This research project is focused on examining the feasibility of converting lignocellulosic-based solid waste streams destined for landfill, into a valuable biochar product. Biochar has many applications including a soil amendment to improve soil fertility and a low-cost adsorbent such as control of odorous sulphur pollutants in air emissions and as an adsorption surface for toxic metals in industrial waste streams.
We have delivered the first inventory of useful lignocellulosic-derived material present in St. Johns municipal waste by sampling a number of household garbage pickups. We have further extended this inventory to institutional waste (Memorial U.) and have also examined demolition and garden waste as potential biochar feedstock. Individual feed stocks (i.e., newsprint, inked white paper, corrugated box, etc.) were collected and characterized. Biochar were produced from a home-made pyrolysis unit. Important chemical and physical properties of the samples were measured for commercial use in soil amendment, industrial use as gas and contaminant adsorbent and for the production of activated carbon.
Results: Samples which gave highest yields of low ash biochar were plywood and wood (demolition waste) followed by wood chips and twigs (garden waste). These samples can be used for making activated carbon. Samples which produced biochar suitable as effective adsorbents were newsprint and paper towels. A promising number of other biochar samples were deemed useful as a commercial soil amendment additive.
Future work: We plan to design and build a pilot-scale pyrolysis unit of simple design, inexpensive and using 50 gal barrels (Barrel-pyr). The 10 kg-quantities of biochar product (from mixed lignocellulosic waste) will be used in demonstration garden plots. Small farms and rural communities will be encouraged to use of the Barrel-pyr as a way of diverting solid wastes while improving soil properties. In future studies, chicken manure and fish plant waste will be utilized in biochar production.
