模型。工艺资本和生产成本对估计物理性质的敏感性将是一个菜单选项。捷径模式将作为直接在网络环境中进行严格过程模拟的先驱，拟议研究的更广泛影响将包括综合研究和教育以及综合多样性。作为化学工程热力学领先文本的合著者，PI已经整合了以前NSF支持的相关结果。PI现在参与教学化学工艺设计，这门课程应该发展到包括需要广泛分子洞察力的产品设计。在短期内，物理性质估计在传统设计中的作用可以用作引入许多基于分子的设计工具的跳板，同时将应用程序引导到粘度和挥发性等物理性质。这项建议的前身目前正在支助一名女全日制研究生和一名男女交替担任助教和研究助教。PI希望在整个项目的剩余时间内保持这种平衡。

J. Richard Elliott, University of Akron"GOALI: Combining Discontinuous Molecular Dynamics and Chemical Process Simulation"Molecular modeling will be integrated with a chemical process simulation package to provide a complete, rigorous, and accurate framework for physical property prediction and correlation. Chemical process simulators are becoming the primary interface for industrial chemical knowledge. The PI has recently discovered that perturbation theory is much more accurate than previously appreciated, especially for polyatomic molecules. Discontinuous molecular dynamics (DMD) simulation combines with perturbation theory and the virial expansion to provide a basis for highly leveraged computational effort in all aspects of molecular modeling. An existing DMD program will run the minimal number of simulations necessary with reasonable speed on low-cost microprocessors. The resulting segmental potential models will act as molecular scale group contributions, analogous to conventional engineering group contribution models. The PI implement methods of calculating transport properties like viscosity, thermal conductivity, and diffusivity in addition to the equilibrium and coexistence properties that he has computed in the past. This research will use pre-tabulation of the essential simulation data for reference fluids, with detailed perturbation calculations to be performed with high efficiency at later times. The accuracy of this fundamental methodology will be evaluated in comparison with existing semi-empirical methods by comparison to a large database of experimental values. The PI will establish the degree to which the perturbation perspective can provide similar leveraging in the estimation of transport properties, as well as equilibrium properties. This work will be performed in collaboration with The University of Akron and the technical staff from ChemStations, Inc. The resulting product will be an internet site which clients can access for zero cost up front and relatively low hourly fees varying according to the intensity of the server side computation requested. Services provided will include molecular modeling of transport and equilibrium properties like vapor pressure, activity, water solubility, octanol partition coefficients, viscosity, and the ability to infer knowledge about one property from measurements of other properties through a common molecular model. Within the range of options will be a comprehensive collection of semi-empirical methods with estimates of the accuracy of each property. The scope of this project includes a thorough evaluation of the accuracy of semi-empirical models and the molecular based models against a database of approximately 1800 compounds. Also included will be flowsheeting and process simulation based on shortcut unit operation models. The sensitivity of the process capital and production costs to the estimated physical properties will be a menu option. The shortcut model will serve as a precursor for rigorous process simulation directly within a web-based environment.The broader impacts of the proposed research will include integrated research and education and integrated diversity. As the co-author of a leading text on Chemical Engineering Thermodynamics, the PI has already integrated results of related previous NSF support. The PI is now involved in teaching Chemical Process Design, a course that should evolve to include product design requiring extensive molecular insight. In the near term, the role of physical property estimation in traditional design can be used as a springboard for introducing many of the tools of molecular based design while directing applications to physical properties like viscosity and volatility. The predecessor to this proposal is currently supporting one female graduate student full-time and one male and one female who are alternating between teaching and research assistantships. The PI expects to maintain this balance throughout the remainder of the project.