(4a) Process Intensification of Combined Carbon Capture and Utilization Using Multi-Functional Materials and Catalysts

As atmospheric CO₂ concentrations continue to reach historically high levels (417 ppm as of June 2021) and as predictions forecast the prolonged use of carbon-emitting fossil fuel energy, the development and commercialization of carbon management technologies are necessary to mitigate the negative effects of associated climate change. Among the suite of carbon management technologies, carbon capture and utilization (CCU) is especially attractive. Converting CO₂ into valuable chemicals (such as fuel) provides a stream of revenue that can offset the cost of capture, making this a more viable process than carbon capture and storage (CCS). Additionally, fuels synthesized with CO₂ from direct air capture (DAC) (and necessarily blue/green H₂) make for more sustainable alternatives to fossil fuels.

One major challenge present in CCU technologies is the energy and cost intensive compression and transportation of CO₂ after capture for conversion at a remote facility. To this end, multi-functional materials (such as dual function materials, DFM, as known in literature) offer a solution to intensify the CCU process by allowing capture and conversion to occur using just one material in a single reactor. Current state-of-the-art DFM achieves efficient DAC and point-source capture of CO₂ with subsequent catalytic conversion to methane (renewable natural gas, RNG). While RNG is an excellent transition fuel, other carbonaceous synthetic fuels will be required for markets that are harder to decarbonize (such as heavy-duty transportation and chemical production) as renewable electricity becomes more accessible. This reality motivates my research interest in designing multi-functional materials that allow for combined CO₂ capture and catalytic conversion to higher-value C1 precursors for carbonaceous fuels and commodities.

To achieve this, there will be three main objectives: (1) Optimization of sorbent+catalyst blends that allow for cyclic capture and catalytic conversion to target C1 precursors such as methanol, syngas, and methane. (2) Reactor studies to establish feasibility of cyclic operation and materials’ stability as well as feasibility of intensifying process by adding downstream catalysts for further upgrading (i.e. methane utilization, Fischer-Tropsch products from syngas, olefins from methanol). (3) In-situ and operando spectroscopic characterization for fundamental understanding of capture and reaction mechanisms as well as changes in surface structure and composition.

PhD Research (Columbia University, Advised by Prof. Robert Farrauto)

Thesis: Dual function materials (DFM) for combined CO₂ capture and catalytic conversion: point source and direct air capture

My doctoral work focused on testing a dual function material (DFM) for aging stability and adapting the technology to DAC conditions for further commercialization. The DFM was pioneered by our group to reduce the energy and cost requirements for typical carbon capture and utilization schemes. It is made up of a dispersed alkaline sorbent and catalytic metal both dispersed on a high surface area Al₂O₃ carrier. The adsorbent first captures CO₂ (from power plant exhausts or directly from ambient air) and once waste or renewable H₂ is introduced in a second step, the catalyst (i.e. Ru and/or Ni) facilitates conversion to methane.

Under simulated power plant exhaust conditions, DFM with low Ru loading (<1%) was cycled long-term to characterize its stability and identify any possible mode of deactivation. These tests showed that Ru loading plays a critical role in the stability of the material. I also led feasibility studies, in collaboration with engineering company Susteon, to adapt DFMs for DAC and subsequent catalytic methanation by investigating the effects of process parameters (i.e. temperature, flow rate, feed gas composition) on their performance and kinetics.

Teaching Interests

Teaching is the primary reason for my pursuit of an academic career. I believe in teaching engineering fundamentals in an applicable way that prepares students for situations beyond their academic career. My instruction promotes community learning and contextualization, which train students to work collaboratively and to foster an understanding of the broader implications of their work. A major learning outcome of my courses is effective science communication, which is a skill required in the cooperative and public-reaching settings chemical/environmental engineers occupy in both industry and research environments. During my Ph.D. I was a teaching assistant in several classes, which included grading and designing homework assignments and exams, giving technical lectures and holding problem-solving session, and holding office hours. Most recently, I co-instructed a project-based design course for chemical and environmental engineering undergraduates, titled “Sustainable Cities”. Students participated in a 6-week project to redesign a portion of a city based on design prompts taken from the C40 network “Students Reinventing Cities” design challenge.

I am comfortable and willing to teach any undergraduate chemical engineering course, but am particularly interested in teaching foundational undergraduate courses such as mass and energy balances and kinetics/reaction engineering as well as more advanced graduate kinetics and catalysis courses. I also value more hands-on and applied courses such as unit operations lab or senior design. Beyond the established curriculum, I am interested in designing elective courses in industrial and environmental heterogeneous catalysis, CO₂ management, and alternative energy systems.

Beyond practical teaching, I have been engaged in active pedagogical conversations such as reevaluating grading, addressing academic integrity (especially in the context of online learning), and fostering inclusive and diverse classrooms the last couple of years in my Ph.D. career. I look forward to continuing these discussions at my future institution and putting what I will continue to learn into practice so as to graduate engineers that can work collaboratively, remain self-aware, and effectively communicate their efforts in designing a better world.