Waste Sawdust Research Articles

Composites from Sawdust–Rice Husk Fibers

Sawdust waste and rice-husk fibers, which are lignocellulosic materials, were assessed in terms of their fiber-matrix adhesion and dispersion in composites. Different types of adhesives were used. The mechanical and water absorption properties were investigated. Overall, for the produced composites, the incorporation of phenol-formaldehyde resin into sawdust–rice husk ethylene vinyl acetate composite resulted in the best mechanical properties. The superior reinforcing characteristics of phenol-formaldehyde resin were shown by scanning electron microscopy (SEM), which revealed better fiber-matrix adhesion. Water absorption tests revealed that the presence of the adhesives affected the amount of water absorbed.

Cement composites with limestone dust and different grades of wood sawdust

This paper presents a parametric experimental study which investigates the potential use of limestone powder wastes (LPW) and wood sawdust wastes (WSW) combination for producing a lightweight composite as a building material. Some of the physical and mechanical properties of brick materials having various levels of LPW and WSW with different particle sizes are investigated. The obtained compressive strength, flexural strength, unit weight, ultrasonic pulse velocity (UPV) and water absorption values satisfy the relevant international standards. The results show the effect of high level replacement of WSW with LPW does not exhibit a sudden brittle fracture even beyond the failure loads, indicates high energy absorption capacity, reduce the unit weight dramatically and introduce a smoother surface compared to the current bricks in the market. It shows a potential to be used for walls, wooden board substitute, alternative to the concrete blocks, ceiling panels, sound barrier panels, absorption materials, etc. Recycling of unmanaged WSW and LPW as new brick material supplements appears to be viable solution not only to the environmental problem but also to the problem of the economic design of buildings.

Limestone dust and wood sawdust as brick material

The majority of abandoned limestone powder wastes (LPW) and wood sawdust wastes (WSW) is accumulated from the countries all over the world and causes certain serious environmental problems and health hazards. This paper presents a parametric experimental study which investigates the potential use of WSW–LPW combination for producing a low-cost and lightweight composite as a building material. Some of the physical and mechanical properties of concrete mixes having high level of WSW and LPW are investigated. The obtained compressive strength, flexural strength, unit weight, ultrasonic pulse velocity (UPV) and water absorption values satisfy the relevant international standards. The results show that the effect of high-level replacement of WSW with LPW does not exhibit a sudden brittle fracture even beyond the failure loads, indicates high energy absorption capacity, reduces the unit weight dramatically and introduces smother surface compared to the current concrete bricks in the market. It shows a potential to be used for walls, wooden board substitute, economically alternative to the concrete blocks, ceiling panels, sound barrier panels, etc.

Sawdust—A green and economical sorbent for the removal of cadmium (II) ions

The ability of sawdust (treated and untreated) waste, a waste material derived from the commercial processing of cedrus deodar wood for furniture production, to remove/preconcentrate Cd(II) ions from aqueous solution was determined. Sorption was found to be rapid (∼97% within 8 min). The binding of metal ions was found to be pH dependent, optimal sorption accruing at around pH 4–8. Potentiometric titrations of sawdust revealed two distinct p K a values, the first having the value similar to carboxylic groups (3.3–4.8) and second comparable with that of amines (8.53–10.2) with the densities 1.99 × 10 −4 and 7.94 × 10 −5, respectively. Retained Cd(II) ions were eluted with 5 ml of 0.1 mol l −1 HCl. Detection limit of 0.016 μg ml −1 was achieved with enrichment factors of 120. Recovery was quantitative using sample volume of 600 ml. The Langmuir and D–R isotherm equations were used to describe partitioning behavior for the system at different temperatures. Kinetic and thermodynamic behavior of sawdust for Cd(II) ions removal was also studied.

Preparation of Cellular Iron Using Wastes and its Application in Dyeing Wastewater Treatment

Cellular iron (porous iron) was prepared using a mixture of iron filings (waste from machinery industry) or pure iron powder with sawdust (waste from wood industry) and Bisphenol A epoxy resin, heated at 700–750∘C. The porosity of cellular iron increased with the amount of sawdust serving as space-holding filler in the mixture. Carbon oxide gases as burning products of sawdust formed a reducing furnace atmosphere and created additional pores in the iron matrix. When the ratio of iron filings to sawdust was 2:1, the porosity of cellular iron was up to 80%. Batch and column experiments of treating dyeing wastewaters with cellular iron indicate that the decolorization process, a quasi-first order reaction, was pH-dependent. Under acidic conditions, the color removal efficiency using cellular iron was up to 75–80% and three times faster than that using iron filings. The proposed technology has great potential for use in cellular iron mass production and wastewater treatment.

An Improved Compost Using Cotton Waste and Fermented Sawdust Substrate for Cultivation of Oyster Mushroom

A composting technique was assessed to enhance efficiency in oyster mushroom substrate. Poplar sawdusts and by-product of winter mushroom added by 10% of rice bran were composted outdoors at 20°C to 28°C for 12 days. The duration of fermentation was shortened 3 days in fermented sawdust plot. The yield obtained from waste cotton substrate with fermented poplar sawdust was 742 g, whereas the yield from control 663 g. In addition, the substrate with by-product of winter mushroom was the most effective to composting. It was useful to apply the fermented sawdust and by-product to waste cotton for compost and sporophore production of oyster mushroom.

04/02478 Thermoeconomic optimization of heat recoverysteam generators operating parameters for combined plants: Casarosa, C. et al. Energy, 2004, 29, (3), 389–414

Under the sponsorship of the Pennsylvania Electric Company (Penelec), and with the support of EPRI, the U.S. Department of Energy, and the Pennsylvania Department of Conservation and Natural Resources, Penelec and Foster Wheeler Environmental Corporation conducted low percentage (3% by weight) wood cofiring tests at Units 2 and 3 of the Shawville Generating Station in November 1995. Unit 2 is a 138 MWe (gross) wall-fired pulverized coal boiler equipped with ball and race mills, table feeders, and low-NOx burners. Unit 3 is a 190 MWe (gross) tangentially-fired pulverized coal boiler equipped with bowl mills, paddle feeders, and low-NOx burners. There is no spare capacity in the pulverizing systems of either unit when operating under full load conditions.This project was unique in a number of respects, expanding the knowledge and cofire experience base achieved in other previous projects (ref. 1). First, the project tested the use of blended biofuels in boilers equipped with low NOx burners. Additionally, three types of biofuel were tested: (1) mill waste sawdust, (2) utility right-of-way trimmings, and (3) harvested hybrid poplar. Biofuels were processed off-site, blended at a nearby coal blending yard, and then trucked to the unmodified Shawville Station on a “just-in-time” schedule basis. The off-site fuel preparation and blending operations provided an adequate supply of blended biofuel and coal to allow the project to meet its overall test objectives, and also provided much useful new data and information needed to help establish commercial processing facilities.Plant operating technical objectives were to determine the impacts of using low percentage biofuel blends on boiler capacity, efficiency, stability, temperature, and air/solid waste emissions. Significant boiler capacity limitations were experienced on both units when cofiring 3 percent biomass blends. The 138 MWe boiler lost 8–10 MWe of capacity due to feeder limitations, and the 190 MWe boiler lost 15 MWe of capacity due to significant reductions in mill outlet temperatures. For both units, the 3 weight percent biofuel blends behaved like wet coal.Significant new information was developed with respect to both fuel processing and plant performance issues. This paper describes the project and the test results and explores the CO2 mitigation impacts of firing blends of coal and biomass that are prepared off-site.

Effects of the Incorporation of Sawdust Waste Incineration Fly Ash in Cement Pastes and Mortars

This paper presents the result of a study on the use of sawdust waste incineration fly ash (SWIFA) as supplementary cementing materials. Tests on the setting times and strength development of cement paste and mortar with up to 30 percent SWIFA were carried out. Results of the setting times and compressive strengths show that with increasing amounts of SWIFA, the setting times of the paste were extended and the compressive strengths decreased. Pozzolanic activity index of the material was also confirmed to be approximately 76 percent and that the material performed better in a nitric acid solution environment than in sulphuric acid solution.

Alternative-Source Cellulose Composite

Composite from recycled newsprint would result in the effective use of a waste product which is currently burned or land-filled, as well as potential reduction in the cost of manufactured composite. In this work, old newsprint (ONP) together with waste polyurethane foam from packaging were used to produce composite. The physical and mechanical properties, polymer concentration, volume resistivity as well as pressure were studied. The increase of pressure from 25 to 50 KN was found to improve the mechanical properties more than twice the polymer concentration. This may be attributed to the higher ability of polyurethane foam to make crosslinks with the free OH groups of cellulose and hemicellulose when the pressure is increased. Also, it may be attributed to the lignin of the ONP, which, under heat above 160°C and higher pressure flow, acts as a thermosetting adhesive, enhancing the naturally occurring hydrogen bonds. Waste sawdust of particleboard and palm leaves, pulped mechanically at 120°C, was blended individually to the ONP at a certain percentage. The mechanical properties and water resistance were improved by approximately 10%. The volume resistivity of the produced composites was measured. It was found that it had increased, as had the pressure, polymer concentration, and mechanical properties.

Research on gasification process of loose biomass material with oxygen-enriched air in fluidised bed gasifier

Fluidised bed gasification technology with oxygen-enriched air suitable for gasifying loose biomass materials was developed. Gasification experiments with different biomass materials such as rice straw, rice hull, wheat straw, sawdust and municipal wastes, were carried out. The tests showed that biomass materials can be gasified continuously at a temperature between 600 and 750°C. The heating value of wood gas is more than 5.8 MJ/Nm³. Catalysed gasifying processes for biomass materials were exploited and the results showed that catalysts can regulate gas compositions effectively.

Kinetic and equilibrium modeling of liquid‐phase adsorption of lead and lead chelates on activated carbons

AbstractThe sawdust (SD) waste generated in the timber industry was converted to a low‐cost activated carbon (SDAC) using a simpler and cheaper activation process, single‐step steam pyrolysis activation. The possibility of utilizing SDAC for the removal of lead (Pb(II)) in the absence of ligands and nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) chelated Pb(II) complexes from the liquid phase was examined and the results were compared with those for commercial activated carbon (CAC). SDAC shows a high adsorption capacity for Pb(II) and Pb(II) chelates compared with CAC. The extent of adsorption of Pb(II) and Pb(II) chelates on activated carbons was found to be a function of solution pH and species distribution of Pb(II) and Pb(II) chelates. The optimum pH range for the removal of Pb(II) in the absence of ligands by SDAC was 6.5–8.0, whereas its maximum removal by CAC was observed at pH 6.5. In the presence of ligands, the extent of Pb(II) adsorption was enhanced in the pH range 2.0–5.0 and was reduced significantly in the pH range 6.0–8.0. The maximum uptake of Pb(II) chelates for both carbons was observed at pH 5.0. Kinetic models such as pseudo‐first‐order, pseudo‐second‐order and pore diffusion were tested to investigate the adsorption mechanism. Batch kinetic studies showed that the adsorption of Pb(II) from aqueous solutions with and without ligands could be best described by a psuedo‐first‐order model for both carbons. The effect of pH on the adsorption isotherms of Pb(II) and Pb(II) chelates was also investigated. The applicability of the Langmuir and Freundlich isotherms, established for various initial concentrations of the adsorbate and for different pH values, was tested at 30 °C. Copyright © 2003 Society of Chemical Industry

Improvement of power generation and cleaning of exhaust gas by utilizing waste material and coal

Under the sponsorship of the Pennsylvania Electric Company (Penelec), and with the support of EPRI, the U.S. Department of Energy, and the Pennsylvania Department of Conservation and Natural Resources, Penelec and Foster Wheeler Environmental Corporation conducted low percentage (3% by weight) wood cofiring tests at Units 2 and 3 of the Shawville Generating Station in November 1995. Unit 2 is a 138 MWe (gross) wall-fired pulverized coal boiler equipped with ball and race mills, table feeders, and low-NOx burners. Unit 3 is a 190 MWe (gross) tangentially-fired pulverized coal boiler equipped with bowl mills, paddle feeders, and low-NOx burners. There is no spare capacity in the pulverizing systems of either unit when operating under full load conditions.This project was unique in a number of respects, expanding the knowledge and cofire experience base achieved in other previous projects (ref. 1). First, the project tested the use of blended biofuels in boilers equipped with low NOx burners. Additionally, three types of biofuel were tested: (1) mill waste sawdust, (2) utility right-of-way trimmings, and (3) harvested hybrid poplar. Biofuels were processed off-site, blended at a nearby coal blending yard, and then trucked to the unmodified Shawville Station on a “just-in-time” schedule basis. The off-site fuel preparation and blending operations provided an adequate supply of blended biofuel and coal to allow the project to meet its overall test objectives, and also provided much useful new data and information needed to help establish commercial processing facilities.Plant operating technical objectives were to determine the impacts of using low percentage biofuel blends on boiler capacity, efficiency, stability, temperature, and air/solid waste emissions. Significant boiler capacity limitations were experienced on both units when cofiring 3 percent biomass blends. The 138 MWe boiler lost 8–10 MWe of capacity due to feeder limitations, and the 190 MWe boiler lost 15 MWe of capacity due to significant reductions in mill outlet temperatures. For both units, the 3 weight percent biofuel blends behaved like wet coal.Significant new information was developed with respect to both fuel processing and plant performance issues. This paper describes the project and the test results and explores the CO2 mitigation impacts of firing blends of coal and biomass that are prepared off-site.

Heavy oil microfiltration using ceramic monolith membranes

Powdered active carbon was converted into active carbon monoliths (ACMs) without reducing specific surface (SSA) by adding H3PO4-impregnated waste sawdust (HIWS) before extrusion. The effects of activation time on the morphologies, textural properties, and compression strength of the prepared ACMs were investigated. The HIWS could act as an easy-making binder for conversion of powdered active carbon into ACMs having a higher SSA than the powdered active carbon. The SSA and compression strength of the ACMs increased with prolonging the activation time. Monolithic active carbon with a SSA of 715 m2/g and compression strength of 4.8 MPa was produced by heating at 560 °C for 160 min. This research might lead to cost-effective conversion of powdered active carbon into ACMs without compromising SSA.

Some lignocellulosic wastes used as raw material in cultivation of the Pleurotus ostreatus culture mushroom

Yield values, diameters and numbers of fruit bodies obtained from the cultivation of Pleurotus ostreatus mushrooms were determined and the effects of different substrate combinations on productivity were investigated. Wastes of some lignocellulosic materials such as leaves of hazelnut (LH), leaves of tilia (LT) and leaves of European aspen (LEA), wheat straw (WS), sawdust (S) waste paper (WP) were used for producing P. ostreatus. The best main material and the best substrate combination for mushroom productivity were WS and WS+WP (50%+50%), respectively. Mixtures which involve WP generally produced higher yield values when compared to the other combinations. Mixtures which contained bran (25%) increased the risk of contamination. The lowest yield and the smallest fruit body diameters values were obtained from LT (100%) and LEA+S (50%+50%). The greatest number of fruit body was obtained in the combination WS+LH+WP (30%+50%+20%). The largest diameter of fruit body was obtained from OT (100%), even though few fruit bodies were observed.

00/02431 Catalytic steam gasification of pine sawdust. Effect of catalyst weight/biomass flow rate and steam/biomass ratios on gas production and composition

The objective of this study was to manufacture fire-resistant biocomposite sandwich plates using waste sawdust as filler and an inorganic potassium aluminosilicate binder. Using binder contents of 29% and 34%, twelve biocomposite plates were fabricated without using any specialized equipment, heat, or pressure, thus producing an environmentally conscious biocomposite material. Several of the plates were strengthened with carbon and glass fiber reinforcements to create a more durable sandwich structure. The influence of binder content and reinforcement type on the heat release rate and smoke emission characteristics were investigated using the OSU heat calorimeter and the NBS smoke chamber, respectively. All specimens passed the Federal Aviation Administration requirements for heat release and smoke emission, the criteria used for evaluation of the test results in this study. Relative to 15 other wood plastic composites that utilize organic polymers, the inorganic biocomposite showed superior heat release rates during 5 min of fire exposure.

Briquettability of Lignite and Woody Wastes Composite Fuel

Woody wastes have favorable burning characteristics compared to lignite, as well as low ash content and reduced smoke emission. The aim of this study was to blend lignite with woody wastes to obtain a solid fuel that retains the advantageous characteristics of woody materials. Blends with lignite were made up with 7, 9, 12, 15, and 20% of waste and then briquetted under pressures of 400, 550, 700, and 800 MPa. Sunflower shell, sawdust, and paper mill wastes were used in different amounts with molasses as binder. Studies were carried out on a laboratory scale to determine optimum parameters for briquetting, such as moisture content of lignite and pressure. Briquetting of lignite without waste materials produces products of low strength. The strongest briquettes were obtained with waste contents of 12 - 20% and lignite moisture contents of 10 - 12% at briquetting pressures of 550, 700, and 800 MPa. Briquettes with adequate mechanical strength are obtained from lignite-waste blends with the addition of 8% molasses.

Measured and estimated methane and carbon dioxide emissions from sawdust waste in the Tennessee Valley under alternative management strategies

Wood waste is a potential source of methane production due to its high degradable organic carbon content and an on-site storage method that is conducive to development of anaerobic conditions. Future emissions from wood waste could be even higher if waste piles must be converted to landfills by soil capping in order to comply with national criteria for solid waste disposal. In order to estimate current and potential methane emission rates a set of field and laboratory measurements were undertaken. Gas samples for analysis of methane and CO 2 were collected from the surface of sawdust piles using chambers placed on the pile surface, and at depths of 1.5, 3.0 and 4.6 m using a sampling probe. Two piles in each of the following age ranges were sampled: 0–1, 1–4, 3–5, and 5–8 years. In the laboratory study, sawdust samples from the 3.0 m depth were incubated under 20% CO 2 in nitrogen at 32, 40 and 48°C to simulate the temperature range and anaerobic conditions occurring in typical sawdust piles. Field measurements indicated that methane comprised 20% of the biogas generated from sawdust piles. Emissions from the pile surface averaged 1.68 mg m −2 h −1 compared to literature estimates from landfills on the order of 0.125-125,000 mg m −2 h −1 (Bogner and Scott, 1995), with the low emission rates suggesting that a large percentage of the methane produced was either oxidized or otherwise consumed before reaching the pile surface. Emissions to the atmosphere estimated from annual sawdust production in the Tennessee Valley range from 15–44 metric tons per year. Incubation studies indicated highest methane generation at 32°C with a reduction in emissions in excess of 70% when the temperature was increased to 48°C. Estimates of methane production indicate that soil capping of disposed sawdust could increase methane production by 2–2.5 times over the biodegradation lifetime of the sawdust stored on-site. Assuming the global warming potential of methane is 21 times that of CO 2, combustion of wood waste rather than on-site storage or capping would provide a CO 2 offset of 1.2 or 3.8 tons, respectively, for each ton of sawdust burned.

The effect of pressure fluctuations on PAHS emission and combustion efficiency during incineration

Periodic fluctuations of pressure can be observed in a normally operated gas‐solid fluidized bed, which is also an indicator of combustion efficiency during waste incineration. The pressure fluctuations offer valuable information regarding the fluidization phenomenon in a fluidized bed reactor. Such information provides insight into the extent of mixing in the bed in addition to the combustion action under various operating conditions. In this study, we examined the effects of pressure fluctuation on PAHs emission and combustion efficiency during incineration. Experiments were performed in a laboratory‐scale fluidized bed reactor with a 100 cm bed height (10 cm I.D.) and 100 cm freeboard (25 cm I.D.). The operating parameters evaluated include: (1) Various waste compositions: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), sawdust, tire and mixed waste and, (2) Air flow rate.

Elemental characterization of different matrices including coal, sawdust, fly-ash and landfill waste samples using INAA and PIXE analyses

Instrumental neutron activation analysis (INAA) based on a nuclear reactor and proton induced X-ray emission (PIXE) based on a 2 Me V Van de Graaff accelerator were used to analyse different environmental samples including coal, sawdust, fly ash and landfill materials. These samples represent a large component of the solid waste being buried in the ground, and may be a potential source of toxicity which can have not only adverse effects on the soil and ground water, if diffused during leaching processes, but may also be transferred to humans through the food chain. Both techniques were employed to determine trace element concentrations in these matrices. The concentration of 30 elements were detemined, namely Na, Mg. Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Cd, Ba, La, Sm, Eu, Tb, Ho, Yb, Hf, Ta and Th. The detection limits in the various sample matrices were calculated and a comparison was made for those elements commonly detected by both techniques.

The shawville coal/biomass cofiring test: A coal/power industry cooperative test of direct fossil-fuel CO2 mitigation

Under the sponsorship of the Pennsylvania Electric Company (Penelec), and with the support of EPRI, the U.S. Department of Energy, and the Pennsylvania Department of Conservation and Natural Resources, Penelec and Foster Wheeler Environmental Corporation conducted low percentage (3% by weight) wood cofiring tests at Units 2 and 3 of the Shawville Generating Station in November 1995. Unit 2 is a 138 MWe (gross) wall-fired pulverized coal boiler equipped with ball and race mills, table feeders, and low-NOx burners. Unit 3 is a 190 MWe (gross) tangentially-fired pulverized coal boiler equipped with bowl mills, paddle feeders, and low-NOx burners. There is no spare capacity in the pulverizing systems of either unit when operating under full load conditions. This project was unique in a number of respects, expanding the knowledge and cofire experience base achieved in other previous projects (ref. 1). First, the project tested the use of blended biofuels in boilers equipped with low NOx burners. Additionally, three types of biofuel were tested: (1) mill waste sawdust, (2) utility right-of-way trimmings, and (3) harvested hybrid poplar. Biofuels were processed off-site, blended at a nearby coal blending yard, and then trucked to the unmodified Shawville Station on a “just-in-time” schedule basis. The off-site fuel preparation and blending operations provided an adequate supply of blended biofuel and coal to allow the project to meet its overall test objectives, and also provided much useful new data and information needed to help establish commercial processing facilities. Plant operating technical objectives were to determine the impacts of using low percentage biofuel blends on boiler capacity, efficiency, stability, temperature, and air/solid waste emissions. Significant boiler capacity limitations were experienced on both units when cofiring 3 percent biomass blends. The 138 MWe boiler lost 8–10 MWe of capacity due to feeder limitations, and the 190 MWe boiler lost 15 MWe of capacity due to significant reductions in mill outlet temperatures. For both units, the 3 weight percent biofuel blends behaved like wet coal. Significant new information was developed with respect to both fuel processing and plant performance issues. This paper describes the project and the test results and explores the CO2 mitigation impacts of firing blends of coal and biomass that are prepared off-site.