Search

Background and Objectives: The reduction of forest wood resources has increased the necessity of using alternative primary resources including weedy non-wood plants, wood of fast-growing trees and agricultural residues in papermaking industries. On the other hand, most of the country's agricultural waste is consumed in animal husbandry industries, and wood farming also faces many challenges due to costs such as removing the roots after cutting the tree. Hence the need to use a weedy non-wood raw material seems essential. terjin (Saccharum ravennae) is one of the native weedy non-wood resources of the country, which has a good distribution in the country, and so far, its potential for use has not been evaluated. Therefore, the purpose of this research is to investigate the chemical and morphological characteristics of terjin, as well as the production and evaluation of refined and unrefined soda-anthraquinone pulp from it as a raw material to offer to papermaking industries. Materials and Methods: In this research, terjin leaves were obtained from Gorgan region located in Golestan province. In order to measure the biometric characteristics of terjin, the samples were cut using the Franklin method, and then the dimensions of its fibers were measured using an optical microscope, and then their biometric coefficients were calculated. In order to measure the chemical properties of the fibers, the samples were first grinded and then their chemical properties, including the percentage of ash, extractives, lignin (klason) and cellulose were also measured based on the TAPPI standard. In order to prepare pulp from terjin, the samples were cooked at different levels of time (30 and 60 minutes) and chemical (alkalinity 14, 16 and 18%) under a temperature of 160 °C and 0.1% anthraquinone consumption, and then their yield, freeness and kappa number was measured. In the following, the pulps were refined to freeness of 350 ± 20 ml CSF, and then handsheet paper with a grammage of 60 g/m2 was prepared from refined and unrefined pulps, and their physical, optical and resistance characteristics were measured by TAPPI standards. Finally, the results were evaluated and analyzed using one-way analysis of variance and Duncan's test in SPSS software environment. Results: The results showed that the length, diameter, lumen diameter and wall thickness of the fibers were 1.85 mm, 10.82 µm, 5.32 µm and 2.75 µm, respectively; and biometric coefficients including Slenderness ratio, Flexibility coefficient and Runkel ratio were 171.14, 49.12 and 103.60 respectively. Its chemical composition included percentage of ash, extractive, lignin and cellulose were 5.75, 2.53, 26.73 and 44.63 respectively. The results of pulping showed that with the increase of alkalinity percentage and cooking time, yield, kappa number and freeness of pulp decreased. Also, the results showed that refining and increasing the alkalinity percentage and cooking time increase the density, decrease the opacity and increase the resistance characteristics of pulp. According to the results, the brightness increased with the increase in alkalinity percentage, while the increase in cooking time and the use of refining treatment did not have a significant effect on the brightness of the soda-anthraquinone pulp obtained from terjin. According to the results, the best characteristics were obtained after refining the pulp obtained from cooking at 18% alkalinity for 30 and 60 minutes, and also at 16% alkalinity for 60 minutes. Conclusion: In general, terjin has better morphological and chemical characteristics than many non-woody plants, and in some cases, such as fiber length, its characteristics are comparable to hardwood. Also, refined and unrefined soda-anthraquinone pulp of terjin has relatively good and acceptable papermaking characteristics, and it can be suggested to the papermaking industry as a part of the raw material for the production of pulp. [ABSTRACT FROM AUTHOR]

This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. Cellulose, lignin, extractive material (acetone solved) and ash were measured 41.66, 16.00, 1.63, and3.46 percent, respectively. Cooking condition was determined as follow: Soda as 16, 18, and 20 percent on the basis of rapeseed dry straw, temperature was set at 175 and 185 Cº, cooking time was set at 40 and 70 minutes, and straw to liquid ratio was set at 1/8. The amount of anthraquinone added to cooking liquor was 0.2%, based on rapeseed dry straw. Using severe cooking factors caused reduction of yield and Kappa number in both methods. Refining was performed on selected pulps in order to reach 35025 (ml,CSF) freeness. The 60 gr/m² hand sheets were made in order to determine mechanical strength and physical properties. Average thickness, density and bulk is measured at 86.4µ, 0.69gr/cm³ and 1.44cm³/gr respectively. Average tear index, burst index, breaking length and tensile indexare measured at 4.6 mN.m²/gr, 3.5 kpa.m²/gr, 7.4km and 72.6Nm/g respectively. The results showed that however screen yield of rapeseed straw pulp is low but kappa number and mechanical properties of pulp is suitable,compared with the other agriculture residues, so Rapeseed pulp can be used in paper making industries.

Bleach boosting effect of xylano-pectinolytic enzymes produced by Bacillus pumilus AJK was evaluated on plywood veneer soda anthraquinone pulp. Enzyme dose of 6 IU xylanase and 2.4 IU pectinase per g pulp at pH 8.5, temperature 55 °C and retention time of 120 min mitigated kappa number of pulp by 9.375%, thus exhibiting remarkable delignification efficiency. The consumption of chlorine and chlorine dioxide diminished by 25% and 23.8% respectively in subsequent bleaching stages with no detrimental effect on the brightness of pulp. Enzyme treated pulp exhibited improved physical properties viz. breaking length, burst factor, tear factor and viscosity. Furthermore, this approach resulted in 16.67% and 18.03% decrease in the BOD and COD values of effluents. This is the first report representing the use of xylano-pectinolytic enzymes, produced concurrently by a cellulase free bacterial strain utilizing agro-residues based production media for bleaching of softwood soda anthraquinone pulp. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to evaluate the influence of mild alkaline pre-extraction on the hemicelluloses removal of rice straw. In addition, the performance of cellulose nanofibers (CNFs) addition on some physico-mechanical properties obtained from extracted and un-extracted (control) samples were investigated. An optimum compromise was found as operating conditions (10% soda, 50°C, and 90min) that provided moderate hemicelluloses removal (48.1%). The residual extracted rice straw particles were subjected to soda–anthraquinone pulping at 160°C for 30–60min with 6 to 18% active alkali charge. Compared with the control samples, the screened yield and Kappa number for extracted pulps decreased slightly. Extracted samples showed better air resistance compared with the un-extracted (control) pulps. However, pre-extraction was found to negatively impact on some mechanical properties such as decrease in burst and tensile indices while addition of CNFs and refining of fibers could improve the strength properties considerably. In general, the addition of CNFs in any concentrations considerably enhanced tensile and burst indices of the sheets in extracted and un-extracted conditions, compared with the unfilled ones. The improvement in mechanical properties was considered one of the key benefits brought by CNFs reinforcement. On the other hand, the stretch properties of the beaten pulps are higher than those of control samples. SEM observations showed that CNFs were deposited on the voids between the rice straw fibers. [Copyright &y& Elsevier]

Highlights: [•] Polynomial equations that reproduced the properties of the pulp and paper sheets. [•] An optimum operational conditions were found. [•] These conditions can save chemical reagents, energy and immobilized capital. [ABSTRACT FROM AUTHOR]

Abstract: Paper pulp manufacturing is the main non-food industrial utilization of plant biomass. Non-wood and agricultural residues are potential raw materials in the production of specialty papers. This chapter aims to quantify the environmental impacts associated with non-wood high quality paper pulp manufacture via soda-anthraquinone (AQ) cooking process by means of the application of LCA methodology in a cradle-to-gate analysis. Hemp (Cannabis sativa) and Flax (Linum usitatissimum) were evaluated as raw materials for the production of high quality non-porous pulp. A specialty paper pulp mill was analysed in detail and process chain was divided in six subsystems: agricultural activities, chemicals production, electricity production, transport, pulp production and waste treatment. Inventory data came from interviews and surveys (on-site measurements). When necessary, the data were completed with bibliographic resources. Abiotic resources depletion (AD), global warming (GW), ozone layer depletion (OLD), human toxicity (HT), ecotoxicity, photochemical oxidant formation (POF), acidification (A) and eutrophication (E) were the impact categories analysed in this study. According to the results, the environmental impact is mainly caused by the production of chemicals, electricity and fibres (agricultural activities) due to greenhouse gases emissions, phosphorous and nitrogen compounds emissions. The activities inside the pulp mill present minor contribution to almost all impact categories, excluding GW (15%) and E (6%) as well as OLD (25%). This study provides useful information for non-wood based industries related not only to pulp manufacture but also to panels or biorefineries with the aim of increasing their sustainability. [Copyright &y& Elsevier]

The AOpAZRP bleaching sequence (A is an acid treatment, Op an oxygen and peroxide stage, Z an ozone stage, R a reductive treatment and P a peroxide stage) have been applied to oil palm empty fruit bunches (EFB) soda-anthraquinone and diethanolamine pulp. On similar Kappa numbers for the two types of pulp (14.2 and 17.3), paper from unbleached soda-anthraquinone pulp exhibited increased tensile index (25.8Nm/g), stretch (2.35%), burst index (1.69kN/g), tear index (0.50mNm2/g) and brightness (60.6%) relative to paper for unbleached diethanolamine pulp; but the latter type of pulp exhibited higher viscosity (659mL/g) than the former. Upon bleaching with the AOpAZRP sequence, diethanolamine pulp exhibited higher viscosity (783mL/g), and the properties of the paper sheets were close to or even better to those from soda-anthraquinone pulp, namely: 22.2 vs 20.4Nm/g tensile index, 1.30 vs 1.42kN/g burst index, 0.71 vs 0.70mNm2/g tear index and 71.3% vs 77.5% brightness. Therefore, the properties of paper from diethanolamine pulp evolved more favourably during bleaching than did those of paper from soda-anthraquinone pulp. [Copyright &y& Elsevier]

The influence of soda-anthraquinone pulping variables (temperature, time and soda concentration) and beating (number of PFI beating revolution) of palm oil empty fruit bunches (EFB) on the resulting paper sheets was studied, with a view to identifying the optimum operating conditions. Equations were derived that reproduced the properties of the paper sheets with errors less than 10–12% in 90–95% of cases. An optimum compromise was found as regards operating conditions (15% soda, 170°C, 70min and 2400 number of PFI beating revolutions) that provided paper properties departing by less than 12% from their optimum values (59.63Nm/g tensile index, 4.48% stretch, 4.17kN/g burst index and 7.20mNm2/g tear index), and a beating grade of 47.5°SR, acceptable to obtain paper sheets. Because these conditions involve a lower soda, temperature, time and beating than those required to maximize the studied paper properties, they can save chemical reagents, energy and immobilized capital for industrial facilities. On the other hand, the stretch properties of these pulp beaten are higher than those of others non-wood pulps, as wheat straw and olive wood. [Copyright &y& Elsevier]