Supercritical extraction of wood

Grandmaison, J.L. Ahmed, A. Kalaiguine, S. "Solid residues from supercritical extraction of wood characterization of their constituents." In This Volume. 

Solid Residues from Supercritical Extraction of Wood... 

To compare lignins produced from supercritical fluid extraction of wood with lignins from conventional pulping processes, a kraft pine lignin... 

McDaniel, L. Ashraf-Khorassani, M. Taylor, L. T. "Supercritical Fluid Extraction of Wood Pulp with Analysis by Capillary Gas Chromatography-Mass Spectroscopy", J. Supercrit. Fluids, 2001,19,275. 

Supercritical fluid solvents have been tested for reactive extractions of liquid and gaseous fuels from heavy oils, coal, oil shale, and biomass. In some cases the solvent participates in the reactions, as in the hydrolysis of coal and heavy oils with water. Related applications include conversion of cellulose to glucose in water, dehgnincation of wood with ammonia, and liquefaction of lignin in water. 

Wood, J. A., Bernards, M. A., Wan, W., and Charpentier, W. (2006). Extraction of ginsenosides from North American ginseng using modified supercritical carbon dioxide. J. Supercrit. Fluids 39,40-47. 

The extraction of pentachlorophenol (PCP) from pressure-treated wood wafers with supercritical carbon dioxide (SC-CO2) was studied in a continu-ons-flow extractor (Sahledemessie et al., 1997). 

Supercritical Fluid Extraction of Lignin from Wood... 

Reactive extraction of lignin from red spruce has been studied using supercritical methylamine and methyla-mine-nitrous oxide binary mixtures. The wood residues and precipitated fractions after extractions have been characterized by chemical and spectroscopic procedures. 

Supercritical fluid extraction is a new separation technique that finds a number of applications in the natural products, biochemicals, food, pharmaceuticals, petroleum, fuel, and polymer industries (1-8). There is now an interest in applying this technology in the pulp and paper industry (9,10). In a recent comprehensive study on the interaction of supercritical fluids with lignocellulosic materials, it has been shown that lignin can be not only extracted from wood by reactive supercritical fluids but also separated as solid products in solvent-free form by reducing the extraction fluid pressure from a supercritical to sub critical level (11,12). 

Extraction of lignocellulosic materials with dioxane has been used for quite some time as a method for lignin isolation at atmospheric pressure (1) or, as recently reported, at high pressure and with supercritical C02 mixtures (2-5). In this case, it was possible to extract from wood lignin oligomers with a low degree of chemical modification, hemicelluloses were also depolymerized and extracted, but cellulose remained without significant mass losses. 

As biomass samples, sugi Cryptomeria japonica D. Don) and buna (Fagus crenala Blume) woods were selected for supercritical water treatment. In addition, microciystalline cellulose (avicel), glucomannan extracted from softwood dissolving pulp, larch xylan (Shigma Co., Ltd.), and milled wood lignin (MWL) from buna wood were studied to understand reaction behaviors of wood components dunng supercritical water treatment. 

Supercritical CO2 has been considered as a potential alternative to conventional solvents due to its relative non-toxicity and non-flammability, as well as its low critical temperature and pressure. Supercritical fluid extraction (SFE) has been used for example in the extraction of fatty acids from diverse matrices such as grape seeds , ginseng seeds, wood pulp , and infant formula . The absence of oxygen and light during the supercritical extraction process helps prevent degradation of the extract. For example, Tipsrisukond, et al." found... 

In this paper we report our efforts to characterize the solid residues produced in a series of experiments with the semicontinuous extraction of Populus tremuloides (aspen wood) in supercritical me-thanol iSi, at temperatures ranging from 250 to 350°C (Supercritical Extraction residues or SCE residues), by using wet chemistry and chromatographic, thermogravimetric and spectral methods such as DRIFTS 2 > and ESCA. ... 

Li, L. Kiran, E. Supercritical fluid extraction of lignin from wood. In Lignin Properties and Materials, ACS Symposium Series 397 Glasser, W.G., Sarkenen, S., Eds. ACS Washington, DC, 1989 42-57. 

Reyes T, Bandyopadhyay S, McCoy B (1989) Extraction of lignin from wood with supercritical alcohols. J Supercrit Fluids 2(2-3) 80-84... 

Pasquini, D., Pimenta, M. T. B., Ferreira, L. H., Curvelo, A. A. S. Extraction of lignin from sugar cane bagasse and Finns taeda wood chips using ethanol-water mixtures and carbon dioxide at high pressures. The Journal of Supercritical Fluids 2005, 36, 31-39. 

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