Julia Valla, Assistant Professor at the Chemical and Biomolecular Environmental Department of the University of Connecticut received a CAREER Award from the National Science Foundation to research the removal of sulfur molecules from transportation fuels. The award for $500,000 will revolutionize sulfur removal using adsorption in ion exchanged zeolites.  

Valla began working on sulfur removal as a Ph.D student. By the end of the five years of her CAREER project, Valla aims to develop novel filters that can efficiently and economically remove the sulfur molecules from fuels.  

“The CAREER award was very important for me because I can continue research what I started 18 years ago. It is important that I can evolve on findings that I have already created,” Valla said.  

She explained that sulfur molecules found in transportation fuel are toxic. They have adverse effects on the environment and subsequently on humans. Sulfur oxides which can be emitted from cars can cause acid rain, which causes environmental pollution.  

“The reason why I keep pushing this effort is because the sulfur molecules, this impurity has very detrimental effects on the environment and consequently on humans, and on our lives,” Valla said, “The fossil fuels, whether we like it or not, is still our main source of energy. We do need to, of course, be looking to renewable energy resources and put our efforts into research on renewable energy. However, it’s also important to do something about the fossil fuels that we use now.” 

Currently, sulfur is removed from fuels in a process called hydrodesulfurization in the refinery. Valla said the process requires severe conditions and the use of hydrogen makes it an expensive process. Her research will focus on utilizing ion-exchanged zeolites, specifically zeolite Y, which is a porous mineral. The zeolites will be tested for their selectivity in binding to sulfur and not to other molecules in the fuel, and how well they adsorb the sulfur to reach the mandatory government standards.  

The zeolites can be regenerated and reused, which makes them a more affordable alternative to hydrodesulfurization.  

“The major challenge is to create a sorbent that has high selectivity in sulfur molecules, meaning that it will adsorb the sulfur molecules, leaving the other molecules in the fuel intact, ” Valla said.  

This project will be an iterative process that uses experiments and models to “create fundamental knowledge on how the properties of metals and bimetals-exchanged Y zeolites, such as pore size, metals properties, location, oxidation state and interaction, affect the adsorption process.”  

Valla will be working to optimize a zeolite so that it can be extremely selective in finding sulfur molecules and then adsorb them.  

She explained that this research can lead to a product that can have significant impact on the environment and consequently humans. 

“As the regulations become more strict, the refineries need to use more severe and expensive conditions in the hydrodesulfurization process, so if we find something now that’s more economical and visible that will save us a lot of lives, and environmental problems,” Valla said.  

Written by: By Sarah Al-Arshani 

Photography by: Thomas Hurlbut