Sawdust

About: Sawdust is a research topic. Over the lifetime, 5526 publications have been published within this topic receiving 86499 citations. The topic is also known as: wood dust & hard wood dust.

Sources of Fine Organic Aerosol. 9. Pine, Oak, and Synthetic Log Combustion in Residential Fireplaces

Abstract: Combustion of wood in residential fireplaces contributes approximately 14% on an annual average of the total primary fine particle organic carbon (OC) emissions to the Los Angeles urban atmosphere and up to 30% of the fine particulate OC emissions on winter days. This paper presents comprehensive organic compound source profiles for smoke from burning pine, oak, and synthetic logs in residential fireplaces. Mass emission rates are determined for approximately 200 organic compounds including suites of the n-alkanes, n-alkenes, cyclohexylalkanes, n-alkanals, n-alkanoic acids, alkenoic acids, dicarboxylic acids, resin acids, hydroxylated/methyoxylated phenols, lignans, substituted benzenes/benzaldehydes, phytosterols, polycyclic aromatic hydrocarbons (PAHs), and oxy-PAHs. Wood smoke constituents reflect to a great extent the underlying composition of the wood burned: pine and oak logs produce smoke that is enriched in lignin decomposition products, pine smoke is enriched in resin acids and their thermal alteration products, while smoke from the synthetic log burned here bears the major signature of the petroleum products combined with traces of the sawdust components from which it is made. Resin acids are discussed as potential wood smoke tracers in the environment, and it is shown that the time series of resin acids concentrations in the Los Angeles atmosphere follows the extreme seasonal variation in wood use reported in previous emissions inventories for the Los Angeles urban area.

Production of green aromatics and olefins by catalytic fast pyrolysis of wood sawdust

Abstract: Catalytic fast pyrolysis of pine wood sawdust and furan (a model biomass compound) with ZSM-5 based catalysts was studied with three different reactors: a bench scale bubbling fluidized bed reactor, a fixed bed reactor and a semi-batch pyroprobe reactor The highest aromatic yield from sawdust of 14% carbon in the fluidized bed reactor was obtained at low biomass weight hourly space velocities (less than 05 h−1) and high temperature (600 °C) Olefins (primarily ethylene and propylene) were also produced with a carbon yield of 54% carbon The biomass weight hourly space velocity and the reactor temperature can be used to control both aromatic yield and selectivity At low biomass WHSV the more valuable monocyclic aromatics are produced and the formation of less valuable polycyclic aromatics is inhibited Lowering the reaction temperature also results in more valuable monocyclic aromatics The olefins produced during the reaction can be recycled to the reactor to produce additional aromatics Propylene is more reactive than ethylene Co-feeding propylene to the reactor results in a higher aromatic yield in both continuous reactors and higher conversion of the intermediate furan in the fixed bed reactor When olefins are recycled aromatic yields from wood of 20% carbon can be obtained After ten reaction–regeneration cycles there were metal impurities deposited on the catalyst, however, the acid sites on the zeolite are not affected Of the three reactors tested the batch pyroprobe reactor yielded the most aromatics, however, the aromatic product is largely naphthalene The continuous reactors produce less naphthalene and the sum of aromatics plus olefin products is higher than the pyroprobe reactor

Removal of heavy metals from aqueous solution by sawdust adsorption

Abstract: The adsorption of lead, cadmium and nicel from aqueous solution by sawdust of walnut was investigated. The effect of contact time, initial metal ion concentration and temperature on metal ions removal has been studied. The equilibrium time was found to be of the order of 60 min. Kinetics fit pseudo first-order, second-order and intraparticle diffusion models, hence adsorption rate constants were calculated. The adsorption data of metal ions at temperatures of 25, 45 and 60°C have been described by the Freundlich and Langmuir isotherm models. The thermodynamic parameters such as energy, entropy and enthalpy changes for the adsorption of heavy metal ions have also been computed and discussed. Ion exchange is probably one of the major adsorption mechanisms for binding divalent metal ions to the walnut sawdust. The selectivity order of the adsorbent is Pb(II)≈Cd(II)>Ni(II). From these results, it can be concluded that the sawdust of walnut could be a good adsorbent for the metal ions from aqueous solutions.

Selective degradation of wood lignin over noble-metal catalysts in a two-step process.

Abstract: Direct conversion of lignin into alkanes and methanol was carried out in a two-step process (hydrogenolysis and hydrogenation) involving initial treatment of white birch wood sawdust with H2 in dioxane/water/phosphoric acid using carbon supported Ru, Pd, Rh, or Pt as catalysts. The resulting monomers and dimers obtained by selective C-O hydrogenolysis were then hydrogenated in near-crit. water empolying Pd/C as the catalyst. The study is of interest with respect to prodn. of biofuel from lignin.