Modeling and Optimization of Pelleting Processes: Biomass and Biochar Pellet for Energy and Agricultural Applications

Research Poster Engineering 2025 Graduate Exhibition

Presentation by Md Mashiur Rahman

Exhibition Number 67

Abstract

Biomass pelleting is a sustainable research area with significant potential in application as a solid biofuel in combined heat and power (CHP) systems, agriculture, and other applications. However, key process parameters, such as pressure, temperature, and die aspect ratio critically influence pelleting performance. As of now, a comprehensive methodology to fully characterize, model and optimize the pelleting process including its mechanical and thermal performance remains undeveloped. Such a methodology is essential for optimizing the process’s operational parameters for biomass and biochar pellets. Therefore, this research aims to address these gaps by instrumenting a farm-level pelletizer to measure the thermomechanical behavior of the pelleting process. Pelleting experiments were conducted using pinewood and mixed hardwood. Data on temperature, pressure and energy consumption were collected across three zones using data loggers. Analysis revealed that radial pressure acting on the die channel wall decreased exponentially with depth, while the die temperature increased linearly over time. Comparative analysis showed that mixed hardwood required higher average energy consumption and a longer compression time to form pellets compared to pinewood, highlighting significant differences in the thermomechanical behavior of the two feedstocks. Collected data will be utilized to develop mathematical models and optimize the pelleting process by response surface methodology. A simulation model will further enhance mechanistic understanding and predict pelleting performance across various biomass and biochar feedstocks, supporting scalability from farm-level to industrial pellet production. This research advances the understanding of thermomechanical conversion mechanisms in biomass pelleting, laying the foundation for process optimization and broader application.

Importance

This research study is important because it enhances the efficiency and sustainability of biomass pelleting, a key process in renewable energy and agricultural applications. By investigating how temperature, pressure, and energy use affect pellet formation, this research provides valuable insights into optimizing the process for different types of biomass. Understanding these factors can lead to improved pellet quality, reduced energy consumption, and better performance in heating and power systems. Additionally, developing developed mechanistic models and simulations will help scale up small-scale pellet production to industrial levels, making biofuels more accessible and cost-effective. This work supports the broader transition to renewable energy by improving the reliability and efficiency of biomass as a sustainable fuel source.

DEI Statement

This research supports diversity, equity, and inclusion by advancing sustainable energy solutions that can benefit underserved and rural communities. Biomass pelleting provides an affordable, renewable fuel source, reducing reliance on expensive or inaccessible energy options. By optimizing the process for farm-level applications, this study promotes energy independence for marginalized low-income and rural communities that often face energy insecurity. Additionally, by investigating a range of biomass feedstocks, the research considers diverse regional resources, ensuring broader applicability. The study’s focus on accessibility and scalability aligns with economic justice and social mobility, offering sustainable energy solutions to those historically excluded from technological advancements in renewable energy. This work contributes to a more inclusive-equitable transition to clean energy by developing a circular economy.