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A life cycle approach was used to assess greenhouse gas (GHG) emissions and energy balances of switchgrass pyrolysis in an auger reactor for biochar production, with bio-oil and syngas as co-products. The system boundaries included the cultivation of switchgrass on marginal lands, harvesting, transport, conditioning, pyrolysis, the amendment of biochar in soil to sequester carbon (C) and to reduce N 2 O emissions, and the valorisation of bio-oil and syngas as energy sources. Two pyrolysis scenarios were evaluated. Scenario A involves a lower pyrolysis temperature and a shorter solid residence in the reactor as compared to scenario B. A negative GHG emissions balance of −2110 and −2561 kg CO 2 e Mg −1 biochar was obtained for scenarios A and B, respectively. Biochar C sequestration contributed the most to the reduction of GHG emissions in scenario B due to the high C content and stability in biochar. However, scenario B resulted in a higher energy consumption (13,563 MJ Mg −1 biochar) than scenario A (2925 MJ Mg −1 biochar) due to a higher energy consumption of the pyrolysis unit. These results confirm that pyrolysis of switchgrass for biochar and bio-oil production can be a negative emission technology, but pyrolysis operating parameters should be selected carefully. [ABSTRACT FROM AUTHOR]

Pyrolysis converts lignocellulosic biomass into bio-oil, which result in at least four times with more energy density than raw biomass. Bio-oil could be exploited in heating, power generation or extraction of chemicals. However, quality of bio-oil is not adequate enough to be used in equipment for energy applications. Product yield and l composition of bio-oil have a close relationship with feedstock chemical composition, thus some pre-treatments are used to optimize bio-oil properties, such as chemical composition, heating value and ash content, achieving a better bio-oil quality before pyrolysis. This work reviews the key characteristics of lignocellulosic biomass and the role of chemical composition during pyrolysis reaction to expect a bio-oil with low oxygen content, low water content and low acidity. Therefore, physical, thermal, chemical and biological treatments prior to pyrolysis, are presented and discussed as a possible solution that leads to an improvement in bio-oil quality. • Biomass composition and treatments are reviewed to improve quality of pyrolytic oil. • Pre-treatments are used to enhance deoxygenation in bio-oil. • Pre-treatments were summarized as an economical and technical feasible solution. [ABSTRACT FROM AUTHOR]

Highlights: [•] Combustion of agricultural and forest biomasses was experimented in a 17.6kW unit. [•] Quantity and quality of emissions were closely related to fuel characteristics. [•] Bulk density, air ratio, residence time and temperature could influence emissions. [•] Agricultural biomass combustion emitted most SO2, NO2 and PM than forest biomass. [•] NOx and SO2 emissions limits could be included in the Quebec regulations. [ABSTRACT FROM AUTHOR]

Jerusalem Artichoke ( Helianthus tuberosus L.) stalk particles were studied as an alternative raw material for cement composites. Cement-bonded particleboards measuring 300 × 300 × 10 mm with nominal density of 1250 kg/m 3 were produced and assessed. Particleboards were subjected to two curing conditions: (1) – 48 h in a climatic chamber, followed by 25 days in an air saturated environment; and (2) – 48 h in a climatic chamber, and then in a dioxide carbon (15% concentration) environment (24 h), followed by 24 days in an air saturated environment. Physical and mechanical characterizations were carried out for both particleboard samples at 28 days. The particleboard tested in this study may be applied for industrial purposes, since cement-bonded Jerusalem Artichoke particleboards meet the mechanical requirements of the ISO 8335 Standard for building applications. Furthermore, thickness swelling and water absorption of the particleboards were lower than values reported in the literature and Standards requirements. In view of the results, Jerusalem Artichoke stalk particles are suitable to be used to produce cement-bonded particleboards for construction applications. [ABSTRACT FROM AUTHOR]

Abstract: Wood and agricultural crop residues are abundant, renewable and relatively low cost biomasses. Their combustion can replace fossil fuels in several applications. A major concern with biomass combustion is the emission of particulate matter (PM) in the atmosphere. The World Health Organization (WHO) has developed ambient air quality guidelines, notably maximum average annual levels of 20μg/m3 for PM10 (particulate matter<10μm). Combustion standards generally assess total PM at the chimney stack, with variable levels depending on local legislation, industrial activity, population density, etc. (e.g. 100–200mg/m3 in Massachusetts, 150mg/m3 in Québec, and 600mg/m3 in New York). Some areas mandate relatively low PM levels from boilers (50mg/m3 in Europe, 20mg/m3 in Germany starting in 2015). The availability of conditioned and relatively dry biomass, along with PM removal technologies (e.g. cyclones, scrubbers, precipitators, and baghouse filters), will become important requirements for future biomass combustion. [Copyright &y& Elsevier]