Fall 2025 Seminar Series

September 17, 2025

Selective Catalytic Transformations of Polyolefins

Aaron Sadow, Ames National Lab and Department of Chemistry, Iowa State University

4:00 p.m., Larrañaga Engineering Auditorium

Abstract: We are investigating catalytic materials and methods that regulate the cleavage of C–H bonds or C–C bonds in polyolefins, to introduce functional groups at selected positions or to create narrow distributions of shorter, partially deconstructed chains. This approach involves the design and synthesis of 3D porous inorganic metal oxide architectures which contain catalytic sites in well-defined positions in the material, along with spectroscopic investigations and theoretical models of polymer adsorption and translocation in the pores. In parallel, we are developing catalytic sites and reactions that break C–C and C–H bonds in aliphatic hydrocarbon polymers. As these catalytic sites are incorporated into 3D architectures and studied in polyolefin deconstruction reactions, our team is developing theoretical, kinetic models and in situ spectroscopic methods for studying the ‘macromolecular’ mechanisms that influence the average chain lengths of products and the dispersity of product distributions.

Such approaches using micro or mesoporous materials can lead to processive catalysis, whereby a polymer chain is adsorbed into the pores of the inorganic oxide and is successively cleaved into smaller fragments without release of the ever-shortening polymer chain. Nanoparticles, responsible for C-C cleavage, localized in the pores at uniform distances from the pore mouth, then cleave polyolefin chains into semi-regular smaller chain lengths. We will present our studies of these architectures and catalytic reactions in the selective deconstruction of polyolefins.

Bio: Currently David C. Henderson Chair of Chemistry and Director of the Institute for Cooperative Upcycling of Plastics (iCOUP), a DOE-BES funded EFRC.

September 10, 2025

Understanding the Flow Behavior of Complex Non-Newtonian Fluids in Curved (Coiled) Tubing

Subhash Shah

4:00 p.m., Larrañaga Engineering Auditorium

Abstract: Coiled Tubing (CT) services are one of the fastest growing oilfield technologies. CT has been widely used in well drilling, wellbore cleanouts, stimulation, logging, perforation, and many other well interventions. The success of a treatment profoundly depends on the proper selection of fluids and their properties. Even though fluids are widely used in all CT services, little attention has been paid to thoroughly evaluate and understand the behavior of complex fluids. In many instances the cause of an unsuccessful treatment is the failure of our understanding the true behavior of fluid.

Fluid flow in CT is significantly different than straight pipe because of coiled tubing curvature and secondary flows it generates. Fluids in CT experience a different level of shear and turbulent intensity. It has been shown that fluids in CT exhibit significantly higher frictional pressure losses (up to 200%), less drag reduction, severe pipe erosion (with slurries), greater fluid degradation due to shear, etc. when compared to straight pipe. These characteristics are dependent on fluid type and concentration, CT size and dimensions, operating parameters such as temperature and pressure, shear rates, pH, salinity, density, and pipe roughness.

The lecture will highlight research findings with several fluids and present appropriate correlations for their proper hydraulics predictions. Case studies of wells fractured using CT will be provided to demonstrate the application of the correlations used in hydraulics calculations.

Bio: Dr. Subhash Shah, Ph.D. is an Emeritus Professor in the Mewbourne School of Petroleum and Geological Engineering at the University of Oklahoma. He retired from OU after serving 22 years as Stephenson Chair Professor and as the Director of OU’s Well Construction Technology Center. He also served for 6 years as Shell Chair Professor and Chief Mentor in the School of Petroleum Technology, Pandit Deendayal Petroleum University, India. Dr. Shah is one of the world leaders in hydraulic fracturing, horizontal/multilateral well completions/stimulation, and coiled tubing technology. He has a distinguished career in the oil and gas industry that spans over 48 years: 18 years with Halliburton as “Distinguished Technical Member” and 30 years in academia/consultant. He is recognized as the Society of Petroleum Engineers “Distinguished Member” and as “Distinguished Lecturer.” He is a recipient of “SPE Completions Optimization and Technology” award. He is a “Fellow” of the American Institute of Chemical Engineers. Dr. Shah is a “Distinguished Alumni” of the College of Engineering and “Alumni Emeritus” of The University of New Mexico.

Dr. Shah holds a B.E. from M.S. University of Baroda, India, and M.S. and Ph.D. from University of New Mexico, USA, all in chemical engineering. His research has resulted in more than 300 technical publications in over 35 international journals. He has written five chapters in technical books and is a co-author of two books.

September 3, 2025

Solar Thermal Energy Storage Technologies for the 21st Century

Kenneth Armijo, Sandia National Laboratories

4:00 p.m., Larrañaga Engineering Auditorium

Abstract: Concentrating solar power (CSP) systems generate solar energy by using mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a small area. Thermal Energy Storage (TES) systems, which use molten salt, can be used to enhance utilization efficiencies and performance, particularly at high temperatures. The primary advantage of using TES over photovoltaics (PV) and batteries is that as a thermal technology, running a conventional thermal power block, a CSP or Nuclear Energy (NE), small modular reactor (SMR) system can store the heat of solar energy in molten salts or other next generation media, which enables these plants to continue to generate electricity whenever it is needed, whether day or night. TES enhances dispatchability form solar or NE to be a competing form of base-load power with other current energy processes that can have a negative impact on the environment. This technology is also particularly valuable in places where there is already a high penetration of PV because an evening peak is being exacerbated as PV ramps down at sunset. Production potential of solar energy in southwestern states stands apart from the rest of the U.S. where states like New Mexico have the incredible potential for producing solar energy, in addition to other commercial products such as ammonia, hydrogen and fresh water from desalination with this resource. In this presentation, Dr. Kenneth Armijo, will discuss the processes and importance of producing energy from solar and nuclear energy and how TES stands to significantly impact base-load energy production for the U.S. and the world.

Bio: Dr. Kenneth Armijo is a systems engineering staff member and Test Director who leads molten salt, molten alkali metals & controls R&D at the National Solar Thermal Test Facility (NSTTF). His research interests are in alternative energy technologies and sustainability, as they pertain to scientific and technological innovation, business and policy. Dr. Armijo holds a Ph.D. in Mechanical Engineering from the University of California, Berkeley with minors in Energy and Resources, and business credentials in Management of Technology from Berkeley's Haas School of Business. Presently, Dr. Armijo’s research in concentrating solar power (CSP) consists of system design for high-temperature (>720 °C) thermodynamic and commercial R&D systems, employing ternary chloride molten salts and alkali metals (sodium) as the heat transfer fluid. His research has also consisted of falling particles for centralized concentrating solar receivers. He also leads research activities pertaining to solar Stirling Engine applications as well as for solar reactor R&D and high-flux materials characterization. Dr. Armijo also serves as a lead Test Director for high-temperature materials research for power towers and solar furnace investigations.

August 27, 2025

Chemical Engineering as the Connecting Piece: Examples from Nuclear and Agriculture

Catherine Brewer, Professor and Associate Academic Department Head, Chemical & Materials Engineering, New Mexico State University

4:00 p.m., Larrañaga Engineering Auditorium

Abstract: The NuChemE Pipeline project, short for “Evaluating New Materials and Processes for Radioactive Tank Waste Processing: Workforce Development in f-Element Chemistry, Nuclear Chemical Engineering, and Supply Chain Management” is a 3-year, multi-institution grant funded by the Department of Energy’s Office of Environmental Management (DOE-EM). Dr. Brewer will introduce how gadolinium (Gd) can be sourced domestically from coal fly ash and used to stabilize high-level waste in clean-up efforts at Manhattan Project/Cold War uranium and plutonium facilities. The grant includes interdisciplinary research and capacity building for f-element (lanthanide and actinide) separations and supply chain management to support radioactive tank waste management at the Savannah River Site. The education components at NMSU include expansion of the Nuclear Chemical Engineering minor, new courses: CHEM 473 Radiochemistry and CHME 370V Discovery & Uses of Radioactive Materials, and a summer hands-on lab training and travel program.

On the agriculture side, chemical engineering represents the processing part of making value-added products from underutilized biomass. Dr. Brewer will give examples of how her group studies mosquito repellents from plant extracts; chemicals and fibers from hemp wastes; and renewable energy and biochars from forestry biomass.

Bio: Before joining NMSU in 2013, Catherine “Catie” Brewer completed a B.S. in Chemistry at Indiana U. of Pennsylvania, a Ph.D. in Chemical Engineering and Biorenewable Resources & Technology at Iowa State University, and a postdoc at Rice University. She is currently a John Kaichiro & Tome Miyaguchi Nakayama Endowed Professor in Engineering for interdisciplinary research and education. Dr. Brewer served as associate editor for two years and co-editor-in-chief for two years for Renewable & Sustainable Energy Reviews. She has also served as community program chair and other leadership roles in the American Society of Agricultural & Biological Engineers (ASABE). Her research interests include biomass utilization, biochar, soil and water remediation, renewable fuels, sustainable agriculture, and uses of radioisotopes. She teaches introduction to chemical engineering calculations, senior capstone design, and electives related to brewing and nuclear chemical engineering.