Institute Seminar Series: from waste to worth: engineering biochar for a circular carbon economy

Speaker

Payam Ghorbannezhad.

Abstract

The escalating crisis of biogenic waste—exemplified by sewage sludge and food waste—poses a dual threat to global sustainability by exacerbating greenhouse gas (GHG) emissions and squandering valuable resources. With food waste alone contributing ~170 million metric tons of CO₂ annually in the U.S. (U.S. EPA), and the EU producing over 10 million tons of sewage sludge each year, innovative and scalable solutions are urgently needed to transition toward a circular bioeconomy. This study presents a novel, integrated approach to valorize these waste streams through the copyrolysis of sewage sludge and food waste into engineered biochar. We systematically investigate the optimization of carbonization, activation, and surface modification parameters to enhance the biochar's structural properties, adsorption capacity, and environmental functionality. Our findings demonstrate that this engineered biochar exhibits superior performance in key applications, including:

• Carbon Sequestration: Acting as a stable carbon sink to mitigate atmospheric CO₂.
• Environmental Remediation: Effectively immobilizing heavy metals and adsorbing hazardous contaminants.
• Soil Enhancement: Serving as a high-value soil amendment to improve fertility and stability.

A critical focus of this research is addressing the inherent challenges of utilizing waste-derived materials, such as tuning surface functional groups and ensuring the secure stabilization of heavy metals to prevent secondary pollution. The results confirm that our tailored biochar not only meets but exceeds the efficacy of traditional counterparts, offering a sustainable and economically viable pathway for waste management. 

This work establishes a foundational framework for converting high-volume biogenic wastes into functional materials, paving the way for large-scale implementation in carbon capture, wastewater treatment, and sustainable agriculture. We conclude that engineered biochar is a cornerstone technology for achieving a circular carbon economy, transforming environmental liabilities into valuable assets.

Biography

Visiting professor at UK Biochar research centre at the University of Edinburgh and senior researcher at IKFT, KIT University in Germany. He was an assistant Professor, Department of Biorefinery Engineering, Tehran, Iran. He holds a Ph.D. in Chemical Engineering from the University of Groningen (The Netherlands) and Gorgan University. His expertise lies in biomass valorization, thermochemical conversion, and circular bioeconomy solutions. Dr. Ghorbannezhad’s research focuses on biomass valorization via catalytic fast pyrolysis and producing engineered biochar from food waste and sewage sludge for soil amendment and carbon capture. He has extensive international collaboration experience and has authored over 30 peer-reviewed publications in journals such as Fuel and Sustainable Energy & Fuels. He is a recipient of the prestigious Alexander von Humboldt Fellowship (2024) as experienced researcher in Germany, a Post-Doctoral Fellowship at the University of Groningen (2016–2017), and several national academic honors. His work combines advanced catalytic processes with sustainability assessments like LCA and TEA.

Contact

Email ifs@surrey.ac.uk for the Teams link and with any questions.