Search results for "extractives"
showing 10 items of 14 documents
L'emploi des roches décoratives dans l'architecture du haut Moyen Âge en Bourgogne : réflexions sur les chapiteaux et colonnes : nouvelles analyses
2004
International audience
Development of fast analysis methods for extractives in papermaking process waters
2011
A fast analysis method with an online sample enrichment technique for the analysis of resin and fatty acids present in papermaking process waters was developed. This method was based on atmospheric pressure chemical ionization (APCI) and mass spectrometry (MS) for the detection of [M-H]- ions of compounds of interest. The method was applied to the control of the most prevalent resin (dehydroabietic and abietic) and fatty (palmitic, stearic, oleic, and linolenic) acid levels in papermaking process waters. Continuous data on these acids are of practical importance when predicting possible deposit-derived problems in the paper machine. The first part of the study was focused on the development…
Refractory organic pollutants and toxicity in pulp and paper mill wastewaters
2015
This review describes medium and high molecular weight organic material found in wastewaters from pulp and paper industry. The aim is to review the versatile pollutants and the analysis methods for their determination. Among other pollutants, biocides, extractives, and lignin-derived compounds are major contributors to harmful effects, such as toxicity, of industrial wastewaters. Toxicity of wastewaters from pulp and paper mills is briefly evaluated including the methods for toxicity analyses. Traditionally, wastewater purification includes mechanical treatment followed by chemical and/or biological treatment processes. A variety of methods are available for the purification of industrial w…
Behaviour of Extractives in Norway Spruce (Picea abies) Bark during Pile Storage
2022
The current practices regarding the procurement chain of forest industry sidestreams, such as conifer bark, do not always lead to optimal conditions for preserving individual chemical compounds. This study investigates the standard way of storing bark in large piles in an open area. We mainly focus on the degradation of the most essential hydrophilic and hydrophobic extractives and carbohydrates. First, two large 450 m3 piles of bark from Norway spruce (Picea abies) were formed, one of which was covered with snow. The degradation of the bark extractives was monitored for 24 weeks. Samples were taken from the middle, side and top of the pile. Each sample was extracted at 120 °C with both n-h…
The effect of thermal drying on the contents of condensed tannins and stilbenes in Norway spruce (Picea abies [L.] Karst.) sawmill bark
2021
Norway spruce (Picea abies (L.) Karst.) bark contains marked amounts of polyphenolic compounds. Condensed tannins (CTs) and stilbenes show commercial potential as antioxidants, antimicrobials, preservatives in food and cosmetic applications, technochemical products, and pharmaceuticals. Storing of bark before the conversion process leads to substantial losses of extractives compounds. In the present study, the potential of thermal drying for maintaining extractives content was assessed based on an experiment in which bark samples were dried in convection kilns at 40, 50, 60, and 70 °C temperatures. The development of CTs and stilbene contents and CT degradation were followed for 28–34 h. CT…
Sulfur-free pulping of hot-water-extracted spruce sawdust
2016
Softwood (Picea abies) sawdust was hot-water-extracted with two multi-phase processes (160-180°C, 100-280 min, and liquor-to-wood ratio 5 l/kg) corresponding to P-factors of ~780 (yield 80.0%) and ~4580 (yield 72.4%). The pre-treated materials were then pulped with the soda-AQ cooking (170°C, NaOH charge 20%, AQ charge 0.1%, 30-150 min, and liquor-to-wood ratio 5 l/kg), resulting in a yield range of 36.1-61.4% (for reference cooks without pre-extraction 47.9-60.0%). It was observed that the pre-extraction under moderate conditions enhanced the dissolution especially of large-molar-mass lignin during cooking, and the total amount of the dissolved lignin was also higher than that removed from…
Effect of Seasonal Storage on Single-Stem Bark Extractives of Norway Spruce (Picea abies)
2021
Increasing the net value of forestry side-streams has both ecological as well as economic benefits for emerging biorefining industries. Spruce bark represents one of the nature’s abundant sources of valuable extractives. In this study, the impact of storage on the quality and quantity of Norway spruce (Picea abies) extractives was examined as a function of storage time, environmental conditions and season (i.e., winter or summer). The bark from stored spruce saw logs was extracted with an accelerated solvent extractor (ASE) at 120 °C with hexane and water. The produced extracts were analysed qualitatively and quantitatively by gas chromatography with a flame ionisation detector (GC-FID) and…
Chemical Pretreatments of Wood Chips Prior to Alkaline Pulping - A Review of Pretreatment Alternatives, Chemical Aspects of the Resulting Liquors, an…
2015
The chemical industry is being forced to evaluate new strategies for more effective utilization of renewable feedstocks to diminish the use of fossil resources. In this literature review, the integration of both acidic and alkaline pretreatment phases of hardwood and softwood chips with chemical pulping is discussed. Depending on the pretreatment conditions, high-volume sulfur-free fractions with varying chemical compositions can be produced. In case of acidic pretreatments, the major products include carbohydrates (mono-, oligo-, and polysaccharides), whereas under alkaline (i.e., aqueous NaOH) pretreatment conditions, the sulfur-free fractions of aliphatic carboxylic acids, lignin, and ex…
Chemical characterization of okra stalk (Abelmoschus esculentus) as potential raw material for biorefinery utilization
2018
In the present work, okra stalk (Abelmoschus esculentus) was chemically characterized to evaluate its appropriate exploitation as a biorefinery feedstock. The chemical composition of this renewable lignocellulosic material yielding maximum up to 120 tons per hectare was primarily determined by methods of wood chemical analysis. In terms of its main organic constituents, its dry matter contained 65.0% carbohydrates (cellulose, hemicelluloses and other polysaccharides), 20.5% lignin and 5.0% extractives. In addition, thermogravimetric analyses revealed that the content of proteins and inorganics was 6.6 and 3.3% of the dry matter, respectively. Among the inorganic elements determined by induc…
Availability of extractives from various Norway spruce (Picea abies) stumps assortments
2022
Stumps and knotwood of Norway spruce (Picea abies) are valuable sources of wood extractives. Although lignans from knotwood have already been utilized in value-added products, the behavior and valorization of stump-derived extractives are less studied. In this study, the composition of lipophilic and hydrophilic extractives, particularly lignans, from various spruce stump samples (stump bottom, stump heart, and crushed stump samples) stored outside were studied. Lipophilic and hydrophilic extracts were separated with an accelerated solvent extraction (ASE) apparatus using n-hexane and hot water, respectively. The detailed extractives content of samples was then determined by gas chromatogra…