|Anderson, William - Bill|
Submitted to: The 1890 Association of Research Directors Biennial Research Symposium
Publication Type: Abstract only
Publication Acceptance Date: 4/4/2011
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Pyrolysis process is one of the technologies used to convert biomass to energy. During the process, up to 40% of the initial biomass is recovered as biochar, the co-product of the process. Feedstock composition and chemistry is altered during the process, rendering its components (e.g. carbon, nutrients) less biodegradable and available. The biochar co-product can be used as a soil additive to overcome soil limitation, providing constructive use for the byproduct. The quality of the biochar as soil amendment and its environmental impact are likely to depend on feedstock source and processing conditions. We evaluated the characteristics of biochar from chicken litter and from plant residue processed under different conditions. Chicken litter was processed in slow pyrolysis at 350 and 700 deg C. Chicken litter from additional source, and alfalfa stem, bamboo, miscanthus, and sorghum plant material were processed in fast pyrolysis at 450-500 deg C. Subsamples of all biochars were further steam-activated at 800 deg C. Biochars were analyzed for total elemental analysis, CaCO3 equivalent (CCE), mineralogical composition, FTIR spectra, and for water, Mehlich-3, and Synthetic Precipitation Leaching Procedure (SPLP; EPA Method 1312) extractable elements. Biochar CCE increased with temperature and with steam activation. Activation resulted in overall increase in macro- and micro- nutrients content, while decreasing their Mehlich-3 content. Element solubility was feedstock, process, and element dependent. The results of the study suggest that feedstock and pyrolysis processes markedly affect biochar properties. Management practices need to be further refined in order to assure agronomically beneficial and environmentally safe use of biochar in soil.