جستجوی مقالات مرتبط با کلیدواژه « آب داغ » در نشریات گروه « صنایع چوب و کاغذ »

In this research, the effect of hot water and alkaline pre-extractions on properties of bagasse monoethanolamine-AQ pulps was investigated and the results were compared with that of soda pulping. The pre-extraction with alkaline charge of 10%, time of 30 min resulted in total yield and holocellulose of 94.7% and 71.6%, respectively. The hot water pre-extraction with L/W of 10/1 and time of 45min lead to total yield and hollocellulose of 94% and 69.4%, respectively. These trails were selected as the optimum conditions. Monoethanolamine was used as pure and also in different proportions with water for cooking unextracted and pre-extracted bagasse. Variables in monoethanoleamine pulpng were ratio of monoethanolamine to water at three levels (100/0, 75/25, and 50/50%) and the ratio of the liquor to bagasse of 6 to 1, cooking time of 60 min, the temperature of 165°C and AQ charge of 0.1% considered as constant. According to the results, the MEA-AQ pulps produced with MEA/H2O ratio of 75/25 (from unextracted bagasse) have the highest total yield (61.9 %) and the acceptable kappa number (19.5). Pre-extraction resulted in improving of the yield in both MEA-AQ and soda pulping processes. After pre-extraction, the tensile index and breaking length of pulps dropped. In contrast, the tear index of pulps produced from pre-extracted bagasse in both pulping processes was increased. The brightness of soda pulps from un- and pre-extracted bagasse was more than that of MEA-AQ pulps. After pre-extraction, the opacity of pulps remains almost unchanged.

In this study, the liquorice root (Glycyrrhiza glabra) that was extracted in the factory in Kerman province, pre-hydrolyzed and then chemical compositions (Extractives, Lignin content, Holocellulose percent), the hydrolysis process yield and weight loss of the waste was measured. Pre-hydrolysis process was done on the above mentioned waste by hot water, hot water followed by 0.5 percent sulfuric acid and also alone sulfuric acid with different concentrations (0.5, 1, 1.5 and 2 percent) The samples were pre-hydrolyzed in hot water at 150 °C and 30, 60 and 90 minutes as well as in the mixture of hot water and 0.5 % sulfuric acid at 150 °C and 60 minutes and also in pure sulfuric acid, at 130 °C and at 60 minutes. The results showed that the pre-hydrolyzed treatment with hot water in 60 minutes had been favorable performance in the respect of weight loss, lignin content and holocellulose percent. Also, in the case of pre-treatment including sulfuric acid, 2% dose can be good selected option in term of maximum holocellulose percent and minimum lignin content so that it can be suggested to produce higher value-added products such as bioethanol from licorice root bid.