Chemical Pretreatments of Wood Chips Prior to Alkaline Pulping - A Review of Pretreatment Alternatives, Chemical Aspects of the Resulting Liquors, and Pulping Outcomes

Lehto, Joni; Alén, Raimo

doi:10.15376/biores.10.4.lehto

Cited by 29 publications

(12 citation statements)

References 295 publications

(421 reference statements)

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“…In addition, compared to ethanol, methanol has less viscosity, polarity and surface tension. The low surface tension and increased pressure, together with the ability of methanol to dissolve resins, have a positive impact on the penetration of chemicals into the chips [48,49].…”

Section: Effect Of Methanol Additionmentioning

confidence: 99%

Alkaline Sulfite Anthraquinone and Methanol (ASAM) Pulping Process of Tropical Bamboo (Gigantochloa scortechinii)

Paridah¹,

Moradbak²,

Mohamed³

et al. 2018

Bamboo - Current and Future Prospects

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This chapter explores the characteristic potentials of alkaline sulfite anthraquinone and methanol (ASAM) pulping of bamboo culms (Gigantochloa scortechinii) in the industrial production of pulp and paper for packaging. The biometric characterization results of the bamboo culms show that bamboo has fiber length of 1980-4000 μm, Runkel ratio of 0.86, and flexibility ratio of 50.19, while the chemical compositions of the bamboo contain 47.67% cellulose, 68.33% holocellulose, 26% lignin, and 3.69% solvent extractive, which give good paper quality fiber and also falls within the range of wood from softwoods species. The study revealed that the optimum ASAM pulping parameters was at 16% NaOH and 90 min cooking time, resulting in Kappa number of 14.17 and pulp yield of 49.06%, while the paper tensile index of 20.86 Nm/g, tear index of 22.64 mN.m2/g, and brightness of 39.32% were obtained. The biometric and chemical characterizations of the ASAM pulped bamboo have shown that ASAM pulped bamboo produces high-quality pulp and paper suitable for packaging and printing paper. Hence, the use of bamboo materials can reduce the burden on the forest, due to the increasing demand for paper and paper products, while supporting the natural biodiversity.

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Section: Effect Of Methanol Additionmentioning

confidence: 99%

Alkaline Sulfite Anthraquinone and Methanol (ASAM) Pulping Process of Tropical Bamboo (Gigantochloa scortechinii)

Paridah¹,

Moradbak²,

Mohamed³

et al. 2018

Bamboo - Current and Future Prospects

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“…[14][15][16][17][18][19] One of the most promising techniques involves various pretreatment processes in which wood chips are extracted with pressurized hot water [20,21] and partially solubilized prior to delignification. Pretreatment produces mainly carbohydrate-derived fragments, which can be further converted into value-added chemicals, biofuels, or other biomaterials.…”

Section: Introductionmentioning

confidence: 99%

Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping

Chen

Alén

Lehto

et al. 2016

Journal of Wood Chemistry and Technology

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FinlandSulfur-free pulping has an environmental advantage over the traditional kraft process. This paper describes the combustion properties of the black liquors produced from silver birch (Betula pendula) sawdust using three different cooking processes: two sulfur-free cooks (sodaanthraquinone and oxygen-alkali), and one reference kraft cook. It also considers the corresponding black liquors from an integrated forest biorefinery, in which a hot-water pretreatment of feedstock was performed prior to pulping. With the same cooking time, the total burning times for the sulfur-free black liquors were higher (15-55%) than those for the conventional kraft black liquors. However, no significant differences were noted between the total burning times for black liquors from pretreated feedstock and those from untreated feedstock. Especially in the case of untreated feedstock, the results showed that the kraft black liquors typically swelled more (25-45%) than the sulfur-free black liquors. It was further observed that the kraft and soda-anthraquinone black liquors from the untreated feedstock swelled more than those from the pretreated feedstock, while the oxygen-alkali black liquors swelled less.Keywords: Aliphatic carboxylic acids, Betula pendula, black liquor, combustion properties, hotwater pretreatment, kraft pulping, lignin, sulfur-free pulping 2 INTRODUCTIONIn the pulp and paper industry, the principal delignification process for the manufacture of papermaking fibers is kraft pulping using aqueous sodium hydroxide and sodium sulfide as the cooking chemicals. [1,2] In addition, environmentally friendly delignification methods have been developed, mainly because of odor problems associated with sulfur-containing emissions; these include processes using sulfur-free cooking chemicals such as soda-anthraquinone (AQ). [3][4][5][6][7][8] However, due to the possible health risks, [9,10] it has been recommended that the use of AQ should be decreased. For this reason, delignification of wood with oxygen and alkali [11][12][13] (O 2 -NaOH) may offer a potential sulfur-free method. One-stage delignification of wood by oxygen in the pH region 7-9 has been subjected of numerous studies especially in the 1950-1970s. The characteristic feature of this delignification process is the extensive oxidation degradations of lignin and carbohydrates resulting, for example, in black liquors that have lower heating value than those from the kraft and soda-AQ pulping. The delignification rate in the O 2 -NaOH pulping is usually also slightly lower than that detected in the kraft and soda-AQ pulping.Modern pulp mills could serve as a platform for achieving more efficient use of wood and nonwood materials. [14][15][16][17][18][19] One of the most promising techniques involves various pretreatment processes in which wood chips are extracted with pressurized hot water [20,21] and partially solubilized prior to delignification. Pretreatment produces mainly carbohydrate-derived fragments, which can be further converted into value-added chemicals...

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“…The paper making process involves a number of stages including debarking, pulping, bleaching and papermaking (Lehto and Al en, 2015). Pulping is meant to reduce the lignocellulosic material in the raw material to pulp by mechanical, chemical or a mixture of both methods (Shukry et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Optimization of pulp production from groundnut shells using chemical pulping at low temperatures

Musekiwa

Moyo

Mamvura

et al. 2020

Heliyon

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Paper production through chemical pulping has been identified as one of the ideal avenues of exploring the uses of groundnut shells as they are rich in cellulose. Ideally, the cellulose can be used to synthesize fibres that can be converted into useful paper products. In this study, chemical pulping was the chosen process for liberating the fibres as it is effective in dissolving lignin embedded within the cellulose. In addition, the fibres produced have superior physical properties compared to mechanical pulping. It is imperative that optimal conditions are identified for the chemical treatment process, in order to ensure that energy and chemical consumption are minimized. All these measures are aimed at reducing production costs and make chemical pulping economically viable, as compared to the mechanical pulping process which is less costly. Response surface methodology (RSM) was used in this study to evaluate the effect of three independent variables (cooking time, temperature, and sulphidity) on pulp yield and kappa number. These parameters are critical in the chemical pulping process and the optimal conditions obtained were 180 min, 100 C and 23.6 wt.%, respectively. At the optimal cinditions, the pulp yield was 64.39wt% with a kappa number of 19.5. The results showed that all parameters investigated, had a statistically significant effect on the production of pulp. The increased cooking time was efficient in ensuring complete impregnation of the groundnut shells with chemicals for pulping and ensuring that the dissolution of lignin is not selective and does not result in dead spots inherently compromising the quality of the pulp. On the other hand, lower temperatures limited the peeling effect due to hydrolysis of carbohydrates which increased pulp yield due to a higher cellulose retention. Consequently, this contributed towards obtaining pulp that is well cooked, has a low bleach consumption and a higher quality.

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Chemical Pretreatments of Wood Chips Prior to Alkaline Pulping - A Review of Pretreatment Alternatives, Chemical Aspects of the Resulting Liquors, and Pulping Outcomes

Cited by 29 publications

References 295 publications

Alkaline Sulfite Anthraquinone and Methanol (ASAM) Pulping Process of Tropical Bamboo (Gigantochloa scortechinii)

Alkaline Sulfite Anthraquinone and Methanol (ASAM) Pulping Process of Tropical Bamboo (Gigantochloa scortechinii)

Combustion Properties of Birch (Betula pendula) Black Liquors From Sulfur-Free Pulping

Optimization of pulp production from groundnut shells using chemical pulping at low temperatures

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