Brennecke Group Presents: “Multi-Scale Simulations Relevant for the Energy and Materials Sectors” by Alberto Striolo

Host: Dr. Joan Brennecke

ABSTRACT:

Many academic computational studies are conducted on homogeneous, atomically flat idealized systems. However, most practical systems show surfaces that are not chemically homogeneous, nor atomically flat. Can we extrapolate our understanding developed on idealized substrates to imperfect, real ones? How can we adapt the simulation strategies to take into consideration the main aspects of realistic systems? What are such ‘main’ aspects? In this presentation some examples from our recent research will be presented, together with possible applications in the energy sector.

We will start from atomistic molecular dynamics simulations conducted for identifying possible mechanisms by which hydrocarbons can be dislocated from sub-surface formations. When conducted on idealized systems such simulations can provide information that is often qualitatively, and sometimes quantitatively in agreement with experiments. Although these results are encouraging, practical applications require quantifying the effect of heterogeneous properties on macroscopic observables. For example, fluid transport through shale rocks is difficult to predict because the pores are narrow, the pore connectivity is low, and the rocks are very heterogeneous. In these conditions, it is known that phenomenological equations such as the Darcy’s law, as well as analytical models such as the effective medium theory can fail. We have applied a stochastic approach, based on the kinetic Monte Carlo algorithm, which has proven valuable both in up-scaling the atomistic molecular dynamics simulation results and in attempting to quantify rock permeability based on materials characterization.

The second example is related to the flow assurance problem: clathrate hydrates can form in oil & gas pipelines, blocking and sometimes rupturing the pipes. We studied molecularly thin films of surfactants adsorbed on methane hydrates. In some cases, we observed a ‘frozen interface’. Interestingly, the surfactants that showed such structure are effective in preventing the formation of hydrate plugs. Did we identify a property useful to discover new surfactants for applications?

The third example is further from a direct application, and it concerns the use of surfactants to change surface properties. This could be relevant in sub-surface operations as well as for mineral processing. We employed coarse-grained simulations to predict the morphology of self-assembled surfactant aggregates on structured surfaces. The results clearly show that we cannot extrapolate our understanding of surfactant behavior on homogeneous surfaces to predict surfactants behavior on realistic substrates. Although direct experimental evidence is missing, indirect evidence abounds.

Are these results just nice pictures, or could they help trigger innovations, e.g., in materials synthesis?

BIOGRAPHY:

Professor Alberto Striolo is a Chemical Engineer by training. He received his Ph.D., in Chemical Engineering, from the University of Padova, Italy, in 2002. He conducted his graduate studies under the supervision of Prof. Alberto Bertucco, in Padova, and Prof. John Prausnitz, at the University of California, Berkeley. He was a post-doctoral researcher in the groups of Prof. Keith Gubbins, North Carolina State University, and Prof. Peter Cummings, Vanderbilt University. In 2005 he joined the University of Oklahoma, USA, as an Assistant Professor in the School of Chemical, Biological and Materials Engineering. Tenured and promoted to Associate Professor, he was awarded the Regents Award for Superior Research and Creative Activity, the Presidential Professorship, and the Junior Faculty Research Program Award. He spent sabbaticals at Princeton University, NJ, and at Lawrence Berkeley National Laboratory, CA. In 2013 he joined University College London, where he is Professor of Molecular Thermodynamics, Deputy Head of Department (Enterprise), and where he introduced, and now directs the post-graduate-taught masters program in ‘Global Management of Natural Resources’.

Prof. Striolo’s research is focused on quantifying how interfaces affect the properties of fluids. While this research is exquisitely fundamental, Prof. Striolo and his group thrive to uncover the structure-function relations that connect these molecular-level observations to large-scale applications of societal relevance.

Prof. Striolo is author or co-author of over 140 peer-reviewed journal articles. According to Google Scholar, his papers have been cited over 5,400 times and his h-index is 44. Prof. Striolo coordinates two Horizon 2020 consortia, both supported by the European Commission: ShaleXenvironmenT, which started in 2015, and Science4CleanEnergy, which started in September, 2017. A Chartered member of the IChemE, in 2017 Prof. Striolo was elected Fellow of the Royal Society of Chemistry and Fellow of the Institute of Physics.