Surface-Layer Semivolatiles Impact on Hydrochar Application For Fuel and Environment

Recovering waste biomass from agricultural and industrial processes is a means of upscaling a carbon source that otherwise would contribute to greenhouse gas emissions. Thermochemical conversion processes transform agro-industrial waste biomass into liquid bio-oils and solid chars, which have applications as fuels and environmental remediation materials. This dissertation investigates the properties and applications of thermochemical conversion products of agro-industrial waste, focusing on hydrothermal carbonization (HTC) and pyrolysis. The studies in this dissertation focus on the extraction semi-volatile organic compounds from the surface of hydrochar known as secondary char (SC). Over the past decade, studies have shown SC to be a hinderance in HC application for fuels and the environment, due to early burn-out time and phytotoxicity to plants. A major goal of this dissertation was extracting the SC to recover primary char (PC), a material more akin biochar derived from pyrolysis, which was hypothesized to be better suited for environmental applications. It was found that extracting SC from HC improves several properties that point towards PC being a more suitable material for soil remediation than HC. SC composition was found to be heavily dependent on feedstock composition, with cellulose-based materials producing compounds that are regarded as platform chemicals. Cascading valorization schemes combining HTC and pyrolysis were investigated to optimize bio-oil and biochar yields. Clay catalysts were integrated into these processes to enhance bio-oil quality, with strategic insertion points influencing hydrocarbon content. Synergistic effects observed in mixed waste pathways demonstrate potential for improved energy density and product quality, offering promising pathways for sustainable fuel production. This work contributes to the field of thermochemical conversion by suggesting ways to optimize valorization pathways based on biomass type and desired products and applications to achieve a circular bioeconomy.

Name thesis:degree_name

Ph. D., Biological and Environmental Engineering

Level thesis:degree_level

Doctor of Philosophy

Discipline thesis:degree_discipline

Biological and Environmental Engineering

Grantor

Cornell University

Year dc:date.issued

2024

Author dc:creator

• Karod, Madeline

Committee members dc:contributor.committeemember

• Tester, Jefferson
• Reid, Matthew

• biochar
• biomass
• hydrochar
• hydrothermal carbonization
• pyrolysis
• secondary char

Language dc:language.iso

en

DOI

https://doi.org/10.7298/3ha2-eb07

Dc Identifier Other

ProQuest Submission ID: 14172
ProQuest Publication ID: 31139807

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/116487