Accurate modelling of particle shrinkage during biomass pyrolysis is key to the production of biochars with specific morphologies. Such biochars represent sustainable solutions to a variety of adsorption-dependent environmental remediation challenges. Modelling of particle shrinkage during biomass pyrolysis has heretofore been based solely on theory and ex-situ experimental data. Here we present the first in-situ phase-contrast X-ray imaging study of biomass pyrolysis. A novel reactor was developed to enable operando synchrotron radiography of fixed beds of pyrolysing biomass. Almond shell particles experienced more bulk shrinkage and less change in porosity than did walnut shell particles during pyrolysis, despite their similar composition. Alkaline pretreatment was found to reduce this difference in feedstock behaviour. Ex-situ synchrotron X-ray microtomography was performed to study the effects of pyrolysis on pore morphology. Pyrolysis led to a redistribution of pores away from particle surfaces, meaning newly formed surface area may be less accessible to adsorbates.
This research was supported by Queen Mary University of London. We acknowledge Diamond Light Source for time on beamline I13 under Proposal MG21587. This research utilised Queen Mary’s Apocrita HPC facility, supported by QMUL Research-IT. http://doi.org/10.5281/zenodo.438045. The authors would like to acknowl- edge Dr. Kaz Wanelik and Simon Logan for technical support at Diamond Light Source, as well as Jun Ma for developing the reactor control program at QMUL. M.R.B. would like to acknowledge Paul-Enguerrand Fady for proofreading the manuscript.
Data Availability StatementThe data that support the findings of this study are available from the corresponding author upon reasonable request.
The custom code used to process and analyse the data that support the findings of this study is available under a GNU Affero General Public License v3.0 via Zenodo with the identifier https://doi.org/10.5281/zenodo.3568050.
- Chemical Engineering
- Porous materials