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.

Nitrogen-enriched activated carbons prepared by the activation of coniferous tree sawdust and their application in the removal of Nitrogen dioxide

Abstract: A technology of obtaining nitrogen-enriched activated carbons from coniferous tree sawdust by direct activation of the precursor and physical activation with CO2 is described. The effect of activation time, pyrolysis temperature as well as modification with urea on the textural parameters, acid–base character of the surface and sorption properties of activated carbons has been tested. The resulting carbons were characterised by low-temperature nitrogen sorption and determination of the number of surface oxygen groups. The sorption properties of the materials obtained were characterised by nitrogen dioxide adsorption in dry and wet conditions. The final products were nitrogen-enriched microporous activated carbons of medium-developed surface, showing very diverse nitrogen content and acidic–basic character of the surface. The results obtained in our study have proved that through suitable choice of the activation and modification procedure of coniferous tree sawdust, activated carbons can be produced with high capacity towards nitrogen dioxide adsorption, reaching to 69 and 46 mg NO2/g in dry and wet conditions, respectively. The results of our study have also shown that the adsorption ability of carbonaceous adsorbents depends both on the method of preparation as well as on the textural parameters and acid–base properties of the adsorbents surface.

A porous carbon foam prepared from liquefied birch sawdust

Abstract: Carbon foam was prepared by submitting birch sawdust to liquefaction, resinification, foaming, carbonization, and activation steps The foam was characterized by TG and DTG, XRD, SEM, and nitrogen adsorption at 77 K A mechanism for the formation of the porous carbon foam was proposed Solid non-graphitized lightweight carbon foams with specific surface areas of 534–555 m2/g and cell sizes of 100–200 μm were obtained, depending on the carbonization or activation temperature used The intermediate liquefied birch-based resin foam exhibits thermal stability superior to liquefied wood and inferior to phenolic resin, and decomposes rapidly in two stages, at 2857 and 4129 °C, respectively Further activation of the carbon foam in a stream of nitrogen above 800 °C improves the pore structure and homogeneity of the cell size significantly The matrix of the foams contains a large number of micropores, and the microstructure becomes more ordered as the activation temperature is increased

Energy Utilization of Spent Coffee Grounds in the Form of Pellets

Abstract: Nowadays it is important to limit the use and combustion of fossil fuels such as oil and coal. There is a need to create environmentally acceptable projects that can reduce or even stop greenhouse gas emissions. In this article, we dealt with the objectives of energy policy with regard to environmental protection, waste utilization, and conservation of natural resources. The main objective of the research was to assess the possibility of the use of spent coffee grounds (SCG) as fuel. As a part of the solution, the processing of coffee waste in the form of pellets, analysis of calorific value and combustion in the boiler were proposed. The experiments were done with four samples of pellets. These samples were made from a mixture of wood sawdust and spent coffee grounds with ratio 30:70 (wood sawdust: spent coffee grounds), 40:60, 50:50 and 100% of spent coffee grounds. The calorific values were compared with wood sawdust pellets (17.15 MJ.kg−1) and the best lower calorific value of 21.08 MJ.kg−1 was measured for 100% of spent coffee grounds. This sample did not achieve the desired performance during the combustion in the boiler due to the low strength of the sample.

Some Chemical Compositional Changes in Miscanthus and White Oak Sawdust Samples during Torrefaction

Abstract: Torrefaction tests on miscanthus and white oak sawdust were conducted in a bubbling sand bed reactor to see the effect of temperature and residence time on the chemical composition. Process conditions for miscanthus and white oak sawdust were 250–350 °C for 30–120 min and 220–270 °C for 30 min, respectively. Torrefaction of miscanthus at 250 °C and a residence time of 30 min resulted in a significant decrease in moisture—about 82.68%—but the other components—hydrogen, nitrogen, sulfur, and volatiles—changed only marginally. Increasing torrefaction temperatures to 350 °C with a residence time of 120 min further reduced the moisture content to 0.54%, with a significant decrease in the hydrogen, nitrogen, and volatiles by 58.29%, 14.28%, and 70.45%, respectively. Regression equations developed for the moisture, hydrogen, nitrogen, and volatile content of the samples with respect to torrefaction temperature and time have adequately described the changes in chemical composition based on R2 values of >0.82. Surface plots based on the regression equation indicate that torrefaction temperatures of 280–350 °C with residence times of 30–120 min can help reduce moisture, nitrogen, and volatile content from 1.13% to 0.6%, 0.27% to 0.23%, and 79% to 23%, with respect to initial values. Trends of chemical compositional changes in white oak sawdust are similar to miscanthus. Torrefaction temperatures of 270 °C and a 30 min residence time reduced the moisture, volatiles, hydrogen, and nitrogen content by about 79%, 17.88%, 20%, and 5.88%, respectively, whereas the carbon content increased by about 3.5%.

Pretreatment of hardwood (eucalyptus regnans) sawdust by autohydrolysis explosion and its saccharification by trichodermal cellulases

Abstract: Autohydrolysis explosion pretreatment of hardwood (Eucalyptus regnans) sawdust at 200°C and 6.9 MPa gas pressure (steam + nitrogen) for 5 min solubilized 85% of the total hemicellulose components and produced a pulp that was highly accessible to attack by cellulases from Trichoderma reesei C-30 and by a commercial preparation, Meicelase. The autohydrolysis liquor, representing 15% of the original weight of the sawdust on a solids basis, consisted mainly of xylose, xylose oligomers and minor amounts of galactose, mannose, arabinose, glucose and uronic acids. Enzymic hydrolysis of pretreated E. regnans pulps using Trichodermal cellulases resulted in saccharification yields of <50% within 24 h from 10% (w/v) substrate slurries and 20 cellulase (FPU) units per g of pretreated pulp. The cellulose-to-glucose conversions were lower and this was attributable to the production of a compound(s) during enzymic hydrolysis that was inhibitory to the β-glucosidase component, but not the cellulases, in the Trichodermal ...