Bioenergy production using woody biomass is a fast developing application since this fuel source is considered to be carbon neutral. The harnessing of bioenergy from these sources produces residue in the form of ash. As the demand for bioenergy production increases, ash and residue volumes will increase. Major concerns arising from the management of this byproduct include: storage availability, usage, product disposal and the implications of the presence of unburned carbon. This research studies various ash types, identifying specific fractions of technological, environmental and economic viability. Fractions of energy importance, inorganic distribution and catalytic properties of specific ash types are investigated. Ash from three systems were investigated, an industrial boiler, a fixed bed updraft gasifier and a wood pellet burner. Analyses of the boiler ash included particle fractionation, proximate and ultimate analysis, Brunauer-Emmett-Teller (BET) surface area, thermogravimetric analysis (TGA) and bulk density. Samples were separated into various fractions based on particle sizes. The fixed carbon in the as-received boiler ash samples was 30 and 50 % and the higher heating value (HHV) ranged from 5 - 25 MJ/kg of the different fractions. 68 % or more of the energy could be recovered in fractions ≥ 425 μm. High carbon ash was successfully gasified in a fluidized bed reactor at low temperatures and atmospheric pressure. The pH of the as received samples for the gasifier, boiler and pellet burner were 10.36, 12.49 and 13.46, respectively. Ni with a concentration of 229 mg/kg in the pellet burner ash, exceeded the maximum limit for soil amendments (in British Columbia, Canada) within the particle size fraction ≥ 850 μm but <2000. All samples were significantly enriched in both Ca (50-61 %) and K (10-26 %). Wood ash derived catalyst obtained from a gasifier and a wood pellet burner influenced gasification reactivity. The pellet burner ash was a more effective catalyst than the gasifier a
Full scale anaerobic co-digestion of fruit and vegetable waste (FVW) and municipal wastewater primary sludge significantly increased biogas production. Digester operation remained stable. Undigested FVW was visible in dewatered sludge suggesting that FVW should be added to the first stage digester to prevent short-circuiting and increase the hydraulic retention time (HRT) of the FVW. Batch lab results confirmed that co-digestate addition to first stage sludge (FSS) is preferred to second stage sludge (SSS). FSS produced significantly more methane (514 ± 57 L CH₄ kgVS⁻¹ added) than SSS (392 ± 16 L CH₄ kgVS⁻¹ added). In a related study, combined alkaline and ultrasonic pre-treatment of thermomechanical pulp mill sludge (PMS) significantly increased the soluble TS, VS and COD of the PMS over non-treated sludge. Pre-treatment did not significantly improve biogas production over 28 d, but did increase VS reduction, and the initial rate of methane production. Overall, biogas production from PMS was inconsistent.
Assessing the shelf life of wood from mountain pine beetle (Dendroctonus pondersoa [Hopkins]) killed lodgepole pine (Pinus contorta var. latifolia) in terms of its compatibility for Portland cement was examined. Two methods of assessment were used, based on the behavior of the exothermic chemical reaction of cement hydration, accounting for the difference between neat cement paste and wood-cement mixtures. A new wood-cement compatibility index meant to integrate current approaches was defined. No evidence was found of limitations in terms of beetle-killed heartwood wood compatibility with cement except for the white rot infested samples. An outstanding physicochemical behavior characterized the mixtures of blue-stained sapwood and cement. Three compositions of ingredients were proposed for fabricating wood-cement boards that would meet the technical specifications given by the gypsum board standards with respect to strength and stiffness. In absence of pressing, the water was the factor used to regulate workability during the molding process.--P.ii.
This thesis targets the world most critical and scarce resource, water. As rural and urban population increase, demand for water also increases. It is essential that a water conservation strategy be adopted to ensure efficient use of water resources. Three major contributions towards such a strategy are presented in this thesis. The first contribution provides a green sustainability value index that can be used as a measure of a facility's sustainability. The second contribution generalizes a scheme for the application of water cascade analysis (WCA) at a hospital with approximate water saving of 50% at minimal cost. The third contribution illustrates the flexibility of applying WCA at complex urban facilities with unbiased identification of pinch point for reuse. The WCA algorithm used for assessment is proposed to replace the convoluted schemes in the literature that may have deterred practitioners from using it. --Leaf ii.
Chromium is a transition metal element but it is also considered a heavy metal due to its potential toxicity when discharged into the environment through effluent streams. Biosorbents such as wood sawdust, biochar, and ashes from industrial boilers and gasifiers are investigated here to remove chromium from the environment. The removal efficiency of Cr(III) from aqueous solutions using sawdusts and biochars from soft pine (SP), yellow poplar (YP), red oak (RO), and Douglas fir (DF) were improved after treatment with aqueous ammonia. Among them, the removal efficiencies were 51.14% and 50.92% using ammonia-treated SP and YP, respectively and at 99.95% and 99.41%, respectively for boiler and gasifier ashes. However, the boiler ash and ammonia-treated YP had lower biosorption abilities for Cr(III) in chromium-plating and tannery effluents compared to aqueous solutions. The complex composition of these industrial wastewaters and the presence of other metal ions may have influenced the chromium sorption. --Leaf [i]
This study used both primary and secondary sources of information as well as exploratory research to evaluate: 1. The nature and amount of biomass feedstock available in BC and in northern BC 2. The status of the technologies that are emerging in the market place for conversion of biomass into fuels and chemicals 3. The incentives offered by the provincial and federal governments to assist and promote the development of a bio-fuel industry in northern BC 4. The options that can be used to finance these technologies in northern BC. --P.iii.
