Pulping and papermaking properties of Tunisian Alfa stems ( Stipa tenacissima)—Effects of refining process (original) (raw)
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This paper studied the chemical composition of Seven (7) samples of Nigeria-grown agro-based fibers such as Empty Fruit Bunch of Oil Palm (EFB), Rice straws, Wheat straws, Sugar cane bagasse, Corn stalk, Coconut fruit bunch and of course Kenaf Bast (Hibiscus cannabinus) as reference. This investigation is aimed at evaluating the potential of these fibers for production of paper grade pulp. The samples were chemically characterized. Parameters investigated include some chemical properties such as % moisture, 1% caustic solubility (%), hot water solubility (%), extractives (%), holocellulose (%), α-cellulose (%), lignin (%) and percentage ash contents. The results revealed that there were significant differences among the agricultural residues in chemical compositions. The samples were then cooked by the MEA process. The resulting pulps were fully bleached by the D1-Ep-D2 sequence and characterized for their beatability, drainability and physicalmechanical properties. The lignin content of all the samples investigated were low (below 20%), indicating that they should be easier to pulp. In practice, this means that these materials would need milder pulping conditions (lower temperatures and chemical charges) in order to reach a satisfactory kappa number. They would also undergo bleaching more easily and with the utilization of fewer chemicals. The MEA pulp from most of agro-biomass cooked to kappa number 17.5 presented good screened yield with liquor charge demand of 75.0% MEA and 0.5% Surfactant. The pulps resulting from the MEA pulping at kappa no 17.5, were fully bleached by a totally chlorine-free sequence performed in three stages, using 50% hydrogen peroxide in the first stage at 10% pulp consistency, 70 o C for 15 minutes, followed by 1.5% NaOH in the second bleaching stage at a temperature of 80-90 o C for 10 minutes and at the same pulp consistency (10%), while the third and final stage involve a repeat of the process employed in the first stage to achieve an ISO brightness of approximately 90.0%. This sequence is represented in a shorthand form as D1-Ep-D2. The bleached MEA pulps cooked to 17.5 and 10.6 kappa number showed similar refinability and resistance to drainage, but the tensile and burst index were highest for the 17.5 kappa pulp at beating energy consumptions in the range of 0-6 Wh. It was concluded that both 10.6 and 17.5 kappa pulps from most of the agro-biomass are suitable for the production of paper grade pulps, but the highest kappa 17.5 pulp is more economically attractive given its highest pulping yield, despite the significantly increased of chemical demand for bleaching.
Pulp and fiber characterization of wheat straw and eucalyptus pulps–A comparison
The response to refining of wheat straw and eucalyptus pulps as well as the relationships between refining, fiber properties, and paper properties are described in this paper. Pulps were bleached applying different bleaching sequences and thereafter refined to varying degrees. Pulp and fiber properties were investigated and set into relation to the final sheet properties. The results show that wheat straw pulps respond to refining more easily than eucalyptus pulps and that the differences are due mainly to morphological and ultrastructural differences as well as fines content and xylan content. The development of strength properties of the different pulps was found to be strongly correlated to the number of dislocations, i.e. weak points in the fiber wall, as well as to the morphological appearance of the pulp fibers after refining. A higher initial number and a faster development of dislocations together with the creation of large amounts of fines explain the slower and lower development of strength properties of wheat straw pulps than of eucalyptus pulps. Removal of fines from wheat straw pulps improved not only the drainability of the pulp suspension but also the mechanical and optical sheet properties. This indicates that the fines in the wheat straw pulps act mainly as filler with low bonding properties. The fact that fractionated D(EOP)D wheat straw pulps can deliver good mechanical sheet properties at very good drainability with no or only minor refining is very interesting when evaluating the potential of replacing or partially replacing eucalyptus with domestic Chinese raw materials in furnishes for production of different paper products.
The objective of this research study is to examine the potentials of a novel environmentally friendly pulping process in converting some selected Nigeria cultivated agro-wastes into high yield paper pulp. The chemical and morphological characteristics of Ten (10) Nigerian cultivated agro-based fibers were investigated. Pulping trials were carried out using the monoethanolamine (MEA) process comparing the potentials of each agro-biomass in furnishing high yield pulp. The operating conditions such as the concentration of the cooking liquor (50%, 75%, 100%), the maximum cooking temperature (150, 160, 170 o C) and cooking time (60, 90, 120minutes) were applied systematically to establish optimal pulping conditions and optimum result. The lignin content of EFB (18.29%) was low; indicating that EFB should be easier to pulp. The optimum cooking conditions for MEA pulping were 75% MEA concentration, 90 minutes cooking time, and 150°C cooking temperature. The laboratoryscale experimental results indicated that MEA pulping process is particularly well suited for the pulping of agro-based fibers e.g. EFB of Oil Palm, which was de-lignified to a low kappa number value of 18.6, pulp yield of 49.93% and screen yield of 46.27% recording a reject of only 3.66%. It was observed that most of the materials with the exception of wheat straw and kenaf bast fiber showed a similar lignin content (around 18%), with rice straw and corn stalk showing slight variation. More variations were observed in the holocellulose and α-cellulose contents; also, sugar cane bagasse showed the highest percentage of α-cellulose with respect to total holocellulose. Comparing data on holocellulose, α-cellulose and lignin of the ten (10) agro base fiber investigated, it could be observed that EFB has slightly lower αcellulose and holocellulose contents than all the agro-base fiber investigated with the exception of CFB, wheat and rice, but slightly similar in lignin contents only to pineapple leaves, bagasse and CBF. Based on these results, it seems appropriate to use EFB as a cellulose source suitable for the production of cellulose pulp and paper. MEA process is more economically attractive given its high pulp yield, despite the significant increase in chemical demand for bleaching. MEA pulping is a good alternative to soda pulping furnishing high pulp yield with less cooking temperature, i.e. 150 o C, thereby saving a considerable amount of energy with less odoriferous pollutants and pollution load associated with the soda process.
Production of dissolving grade pulp from alfa
BioResources
Alfa, also knows as Stipa tenacissimaI or “halfa”, is grown in North Africa and south Spain. Due to its short fiber length, paper made from alfa pulp retains bulk and takes block letters well. In this study alfa was evaluated for bleached pulp production. Two cellulose pulps with different chemical compositions were pulped by a conventional kraft process. One sample was taken from the original alfa material and another from alfa that had been pretreated by diluted acid. The pulp produced from the pretreated alfa was bleached by the elemental-chlorine-free sequences DEPD and DEDP. The yield, Kappa number, brightness, and α- cellulose content of bleached and unbleached pulps were evaluated. The results showed that during the chemical pulping process, treated alfa cooked more easily than the original alfa. The treated alfa pulp also showed very good bleaching, reaching a brightness level of 94.8% ISO with a yield of 93.6% at an α-cellulose content 96.8(%) with a DEDP bleaching sequence...
Non-Wood Fibers: Relationships of Fiber Properties with Pulp Properties
ACS Omega, 2021
In this investigation, the relationship between fiber properties and papermaking properties of 22 non-wood materials at the unrefined and refined states was assessed. The fiber length had positive and the cell wall thickness had negative correlation on the strength properties for the refined pulp. The relationship between papermaking properties with pulp quality, such as fines, curl index, kink index, external fibrillation, and coarseness, was also determined. The correlations of multiple regression equations of fiber quality parameters were 70.4% for the tensile index and 84.9% for the tear index for the refined pulp. The correlations of multiple regression equations of chemical characteristics of the samples were 81.9% for the pulp yield and 42.7% for the kappa number. Holocellulose and αcellulose had a positive and lignin had a negative effect on the pulp yield.
Journal of Scientific & Industrial Research, 2004
Indian pulp and paper industries are facing an acute shortage of good quality of wood fibre with other associated problems. So they could not match their final product vis-a-vis to the finished products in globally competitive market. To overcome a serious lack of domestic wood fibres, morphological as well as chemical investigations on abundantly available and fast growing non-woody fibrous plants, which resemble in some aspects with softwoods and bamboo, have been undertaken. Keeping this challenge in view the pulp and paper making characteristics of three non-woody plants namely, Eulaliopsis binata, Cajanus cajan, and Sesbania sesban have been studied extensively. Eulaliopsis binata, which is popularly known as 'Sabai grass', consists of long leaf fibres. The fibre length of sabai grass is more than that of bamboo but fibre diam is 2.5-times lower than bamboo. Sabai grass consists of high cellulose and pectose with low lignin content. Sesbania sesban popularly known as &#...
Non-wood fibers as raw material for pulp and paper industry
Nordic Pulp & Paper Research Journal, 2020
Pulp and paper industry in the world have been growing fast. As a result, there has been a massive request for pulp and paper raw materials. The raw materials used in papermaking can be classified into three groups: wood, non-wood, and recycled wastepaper. The Non-wood raw material is an important fiber resource in the regions where forest resources are limited. The current usage of non-wood plant fibers, as rice straws, corn stalks, cotton stalks, and bagasse would play a chief role in increasing papermaking raw materials. Using of non-wood plant fibers in the paper industry associated with some problems, including collection, transportation, storage and handling, washing, bleaching, papermaking, chemical recovery, supply of raw material and the properties of finished paper. Recently, a high-tech innovation in all the fields of papermaking has made non-wood more reasonable with wood as a raw material for papermaking. Although till now, use of non-wood fibers for pulp and paper manu...
Exploring Sudanese agricultural residues as alternative fibres for pulp and paper manufacturing
IOP Conference Series: Materials Science and Engineering, 2018
In this work, the chemical composition, fibre dimensions and morphology, elemental analysis and paper characterisation of sesame, millet, karkadeh and sorghum stalks were studied. Soda and soda-anthraquinone pulping as sulfur-free processes were applied. It was found that, the cellulose content of karkadeh, sesame, millet and sorghum stalks were 45.80, 42.30, 40.99 and 35.40%, respectively. Klason lignin was found to be highest in sesame 20.85% while it was 19.32, 18.20 and 10.32% in karkadeh, millet and sorghum, respectively. Moreover, karkadeh showed highest pulp yield (46.60% and 43.50%) with viscosity of (655 ml/g and 640 ml/g) and kappa number of (18.00 and 19.40) for soda-AQ and soda pulps, followed by sesame, okra and sorghum, respectively. Overall strength properties of the handsheet made from karkadeh pulp were significantly higher than those made from sesame, millet, and sorghum pulps. Morphological analysis and chemical composition of the studied fibrous materials showed their suitability for producing paper of various grades including writing and printing paper as well as packaging applications.
2010
The chemical composition of several non-woody plant fibers (bast fibers from flax, hemp, kenaf, jute; leaf fibers from sisal, abaca and curaua; and giant reed), which are used as raw materials for pulp and papermaking, has been evaluated. Particular attention was paid to the composition of the lipophilic compounds and the structure of the lignin polymer since they are important components of the fiber that strongly influence the pulping and bleaching performances.
The Impact of Storage Conditions of Pulp on Its Susceptibility to Refining and Properties of Fibers
2016
This article presents the impact of a degree of polymerization on the papermaking potential of paper. Bleached pinewood kraft pulp from one of paper mills was used for research purposes. The main objective of this work was to investigate the influence of a degree of polymerisation of pulp on the properties of fibres such as water retention value (WRV) and the fines content etc. Different degrees of polymerization were obtained as a result of the pulp drying at different temperatures (105 ̊C, 130 ̊C and 150 ̊C) for a period from 1 hour up to 150 hours. During the drying process, a visible decrease in a degree of polymerization of cellulose in hornified fibres occurs. Significant differences in pulp properties can be observed in particular in case of pulps dried at a very high temperature (150°C) and in case of a long drying time (150 h).