(4an) Advancing Sustainability: Separation Innovations for Net Zero Emissions

The significant parts of the world's energy supplied to the industry are used for separation processes, including seawater desalination, hydrogen production from natural gas, and pharmaceutical product refinement through extensive separation strategies before market release. As the world advances toward net-zero emissions and sustainable development, innovative and low-carbon footprint separation processes are essential. Membrane technology is pivotal due to its advantages over other separation methods. It has been successfully implemented in seawater desalination, petroleum fractionation, natural gas dehydration, purification, and the production of pure components in the pharmaceutical and health sectors.

The integration of membrane processes into existing industrial challenges depends on membrane permeance and selectivity. Polymeric membranes hold significant potential in this sector due to their flexibility and processibility. Most of these materials require solvents to create polymer dopes for fabrication into flat sheets or specialized hollow fibers, which offer a higher surface-to-volume ratio and packing density. The solvent-non-solvent-induced phase separation process introduces a porous structure during membrane fabrication, determining its final properties and applications. Furthermore, critical applications such as gas separation and purification can benefit from varying membrane porosity through interfacial polymerization, opening new horizons for membrane applicability. To fabricate membranes, the polymer is initially dissolved in an appropriate solvent. The resulting solution is then cast or spun into flat sheets or hollow fibers. The formation of pores in these membranes largely depends on the type of solvent used, the polymer composition, the set parameters, and any additives included. Although the membrane market was established a decade ago, it faces potential impacts from new regulations aimed at achieving net-zero emissions. Regulations on fluorinated polymers and traditional solvents like 1-Methyl-2-pyrrolidone and dimethylformamide present significant challenges to the membrane industry. The adoption of alternative solvents is a crucial strategy in membrane research, making this an opportune time for innovation.

My master's and doctoral studies in Membrane Engineering, funded by European Union Erasmus Mundus scholarships, set me apart. I received training in some of the world's best membrane labs, including the Institute European des Membranes in Montpellier, the University of Twente in the Netherlands, the University of Zaragoza in Spain, and the University of Nova de Lisboa in Portugal. This training encompassed material science, process optimization, simulations, and membrane technology, equipping me with enthusiasm and solutions for separation challenges. After earning my doctorate, I focused on membrane processes as alternatives to energy-intensive separation methods. During my first postdoctoral studies in the Membrane Science and Technology Center (MAST) at the University of Arkansas, Fayetteville, USA, I worked on developing metal-organic frameworks (MOFs) that show promise for azeotropic separation. Using a simple reduction technique on copper-based MOFs, I achieved the separation of heptane and toluene through cationic π–π interaction between the reduced MOFs and the benzene ring in toluene.

Upon joining KAUST, I encountered more challenges in the advanced membranes and porous materials field. The kingdom was preparing for the G20 summit and its 2030 vision plans, which inspired me to write proposals for sustainable membrane production and to translate bench-scale results into prototypes. One major project I was involved in was the KAUST cooling initiative, aimed at developing an energy-efficient air conditioning system capable of saving over 30% of energy compared to current systems that use hydrofluorocarbons. Under the guidance of Prof. Suzana Nunes, a pioneer in membrane technology, my team developed energy-efficient dehumidification units using polymeric hollow fibers with a coefficient of performance ranging from 2.5 to 3.This project started in April 2019 and concluded in December 2022. The system operated continuously for over 18 months under harsh Arabian conditions with minimal performance decline. This success motivated us to propose a translational grant for a $1,000,000 project for further development. The proposal was accepted in 2021 and ran for over two years, focusing on developing hollow fiber and flat sheet modules for gas dehydration and interfacial polymerization towards a sustainable organic solvent nanofiltration process. This translational grant enabled our lab to acquire spinning, coating, and module-making instruments on a semi-industrial scale. The extensive initial training provided by the manufacturers and the training I offered to other lab personnel endowed me with unique skills. These semi-industrial operations for flat sheet and hollow fibers elevate our research, enabling us to develop advanced separation solutions to achieve net-zero emissions.

As we move towards greener membrane fabrication processes, I have previously worked on developing eco-friendly coatings for dehydration applications using ionic liquids. The prototype has been operational for over 12 months, achieving more than 90% efficiency in dehydrating the incoming stream. When assessing the ECO factor (a measure of greenness), our process was on the verge of being classified as green (an ECO factor above 75% is considered green). My focus is on deep eutectic solvents (DES), which are being explored as potential replacements for harmful solvents. The components of DES, such as natural menthol and raspberry ketones, are abundant in nature and pose no health or environmental hazards. We are using DES and polyetherimide to spin hollow fibers, achieving a greener process with an ECO factor exceeding 90% for gas separation applications. Our promising preliminary results encourage further exploration of DES based on natural solvents for fabricating membranes with polymers like polyimide, polyetherimide, and poly(ethylene terephthalate) (PET). This approach also opens the possibility of using recycled polymers. Our submitted proposal to the KAUST Innovation Grant, seeking $200,000, outlines the exploration of other non-fossil-based polymers, more sustainable fabrication processes, scaling up our findings, and conducting green metric analyses. Additionally, during cost-cutting strategies, it's essential to consider prototype design. Miniaturization efforts must ensure higher packing density in a small area, achievable with hollow fibers.

To advance my work, I will leverage my expertise in membrane technologies and focus my research on two key areas: Energy and Environment. Proper humidity levels are crucial for various applications: human comfort (40-60%), pharmaceutical industry (10%), lithium-ion batteries (1%), and space equipment. Air conditioning units, which consume about 10% of the energy in the U.S., play a major role in dehumidification but rely on hydrofluorocarbons, contributing to significant greenhouse gas emissions. Membrane technology offers a pivotal solution for dehumidification by operating under isothermal conditions, leading to substantial energy savings. Both flat sheets and hollow fibers provide effective solutions with highly porous support and thin selective layers, enhancing water sorption capacity. This includes using specialized block copolymers and greener polyphenols. Miniaturized setups can further reduce capital costs. As I work towards developing an industrial-scale prototype, it is essential to commercialize the bench-scale component. Collaborating with experts in mechanical and process engineering is necessary for building the prototype. Additionally, securing commitments from companies to provide the required space and infrastructure for testing the prototype is crucial.As we try to achieve greener economy, lithium-ion batteries play a critical role. Currently, only 2% of the lithium used in the USA and Canada is domestically sourced, with the remaining 98% imported from Australia, South America, and China. The USA ranks among the largest global users of lithium-based car batteries. To address the scarcity of domestically sourced lithium, exploring alternatives like extraction from seawater or brine generated in geothermal plants is crucial. Brine also contains essential elements such as nickel, graphite, and copper. Meeting the demand for approximately 4.5 million tons of lithium annually by 2100 to achieve net-zero emissions will require innovative approaches like nanofiltration. This method uses interfacial polymerization to create thin, selectively permeable membranes, crucial for recovering valuable metals from brine. Pilot-scale units will be pivotal in commercializing this technology.

Teaching Interests

I am deeply interested in teaching chemical engineering and materials science to both undergraduate and graduate students level. My background in chemical and materials science strongly supports this goal. I aim to introduce new course on sustainable separation and zero carbon emissions, addressing the challenges and strategies for development and implementation. This course should incorporate both technological and governmental perspectives, providing an overview of the difficulties involved and potential improvements. The goal is to encourage graduate students to think about green processes and contribute toward achieving zero emissions.

During my postdoctoral and scientist positions, I had the privilege of mentoring master's and doctoral students and Postdocs. I learned that students are eager to engage with these subjects but often need more foundational knowledge to generate ideas and participate in discussions. I believe it is my responsibility to equip them early with the knowledge needed to pursue research careers. Additionally, I want to emphasize wet lab training for undergraduate and graduate students, helping them consider research as a viable career option. During my postdoctoral studies in Arkansas, I had the opportunity to train some REU students. They were talented but unsure of what to do after their undergraduate studies and unfamiliar with how research laboratories operate. This experience ignited my passion for training more undergraduates from the beginning so that when they progress, they are well-prepared to make informed decisions with prior knowledge.