Alkaline Pulping of Hemp Woody Core: Kinetic Modelling of Lignin, Xylan and Cellulose Extraction and Degradation

Groot, B. de; Dam, J.E.G. van; Riet, K. van ’t

doi:10.1515/hfsg.1995.49.4.332

Cited by 44 publications

(41 citation statements)

References 17 publications

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“…They studies were concerned with the processing of hemp raw materials (stalks, woody-core or bast) into soda pulps (Van der Werf et al 1994;De Groot et al 1995Dutt et al 2005;Fišerova et al 2013), organosolv pulps (Zomers et al 1995;Barberà et al 2011), thermomechanical pulp (TMP), cold caustic soda (CCS) pulp (Lisson 2001), alkaline peroxide extrusion pulp (APXP; DeJong et al 1999), enzymatic-mechanical pulp (Ekblad et al 2005), chemithermomechanical pulp (CTMP), sulphite pulps (Bączyńska et al 1993;Stupińska and Madaj 1996;Stupińska et al 2005;Dutt et al 2005) and kraft pulps Surma-Ś lusarska 2010a, 2011;Dutt et al 2005). Also studied were the kinetics of the delignification of hemp stalks and hemp woody-core (Abdul-Karim et al 1995;Dang and Nguyen 2006) and properties of bleached pulps from hemp roots (Miao et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Properties and fibre characterisation of bleached hemp, birch and pine pulps: a comparison

Danielewicz

Surma-Ślusarska

2017

Cellulose

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The papermaking potential of bleached kraft pulps made from hemp stalks, hemp woody-core and hemp bast fibres was studied and compared with that of bleached birch pulp and pine kraft pulp. It has been shown that among the pulps from these raw materials, hemp stalk pulp has the most useful properties for papermaking. The disadvantages of hemp woody-core pulp and hemp bast fibre pulp as papermaking intermediates proved to be low tear resistance and low tensile strength, respectively. Results indicate that the main reasons for the low tensile strength of hemp bast fibre pulp are the low susceptibility of their fibres for internal fibrillation and low hemicellulose content. The technology used in this work for the processing of hemp bast fibres into papermaking pulp made it possible to obtain pulp with high a-cellulose content from this fibrous raw material with a high yield in a much simpler way than when such pulps are obtained from wood.

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Section: Introductionmentioning

confidence: 99%

Properties and fibre characterisation of bleached hemp, birch and pine pulps: a comparison

Danielewicz

Surma-Ślusarska

2017

Cellulose

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“…Pulping of thin hemp woody core was conducted in flow-through reactors (De Groot et al 1995). The hemp cores were impregnated at room temperature and then delignified isothermally at various sodium hydroxide concentrations (0.25 -2.0 M) and various temperatures 150 -180°C in flow-through reactors with a liquor-towood ratio of 30:1.…”

Section: Pulping Conditionsmentioning

confidence: 99%

“…It is anticipated that this model can also characterise the delignification kinetics of other lignocellulosic materials because the heterogeneous nature of the relevant reactions are similar. In this study this Nuclei Growth model will be tested against published data which were obtained from alkaline delignification of thin hemp woody core in isothermal flow-through reactors (De Groot et al 1995), ethanol-alkali organosolv delignification of fibre crop giant reed (Shatalov and Pereira 2005), acid-catalysed organosolv fractionation of wheat straw (Siridas and Koukios 2004), organosolv delignification of cottonwood in batch and flowthrough reactors (Tirtowidjojo et al 1988), kraft delignification of bamboo (Vu et al 2004) and alkaline delignification of flax fibres (Petrova et al 2004). We will attempt to identify the model parameters taking into account the effects of the type of lignocellulosic material and pulping processes.…”

Section: Introductionmentioning

confidence: 99%

A universal kinetic equation for characterising the fractal nature of delignification of lignocellulosic materials

Dang

Nguyen

2006

Cellulose

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A kinetic model was developed, based on the power law of growth and Avrami's nuclei growth concepts, to describe the heterogeneous nature of pulping kinetics, taking into account the effects of chemical concentration and temperature. The general form of the kinetic equation is first order with a timedependent rate coefficient. The model was statistically tested using published data obtained from delignification of lignocellulosic materials (hemp woody core, giant reed, wheat straw, cottonwood, bamboo and flax fibres). The activation energies of the delignification range from 71 to 136 kJ/mol. The p-values obtained from the regression analysis are significantly small indicating that all the estimates of the model parameters were significant with very high levels of confidence. The correlation coefficients R 2 for these models range from 0.76 to 0.98.

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“…During the chemical pulping process at high-temperature and high-pressure, degradation of lignin occurs and dissolves into the spent liquor. The delignification reactions involved the cleavage of non-phenolic β-O-4 linkage, phenolic α-O-4 linkage and releasing from the associated by the polysaccharide 8,9 .…”

Section: Introductionmentioning

confidence: 99%

Characterization of Lignin Precipitated From The Soda Black Liquor of Oil Palm Empty Fruit Bunch Fibers by Various Mineral Acids

Ibrahim

Chuah

Ishak

2017

AJSTD

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Soda lignin from oil palm empty fruit bunch was directly isolated by various mineral acids i.e. sulfuric acid, hydrochloric acid, phosphoric acid and nitric acid at three levels of concentration (20% v/v, 60%v/v and concentrated). A comparison study was performed through physicochemical properties and structural features using FT-IR, UV, 13 C-NMR and nitrobenzene oxidation. The FT-IR results showed that there is no significant difference between the main structures of the lignin isolated by various acids. However, low concentration of phosphoric acid is preferable because of its highest yield. The S: V: H ratio of 7-15:6-11:1 as evaluated by the nitrobenzene oxidation procedure suggests that soda lignin can be classified as belonging to either the cereal straw on grass type. The UV results indicate that phosphoric acid consistently gave the highest absorbance value among the four acids tested in this study regardless of its concentration level. The C 13 -FTNMR spectra, suggest that the lignin structure is independent of the type of acid used for precipitation.

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Alkaline Pulping of Hemp Woody Core: Kinetic Modelling of Lignin, Xylan and Cellulose Extraction and Degradation

Cited by 44 publications

References 17 publications

Properties and fibre characterisation of bleached hemp, birch and pine pulps: a comparison

Properties and fibre characterisation of bleached hemp, birch and pine pulps: a comparison

A universal kinetic equation for characterising the fractal nature of delignification of lignocellulosic materials

Characterization of Lignin Precipitated From The Soda Black Liquor of Oil Palm Empty Fruit Bunch Fibers by Various Mineral Acids

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