Chemical conversion
Saeed Hasani; Mohammad Talaei poor; behzad baziyar; Amir Homan Hemmasi; Saeed Mahdavi
Abstract
AbstractIn this study, black poplar (Populus nigra) cut from Zanjan province was used in two age groups of 18 and 38- year-old. Timbers with thicknesses of 4, 5 and 6 cm were prepared from each age group. The prepared timbers were modified during the heat treatment process (Thermowood) at a constant ...
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AbstractIn this study, black poplar (Populus nigra) cut from Zanjan province was used in two age groups of 18 and 38- year-old. Timbers with thicknesses of 4, 5 and 6 cm were prepared from each age group. The prepared timbers were modified during the heat treatment process (Thermowood) at a constant temperature of 212 °C. Experimental samples were obtained from the surface and middle depth of heat-treated timbers. Heat-treated and control wood samples were subjected to accelerated weathering for 150 hours. Color lightness (L*), color difference (ΔΕ*) and water droplet contact angle were measured for heat-treated and control samples before and after weathering. In order to investigation of the wettability content, the method of measuring the contact angle of the water drop - static according to the ASTM D 5946 standard was used. In general, before weathering, the brightness of the heat-treated samples decreased compared to the control sample, but after weathering, the color lightness of the control samples decreased and the color lightness of the heat-treated samples increased. Also, the content of color difference of samples after weathering compared to before weathering showed a significant decrease statistically. Heat treatment increased the contact angle of water droplets of the samples 60.31% and the contact angle of water droplets of the heat-treated and control samples increased significantly after weathering compared to before weathering.
Alireza Asgari; Amirhooman Hemmasi; Behzad Baziyar; Mohammad Talaeipour; Amir Nourbakhsh
Abstract
The mechanical (tensile strength and modulus, bending strength and modulus), humidity (water absorption and thickness swelling) and biodegradability properties of wood-plastics produced from polypropylene and poplar wood-flour (wood flour in three levels of 0, 20 and 25 percentage) in the presence of ...
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The mechanical (tensile strength and modulus, bending strength and modulus), humidity (water absorption and thickness swelling) and biodegradability properties of wood-plastics produced from polypropylene and poplar wood-flour (wood flour in three levels of 0, 20 and 25 percentage) in the presence of starch powder (at four levels of 0, 5, 10 and 15 percentage) are assessed as a bio strength agent. The material mixing process is run in two stages of applying an extruder machine and applying an internal mixer haake machine. The mechanical and humidity tests specimens are produced by mold injection method and the biodegradability test specimens are formed by hot press method. The tests are run according to standards and procedures. The results indicate that an increase in weight percentage of wood-flour in the composition, increase the mechanical strength, water absorption, thickness swelling and biodegradability of composites. An increase in weight percentage of starch powder in the composition, increase the bending strength and modulus, tensile modulus, water absorption, thickness swelling and biodegradability of composites, while decreasing the tensile strength. Additional studies run through the scanning electron microscopy indicate that by adding wood-flour and starch powder to the composition, the intensity of biodegradation increase at the surface of the specimens. By adding starch powder to the composition, the starch powder particles fill the cavities in the composite structure, thus a reduction in the volume of the pores in the composite structure.
Mohamad Bai; Behzad Bazyar; Habibollah Khademi Eslam; Abdolah Najafi; Amir Hooman Hemasi
Abstract
In this study, the effect of cellulose nanofibers and silicon nanoparticles on the properties of nanocomposites made with polyvinyl alcohol was studied and the physical, mechanical and morphological properties of nanocomposites were investigated. Samples were prepared by casting with different ratios ...
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In this study, the effect of cellulose nanofibers and silicon nanoparticles on the properties of nanocomposites made with polyvinyl alcohol was studied and the physical, mechanical and morphological properties of nanocomposites were investigated. Samples were prepared by casting with different ratios of 0, 5 and 10% by weight. The morphology of nanocomposites was examined by scanning electron microscopy. Observations of water vapor permeability and water uptake by adding cellulose and nanoxide oxide nanofibers in pure polyvinyl alcohol control film and nanocomposite films with different compositions were significantly different from each other. Tensile strength of nanocomposites showed that increasing the amount of cellulose nanofibers and silicon nanoparticles increased the tensile strength and the percentage of elongation increased with the addition of cellulose nanofibers and silicon nanoparticles decreased. The results of the present study show that the addition of small amounts of nanocellulose fibers and silicon nanoparticles strengthens the polyvinyl alcohol polymer and improves the physical and mechanical properties and increases the performance of nanocomposites.
Masoumeh Mollaei; Mazaher Moeinaddini; Nematollah Khorasani; Mohammad Azadfallah; Amirhooman Hemmasi
Abstract
Sulfide ions (S-2 ) derived from Na2S remaining in black liqueur are the source of H2S gas production along the black liquor recovery cycle in the Kraft pulp and paper industry. In this study, we tried to prevent the production of H2S by removing the mentioned ions from black liquor by using of synthesized ...
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Sulfide ions (S-2 ) derived from Na2S remaining in black liqueur are the source of H2S gas production along the black liquor recovery cycle in the Kraft pulp and paper industry. In this study, we tried to prevent the production of H2S by removing the mentioned ions from black liquor by using of synthesized adsorbents (Cu-PAC and Cu-BWP100). The adsorbents were produced by immersing powdered activated carbon (PAC) and beech powder with 100 mesh (BWP100) in 0.1 M solution of CuCl2. The adsorbent properties were obtained before and after copper ion loading by FTIR, BET and SEM-FEI analyses. Finally, the performance of these adsorbents in the removal of S-2 from black liquor with three levels of sulfide (22%, 20, 18) was investigated. The results of FTIR, BET and SEM-FEI analysis showed that Cu+ 2 was located on the surfaces of raw organic material without any change in the structure of them. Experimental data for the Cu-PAC adsorbent showed that it was more agreement with the Freundlich equation and more follow to the pseudo-second-order kinetic model, whereas for Cu-BWP100 adsorbent it was the more consistent with the Langmuir equation and adherence to the pseudo-first-order kinetic model. The Cu-PAC adsorbent has the ability to remove 79.93% and Cu-BWP100 60.03% of S-2 from black liquor. The Cu-PAC, with its higher specific surface area, has a higher ability to remove S-2 from the black liquor than the Cu-BWP100. In general, the mentioned adsorbents will have a high ability to reduce H2S production by eliminating S-2.
Chemical conversion
Fatemeh Jadidyan; Mohammad Talaeipoor; Saeed Mahdavi; Amirhoman Hamasi
Abstract
The purpose of this study is the evaluation of bagasse pith for heating energy and activated carbon production. To assess the energy production of the pith, bulk density, melting point, and heating value were measured. Furthermore, percentage of moisture, ash, volatile compounds, fixed carbon, lignin, ...
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The purpose of this study is the evaluation of bagasse pith for heating energy and activated carbon production. To assess the energy production of the pith, bulk density, melting point, and heating value were measured. Furthermore, percentage of moisture, ash, volatile compounds, fixed carbon, lignin, and elements contents were determined. Ash and volatile content average were measured at 30.23% and 67.14%, respectively. The bulk density average of the pith powder with 80 meshes was determined at 0.15 g/cm3. Lignin content and melting point of pith is measured 23.1%, and 1050 °C, respectively. Sulfur content is important in terms of environmental pollution and it was determined 0.3%. Gross heating value was measured directly by calorimeter bomb to 10.30 MJ/kg that is lower than bagasse and wood. The activated carbon produced from pyrolysis of bagasse pith was chemically activated with zinc chloride. The chemically activated carbons were characterized by measuring iodine of 504 mg/g, specific surface (BET) of 478 m2/g, and pore diameter of 7.45 nanometer. It is suitable for liquid absorption according to the pore size.
Composite wood products
Hossein Ahmadi; Amir hooman hemmasi; Saeed Mahdavi
Abstract
The aim of this study is investigating the mechanical properties of recycled HDPE (high-density polyethylene) filled by furfural residue produced from bagasse. For this purpose, rHDPE was used at three levels 58, 68 and 78% and furfural residue as a filler was added at levels of 20, 30 and 40%. The grafted ...
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The aim of this study is investigating the mechanical properties of recycled HDPE (high-density polyethylene) filled by furfural residue produced from bagasse. For this purpose, rHDPE was used at three levels 58, 68 and 78% and furfural residue as a filler was added at levels of 20, 30 and 40%. The grafted maleic anhydride with polyethylene (PE-g-MA) was used at constant amount of 2% as compatibilizer which prepared from Arya polymer Co. The ingredients mixed in two screw extruder and test samples were made using injection molding method. Composite properties such as tensile strength, flexural and V-notch impact were measured according to ASTM standards. The results showed that with increasing the filler content of 20 and 30% by weight, tensile modulus and flexural strength increased compared to the control and then reduced by 40 percent of filler. FTIR spectroscopy of the furfural residue and composite filled by 30% was carried out. Also, by increasing the filler content of 20 to 40% by weight, V-notch impact strength of composite decreased. FTIR spectroscopy revealed that the absorption bands of carbonyl groups (C=O) in 1750-1600 cm-1 wavelength has slightly increased in the present of maleic anhydride compatibilizer which resulted maximum increasing of mechanical properties of composite using 30% residual furfural.
