Pulp and paper
ali ghasemi chahrdehi; Esmaeil Rasooly Garmaroody; Omid Ramezani; ghasem asadpour
Abstract
The aim of this study was to investigate the effect of storage and bleaching of cotton fiber on stability of optical properties of Bond paper. For this aim, industrial unbleached cotton fiber pulp with freeness 13°SR, in two types of fix and agitating was stored for 3-15 days in room temperature ...
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The aim of this study was to investigate the effect of storage and bleaching of cotton fiber on stability of optical properties of Bond paper. For this aim, industrial unbleached cotton fiber pulp with freeness 13°SR, in two types of fix and agitating was stored for 3-15 days in room temperature and after that bleached with hydrogen peroxide. Then, standard handsheets was made from bleached pulp and after air-dried, aged in UV and thermal methods and measured their optical properties. Results showed that agitated samples have more brightness and whiteness and less yellowness than fixed ones and by increasing of storage time this numbers be much and less, respectively. In case of UV treated samples, the brightness and opacity of fixed samples decreased and agitated ones increased. The brightness of fixed and agitated samples with thermal treatment showed up and dawn trend, respectively. Also, UV and thermal treatments, especially in fixed samples lead to much yellowness and much whiteness in agitated ones. Therefore, agitated storage method better than the fixed one so that before and after bleaching present suitable optical properties. In addition, paper made from agitated storage samples has more desirable characteristics and influence of temperature more than UV in present and longtime.
Chemical conversion
Niloufar Davodi; Esmaeil Rasooly Garmaroody; Omid Ramezani; Sepideh Haamedi
Abstract
In this study, in order to control the inhibitory compounds in the bio-refinery, bagasse pith was pretreated under acidic hydrolysis with dilute sulfuric acid 8%, 90 minutes at 120 ° C. Then, by using de-depleting methods of overliming, activated carbon and combining of both, removal of deterrent ...
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In this study, in order to control the inhibitory compounds in the bio-refinery, bagasse pith was pretreated under acidic hydrolysis with dilute sulfuric acid 8%, 90 minutes at 120 ° C. Then, by using de-depleting methods of overliming, activated carbon and combining of both, removal of deterrent compounds from the above pretreatment hydrolyzates was performed. In the overliming, calcium hydroxide and sulfuric acid, in activated carbon method, activated carbon was used at three levels (0.5, 1.5 and 2.5%) and in the combined method of the combination of materials in the two previous methods became after acid treatments and each of the methods of insemination, the amount of recovered sugars and the values of the inhibitory compounds of furfural and hydroxymethylfurfural in the hydrolyzate were measured as two important indicators. The results showed that application of the above methods on hydrolyzate increased the yield of reduced sugars, so that the highest sugar yield (˃32%) was obtained after the independent method of overliming. In addition, active and combined carbon autonomous methods (overlimming and activated carbon) have an optimum activated carbon consumption of 2.5 and 1.5%, respectively. The qualitative study of the presence of inhibitory agents in hydrolyzates showed that furfural and hydroxymethylfurfural have maximum absorption at wavelengths of 276 and 282 nm. Also, an overliming with 2.5% activated carbon as the best method could eliminate up to 100% of inhibitory compounds. On the other hand, the autonomous method of overliming, with the removal of ˃90% of the inhibitory compounds, also has the highest sugar yield. Therefore, taking into account simultaneously the rate of sugar yield and the elimination of deterrent compounds, two independent alternatives of Overliming and Overliming with 2.5% active carbon could be proposed for the production of bioassays, such as bioethanol, xylitol, ... from the pith of bagasse.
Pulp and paper
zahra takzare; kermanian hossein; omid ramezani; Esmaeil Rasooly Garmaroody; Ali Abdolkhani
Abstract
In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, ...
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In this study, the liquorice root (Glycyrrhiza glabra) has been extracted in the Liquorice factory of Kerman, supplied as raw material. The above mentioned waste, after pre-hydrolyzed with sulfuric acid 2% at 130 °C in 60 minutes, is cooked at temperatures of 170 ̊C, the chemicals charge of 20%, and in four times 15, 30, 60 and 90 minutes and rate of liquor to waste 7:1 in Soda process. Obtained Soda pulps were evaluated in yield, lignin percentage, water retention value (WRV), viscosity and crystallinity. Results showed that by prolonging of cooking time, pulp yield and lignin percentage were decreased and WRV increased. Also, pulp viscosity in 30, 45 min was increased by increasing in cooking time that according to other results, it seems that it is false viscosity. In addition, accordance with characterizing of samples by XRD, by progressive cooking time from 15 to 45 min, sample crystallinity decreased and in 60 min its value is increased. According to the pulps viscosity and downward trend of lignin removal with progressive cooking time, this addition can be due to crystallization of hemicellulose like xylan on the crystalline zone of cellulose chain. Therefore, according to the results and based on Bio-refinery concept, cooking time 30 min suggested as the best option for production of high value-added products in saccharification process.
Pulp and paper
Hossein Jalali trshizy; Saeideh Zarea bidkei; Omid Rmazani; Hamidreza Rodi
Abstract
Bio and synthetic polymers; micro and recently nano particles have been applied in wet end section of papermaking industry. Very special attention is focused toward their advantages for controlling the process variables and improving the product quality made from recycled ...
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Bio and synthetic polymers; micro and recently nano particles have been applied in wet end section of papermaking industry. Very special attention is focused toward their advantages for controlling the process variables and improving the product quality made from recycled papers. In the presence of cationic starch polymer as an anionic trash reducer in the pulp slurry, the effects of cationic polyacrylamide (CPAM)-bentonite nanoparticle complex on retention, drainage and paper properties made from old corrugated container (OCC) was evaluated. The results showed that addition of CPAM polymer individually enhanced burst, tensile and tear strength indices. The application of nano bentonite following CPAM has significantly increased all of mentioned pulp and paper properties. Dewatering rate analysis by Dynamic Drainage Jar and laboratory handsheet maker revealed that the time for the paper manufacturing can be reduced. Moreover, raw material to final product ratio (total retention) increased from 96.7% up to 98.7%. Long chain cationic polyacrylamide shows high capability as the flocculation of papermaking ingredients, individually and particularly in combination with nano bentonite, especially for fines which is a high portion in the recycled pulps. Thus the problem resulting from not retaining sufficient ingredients and the pollution load of the paper mill effluent will be reduced.
Mohammad Alishahi; Omid Ramezani; Hossein Kermanian; Mehdi Rahmani nia; Seid Atefeh Nasiri; Sahar Jalalvand
Abstract
In this research, the influence of paper drying condition, as one of the most important variable in paper recycling, on the characteristics of fibers was studied. In this respect, bagasse soda pulp was collected from Pars Paper mill in Khozestan province and handsheets were made. The control hand sheet ...
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In this research, the influence of paper drying condition, as one of the most important variable in paper recycling, on the characteristics of fibers was studied. In this respect, bagasse soda pulp was collected from Pars Paper mill in Khozestan province and handsheets were made. The control hand sheet samples were dried at room temperature and the rest of the handsheets were dried using drum dryer set at 60° C for 3 hours, 100° C for 50 minutes and 120° C for 25 minutes to reach the same moisture content as the sheets dried at room temperature. Then, these handsheets were slushed in water and the pulp properties were determined. The results showed that with increasing the drying temperature, cellulose content did not change while hemicelluloses were reduced. Although the assessment of changing the lignin content with micro kappa method showed an increasing trend, but based on previous literature, it was concluded that the result are not justified. Also, the results indicated that changing the degree of polymerization and crystallinity did not show a consistent trend, showing initial reduction following by increased values. These results were attributed to interaction effect of drying temperature and time.
Omid Ramazani; Ahmad Jahan latibari; Mohammad mehdi Faezipoor; Ali akbar Enayati; Sayed mehdi Manzor alajdad
Abstract
Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables ...
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Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables influences the apparent density of paper, in this study, the influence of OCC pulp freeness, and drying conditions are investigated. The influence of three freeness levels of 350,450, and 550 CSF, drying under strain and unstrained, drying temperatures of 100, 150, 200 C and drying pressure of 7 and 10 kg/cm2 are studied. The relationship between paper making variables and apparent density is developed. All measurements of apparent density were analyzed using Minitab 15 and regression model between independent variables was calculated. The results showed that both pulp freeness and drying temperature had the highest impact on apparent density and both factors increased the apparent density. The response of apparent density of the hand sheets dried at 200 ◦C varied considerably and was analyzed thoroughly. Higher pressure increased apparent density of the sheets. The combined effect of variables is also considered. The combined effect of pulp freeness and drying temperature caused lignin softening and delamination. However, the influence of increasing the drying pressure for unrefined and less refined pulp is not significant. Furthermore, for unstrained drying, the influence of freeness on apparent density was more than strained drying. Manufacturing of more desirable quality papers would be possible considering the obtained results and the effect of Apparent Density on paper strength properties.
