Showing papers on "Sawdust published in 1997"

Pretreatment of yellow poplar sawdust by pressure cooking in water

Abstract: The pretreatment of yellow poplar wood sawdust using liquid water at temperatures above 220°C enhances enzyme hydrolysis. This paper reviews our prior research and describes the laboratory reactor system currently in use for cooking wood sawdust at temperatures ranging from 220 to 260°C. The wood sawdust at a 6–6.6% solid/liquid slurry was treated in a 2 L, 304 SS, Parr reactor with three turbine propeller agitators and a proportional integral derivative (PID) controller, which controlled temperature within ±1°C. Heat-up times to the final temperatures of 220, 240, or 260°C were achieved in 60–70 min. Hold time at the final temperature was less than 1 min. A serpentine cooling coil, through which tap water was circulated at the completion of the run, cooled the reactor’s contents within 3 min after the maximum temperature was attained. A bottoms port, as well as ports in the reactor’s head plate, facilitated sampling of the slurry and measuring the pH, which changes from an initial value of 5 before cooking to a value of approx 3 after cooking. Enzyme hydrolysis gave 80–90% conversion of cellulose in the pretreated wood to glucose. Simultaneous saccharification and fermentation of washed, pretreated lignocellulose gave an ethanol yield that was 55% of theoretical. Untreated wood sawdust gave less than 5% hydrolysis under the same conditions.

Simultaneous saccharification and fermentation of pretreated hardwoods - effect of native lignin content

Abstract: A series of correlations was made between the performance of 15 wood species in simultaneous saccharification and fermentation (SSF) and their respective chemical compositions. A compelling inverse trend (p < 0.001) was demonstrated between the percent conversion of glucan to ethanol during SSF and the Klason lignin content of the wood samples before dilute acid pretreatment. No significant relationships were found between the glucan, xylan, and ash compositions of the native wood samples and ethanol yield. This observation is unique and provides a convenient predictor of biomass conversion efficiency.

Kinetics of Pb(II) adsorption by polyacrylamide grafted sawdust

Abstract: Lead(II) removal efficiency of polyacrylamide grafted sawdust has been investigated through laboratory experiments. Kinetic measurements have been made as a function of solution concentration of Pb(II) ions, pH and temperature. The slow step governing the rate of exchange is diffusion of ions through the exchanger particles. The equilibrium data fit well with the Langmuir isotherms. Thermodynamic parameters were also presented to predict the nature of adsorption. Adsorbent can be regenerated with acid and can then be reused.

Removal of heavy metal ions from water using sawdust-based activated carbon

Abstract: The removal of Pb(II), Hg(II) and Cd(II) by activated carbon prepared from bicarbonate-treated rubber wood sawdust has been found to be concentration, pH and temperature dependent. The percentage adsorption of metal ions increased with decrease in initial concentration of metal ions, increase in adsorbent dosage and temperature. The optimum pH range for the removal of ~b(II) and Hg(II) is 4-8 whereas maximum uptake for Cd(II) is in the pH range 5-9. The applicability of Lagergren kinetic model has also been investigated. The equilibrium data at different temperatures fit well with the Langmuir isotherm. Thermodynamic constant (Ko) and standard free energy (t.GO), enthalpy (M?) and entropy (&5°) changes were calculated for predicting the nature of adsorption. The surface mass transfer coefficient as a function of initial adsorbate concentration has been determined. Desorption studies revealed that spent adsorbent can be regenerated and reused by 0.2 M HC!. The presence of heavy metals in the environment can be detrimental to a variety of living species. Therefore, the elimination of heavy metals from water and wastewater is important to protect public health. Many reports have appeared on the development of activated carbon from cheaper and readily available materials for the removal of metals from water':'. Activated carbon derived from rice husk', coconut shell", waste slurry generated from fertilizer plant', peanut huW' and waste tea leaves" has been successfully employed for the removal of heavy metals from aqueous solutions. Our search for a cheap readily available starting material has identified sawdust as a potentially attractive material for the production of activated carbon for water treatment. Sawdust is a cheap raw material and in abundant supply. The huge deposit of sawdust around sawmills poses problems in its disposal. Besides its utilization in preparing packing materials it has also been recently used in water pollution control"!". The present investigation aims at using bicarbonate treated activated carbon prepared from sawdust, a low cost and highly effective adsorbent for the removal of hea vy metals namely Pb(II), Hg(II) and Cd(I1) from aqueous systems.

Animation of Wood Sawdust for Removing Anionic Dyes from Aqueous Solutions

Abstract: Inexpensive and efficient cellulose-based adsorbents were prepared by the reaction of cross-linked polyethylenimine (CPEI) with an agricultural waste (i.e., wood sawdust). Factors affecting the extent of amination, such a CPEI concentration, pH, time, and temperature of reaction as well as sawdust particle size range, were studied. The obtained adsorbents were found to be highly effective for removal of anionic dyestuffs (i.e., direct, reactive, and acid dyes) from aqueous solutions. The presence of CPEI on and/or within the purified sawdust provides cationic active sites (i.e., amino groups) and enhances the substantivity of wood cellulose for anionic dyes, thereby improving the percent color removal.

Use of chemically modified sawdust in the removal of Pb(II) ions from aqueous media

Abstract: The sorption of Pb(II) on polymerized sawdust has been found to be dependent on contact time, concentration, temperature, article size and pH. Maximum removal of 98.6 percent with 2.0 g/L of sorbent was observed at 10.0 mg/L sorbate concentration, 6.0 pH and 60°C. The process follows first order kinetics with diffusion , controlled nature and the equilibrium data fit well with the Langmuir and Freundlich isotherms.

The destruction effect of a pulse discharge in water suspensions

Abstract: A high-energy capacitor bank in a Blumlein circuit) was discharged over about through a 7 mm electrode gap in water suspensions of different materials - powder, wood materials (sawdust, needles) - and methylhydroxyethylcellulose dissolved in water. The Mach number of the compressional wave produced by the expanding discharge channel achieved a value of about 0.5. The destruction of added materials was tested using various methods: turbidity and covering ability of the -white, acid hydrolysis of beech sawdust, microbiological processes of spruce needles and molecular weight measurements of the cellulose derivative. In the used power conditions the physical destruction of materials dispersed in water (degassing and decomposition of physically bonded particles) is a dominant effect caused mainly by the compressional wave that can affect material in the whole volume. The chemical destruction probably occurs just in the vicinity or inside the plasma channel due to the action of plasma particles or energetic radiation.

Survey and mapping of wood residue users and producers in Louisiana.

Abstract: Natural by-products of the forest products industry are biomass residues such as bark, wood chips, and sawdust Disposing of them poses problems for the air and water One popular waste management solution is to use them for fuel To measure the potential for using wood residue for fuel and other uses, a study was conducted of the primary and secondary wood processors in Louisiana The study revealed that while some firms use wood residues for their own boilers, or sell it to others for fuel, there is still unused waste One reason for this may be the lower cost of competing energy sources A geographic information system (GIS) was used to map all sites claiming to produce and/or consume wood residue These data are layered with timber supply data from the USDA Forest Service A hardcopy directory of biomass sites, including cotton gin trash, rice hulls, and sugar bagasse was developed for public distribution

Solid fuel products free of slag formation and method of producing same

Abstract: A biomass such as bark, wood shavings, peat moss, paper, cardboard, sludges, etc. sawdust has homogeneously blended therein at least 0.025 weight percent of an additive which is capable of raising the fusion temperature of slag forming substances that may be present in the biomass material, above the temperature in a combustion chamber when burning the biomass. The method of manufacturing same is also disclosed. The result is that no slag is formed in the combustion chamber and the impurities accumulated as friable ash can easily be discarded.

Exothermic material for warming

Abstract: The exothermic material consists mainly of iron powder, water solution of sodium chloride, sawdust, active carbon powder and zeolite in the ratio of 10 to 7 to 1 to 1 to 1. The said material may be reused.

Mushroom cultivation medium and mushroom cultivation method using the medium

Abstract: PROBLEM TO BE SOLVED: To obtain a mushroom cultivation medium as a substitute for sawdust from an easily available inexpensive raw material for medium. SOLUTION: Mesocarp 20 of coconut is sufficiently dried to a water content of about 18wt.%. The dried mesocarp 20 is crushed with a crusher and sieved. Fibers are removed from the crushed mesocarp 20 to obtain powdery residue having particle diameter of about 0.5-3mm. The residue is used as a main raw material for a mushroom cultivation medium as a substitute for sawdust to obtain the objective mushroom cultivation medium.

Production of activated carbon using industrial waste containing carbohydrate

Abstract: PROBLEM TO BE SOLVED: To obtain activated carbon useful as a building material, aggregate for health-promoting instrument, a cleaning agent for city water, etc., by the reutilization of industrial wastes with little generation of toxic gas at a low cost by baking industrial waste containing carbohydrate at a specific temperature. SOLUTION: An industrial waste containing carbohydrate (e.g. wood chips or animal and vegetable residues generated from wood manufacturing industry, removal of work, etc., concretely the residue in food preparation industry, sawdust, chaff, beer cake and bean curd refuse) is burned at a temperature not to cause the combustion of carbon, e.g. at 600-800 deg.C to cause little loss of the furnace and suppress the generation of toxic gases originating from chlorine, sulfur, etc.

Treatment of waste slurry of wire saw

Abstract: PROBLEM TO BE SOLVED: To inexpensively and simply treat the waste slurry from a wire saw SOLUTION: Grinding particles are separated from the waste slurry discharged from a wire saw by a decanter 51 and a cut powder or the like is separated by a filter 52 to recover a dispersion and a part of the grinding particles and the dispersion is fed to a preparing tank 2 The remainder of the dispersion is supplied to a waste slurry treatment tank 7 and brought into contact with aerobic bacteria having org matter decomposition properties supported on sawdust By this method, the org matter in the dispersion is decomposed to carbon dioxide and water by bacteria and water is removed by evaporation during treatment or by solid-liquid separation Bacteria, sawdust and inorg matter are contained in the treated matter obtained by the treatment of the waste slurry and the treated matter is subjected to air flying treatment in an air flying treatment apparatus 8 to be separated into sawdust and inorg matter and the sawdust having bacteria bonded thereto is recovered

Reconstituted oak or beech log for smoking food

Abstract: Reconstituted oak or beech log wood is used for smoking e.g. salmon. The reconstituted log (1) is made of wood chips (2), sawdust, flat sheets or thin strips of wood from broad leaved trees such as oak and/or beech. The dried pieces of wood are held together by a starch binder (3), or other compound which will not harm the quality of the product. Strips of wood are positioned offset from each other for strength. The log includes, by weight, 20 to 40% binder, 60 to 80% wood and 0 to 10% flavoring, coloring or preservative additives.

Propagation of Cestrum nocturnum cuttings as affected by different soil media and irrigation intervals

Abstract: Response of Cestrum nocturnum cuttings to different soil media and irrigation intervals was studied under the agro-climatic conditions of Peshawar. Four different combinations of sand, silt, clay and sawdust i.e sand + silt + sawdust (1:1:1), sand + clay + sawdust (1:1:1), silt + clay + sawdust (1:1:1), sand + silt + clay + sawdust (1:1:1:1) were made and were subjected to different irrigation intervals i.e. daily irrigation, irrigation with alternate days and at two days interval. Maximum values for number of cuttings sprouted (86.66%) plant height (38.95 cm), trunk thickness (0.489 cm), stem weight (19.15 g), leaf area (4.53 cm2), number of leaves (43.88), and branches per plant (3.77) were recorded for the plants growing in silt + clay + sawdust. While maximum plant survival (97.77%) was observed in sand + clay + sawdust. All the parameters were found maximum at daily irrigation. Media-irrigations interaction was highest in silt + clay + sawdust at daily irrigation as regards number of cuttings sprouted (100 %), plant height (50.70 cm), stem weight (30.35 g), leaf area (5.76 cm2), number of leaves per plant (62.66).

Method for producing of microcristallic cellulose

Abstract: The purpose of this invention is to develop the method of obtaining microcrystal cellulose from non dry wood mechanical processing wastes (for example sawdust), by using a single-stage vapour cracking process without extra mechanical or chemical after-treatment. The essence of the invention: the deciduous or needle wood sawdust processed with 4% acetic acid is being handled in the reactor for 2-3 minutes with water vapour at 250 degrees C temperature with quick decompression following, discharging the mass from the reactor. All the products have to be used with purpose after mass extraction in watery lixivium solution, the acid component is used for the preprocessing of the next output sample, but the remaining extract's faction can be used as a valuable cohesive substance.

Washing system for wood chips

Abstract: To wash wood chips or sawdust, the mixture of wood chips/sawdust and water is held in a vacuum. The gas contained within the wood expands and rises to the top of the mixture, while impurities sink to the bottom. The wood/sawdust is raised to a level over the mixture feed, and the impurities are removed from the base. Also claimed is an assembly with a suction line (10) connected to the washing vessel (1). The outlet (3) for the washed material is at a level over the entry (2) into the vessel (1). The outlet (4) for the impurities is at the base of the vessel.

Sewage cleaning agent

Abstract: PROBLEM TO BE SOLVED: To enable sewage cleaning to be performed easily and quickly without causing an unpleasant feeling by using a mixture of sawdust, a water-absorbing polymer powder, and a drying agent powder as a sewage cleaning agent. SOLUTION: A mixture prepd. by properly mixing sawdust, a water-absorbing polymer powder, and a drying agent powder is used as a sewage cleaning agent. A perfume such as a herb may be added to the mixture to make an operator not to feel the bad odor of sewage. Japanese cypress sawdust absorbs an oil well and can be homogeneously dispersed in the water-absorbing poylmer powder. For example, 50g of sawdust, 5g of a water-absorbing polymer powder, 2.5g of a drying agent powder, and 2.5g of a perfume are mixed to give the objective agent in an amount of 60g.

Determination of thermophysical properties of partly pyrolyzed fire retardant-treated sawdust

Abstract: Experiments were carried out to investigate the effect of pyrolysis temperature and phosphorus-containing impregnating compounds on thermal properties of specimens made of compacted sawdust.

Method of washing sawdust and arrangement for carrying out the method

Abstract: Methods for washing sawdust are disclosed which include providing a mixture of sawdust and water to a vessel, subjecting the mixture to a reduced pressure so that gases present in the sawdust cause expansion therein and the sawdust rises to the surface of the mixture while the contaminants descend within the vessel, and withdrawing the sawdust from the vessel, in which the sawdust is withdrawn from the vessel at a location above the point where the sawdust and water enter the vessel. Apparatus for carrying out this method is also disclosed.