2025 AIChE Annual Meeting

(390am) Techno-Economic Analysis of Biomass Demineralization: Acid Leaching Process Design

Authors

Meng-Lin Tsai - Presenter, Department of Chemical & Biological Engineering, University of Wisconsin-Madison, Madison WI
Emmanuel Canales, University of Wisconsin-Madison
Alejandro Ayala-Cortés, Instituto de Energías Renovables, UNAM
George Huber, University of Wisconsin-Madison
Global efforts to reduce CO₂ emissions have driven interest in alternative feedstocks, such as biomass, as substitutes for petroleum-based resources (Ahorsu et al., 2018). In a biomass conversion supply chain, harvested biomass undergoes pretreatment (e.g., drying, grinding) before being processed in biomass conversion facilities such as pyrolysis and gasification plants to produce syngas or bio-oil for consumer end use. However, high ash content in biomass poses a major challenge to these processes, leading to tar formation, corrosion, slagging, fouling, and catalyst poisoning (Gao et al., 2020), which largely increases the maintenance cost and could hinder commercial viability. Acid leaching is a promising method for minerals removal since most of the minerals phases present in biomass are soluble in acid solutions(Voshell et al., 2018). This study evaluates the economic and environmental viability of implementing biomass acid leaching as a pretreatment step to facilitate the biomass conversion supply chain.

A process model with three steps is developed to simulate water extraction, acid washing, and biomass drying. In the first step, water extraction is used to recover high-value soluble compounds and remove water-soluble minerals, reducing the acid required in the subsequent treatment step. In the second step, the majority of the remaining minerals are removed through acid treatment. Finally, the biomass undergoes a series of dewatering and drying processes to meet the specifications required for the downstream catalytic process. In the water extraction and acid washing step, we incorporate liquid recycling loops with reverse osmosis to reduce water consumption (Patel et al., 2024). Model parameters are defined from lab-scale batch washing experiments using biomass sources, including wheat middlings and beetle-killed pine. A cost and environmental sensitivity analysis identifies key parameters influencing process performance, including minerals dissolving efficiency, biomass drying efficiency, reverse osmosis rejection rate, and biomass cost. The model provides insights into the economic and environmental impacts of biomass acid leaching within the biomass conversion supply chain. These findings highlight opportunities for optimizing the process, ultimately supporting the transition of chemical supply chains toward sustainable biomass conversion supply chains.

    References:

    Ahorsu, F. Medina, M. Constant ́ı, 2018. Significance and challenges of biomass as a suitable feedstock for bioenergy and bio- chemical production: A review. Energies 11 (12), 3366.

    Gao, Z. Wang, J. Ashok, S. Kawi, 2020. A comprehensive review of anti-coking, anti-poisoning and anti-sintering catalysts for biomass tar reforming reaction. Chemical Engineering Science: X 7, 100065.

    K. Patel, B. Lee, P. Westerhoff, M. Elimelech, 2024. The potential of electrodialysis as a cost-effective alternative to reverse osmosis for brackish water desalination. Water Research 250, 121009.

    Voshell, M. Ma ̈kela ̈, O. Dahl, 2018. A review of biomass ash properties towards treatment and recycling. Renewable and Sustain- able Energy Reviews 96, 479–486.