Optimized multiscale/multiphenomena modeling of membrane distillation process for water treatment

Lead University: Carnegie Mellon University
PI: Lorenz Biegler, Chemical Engineering
Co-PIs: Meagan S. Mauter, Chemical Engineering/Engineering and Public Policy and Myung S. Jhon, Chemical Engineering

In this proposal, we develop a novel multiscale simulation methodology for nanotechnology convergence in the sustainable energy-water nexus. Water purification via membrane distillation (MD) process is chosen as benchmark example, which has great potential to be used in a broad range of applications including power, petrochemicals, oil & gas, as well as salt water distillation. The MD performance will be rigorously simulated via seamlessly integrating atomistic/molecular/meso/macro time and length scales and hybridizing with optimization methodologies. We will adopt a novel middle-out approach in the multiscale modeling by focusing on computationally efficient mesoscale lattice Boltzmann method (LBM) as the centerpiece. LBM will accurately simulate the multiphenomena occurring at microscale for the porous geometries in the membrane including phase change, Knudsen/molecular diffusion, and micro/nano scale heat transfer. Unlike conventional models that simplify the porous structure, leading to overestimates of the performance, our novel computational contribution based on LBM scheme provides accurate design criteria for MD material selection including porosity, thermal conductivity & diffusivity, pore size, and thickness. Furthermore, by combining optimization tools with a complete multiscale approach, we can provide molecular design criteria of the key parameters such as the omniphobicity of the MD material that allows maximum flux in the membrane. In addition, we can use inverse approaches for prediction of new molecularly architectured materials which actively prevent fouling and scaling and can be used in a wide range of water chemistries, as well as temperatures and pressures. The resulting software will provide a ground-breaking and versatile design tool that can reduce immense time and monetary resources spent in experimentally identifying the optimal materials at the molecular level. The success of this benchmark example will provide valuable input to the rapidly growing wastewater treatment industry in Pennsylvania and can also be applied to other nanotechnology convergent areas including energy and sustainability.