Abhimanyu Raj Shekhar is a Bilsland Fellow and fifth-year PhD candidate in Purdue’s Department of Agricultural & Biological Engineering.

Industrial waste, fragile supply chains and decarbonization targets rarely arrive one at a time. In a macroeconomic supply chain, choices made today inside one industry can cascade across suppliers, recyclers and regulators tomorrow. Traditional tools often treat these pieces in isolation, leaving decision makers without a unified view of how to design for true circularity. This fragmentation obscures feedback, delays investment and dulls accountability across value chains.

Abhimanyu Raj Shekhar, a Bilsland Fellow and fifth-year PhD candidate in Purdue’s Department of Agricultural & Biological Engineering, is tackling those challenges together. Working at the intersection of process systems engineering, industrial ecology and data-driven sustainability science, he builds economy-wide material-flow models and hybrid mechanistic-ML surrogate pipelines to redesign industrial networks for circularity. His current efforts link plant-level simulation, reverse-logistics design and market dynamics with optimization to drive circularity in the manufacturing ecosystem. Shekhar attributes Purdue’s cross-functional collaborative ecosystem and industry-facing opportunities as catalysts for team-based projects that link unit operations to enterprise decisions and policy levers. His north star is pragmatic impact: translating rigorous data and models into field-tested playbooks that prevent waste, improve supply chain resilience and make circular manufacturing tangible at scale, making it the “big picture” that drives his research.

What is your research focus, what investigative avenues are you pursuing?

Pharmaceutical drugs move through complex supply chain networks, where process decisions ripple across suppliers, waste handlers and policy, yet most state-of-the-art frameworks split plant process-specific physics from economy-wide material flows.  My research focuses on building a multiscale modeling approach that makes those links explicit: unit-operation and plant-level simulations inform bottom-up Physical Input–Output representations of the pharmaceutical supply chain, so materials, energy and by-products can be traced consistently from process to network. With this foundation, I work on advancing two avenues: refining economy wide material flow analysis using bottom-up physical input-output accounts derived from mechanistic physics-informed models to reveal feasible circular exchanges and hidden bottlenecks; and bringing dynamics into the picture, where “system-identified” surrogate models and optimization effectively capture time-varying exchanges and feedback. I envision that this work will close the gap between plant-scale physics and economy-wide decisions, delivering decision-ready circular designs that cut waste and emissions and sharpen our understanding of what truly drives circularity in the pharmaceutical supply chains.

What spurred your interest in this particular topic and line of research?

Growing up in Dhanbad, also known as the “Coal Capital of India,” it was difficult to ignore the haze, tailings and water discoloration that shadowed everyday life. My earliest inspiration came from my dad, who is also a sustainability professional working closely with the federal government of India. Often our dinner table conversations wandered from the Kyoto and Montreal Protocol to why policies succeed or stall on the ground. That lens met its toolkit during my chemical engineering undergraduate years, where mass balances and reactor design revealed how small process choices scale into systemwide footprints. The connection felt very coherent, where rigorous engineering could serve communities like mine. As the global landscape accelerates with resource shocks, climate risks and circular-economy mandates, I committed to sustainability engineering to develop pragmatic models that carry goals into practice.

Why did you choose Purdue to continue your studies as a graduate student?

As I was wrapping up my undergraduate degree in chemical engineering in 2020-2021, right at the heart of COVID, I was engaged in the research culture at the Vilas Pol Energy Research (ViPER) group at Purdue’s Davidson School of Chemical Engineering. I worked with Prof. Vilas Pol studying the fate of dead lithium-ion batteries and engaging in discussions with graduate students in his group. This was my first exposure to the research and mentorship culture that Purdue offered. I came to Purdue in 2021 looking for depth, mentorship and room to build ambitious work. The Department of Agricultural and Biological Engineering offered a rare and new direct-to-PhD path and a program that ranks among the nation’s best. The real draw was how these labels translate day to day, where advisors engage with ideas, and not operate in a silo. Collaborators are spread across departments, and the access to data, facilities and industry partners encourage systems thinking, which is the backbone of my work in circular industrial design. As an international student, I wanted a place that welcomes perspective and demands rigor. Purdue gave me both, and a platform in the Sustainable Industrial-Natural Coupled Systems (SINCS) research group to work with Prof. Shweta Singh to push circular industrial design from theory to implementable plans that can help companies and communities worldwide today.

When did you first get interested in engineering and science?

My passion for science ignited through watching as a child an Australian educational children’s television show called “Backyard Science,”  where everyday materials transformed into fascinating experiments. I remember I was so fascinated with this show that my courtyard had hibiscus flowers which I made into a pH indicator. When you boil those crimson petals and filter them through a tea strainer to create a magenta solution, you essentially get an indicator solution. Testing household items revealed hidden chemistry: lemon juice shifted it to red; baking soda produced an effervescent blue-green hue. Though I didn't yet understand anthocyanin restructuring, I meticulously documented each color change, creating labeled jars and hand-drawn pH charts. This backyard experiment, sparked by a TV show, taught me that science lives everywhere and not just in laboratories. That progression from watching experiments to conducting them to pursuing chemical engineering to eventually working on my PhD shaped my academic journey.

What’s it like studying at Purdue?

If I must put two words to it, studying at Purdue has been intellectually stimulating. The coursework I have targeted seamlessly integrates advanced optimization, process systems engineering, industrial ecology and data-driven modeling, which has sharpened my real-world perspective. Classes feel very much like collaborative workshops, rich with discussion, coding and problem-solving, while faculty remain remarkably accessible. In the SINCS Group, my research on multiscale circular-economy framework bridges plant-level physics with economy-wide material flows through PIOT-Hub datasets and decision dashboards that transform models into actionable insights. Weekly group meetings with intra-functional and cross-functional collaborative partners create continuous momentum. Beyond academics, the opportunity to mentor incoming graduate students and participating in invited lecture programs has thoroughly enriched my experience. Purdue cultivates a community where intellectual rigor meets collaborative support, fostering both professional and personal growth.

What else have you learned at Purdue, beyond deepening your knowledge of subject matter?

Beyond the technical depth and the subject matter expertise, Purdue taught me how to collaborate effectively with people. I learned to frame problems succinctly, write tighter memos and run meetings with clear roles, timelines and decisions. I manage collaborations by setting expectations early, documenting risks and keeping a steady cadence of check-ins. Communication also matters. There is a saying “Tell me the time, don’t build me a clock,” which means that the number of details that needs to be shared varies with different people, and that is where the short updates, plain language and visuals are very useful. The act of kindness and gratitude matters as well, and so the shout-outs in group meetings, quick thank-you notes and celebrating small wins keep the energy high. Additionally, the art of networking is also an important thing I learned here, which eventually taught me to connect with people at conferences and always be open to share about the research and brainstorm about what makes the field progress in a better manner. Eventually, learning all these aspects leads to a stronger team bonding and better research work.

What is the Purdue research environment like? Have you had chances to teach and publish?

Since I joined Purdue in 2021, I have found Purdue’s research environment to be energetic, generous and focused on real impact. Advisors here make time and have an open-door policy. Peers share code and ideas with positive critiques, and collaboration across departments and outside the university keeps questions grounded in practice and real-world implementation. In the SINCS Group, this spirit shows up in modeling sprints, open data habits and honest internal reviews that push a project from first draft to impactful publication. Teaching and mentoring have been central to how I have grown here. I have had the opportunity to teach ChE 320 twice, guiding discussion and lab sections and learning how to explain complex ideas in plain language. I also delivered invited lectures for ABE 557 that connected process modeling with dynamics and control theory, and I learned as much from the questions as from the preparation. From the publications point of view, I arrived at Purdue with a review and a perspective article (https://engineering.purdue.edu/ChE/news/2022/2022-0311-deplasticize) already authored along with Professor Pol. Since then, I have authored a research article and very recently got a review article with Professor Singh, where we aim to turn circularity-oriented research analysis into guidance for industry and policy. Writing with two different groups sharpened my approach to framing questions, building evidence and closing the loop with readers. I also believe that the effective scientific communication via attending conferences amplify the impact of publishing. I have had the opportunity to present and learn at some major international conferences within my domain, like the biennial conferences of the International Society for Industrial Ecology and the Gordon Research Conference in Industrial Ecology, while also attending annual conference meetings of AIChE and ACS, where conversations with faculty, practitioners and students pressure test assumptions and open new directions. One of my research articles I published with Professor Singh also received the Best Graduate Student Paper Award in the AIChE 2024, which was both an honor and a prompt to raise the bar again (https://engineering.purdue.edu/ChE/news/2024/six-students-receive-aiche-awards-at-2024-conference). This fall I am a Bilsland Fellow. The added time and trust help me refine the dissertation and deliver tools that teams outside the lab can use.

What advice might you give to other students deciding where to attend graduate school?

I would strongly emphasize to account for the people and research culture. This means to choose an advisor and lab culture where you feel respected, challenged and supported. Ask about mentoring time, feedback cadence, authorship norms and how the group handles setbacks. Look for a program that matches your research goals and gives room to explore across departments. Do check for the funding stability, stipend versus local costs, health insurance and conference support. Talk to current students about teaching loads, time to degree and real placement outcomes. For international students, confirm visa guidance and opportunities for internships or practical training. Visit if you can; sit in on a meeting. Notice how people communicate, celebrate wins and share credit. Pick the place where you will learn, build community and do work that matters most. And most importantly, graduate school is something where you focus on the journey, and not the destination, so every step of the way the people and your professional relationships with them matter.

What about the future? What are your goals; what are you looking to accomplish in this field?

I plan to build a career in industrial R&D, where ideas become products, processes and measurable impactful results. My focus will stay on digitalization efforts in the industry related to the circularity, sustainability science and industrial ecology, using data-driven tools to guide real decisions. I want to design resilient and robust supply chain networks that reduce waste, cut emissions and strengthen supply chain health. I hope to translate those designs into actionable components which companies can implement. I will keep publishing, partnering with engineers and policy teams, and mentoring students who care about impact. The goal is elegantly simple: to push the field forward and prove that rigorous science can deliver practical and generalizable solutions at industrial scale.

Might you share with us a little window into your personality: some distinctive trait, habit of mind, hobby/pursuit outside work…?

Do you know about Perry the Platypus from the childhood show “Phineas and Ferb?”  I want to say that curiosity is my default setting, which is probably why Perry the Platypus was my childhood hero. He does possibly every adventurous thing there can be — and I am trying to do 1/10th maybe. I play tennis for focus and to improve my cardio and footwork, and I am also learning to fly small planes to get my private pilot license. I hope to earn my skydiving certificate sometime soon as well. And, of course, weekends often mean hiking; long trails reset my attention and sharpen observation. I also love to do fusion cooking. You should try the Indo-Chinese cuisine which sparked my interest in this. I like the feedback loop of taste, adjust, iterate. That habit spills into research, too: try, measure, refine. Doing different things keeps me grounded, curious and ready to take on the next problem.