The role of biochar in the degradation of sugars during fast pyrolysis of biomass

Plouffe, Colin
Peterson, Chad A.
Rollag, Sean A.
Major Professor
Committee Member
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Bioeconomy Institute
Organizational Unit
Mechanical Engineering
Organizational Unit
Journal Issue
Agricultural and Biosystems EngineeringChemical and Biological EngineeringBioeconomy InstituteMechanical Engineering
With appropriate pretreament, sugars can be a major product from fast pyrolysis of lignocellulosic biomass. Analytical pyrolysis of pure cellulose can produce up to 60 wt% yield of levoglucosan although yields are significantly lower in continuouos pyrolysis at larger scales. Secondary reactions of vaporized levoglucosan are thought to be responsible for this loss of sugar yield, suggesting changes in the design and operation of pyrolysis reactors to minimize these reactions. Micropyrolysis experiments were performed to better understand the mechanism of sugar degradation in the presence of biochar. A 57% loss in levoglucosan yield was observed for cellulose overlain with untreated biochar powder compared to the pure cellulose control sample. The addition of biochar derived from pyrolysis of untreated corn stover to a fluidized bed pyrolyzer reduced sugar yields from cellulose from 61.3 wt% to 21.3 wt% and 41.5–11.6 wt% for conventional and autothermal operation, respectively. The significant drop in sugar yield due to biochar interaction inspired change in feeder configuration for the fluidized bed pyrolyzer to reduce vapor-char interactions. Biomass feeding was changed from in-bed to above-bed injection, which allowed signficant devolatilization to occur above the layer of biochar that exists at the surface of the bed. By reducing secondary reactions, bio-oil and sugar yields increased by 7.9% and 14%, respectively, for autothermal pyrolysis.
This is a manuscript of an article published as Plouffe, Colin, Chad A. Peterson, Sean S. Rollag, and Robert C. Brown. "The role of biochar in the degradation of sugars during fast pyrolysis of biomass." Journal of Analytical and Applied Pyrolysis 161 (2021): 105416. DOI: 10.1016/j.jaap.2021.105416. Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0). Copyright 2021 Elsevier B.V. Posted with permission.
Fast pyrolysis, Levoglucosan, Biochar, Fluidized bed