Degree Type
Dissertation
Date of Award
2012
Degree Name
Doctor of Philosophy
Department
Chemical and Biological Engineering
First Advisor
Robert C Brown
Second Advisor
David A Laird
Abstract
Slow pyrolysis, fast pyrolysis and gasification are thermochemical processes to produce fuel and chemicals from biomass. The char co-products from these processes have much potential as biochars: sustainably produced biomass charcoals used for amending soils and sequestering carbon. As biochar properties vary significantly with feedstock and reaction conditions, biochar characterization is critical for understanding these variations, for obtaining meaningful data from biochar agronomic studies, and for determining the most beneficial and economical application of a given char co-product (fuel, sorbent or soil amendment). This dissertation describes biochar characterization methods used to relate thermochemical reaction conditions such as temperature, heating rate and reaction atmosphere to biochar properties. These methods include proximate analysis, CHNS elemental analysis, BET surface area gas sorption analysis, helium pycnometry, scanning electron microscopy (SEM), X-ray fluorescence spectroscopy (XRF), FT infrared spectroscopy with photoacoustic detection (FTIR-PAS), advanced solid-state 13C nuclear magnetic resonance spectroscopy (NMR), cation exchange capacity (CEC), pH, electrical conductivity, and short-term soil incubations with soil respiration and water retention measurements. One outcome of this research has been the incorporation of biochars derived from corn stover and switchgrass, and derived by fast pyrolysis and gasification, in the wider biochar community discussions.
DOI
https://doi.org/10.31274/etd-180810-2233
Copyright Owner
Catherine Elizabeth Brewer
Copyright Date
2012
Language
en
Date Available
2012-10-31
File Format
application/pdf
File Size
196 pages
Recommended Citation
Brewer, Catherine Elizabeth, "Biochar characterization and engineering" (2012). Graduate Theses and Dissertations. 12284.
https://lib.dr.iastate.edu/etd/12284