Abas Fakhryan; Hossein Hosseinkhani; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness ...
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In this Investigation chemical, physical, morphology, pulp and paper making characteristics of Populus costanzo were studied. The average dry and critical specific gravity was found to be 0.39and 0.36 and the fiber morphology including fiber length , diameter ,lumen and thickness of cell wall 1.14 mm,28.84 µm, 28 µm ,and 2.92 µm was determined respectively. The average chemical composition including cellulose 50.74%, lignin 19.18%, Ext. 1.22% and Ash 1.65% were measured. In order to cook and pulping, Kraft process was used. The maximum yield and kappa number of Populus costanzo at 1 hour cooking time, 150°c cooking temperature and 12% effective alkali condition obtained at 61.91% and 54.83 respectively and the minimum yield and kappa number at 3 hour cooking time, 170°c cooking temperature and 16% effective alkali condition obtained at 45.63% and 13.42 respectively.
Pulp and paper
Farhad Zeinaly; Ali Kazemi Tabrizi; yashar Einollahi; Faraz Asadi Malek Jahan
Abstract
The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying ...
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The first act to ameliorate bleaching process is the major elimination of lignin. Actually, the use of oxygen delignification stage before bleaching process is the essential stage in improving bleaching process and reducing process emission. In this study, the effect of conducting oxygen-delignifying process under different process condition, on chemical, physical, mechanical and optical properties of kenaf bast kraft pulp was investigated. The kenaf bast kraft pulp with the kappa number of 22, 1154 ml/g viscosity, and 38% ISO brightness was prepared. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change significantly. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. Also, the pulp brightness was increased about 7%.
Pulp and paper
Farhad Zeinaly; Ahmad Reza Saraeian; Mohammadhadi Aryaei monfared; Ali Kazemi Tabrizi
Abstract
In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate ...
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In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate bleaching process of chemical pulps is the reduction of colored materials, mostly lignin, which enter to the bleaching section. Thus, the use of oxygen delignification stage after pulping and before bleaching process is the key stage in improving process and cleaner production. In this study, the effect of conducting oxygen-delignifying treatment by two kinds of machines, and under different process condition, on chemical, physical, mechanical and optical properties of bagasse soda pulp was investigated. The bagasse soda pulp with the kappa number of 20, 955 ml/g viscosity, and 37% ISO brightness was prepared from Pars Hafttapeh Company. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition, by two kinds of machines. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. The pulp brightness was increased about 4-6%. And also, due to the need of shorter time in order to reach the reaction temperature in the Iranian made machine, pulp delignifying by this machine was a little lower than Quantum machine.
Pulp and paper
Hosein Valayi; Ahmad Jahan Latibari
Abstract
Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at ...
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Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at 175 C and the soda pulping time was selected at 120 minutes and the soda-ethanol pulping times were 120 and 180 minutes. The highest accepted pulping yield at 58.54% was reached using soda pulping on poplar wood and the lowest yield (49.29%) was related to soda-ethanol pulp produced from beech wood applying 180 minutes pulping time. The accepted yield of soda-ethanol pulping was low, but the kappa numbers of these pulps were almost 20 units lower than soda pulps. The strength properties of soda-ethanol pulps were superior to soda pulps and the difference was statistically significant at 99% confidence level. The results of this study indicated that the delignification of soda-ethanol pulping process is faster than soda pulping from the selected hardwoods especially poplar wood.
Pulp and paper
Farzaneh Shiralizadeh; Sahab Hejazi; Mohammad Ahmadi
Abstract
In this research, rice straw was used as raw material. Potassium hydroxide was combined with monoethanolamine (MEA) as liquor. In another processes NaOH/Na2So3, KOH/K2So3 and KOH 14% was used as references pulp. The results showed that using pure MEA(15%) produced the highest yield and the highest kappa ...
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In this research, rice straw was used as raw material. Potassium hydroxide was combined with monoethanolamine (MEA) as liquor. In another processes NaOH/Na2So3, KOH/K2So3 and KOH 14% was used as references pulp. The results showed that using pure MEA(15%) produced the highest yield and the highest kappa number. By using potassium hydroxide as a additive agent in MEA pulping, the amount of reject, yield and kappa number was decreased and the lowest yield and the lowest kappa number relevant to MEA(15%) combined with KOH (40%). In addition, in KOH pulping observed that, with increasing concentration of MEA, as additive agent, the amount of total yield increased but the kappa number and reject content was decreased. Results showed that the highest tensile index and tear index were relevant to MEA (15%) combined with KOH (20%) and the highest burs index relevant to NaOH/Na2SO3 treatment. According to the optical properties, it was found that the highest brightness was achieved in K2SO3/KOH. The highest opacity relevant to the KOH14% .The result shows that MEA process in combined with Potassium hydroxide can be done success fully on rice straw and properties of pulp production, specially in aspect of mechanical strength, in term of combination is superior than soda and Potassium hydroxide process
Pulp and paper
Seyed_Pedram Hashemi; Asghar Tabei; Seyyed Peyman Hashemi
Abstract
In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks ( Nicotiana tabacum L. 'PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced ...
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In this study the effect of different values of peroxide in three levels 3%, 4%, 5% and sodium hydroxide in two levels 2%, 3%, on bleaching of tobacco stalks ( Nicotiana tabacum L. 'PVH 19') soda pulp was investigated. Tobacco stalks were soda pulped using 22% alkali in 170°C for 100 minutes. Produced pulp had 37.1 % yield and kappa number 62. Bleaching process included two stages: chelating and alkali peroxide bleaching. Results indicated that brightness increased and kappa number decreased by increasing sodium hydroxide and peroxide Hydrogen level.The data related to 3% caustic soda and 5% peroxide treatment without chelating stage, indicated that initial chelating stage significantly affected on the brightness, kappa number and yield of the bleached pulp, and this treatment had the lowest brightness and the highest kappa number and yield among all treatments. Finally, 3% caustic soda-5% peroxide treatment with initial chelating stage had the highest brightness (44.50%) and the lowest yield (83.20%), was selected as the best treatment.
Pulp and paper
Lila Karami motaghi; Hossein Hosseinkhani; Fardad Golbabaei
Abstract
In this study pulp and hand sheets paper characteristics of Salix nigra wood kraft and soda pulp and paper were investigated. Average density of dry and bulk density wood were determined 0.35 and 150 kg/m3 and average fiber dimension consist of fiber length, fiber diameter were measured, 1100 and 30 ...
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In this study pulp and hand sheets paper characteristics of Salix nigra wood kraft and soda pulp and paper were investigated. Average density of dry and bulk density wood were determined 0.35 and 150 kg/m3 and average fiber dimension consist of fiber length, fiber diameter were measured, 1100 and 30 µm, respectively. The chemical composition were determined as cellulose 42%, lignin 28% and extractive 4%. In order to coocking and pulping, Kraft (Sulfate) and soda process were used. For comparison of fiber dimensions, physical properties and chemical composition of the mean and standard deviation, yields of pulp in the form of a factorial randomized complete block design test, the strength properties of handsheets table ANOVA and for group means of the Duncan were used. All paper strengths of two hour cooking show better results than one hour cooking times, and all paper strengths of 22% alkaline show better result than 18%, also all paper strengths of 100% mixture show better result than 25% mixture (100% mixture only contain kraft pulpof salix nigra). The results of hand sheet strength indicated that Kraft pulp of salix nigra wood will provide a suitable to mix with short fiber hard wood pulp.
Saeid Mahdavi; Masoudreza Habibi
Abstract
Cereal straws including grain sorghum varieties can be used for pulp production due to the significant amount of residual straw after harvesting. This study showed that there are no significant differences between fiber dimension and papermaking coefficients of two varieties of sorghum (Kimia and Sepideh). ...
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Cereal straws including grain sorghum varieties can be used for pulp production due to the significant amount of residual straw after harvesting. This study showed that there are no significant differences between fiber dimension and papermaking coefficients of two varieties of sorghum (Kimia and Sepideh). The average of fiber length, fiber width, lumen diameter, and cell wall thickness were measured as 1.19 mm, 23.20, 15.34, and 3.93 µm, respectively. Significant difference (P < 0.05) was found among all chemical composition of two varieties except lignin content. The average content of holocellulose, alpha-cellulose, lignin, extractive, and ash were determined as 62.13%, 37.71%, 21.05%, 9.58% and 6.97%, respectively. The result revealed that pulp strength produced from Sepideh variety was better. However it requires more intense delignification compared to Kimia variety. The highest screen yield (33.19%) was reached applying the treatment combination of 170°C, 12% NaOH, and 75 minutes from the Sepideh variety. Sorghum pulp could be combined with the virgin pulp to compensate cellulose raw material shortage in paper industry.
Pulp and paper
Davod Efhami; Mohammad reza Dehghani
Abstract
In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was ...
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In this work effect of initial alkali charge were investigated on the yield and kappa number of soda beech pulp and alkali consumption pattern. The results indicated that, the regression models are useful for studying the relations between yield, kappa number and alkali consumption. Soda cooking was performed in 30, 40, 50, 60 and 70 gr.lit-1 initial alkali concentration and five different cooking times. The chips dimensions were in the range of 3-5 cm length, 1-2 cm width and 0.05 cm thickness. The results showed that increasing of alkali charge decreased the time of cooking in the same yield or kappa number. Deligninifaction decreased significantly in kappa number lower than 30. In the same kappa number, increased alkali charge gave a lower yield. The alkali consumption was regularly decreased with increasing of initial alkali charge from 30 to 70 gr/lit, but alkali charge consumption pattern varied in less and more than 30 kappa numbers.
Chemistry of wood
Mohammad ali Azad far; Rabie Behroz; Ahmad Jahan - Latibari
Abstract
The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum ...
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The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum Kappa no, yield and brightness, opacity and strength based on 60 g/m2 hand sheets were determined. The results indicated that application of oxygen delignification marginally reduced the opacity of the pulp. Tear strength increased where as tensile and burst strength decreased. Based on the comparison of the data from oxygen delignified pulp, it is concluded that oxygen can be utilized to improve the properties of soda-AQ pulp from OCC prepared for bleaching step. Carbohydrates are preserved while removing lignin. Normalized equations revealed that oxygen delignification at 3% alkali produced the best results.
Pulp and paper
Somayeh Ghasemi; Ahmad reza Saraeyan
Abstract
Comparative study of pulp yield of sap wood and heart wood of Populus deltoides under both Kraft and soda cooking process have been showed that the heart wood pulp has a lower yield than that of sap wood pulp. Yield of heart wood and sap wood soda pulps was 4 percentages higher than Kraft pulp. Contrary ...
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Comparative study of pulp yield of sap wood and heart wood of Populus deltoides under both Kraft and soda cooking process have been showed that the heart wood pulp has a lower yield than that of sap wood pulp. Yield of heart wood and sap wood soda pulps was 4 percentages higher than Kraft pulp. Contrary to yield, residual lignin content (Kappa number) is more in heart wood pulp than sap wood pulp in both processes. Kappa numbers of heart wood and sap wood Kraft pulps were about 34% lower than soda pulps. The results showed that in spite of lower yield of heart wood than sap wood, the residual lignin of heart wood pulp was more than sap wood pulp. The higher delignification efficiency of Kraft cooking is related to cooking liquor compositions, especially Na2S
Pulp and paper
Mohammadreza Dehghani Firouzabadi; Afshin Tvasoli; Saeed Mahdavi
Abstract
We studied the possibility of replacing imported long fiber pulp (ILFP) with kenaf bast fiber soda pulp (KBFSP) to improve the quality of paper made with bagasse soda pulp (BSP). To do so, we produced BSP with kappa number 13.5 similar to that prepared by Pars Paper Mill. We also produced KBFSP with ...
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We studied the possibility of replacing imported long fiber pulp (ILFP) with kenaf bast fiber soda pulp (KBFSP) to improve the quality of paper made with bagasse soda pulp (BSP). To do so, we produced BSP with kappa number 13.5 similar to that prepared by Pars Paper Mill. We also produced KBFSP with kappa number 21.6 similar to the unbleached imported ILFP. The yield percent for BSP and KBFSP were respectively 48.9 and 55.6 %. The maximum pulping temperature was 165 °C; alkaline was 20% based on sodium hydroxide and ratio of liquor to dry weight of the raw material was 8:1. All the three pulps were beaten up to a freeness degree of 400 ml, CSF. Amounts of 0, 10, 20 and 30 percent ILFP and KBFSP were mixed with 100, 90, 80 and 70 percent BSP to produce hand sheets. In all cases of KBFSP mixing with BSP, the thickness of the generated hand sheets were higher than those produced through mixing ILFP with BSP while the density was lower. The difference in burst strength and breaking length of a mixture of 30% KBFSP with 70% BSP in the hand sheets were non-significant as compared with those of ILFP and BSP. Tear strength and opacity of mixing 30% KBFSP with 70% BSP were significantly higher than those of the ILFP and BSP with the same mixing ratio. We suggest that KBFSP provides a suitable replacement for ILFP to improve physical and strength properties of paper made with BSP.
Pulp and paper
Saeid Mehrabi
Abstract
Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon ...
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Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon 44.9, populous deltoids 69.55, and populous euramerican are investigated. The average fiber length of these three colons were 0.854, 1.148, 1.08 mm. respectively and their average dry specific gravity were 0.386, 0461, and 0.341 g/cm3, and also their average cellulose content were 50.5, 51.5, and 49.5 percent.For Kraft process cooking of the mentioned colons, three cooking time, 1, 2, and 3 hours, 17°C cooking heat, 25% sulfidity, and active alkali at 3 levels, 15, 17.5, and 20% were used. The results show that p. alba, colon 44.9, and p. deltoids colon 69.55 with using 20% A.A and 3 hours cooking time have 53% yield and 18 kappa number.
Pulp and paper
Abbas Fakhryan roghani; Abdolrahman Hosseinzadeh; Fardad Golbabaei; Hossein Hosseinkhani
Abstract
Three 4,6 and 12 years old populus deltoides trees were randomly selected and felled from the Safrabasteh Research Station located in Gilan province. Samples were transferred to the Wood chemistry and Paper Making of Research Institute of Forest and Rangelands. By using of kraft processing, percentage ...
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Three 4,6 and 12 years old populus deltoides trees were randomly selected and felled from the Safrabasteh Research Station located in Gilan province. Samples were transferred to the Wood chemistry and Paper Making of Research Institute of Forest and Rangelands. By using of kraft processing, percentage of sulfidity rate of %25, and the temperature of 165°C a addition to modification of effective alkali, up to 14%, 17%, 20% and cooking time at maximum temperature of 60 min., 120 min., 180 min., with a rate of liquide to lignocellulosics malerial equivalent at 5/1 (L/W).Average of yield and kappa number of pulps was measured between 43.83-2.20 and 14.85-30.48 respectively.Pulps were refined up to the freness degree of 350, 400 and 450 c.s.f for 14% effective alkali and 350 c.s.f. for 20% effective alkali. The mechanical properties of 60 grams hand-made papers include breaking length, burst Index, tear Index and folding were also measured.
Pulp and paper
Abbas Fakhryan roghani; Abdolrahman Hosseinzadeh; Fardad Golbabaei
Abstract
In this study, anatomical, physical, pulping and paper making properties of Eucalyptus microtheca grown in Farse province is investigated. Eight trees were sampled for this study. The average dry and critical specific gravity of 8 samples were measured at 0.85 and 0.88 for heartwood and 0.8 and 0.75 ...
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In this study, anatomical, physical, pulping and paper making properties of Eucalyptus microtheca grown in Farse province is investigated. Eight trees were sampled for this study. The average dry and critical specific gravity of 8 samples were measured at 0.85 and 0.88 for heartwood and 0.8 and 0.75 for sapwood respectively. Mean of fiber length, diameter and cell wall thickness were measured at 0.78 mm, 15.68 mm and 4.560 mm for heartwood respectively. The corresponding figures for sapwood are 0.84 mm, 15.72 mm and 4.88 mm.Pulps were produce by two processes, Kraft (as a chemical process) and NSSC (as a semi-chemical process). Pulp properties of these two processes were compared. Yield and Kappa number of Pulp depend on cooking condition are 36.42-53.25 percent and 21.68-87.68 for Kraft Pulps and 64.59-70.91 percent and 130-189 for NSSC pulp respectively. Physical properties of pulps consist of burst and tear Index and breaking length were measured at 3.90-4.84 kPa.m2/g and 8.34-11.01 mN.m2/g and 5.36-6.94 Km for Kraft Pulps respectively. These properties for NSSC Pulp are 1.72-2.89 kPam2/g, 7.46-8.26 mNm2/g and 4.11-5.14 Km.
Pulp and paper
Abdolrahman Hosseinzadeh; Abbas Fakhryan roghani; Amir Nourbakhsh; Fardad Golbabaei
Abstract
In this investigation some anatomical, chemical and pulping suitability of two Iranian hardwood species which predominate in the Caspian forests were examined. The species are carpinus betulus (Hornbeam) and parotia persica (Ironwood).The results of this study revealed that:The average fiber length of ...
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In this investigation some anatomical, chemical and pulping suitability of two Iranian hardwood species which predominate in the Caspian forests were examined. The species are carpinus betulus (Hornbeam) and parotia persica (Ironwood).The results of this study revealed that:The average fiber length of carpinus betulus is 1.4 mm., fiber diameter 18 mm, and cell wall thickness 3.37 mm, while inparotia persica, fiber length, cell diameter and cell wall thickness are 1.34 mm, 17.3 mm and 3.48 mm respectively.The overall average of cellulose content: of carpinus betulus and Parotia persica were measured at 48.5, and 46.1 percent, and the lignin content at 17.5 and 21.5 percent respectively.The wood of each of the above species was cooked by means of a kraft process without difficulty but, there was a slight decrease in yield and kappa number with increase active alkali.The pulping yield with active alkali of14% was about 49.6 and with 20% was 43.44 percent, while the pulping yield of parotia persica in active alkali of 14% was 43.04 and in 20% about 37.79 percent. Thus, it may be concluded that for production of wrapping paper from carpinus betulus and parotia percica, using active alkali of 14% might give better quality paper and for production of printing paper from these two species active alkali of 20 percent might be desirable.
