Showing papers on "Sawdust published in 1998"

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.

Gasification of sewage sludge and other biomass for hydrogen production in supercritical water

Abstract: Digested sewage sludge and other biomass such as wood saw-dust can be mixed with a corn starch gel to form a viscous paste. This paste can be delivered to a supercritical flow reactor by means of a cement pump. Different types of feedstocks are used in this work: sewage sludge (up to 7.69 wt%) mixed in the corn starch paste, poplar wood sawdust (up to 11.46 wt%) mixed in the corn starch paste. When rapidly heated in a flow reactor at pressures above the critical pressure of water (22 MPa) the paste vaporizes. A packed bed of carbon catalyst in the reactor operating at 650°C causes the tarry vapors to react with water, producing hydrogen, carbon dioxide, and some methane with a trace of carbon monoxide. Thus we describe a practical method for the total, supercritical steam reforming of biomass to produce hydrogen at high pressure. The steam reforming process produces effectively no tar. Its only products are a hydrogen rich gas, and a clean water, which can be recycled.

Continuous pH monitoring during pretreatment of yellow poplar wood sawdust by pressure cooking in water.

Abstract: Yellow poplar wood sawdust consists of 41% cellulose and 19% hemicellulose. The goal of pressure cooking this material in water is to hydrate the more chemically resistive regions of cellulose in order to enhance enzymatic conversion to glucose. Pretreatment can generate organic acids through acid-catalyzed degradation of monosaccharides formed because of acids released from the biomass material or the inherent acidity of the water at temperatures above 160°C The resulting acids will further promote the acid-catalyzed degradation of monomers that cause both a reduction in the yield and the formation of fermentation inhibitors such as hydroxymethyl furfural and furfural. A continuous pH-monitoring system was developed to help characterize the trends in pH during pretreatment and to assist in the development of a base (2.0 M KOH) addition profile to help keep the pH within a specified range in order to reduce any catalytic degradation and the formation of any monosac-charide degradation products during pretreatment. The results of this work are discussed.

Removal of CCA from treated wood by oxalic acid extraction, steam explosion, and bacterial fermentation

Abstract: Most preservative-treated wood produced and consumed in the United States is treated with toxic inorganic compounds containing copper, chromium, and arsenic. Because chromated copper arsenate (CCA) is fixed to the wood, CCA-treated wood has not been considered toxic or hazardous and it is currently disposed of in approved landfills. Growing public concern about environmental contamination from treated wood combined with the removal of greater quantities of CCA-treated wood from service have presented a disposal challenge for this fiber source. In this study, CCA-treated wood was processed by acid extraction, steam explosion, and bacterial fermentation and evaluated for removal of copper, chromium, and arsenic. Copper was the easiest to remove by these treatments and chromium the most resistant to removal. Exposing CCA-treated wood to steady-state bacterial growth by continuous culture with Bacillus licheniformis CC01 did not enhance removal of CCA components compared to standard mixed culture when acid extraction preceded bacterial fermentation. Nor did steam explosion, alone or in conjunction with acid extraction and bacterial fermentation, enhance removal of CCA components; the chromium and arsenic components resisted removal. Grinding CCA-treated wood chips into 20-mesh sawdust provided greater access to and removal of CCA components by all processes. However, grinding the chips was unnecessary if they were treated with acid prior to bacterial fermentation. Extraction with oxalic acid as a precursor to bacterial fermentation with B. licheniformis CC01 removed 90% copper (CuO), 80% chromium (CrO3), and 100% arsenic (As2O5) from treated chips. The combination of acid extraction and bacterial fermentation removed 80–100% of these metals from CCA-treated wood.

Composting of Fish Waste with Wood By-Products and Testing Compost Quality as a Soil Amendment: Experiences in the Patagonia Region of Argentina

Abstract: Composting experiments of fish processing wastes and wood by-products were conducted in the Andean-Patagonian Region. Fish wastes were mixed with sawdust + wood shavings (3:1 ratio by weight) with ...

Urban Wood Waste Resource Assessment

Abstract: This study collected and analyzed data on urban wood waste resources in 30 randomly selected metropolitan areas in the United States. Three major categories wood wastes disposed with, or recovered from, the municipal solid waste stream; industrial wood wastes such as wood scraps and sawdust from pallet recycling, woodworking shops, and lumberyards; and wood in construction/demolition and land clearing debris.

Adsorption thermodynamics of Co(II) on polysulphide treated sawdust

Abstract: Sawdust of rubber wood has been subjected to surface modification by treatment with sodium polysulphide. The product exhibits a good adsorption potential for Co(H). The percentage of Co(H) adsorption increases with increase in temperature and decrease in initial Co(H) concentration. Sorbent is effective for the quantitative removal of Co(H) over the pH range 4-10. The applicability of the Lagergren and Freundlich equations for metal removal has been tested at different temperatures and the adsorption has been found to be endothermic. Thermodynamic parameters have also been calculated to predict the nature of adsorption. The spent sorbent can be regenerated by acid and can be reused. Discharges from chemical manufacturing industries, electroplating and metallurgical

Ash characteristics of high alkali sawdust and sanderdust biomass fuels

Abstract: Suspension firing of sawdust and sanderdust fuels is often used in the wood product's industry to raise steam and provide a heat source for drying and curing operations. The unusually high alkali content of these fuels can give rise to a number of problems that affect the operation of downstream plant systems. The research reported here focuses on the physical and chemical properties of the ash generated by these unique and important biomass fuels and uses this information to identify the mechanisms that control mineral-to-ash transformations. Four sanderdust and sawdust fuels, typical of those used to fire industrial-scale suspension burners, are fired in a laboratory-scale tunnel furnace. Size distribution, morphology, and size versus composition are obtained for particles between 0.0075 and 10 μm by combining a cascade impactor and an electrical aerosol analyzer (EAA). Each of the fuels showed a dominant mode of calcium-rich skeletal particles of size ≥8.3 μm that are the residue from char burnout. A second, minor mode that seems to be the result of fragmentation appears at 1–3 μm. This consists of fluxed particles that, while still predominantly calcium, also contain Fe, Al, Mn, and Si. Another minor mode at 0.4 μm also appears to be the result of fragmentation. Much of the alkali mineral matter becomes submicron aerosol via the vaporization, condensation, coagulation mechanism. This large yield of aerosol (of the order of 30% of the total ash mass) appears as chlorides in high chlorine fuels and as sulfates and carbonates otherwise. In general, only a small fraction of the alkali metals are captured by the residual ash, and no metals other than Na and K are generally detected with the aerosol. The aerosol size varies between 0.01 and 0.1 μm depending on experimental conditions.

Clay addition to soilless media promotes growth and yield of greenhouse crops

Abstract: Clay is a major physical component of soil, and by convention is omitted from soilless media. A sterilized, nonswelling chlorite mica clay, sieved to a particle size of <0.3 mm, was used to determine whether its addition to a sawdust medium would improve the production of greenhouse vegetable and flower crops. In early experiments with cucumber, the clay was applied daily as a suspension in the nutrient solution (0, 1, 5, or 10 g.L -1 ). The number of marketable cucumber (Cucumis sativus L.) fruit increased significantly with increasing concentration of clay. The harvest period in these trials was relatively short (up to 4 weeks). In subsequent long-term trials (up to 18 weeks of harvest), the clay was mixed into the sawdust before planting at rates of 0, 4.3, 21.4, and 42.8 g.L -1 of sawdust. Again, the number of marketable cucumber fruit increased significantly with increasing clay concentration. In trials with potted geraniums (Pelargonium x hortorum L.H. Bailey) and hybrid impatiens (Impatiens wallerana Hook.f.), the clay was applied daily to the sawdust as a suspension in the nutrient solution (0, 1, 5, or 10 g.L -1 ). In both species, the number of flowers increased significantly with increasing clay concentration, and the size (fresh and dry mass) of the geraniums also increased. In the absence of plants, addition of clay significantly increased water content of the sawdust at matric potentials tested from -1 to -100 kPa, and increased bulk density.

Carbonization and briquetting of sawdust for use in domestic cookers

Abstract: CARBONIZATION AND BRIQUETTING OF SAWDUST FOR USE IN DOMESTIC

Assessing the availability of wood residues and residue markets in Virginia

Abstract: A statewide mail survey of Virginia's wood products manufacturers was conducted to quantify the generation and consumption of wood residues in Virginia. A total of 266 wood products manufacturers responded to the study. They provided information on the generation, consumption, markets, income or disposal costs, and disposal methods of wood residues. Hardwood and pine sawmills generate approximately 66 percent of Virginia's wood residues. Virginia's wood products manufacturers generate three primary residues: chips, bark, and sawdust. These three residues comprised nearly 83 percent of Virginia's total residue generation in 1996. Approximately 197,400 tons or 6 percent of Virginia's wood residues appear not to have adequate markets. Furthermore, we estimate that primary manufacturers have approximately 267,000 tons of wood residues and secondary manufacturers have nearly 127,000 tons of wood residues without adequate markets in 1996.

Sawdust fluid-bed drying with heating tubes

Abstract: Sawdust drying in a batch fluidized bed with heating tubes submerged in the bed is experimentally analyzed; the results are compared with those obtained in a bed without immersed surfaces. Variables of the hydrodynamic behaviour as well as drying curves are obtained. With these results, the thermal process of the equipment is analyzed, evaluating drying time, product output rates and specific consumption of energy.

Production of material with high content of silica, cellulose and lignin

Abstract: PROBLEM TO BE SOLVED: To simply produce the subject material increased in specific surface area by grinding and useful as an agricultural and horticultural material, a material for cements, a raw material, etc., for a high-purity silica from a raw material which has hitherto been mostly incinerated by carrying out a blasting or a cooking treatment of a woody material. SOLUTION: The blasting or cooking treatment of a woody material such as chaff, rice straw, bagasse or sawdust is carried out using, e.g. 5-30 kg/cm gauge pressure as a pressurizing pressure and the resultant material, as necessary, is then carbonized at, e.g. 300-800 deg.C temperature for 10 min to 3 h in an apparatus, etc., for producing a leaf charcoal or ashed at, e.g. 550-900 deg.C temperature. The blasting or cooking treatment is preferably conducted by adding an acid or a buffer solution so as to provide 10 to 10 mol.dm hydrogen ion concentration.

Changes In Moisture Retention Properties Of Five Waste Materials During Short-Term Mesophilic Composting

Abstract: The effect of composting for a maximum period of 90 days on the water retention characteristics of five waste materials — coconut dust (CD) (also known as coir), mixed sawdust (SD), rice hulls (RH), sapwood sawdust (SW) and heartwood sawdust (HW) was investigated with or without the addition of nitrogen. Total porosity (TP), easily available water (EAW) and water buffering capacity (WBC) were increased with time in all five materials, while air space (AS) was decreased in all the materials except in rice hulls, where it increased. Of all the materials, CD retained the most moisture and RH the least after 90 days. SD, SW and HW had similar characteristics, and separation for utilization is unnecessary. Nitrogen addition did not affect TP and AS but slightly increased EAW and WBC. Formulation and management of potting media using these materials should take into account these moisture retention changes for maximum benefit to plants grown in them.

Process for the total removal of purines, plant for implementing such process and natural fertilizer obtained

Abstract: The procedure consists of mixing purines with cow dung, chicken pellets and sawdust or an equivalent vegetal absorbent material, homogenising the mixture in a vat with a stirring mechanism, to deposit the mixture obtained or biomass in piles from where it is removed, turned over and aerated for about 11 days, moving the piles towards the edge for collection to then deposit the product in beds for maturation or to send them to a parallel installation for grinding, drying, maturing and pelletising the product. The product obtained is a natural fertiliser which can be used directly as a fertiliser or as a raw material in other industrial processes.

Composition for manufacture of fuel briquettes

Abstract: The present invention relates to the fields of fuel industry and utilization of waste from woodworking, paper and pulp, coal and peat mining industries; it represents composition for manufacture of fuel briquettes comprising crushed secondary carbon-containing feed stock: petroleum pitch, coal pitch, coal dust, crushed coal product, crushed peat, wood shavings, sawdust or their mixes and binder: lignin-containing product selected from the group: lignin, lignosulfonate, hydrolytic lignin, black sulfate liquor or their mixes, or mix of one or several above enumerated lignin-containing products with a-cellulose. Composition allows manufacture of ecologically clean fuel briquettes from practically any solid secondary carbon-containing feed stock featuring high calorific value (up to 7000 cal/g), density of 1.04-1.18 g/cm and ash content of 0.8-1.2 %.

Flame-retarding properties of ion-exchanging groups introduced into beech sawdust

Abstract: Ion exchangers prepared from beech sawdust by introduction of weak and strong basic ion-exchanging groups were analysed with thermogravimetry, differential scanning calorimetry and limited oxygen index methods to evaluate their thermal stability and flame-retarding properties. By cross-linking with epichlorohydrin in the presence of NH 4 OH, ion exchangers in free form or in H 3 BO 3 or H 3 PO 4 form were obtained with increased thermal stability in comparison to the starting material. By cross-linking and quaternization of sawdust in one step with 1,3-bis(3-chloro2-hydroxypropyl)imidazolium hydrogen sulfate, a material with better thermal stability and flame-retarding properties was obtained than by the previous procedure. This resulted in greater residues at higher temperatures as measured by dynamic thermogravimetry. The values of rate constants and activation energies of gasification calculated from isothermal thermogravimetric measurements decreased with improved thermal resistance similar to heat effects observed with differential scanning calorimetry. Limited oxygen index values up to 35.6% were obtained.

Production of composite material from wood flour and thermoplastic resin

Abstract: PROBLEM TO BE SOLVED: To facilitate a form of molding processing and to enable stable opera tion by melting and mixing a thermoplastic resin and wood flour in a twin-screw extruder having a vacuum vent and a specific kneeding block to extrude the resulting molten mixture. SOLUTION: Wood flour is supplied to a twin-screw extruder 2 from a compactor 1 while a resin is supplied thereto from the hopper 5 on the upstream side of the compactor 1. The number of kneedlng blocks 3 is set to 1 or 2 to reduce the generation of heat in the wood flour by shearing to prevent the scorching of the wood flour. Further, in order to remove volatile components such as moisture, wood vinegar or the like from the wood flour, vacuum vents 4 are provided at two or more places on the upstream side of the kneading block 3 and at one or more places on the downstream side thereof. As a mixing material, 30-60 pts.wt. of a thermoplastic resin such as a polyester or polyamide is kneaded with 40-70 pts.wt. of the wood flour with moisture content of 5wt.% such as sawdust generated from crushed chips or pulp.

Building material made of thermoplastic resin and manufacture thereof

Abstract: PROBLEM TO BE SOLVED: To improve the productivity and enhance the feel of the wood so that resources can be effectively utilized by forming a building material from an outer member prepared by molding a thermoplastic resin composition containing a specific amount of wood powder in a thermoplastic resin and an inner member prepared by expansion-molding a thermoplastic resin composition. SOLUTION: The building material is formed from an outer layer member prepared by molding a thermoplastic resin composition containing a wood powder of 20-200 pts.wt. per 100 pts.wt. of a thermoplastic resin material and an inner layer member prepared by expansion-molding a thermoplastic resin composition. The thickness of the outer layer is preferably 1-10 mm, while the thickness of the inner layer is 2-300 mm. As the thermoplastic resin, polyethylene, polypropylene and vinyl chloride can be preferably used since they provide improved feel of wood appearances. As the wood powder, sawdust, crushed wood shavings, lumber from thinning, crushed dead tree, etc., are used, and particularly, a wood powder prepared by piling the shavings from lumber mills, partially fermenting and drying them can be properly used since it has high affinity to a resin and an average particle size is 30-500 μm. COPYRIGHT: (C)2000,JPO

Studies on the Development of Casing Materials Using Sawdust Bottle Culture in Cultivated Mushroom, Agaricus bisporus

Abstract: After bottle culture of Pleurotus ostreatus, sawdust was taken out from the bottle and accumulated in the middle of March, and then composted. As the result, Y value was decreased rapidly 30 days after composting, and it was decreased slowly after 30 days. It is considered that 118 days is required for composting, however, it is possible to use for casing material after at least 48 days composting. The pH and total nitrogen content of sawdust based on composting period had tendency to increase as composting was processed. Total carbon and C/N rate had tendency to decrease as time went on. Based on the rate of 10, 30 and 50%, each sawdust was added to clay loam used as casing material for culturing A. bisporrus. Among various treatments, the mycelial growth of A. bisporus was more favorable in the treatment of 30% sawdust than in the single treatment of clay loam. Based on the date necessary for primodium formation of A. bisporus, the primodium formation in the treatment of 30% sawdust was reduced to about 5 days as compared with that of any other treatments When 30% sawdust was added to clay loam used as casing material for culturing A. bisporus, the yield of its fruiting body was increased to 28%.

Mycelial Growth of Phellinus linteus with Various Sawdusts

Abstract: This study was carried out to obtain the basic data on artificial culture of Phellinus linteus. The suitable sorts of sawdusts artifical culture for Phellinus linteus were an oak sawdust, a mulberry sawdust, a peach sawdust. Rice bran, wheat bran and corn seed peel were found to be effective additives, and optimun mixing ratio of an oak sawdust and additives was from to percent. The suitable moisture content of sawdust media was obtained in the range of . The mixture of percent oak sawdust with 20 percent rice bran in polypropylene (850 cc) bottle was suitable for starter production, and it took 55 days to produce the starters at .