Ethanol-Enhanced Alkaline Pulping of Arundo donax L. Reed: Influence of Solvent on Pulp Yield and Quality

Holzforschung ◽  
2002 ◽  
Vol 56 (5) ◽  
pp. 507-512 ◽  
Author(s):  
A. A. Shatalov ◽  
H. Pereira

Summary The effect of solvent on yield and properties of ethanol-alkali pulps from Arundo donax L. was studied. Selectivity of pulping was significantly improved with increase in solvent proportion in the cooking liquor. A rise in ethanol concentration from 20 to 60% (by vol.) increased pulp yield from 44.0 to 48.9%, while decreasing residual lignin from 5.0 to 3.0%. Ethanol addition had a positive effect on preservation of carbohydrate complex against degradation in alkaline medium. Intrinsic viscosity of cellulose was improved up to 35% and xylan content increased from 8.6 to 12.1% with increase in ethanol concentration from 20 to 60%. The preservation of minor non-cellulosic polysaccharides with solvent addition was also observed. The papermaking properties of ethanol-alkali pulps were best for 20% ethanol content. An increase in solvent charge led to a drop in burst, tear and tensile pulp strength. Solvent addition assisted the conversion of glucuronic to hexenuronic acids, whereas the content of HexA in ethanol-alkali pulps of Arundo donax (about 10 μmol/g) was substantially lower than reported for kraft pulps from wood.

2012 ◽  
Vol 36 (6) ◽  
pp. 1163-1172 ◽  
Author(s):  
María Graciela Aguayo ◽  
Regis Teixeira Mendonça ◽  
Paulina Martínez ◽  
Jaime Rodríguez ◽  
Miguel Pereira

Tension (TW) and opposite wood (OW) of Eucalyptus globulus trees were analyzed for its chemical characteristics and Kraft pulp production. Lignin content was 16% lower and contained 32% more syringyl units in TW than in OW. The increase in syringyl units favoured the formation of β-O-4 bonds that was also higher in TW than in OW (84% vs. 64%, respectively). The effect of these wood features was evaluated in the production of Kraft pulps from both types of wood. At kappa number 16, Kraft pulps obtained from TW demanded less active alkali in delignification and presented slightly higher or similar pulp yield than pulps made with OW. Fiber length, coarseness and intrinsic viscosity were also higher in tension than in opposite pulps. When pulps where refined to 30°SR, TW pulps needed 18% more revolutions in the PFI mill to achieve the same beating degree than OW pulps. Strength properties (tensile, tear and burst indexes) were slightly higher or similar in tension as compared with opposite wood pulps. After an OD0(EO)D1 bleaching sequence, both pulps achieved up to 89% ISO brightness. Bleached pulps from TW presented higher viscosity and low amount of hexenuronic acids than pulps from OW. Results showed that TW presented high xylans and low lignin content that caused a decrease in alkali consumption, increase pulp strength properties and similar bleaching performance as compared with pulps from OW.


2010 ◽  
Vol 25 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Riikka Kämppi ◽  
Hanna Hörhammer ◽  
Anja Leponiemi ◽  
Adriaan van Heiningen

Abstract The aim of this study was to find conditions under which it is possible to produce hemicelluloses-rich extract from Siberian larch in addition to pre-extracted pulp with a yield comparable to normal kraft pulp. The study was conducted in order to determine proof of concept of a process utilizing Siberian larch for production of papermaking pulp and biochemically obtained value-added products, i.e. biofuels or lactic acid. By pre-extraction at 160 ºC for 60 minutes approximately 17% of the wood material could be dissolved. At kappa number 30, the pre-extracted kraft pulp gave 5% lower total yield than a conventional kraft pulp. Addition of 4% polysulfide (PS) and 0.1% anthraquinone (AQ) on wood increased the pre-extracted kraft pulp yield nearly to the same level as that of regular kraft pulp. Pre-extraction at 160 ºC for 60 minutes allowed reduction of EA charge by 3% on wood and Hfactor by 300-450. The viscosity of the pre-extracted PSAQ kraft pulps was higher than that of conventional larch kraft pulps and had a somewhat inferior strength and optical properties. The results indicate that under optimized conditions it is possible to produce preextracted PSAQ larch pulp without significant losses in pulp yield and quality, and in addition generate a new feed stock of carbohydrates for further utilization for value-added products.


2021 ◽  
Vol 13 (4) ◽  
pp. 2157
Author(s):  
Ioanna Kakabouki ◽  
Angeliki Kousta ◽  
Antigolena Folina ◽  
Stella Karydogianni ◽  
Charikleia Zisi ◽  
...  

Field experiments were conducted during 2019 in two different locations in Greece (Athens and Farsala) to evaluate the effect of urea and urea fertilization with inhibitors on the agronomic yield and quality characteristics of two cannabis varieties (Cannabis sativa L.), “Uso31”and “Fedora 17”. The experimental design was split-plot with four different fertilization treatments—control, Urea (U), urea with Urease Inhibitor (UI), and urea with Nitrification Inhibitor (NI) and urease inhibitor (UI). The significance of differences between treatments was estimated by using Tukey’s test with a significance level of p = 0.05. The plant height was significantly affected by the different fertilizations and different varieties as well as by the two locations. The maximum plant height was 197 cm for “Fedora 17”in Farsala. The seed yield was higher forthe urea with inhibitors treatment in both varieties. The Cannabidiol (CBD) content was significantly affected by the fertilization—it was higher in urea with inhibitors in “Uso31”and “Fedora 17” treatments. The lowest CBD content value was 1.29% (control) and the highest was 1.69% (urea NI + UI). In conclusion, in both varieties, it seems that urea with inhibitors has a positive effect on their growth, as well as on the increase in cannabidiol (CBD) content.


2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan

The effect of chelating agents Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp yield was 49.52% when DTPMPA dosage is 0.4%, at the same time the Kappa number was lower. With the increasing of DTPMPA dosage in bamboo kraft pulping, the bamboo pulp strength was increased.


Author(s):  
Antonín Vaculík

Caraway has very low competitive ability against most of weed species. Therefore, it is important to choose a suitable herbicide control, especially at biennial caraway. The experiments with the herbicides applied in caraway were found in pure growth, with variety Kepron (with standard length of ve­ge­ta­ti­ve period). The aim of the trials was to find out the differences at achenes yiled and essential oil content after the treatment by the various herbicides, applied preemergently. Also, the selective ac­ti­vi­ty of individual herbicides was tested, including the different doses. The herbicides used in the ex­pe­ri­ments had enough level of selektivity on the plants of caraway. They had a positive effect on the yiled comparing to non-treated control variant in all observed years. There was no statistically significant difference in essential oil kontent between the treated variants and non-treated control. On the basis of these results, the most suitable herbicide was chosen for the „minor“ registration for caraway.


2021 ◽  
Vol 250 ◽  
pp. 71-77
Author(s):  
A. Yu. Gavrilova ◽  
◽  
A. M. Konova ◽  

The article considers the effect of increasing doses and various combinations of mineral fertilizers applied to the cover crop on the yield and quality of a mixture of perennial grasses of two - years use, as well as the effect of fertilizers on the agrochemical parameters of sod-podzolic light loamy soil. The objects of the study were Stodolich meadow clover and Leningradskaya 204 meadow timothy grass. The studies were carried out in two crop rotations - with standard and reduced single doses of mineral fertilizers. The research results showed that in the years (VIII rotation) when the unit dose of fertilizers was increased to N20P20K25, the yield of perennial grasses was higher compared to the harvest in the VII rotation. The most appropriate dose in the VII rotation on perennial grasses of the 1st year was N30P30K45, on grasses of the 2nd year - doses of N30P30K45 and N40P40K60. In the VIII rotation, the highest yield of perennial grasses of the 1st year of use was obtained at a dose of N160P160K200 (8.4 t / ha), of grasses of the 2nd year of use at doses of N80P80K100 and N100P100K125 (6.5 t / ha). Positive effect of increasing doses of mineral fertilizers on the content of soil organic matter has been noted. On the contrary, the soil acidity increased from 4.7 to 4.3 units with an increase of mineral doses. Higher doses of fertilizers increased the content of mobile forms of phosphorus and potassium in the soil.


Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 861-866 ◽  
Author(s):  
Per Tomas Larsson ◽  
Lennart Salmén

Abstract The industrially produced chemical pulps have lower strength properties than those obtained under laboratory conditions, and this difference is referred to as the strength delivery (SD) problem. In this study, the hypothesis was put forward that the SD could, at least in part, be accounted for by the supramolecular structure of the cellulose microfibrils of the fiber wall. To test the hypothesis, two bleached softwood kraft pulps (BSKP) were manufactured from the same starting material with different degrees of cellulose aggregation, but the pulps were otherwise as similar as possible in other controllable respects. The chemical and physical properties, including the pulp strength, were tested. A selective increase of the degree of cellulose microfibril aggregation resulted in a pulp with a decreased tear index (TI) at a specified tensile index, and this decrease was similar in magnitude to what is typically encountered in SD. Accordingly, the current experimental study succeeded in mimicking the SD problem. The lateral fibril aggregate dimensions (LFAD) seem to play a pivotal role and it can be safely concluded in general that the supramolecular structure of cellulose in the fibers may be an important factor contributing to the SD problem.


2012 ◽  
Vol 21 (2) ◽  
pp. 109-116
Author(s):  
Sayma Khanom ◽  
Sonia Hosssain ◽  
Shahid Akhtar Hossain

A field experiment was conducted at Bangladesh Jute Research Institute (BJRI) to observe the response of N, P, K and S on a pre?released white jute (Corchorus capsularis) var. BJC?2197. The experiment was carried out by applying N, P, K, S fertilizers in ten combinations including control. From the experiment it was observed that all the treatments had significant positive effect over control on growth, yield and quality parameters. The highest fiber yield (3.21 t/ha) and stick yield (6.58 t/ha) were recorded with N90P5K30S10 kg/ha treatment. However, the best quality fiber was found with combination of N90P15K30S10 kg/ha treatment. From the economic analysis point of view, it was found that combination of N90P5K30S10 kg/ha was higher (2.30) than N90P15K30S10 kg/ha (2.04). So the former can be considered as the best combination for var. BJC?2197 in terms of BCR, yield and quality. Dhaka Univ. J. Biol. Sci. 21(2): 109?116, 2012 (July) DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11508


2020 ◽  
Vol 262 ◽  
pp. 114550 ◽  
Author(s):  
Xinfei Chen ◽  
Xiaoqian Ma ◽  
Xianghao Zeng ◽  
Chupeng Zheng ◽  
Xiaoluan Lu

Holzforschung ◽  
2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Jean Bouchard ◽  
Jie Wang ◽  
Richard Berry

Abstract It has been proposed that magnesium hydroxide can replace magnesium sulfate as a lower cost cellulose protector. This claim has been evaluated based on four commercial unbleached softwood kraft pulps. The selectivity was improved in the presence of soluble MgSO4, but little or no selectivity improvement was obtained when insoluble Mg(OH)2 was applied. It was further observed that in-situ iron concentration in unbleached pulp affects selectivity of oxygen delignification, while in-situ calcium concentration affects efficiency of magnesium protection. The results favor the hypothesis of formation of a Mg-carbohydrate complex as the major mechanism of cellulose protection by magnesium. The application of a soluble magnesium compound is recommended to improve selectivity in oxygen delignification.


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