Search results for "Hot-water extraction"
showing 5 items of 5 documents
Fast pyrolysis of hot-water-extracted and soda-AQ-delignified okra (Abelmoschus esculentus) and miscanthus (miscanthus x giganteus) stalks by Py-GC/MS
2018
Abstract The thermochemical behavior of various samples of okra ( Abelmoschus esculentus ) and miscanthus ( Miscanthus x giganteus ) stalks (initial, hot-water-extracted, and those from sulfur-free delignification) were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). In all cases, major GC-amenable condensable products were measured semi-quantitatively and classified into several product groups. The formation of these product groups from different feedstock samples with varying mass portions of their structural constituents (carbohydrates and lignin) was investigated at 500 °C and 700 °C with a residence time of 5 s and 20 s. The main product groups were aliphatic comp…
Fast pyrolysis of hot-water-extracted and delignified silver birch (Betula pendula) sawdust by Py-GC/MS
2017
The thermochemical behavior of birch (Betula pendula) sawdust both untreated and after various chemical treatments (hot-water extraction, delignification, and hot-water extraction followed by delignification) was investigated by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). In each case, major GC-amenable condensable products were classified into several compound groups, and the formation of these monomer-related fragments from feedstock samples with varying mass portions of the structural constituents (cellulose, hemicelluloses, and lignin) were determined at 500 °C and 700 °C at hold times of 5 s and 20 s. The formation of pyrolysis products was shown to be characteristically…
Pressurized liquid extraction of organic contaminants in environmental and food samples
2015
Pressurized liquid extraction (PLE) is an automated technique that uses elevated temperature and pressure to achieve exhaustive extraction from solid matrices, so reducing solvent consumption and enhancing sample throughput when compared with traditional procedures. Hence, it can be considered an environment-friendly technique, generating small volumes of waste and reducing costs and time. This review focuses on application of this green technique to the analysis of organic contaminants in food and environmental matrices for monitoring purposes. We examine fundamentals and key aspects of the development of a PLE method, including pressurized hot-water extraction, together with some relevant…
Organic material dissolved during oxygen-alkali pulping of hot-water-extracted spruce sawdust
2016
Untreated and hot-water-extracted (HWE) Norway spruce (Picea abies) sawdust was cooked using the sulfur-free oxygen-alkali (OA) method under the following conditions: temperature, 170 °C; liquor-to-wood ratio, 5:1 L/kg; and NaOH charge, 19% on the oven-dry sawdust. In comparison with earlier studies conducted with birch sawdust, the spruce cooking yield data, together with the amount of the pulp rejects (78% to 86% for reference pulps from the initial feedstock and 73% to 83% for pulps from the HWE feedstock), revealed that the pretreatment stage prior to spruce OA pulping caused different effects on pulping performance. The analyses of the three main compound groups (i.e., lignin, volatile…
Advanced biorefinery concepts related to non-wood feedstocks
2018
Agricultural residues, such as wheat straw (Triticum aestivum), okra stalk (Abelmoschus esculentus), and giant miscanthus (Miscanthus × giganteus, a hybrid of M. sinensis and M. sacchariflorus) were investigated to assess their possible consumption for integrated lignocellulosic biorefining. The efficient fractionation and recovery of all important chemical components (cellulose, hemicelluloses, and lignin) of such feedstocks are a prerequisite for realistic biorefinery concepts. Water is one of the most eco-friendly solvents with the highest potential for industrial use, and it is also suitable for full-scale biorefinery purposes. For example, under pressure at elevated temperatures over 1…