I am pleased to introduce Unnikrishna Menon, a dedicated researcher and expert in the field of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More. Currently a Joint Doctoral Researcher in Environmental Engineering at the Indian Institute of Technology, Kharagpur, and the University of Alberta, Unnikrishna’s work is at the forefront of sustainable waste management and energy solutions. His research focuses on the production and advanced characterization of biochar, with a particular emphasis on its applications in energy storage and environmental remediation. Unnikrishna’s journey began with a foundation in Civil Engineering and a master’s in Energy and Environmental Engineering, where his work on heavy metal-contaminated soils sparked a lasting interest in waste valorization. He is proficient in a range of analytical techniques, allowing him to deeply understand the functional properties of biochar beyond surface-level observations. His innovative approach is exemplified by his development of “pyrohydrochar” from high-lignin yard waste, demonstrating how combining pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More and hydrothermal carbonization can create superior materials for supercapacitor electrodes. Driven by a commitment to the circular bioeconomy, Unnikrishna’s research not only targets high performance but also integrates life cycle assessment (LCA) to ensure environmental viability and scalability. This holistic perspective positions him as a key figure in bridging the gap between academic innovation and industrial application. I am excited to feature his insights on the future of multifunctional biochars and their role in a sustainable society.

Shanthi Prabha : What initially sparked your interest in using waste materials to create biochar, and how did your M.Tech work on electrokinetic remediation of heavy metal-contaminated soil influence your current biochar and heavy metal removal research?

Unnikrishna Menon: My M.Tech work on electrokinetic remediation was my first real exposure to research. What began as a mini project eventually became a publication – thanks to the guidance of Prof. Bhaskar Das and the support of my co-authors. Working in Tamil Nadu, where heavy metal contamination is a real concern, I was inspired by literature on biochar as a soil remediation solution, though we relied on existing electrokinetic facilities at that stage.
My current focus on biochar actually grew out of curiosity. During the COVID-19 pandemic, I spent time following the stock market and saw the rapid boom in EV batteries and energy storage devices. That sparked the realization that there would be huge demand for carbon-based electrodes, which ultimately led me to IIT Kharagpur under the supervision of Prof. Brajesh Kumar Dubey.
Looking ahead, I aim to continue exploring heavy metal remediation through biochar while also addressing a broader priority: managing selected waste streams, converting them into valuable carbon materials, and assessing their applications within a circular framework. Waste management is a pressing challenge in India, and I see biochar as a powerful tool to bridge environmental needs with energy solutions.

SP: Your work has involved both pyrolysis and hydrothermal carbonization (HTC). Could you explain the key differences and why using both processes was essential for developing “pyrohydrochar” from high-lignin yard waste for use in supercapacitor electrodes?

UM: Pyrolysis and hydrothermal carbonization (HTC) are often viewed as separate approaches but complement each other. Pyrolysis operates at high temperatures without oxygen, producing highly porous carbon with good conductivity. HTC, on the other hand, is water-based and ideal for wet, lignin-rich feedstocks like yard waste, creating a dense, carbon product called hydrochar. HTC plays a key role in initial pore development and in removing unnecessary inorganic impurities that can hinder electrochemical performance. When followed by pyrolysis, these pores are further enhanced, resulting in a carbon structure with far greater specific surface area. This is one of the most important factors for energy storage, as it improves ion accessibility and charge storage capacity. By combining both processes, we created pyrohydrochar – a material that integrates HTC’s ability to pre-condition the feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More with the ability of pyrolysis to maximize porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and conductivity. This synergy was crucial for yard waste, which is notoriously difficult to process due to its high lignin content, and it produced a carbon material well-suited for supercapacitor electrodes.

 SP: The term “pyrohydrochar” is unique. What are its specific advantages for energy storage applications compared to other types of biochar, and how does this material help balance environmental impact with energy performance?

UM: “Pyrohydrochar” or “pyro-hydrochar” refer to chars produced through sequential HTC and pyrolysis. This approach was adopted for microstructural tuning, since pyrolysis alone does not always deliver the desired electrochemical performance. We validated this during initial testing at the Multifunctional Energy Materials Laboratory led by Prof. Amreesh Chandra at IIT Kharagpur, which confirmed that the combination of HTC and pyrolysis produced superior electrode materials. Another important aspect of our work was the decision to minimize chemical use. Many studies rely on chemical activation to enhance performance, but they often overlook the environmental cost of doing so. Our study deliberately avoided this, instead coupling performance testing with a life cycle assessment (LCA). While some assumptions were necessary, the LCA offered a benchmark for other researchers, showing how environmental impacts might compare when chemicals are used. This makes pyrohydrochar unique: it is an engineered material that provides enhanced electrochemical performance and a case study in balancing energy performance with environmental responsibility. This trade-off is increasingly relevant as countries worldwide focus on climate change and emissions reduction. I also take this opportunity to thank my coauthors for their valuable contributions, as the paper was truly the result of teamwork and shared effort.

SP: Your recent publication discusses biomass-derived hard carbon for secondary batteries and supercapacitors. What are the key engineering challenges for these materials, and what research avenues show the most promise for addressing them?

UM: That is indeed a very important question. Biomass-derived carbons hold promise for energy storage, but several challenges must be addressed before they can transition from lab-scale studies to industrial applications.

Scalability remains one of the biggest hurdles. Many high-performance results in the lab rely on chemical activation or doping strategies, but such approaches often do not translate well at an industrial scale, especially when their environmental costs are considered. This is where life cycle assessment (LCA) becomes crucial: it helps us evaluate not just performance, but also the sustainability of the process. Another issue is feedstock variability. BiomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More sources are inherently complex and their composition changes with geography, season, and processing. This makes reproducibility a major challenge – the same heat treatment may yield very different structural or electrochemical properties. To ensure reliability, repeated trials on the same feedstock are necessary before scale-up can be attempted. I believe there is a strong need for the community to focus on common feedstocks across multiple labs worldwide, to establish a reliable performance range. Lastly, while some studies use machine learning models to predict capacity or capacitance, these models often oversimplify the system and ignore critical factors like surface chemistry, pore structure, and long-term stability. Until these gaps are addressed, such predictions will remain limited in industrial applicability.

SP: What was the most significant learning experience from your collaboration with Dr. Amit Kumar at the University of Alberta?

UM: This is a very interesting question, and I would like to take this opportunity to thank my supervisor at IIT Kharagpur, Prof. Brajesh Kumar Dubey, for providing this Joint Doctoral Programme (JDP) opportunity. My research journey took a new curve when I reached Alberta. Dr. Amit Kumar is more than just a professor – he has deep collaborations with industry and leads one of the top research groups in energy & environmental systems engineering. At the University of Alberta, my work specifically focused on intermediate pyrolysis of biomass, which was my first exposure to biochar research. The research infrastructure at the University of Alberta was incredible. I had the chance to train on many analytical instruments – SEM, FTIR, BET, XRD, Raman spectroscopy, and more. Although some facilities require sample fees, Dr. Kumar encouraged me to learn those techniques and explore. He gave me the freedom and trust to take charge of my work. Through this collaboration, I gained not only technical skills but also refined how I approach problem-solving, thinking not only about performance but also about scalability, impact, and environmental cost. There are already promising results from the work I did in Alberta, and I hope to share a publication in a few months from now.

SP: You are proficient with analytical techniques like XPS and FTIR. How do these tools help researchers go beyond surface-level observations to truly understand the functional properties of biochar?

UM: Techniques like FTIR and XPS are essential because they reveal the chemistry behind performance. FTIR identifies functional groups (hydroxyls, carboxyls, carbonyls) that govern adsorption and reactivity. XPS shows the chemical states and bonding environment at the material’s surface – exactly where reactions occur. Together, these tools allow you to move beyond simply observing that a material works and answer the more critical question of why it works.

SP: Your research on converting yard waste into a carbon electrode included a life cycle assessment. From a researcher’s perspective, why is it crucial to conduct this type of analysis for new biochar applications?

UM:  As I mentioned earlier, life cycle assessment (LCA) is critical because performance alone does not guarantee sustainability. A material might show excellent results in the lab but still carry hidden costs in terms of energy use, emissions, or resource depletion. LCA helps identify the most impactful steps in the production chain, guiding researchers to target improvements that genuinely reduce environmental burden. From an industrial perspective, a positive LCA is often essential for both funding and market acceptance, since it demonstrates that a technology is not only effective but also sustainable and commercially viable. By conducting LCAs for new biochar applications, we can quantify their true environmental footprint, highlight trade-offs, and ensure that our innovations are aligned with climate and sustainability goals, rather than unintentionally working against them.

SP: How does a multidisciplinary approach, combining fields like biochar production, waste management, and heavy metal remediation, lead to a more comprehensive understanding of biochar’s potential?

UM: Biochar is inherently multidisciplinary. It is not just a material, but a solution that cuts across sectors. By connecting waste management, energy storage, and remediation, we can see biochar as a versatile tool: it can clean contaminated soils, act as a carbon sink, and even power future batteries. Making biochar is not only about turning waste into carbon – it is also about checking whether that material can clean soil, store energy, or reduce pollution. By combining knowledge from different fields, we gain a clearer picture of both the opportunities and the challenges. This integrated approach helps us design solutions that are not only effective in the lab but also practical, sustainable, and impactful in real life.

SP: From your perspective, how can expertise in both lab-scale characterization and life cycle assessment help bridge the gap between academic research and industrial application in the biochar sector?

UM: Lab-scale characterization tells us what a material can do, while LCA tells us whether it should be done at scale. Together, they provide a roadmap from curiosity-driven research to practical implementation.

In my own lab work, my colleague Rajarshi Bhar played a key role in helping me identify where pyrohydrochar production could have environmental impacts. This kind of dual expertise – combining technical performance with sustainability assessment – is what makes our findings more meaningful. For industry, the benefit is clear: when we propose a pyrohydrochar or biochar solution, we can be confident not only in its performance but also in its environmental viability. That kind of evidence is what helps new technologies move beyond the lab and gain real-world adoption.

SP: What do you see as the next major breakthrough in the field of biochar, and what role do you hope to play in it?

UM: I am still very much in the learning process of biochar. It is a tricky material, but I want to ensure that it can be engineered for multiple applications. I believe the next breakthrough will come from multifunctional biochars – materials designed to tackle more than one challenge at once, such as storing energy while capturing carbon, remediating soils, or even being integrated into construction materials. Looking ahead, I see my role at the interface of materials development and sustainability assessment – creating biochars that are not only high-performing but also scalable, impactful, and truly circular. I am also looking forward to the development of biochar standards, which will be crucial for consistency and market confidence.
My aspiration is to build a team that can work across different feedstocks and biochar forms, identifying the right match between material properties and real-world applications. My goal is not just to create new biochars, but to ensure that they contribute meaningfully to both industry and society. I was very eager to attend the North American Biochar Conference in Minneapolis and Biochar IV in Columbia this year to see the international community working together in the biochar field. Unfortunately, due to some personal circumstances, I could not attend. Still, I am excited to connect with researchers worldwide and hope to participate in upcoming conferences to exchange ideas and strengthen collaborations.

SP: Finally, where can the readers of Biochar Today find more information about your research and publications?

UM: Readers can find my publications on my Google Scholar profile (https://scholar.google.com/citations?user=rW1EKtgAAAAJ&hl=en), and ORCID (https://orcid.org/0000-0002-9849-4509), and I also share updates through LinkedIn. I welcome collaboration and discussion, and I’m excited to continue engaging with the wider biochar community through platforms like Biochar Today.