Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.Tha...Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.That is why the data on the size distribution of the particles forming a biomass pellet is crucial to achieving optimum combustion conditions.The current study determines the internal particle size distribution of pellets after wet disintegration,following Iso 17830 standard,and aims to suggest improvements to the mentioned standard based on new measured evidence.Experiments were carried out on white wood pellets(no bark)and brown wood pellets containing bark at four water temperatures:20,40,60,and 95℃,with or without stirring.The particle size distribution of the pre-pelletizer wood particles was also measured and compared with particles in the formed pellets.Ambient water temperature of 20℃ was found to be adequate for the complete disintegration of pellets,and no mechanical stirring was required.About 30% of particles in the disintegrated pellets were 0.5-1.0 mm.Pelletization changes the particle size distribution to smaller particles.The disintegrated bark pellets contained more fines than white pellets.展开更多
The experimental creep data were focused on wood-flour （WF）/poly vinyl chloride （PVC） composites with the variations in additive concentrations of wood flour, silane coupling agent, organomodified montmorillonite ...The experimental creep data were focused on wood-flour （WF）/poly vinyl chloride （PVC） composites with the variations in additive concentrations of wood flour, silane coupling agent, organomodified montmorillonite （OMMT） and nano-cacium carbonate （nano-CaCO3）. Their effects were analyzed using the Four-element Burger Model incorporating microscopic mechanisms. Total creep strain was low with increasing WF while elastic strain was high and plastic flow strain was low in modeling. Modification of WF with silane was beneficial to creep resistance, so did adding low ratio of OMMT （1.5 wt%） and nano-CaCO3 in composites. Thus, it was effective in reducing creep either by stiffening the PVC matrix using rigid nano-particles or by improving their adhesion with resin. However, superfluous quantity of any additament did not benefit the improvement owing to either earlier destruction of their agglomerates or stress-concentrated cracks in the over-incrassated interface.展开更多
Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhe...Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhesive can be used as an alternative binder for wood based composites where environmentally friendly and sustainability of product is important.In this study flyash as precursor is been used in the development of wood geopolymer composite product.Flyash is activated with a combination of sodium hydroxide and sodium silicate solutions at a weight ratio of 1:2.5 for geopolymer formation.The study investigated the properties of wood geopolymer composite made with ratios of wood particle to flyash percentage(23/77),(37/62),(44/55),(50/50)and(57/43).Geopolymer formation was observed by X-ray Diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).Influence of wood particles in wood geopolymer composite were observed by Scanning electron microscope.The study shows that the water absorption and thickness selling properties of all the formulations of wood geopolymer composites are comparable with the medium density particle board and cement-bonded particleboard according to the IS:3087-2005 standard and IS:12406:respectively.Highest mechanical properties and good bond strength was obtained by the composite containing 23%wood particle ratio with 77%percent flyash.However,still improvement in mechanical properties is needed to achieve the mechanical properties comparable to cement bonded particle board.展开更多
文摘Pulverizing is an essential unit operation in co-firing biomass with coal.Pulverizers are only compatible with pellet forms of fibrous biomass materials and crush them down to their original forming particle sizes.That is why the data on the size distribution of the particles forming a biomass pellet is crucial to achieving optimum combustion conditions.The current study determines the internal particle size distribution of pellets after wet disintegration,following Iso 17830 standard,and aims to suggest improvements to the mentioned standard based on new measured evidence.Experiments were carried out on white wood pellets(no bark)and brown wood pellets containing bark at four water temperatures:20,40,60,and 95℃,with or without stirring.The particle size distribution of the pre-pelletizer wood particles was also measured and compared with particles in the formed pellets.Ambient water temperature of 20℃ was found to be adequate for the complete disintegration of pellets,and no mechanical stirring was required.About 30% of particles in the disintegrated pellets were 0.5-1.0 mm.Pelletization changes the particle size distribution to smaller particles.The disintegrated bark pellets contained more fines than white pellets.
文摘The experimental creep data were focused on wood-flour （WF）/poly vinyl chloride （PVC） composites with the variations in additive concentrations of wood flour, silane coupling agent, organomodified montmorillonite （OMMT） and nano-cacium carbonate （nano-CaCO3）. Their effects were analyzed using the Four-element Burger Model incorporating microscopic mechanisms. Total creep strain was low with increasing WF while elastic strain was high and plastic flow strain was low in modeling. Modification of WF with silane was beneficial to creep resistance, so did adding low ratio of OMMT （1.5 wt%） and nano-CaCO3 in composites. Thus, it was effective in reducing creep either by stiffening the PVC matrix using rigid nano-particles or by improving their adhesion with resin. However, superfluous quantity of any additament did not benefit the improvement owing to either earlier destruction of their agglomerates or stress-concentrated cracks in the over-incrassated interface.
基金We thank Indian plywood Industries research and training Institute,an autonomous body of Ministry of environment forest and climate change funded this research project.I thank my co-authors for helping me in the study,analysis,and interpretation of data and in writing the manuscript should be declared.
文摘Geopolymers are inorganic adhesive synthesized from industrial waste such as fly ash thus the development of wood geopolymer composite would be a low carbon footprint material.Geopolymers,being a non-formaldehyde adhesive can be used as an alternative binder for wood based composites where environmentally friendly and sustainability of product is important.In this study flyash as precursor is been used in the development of wood geopolymer composite product.Flyash is activated with a combination of sodium hydroxide and sodium silicate solutions at a weight ratio of 1:2.5 for geopolymer formation.The study investigated the properties of wood geopolymer composite made with ratios of wood particle to flyash percentage(23/77),(37/62),(44/55),(50/50)and(57/43).Geopolymer formation was observed by X-ray Diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).Influence of wood particles in wood geopolymer composite were observed by Scanning electron microscope.The study shows that the water absorption and thickness selling properties of all the formulations of wood geopolymer composites are comparable with the medium density particle board and cement-bonded particleboard according to the IS:3087-2005 standard and IS:12406:respectively.Highest mechanical properties and good bond strength was obtained by the composite containing 23%wood particle ratio with 77%percent flyash.However,still improvement in mechanical properties is needed to achieve the mechanical properties comparable to cement bonded particle board.
