Dissolution of wood

Nakagami, T. (1978). Esterification of wood with unsaturated carboxylic acids. V. Effect of deUg-nification treatments on dissolution of wood esterified by the TEAA method. Mokuzai Gakkaishi, 24(5), 318-323. 

Forss K, Fremer KE (1964) The dissolution of wood components under different conditions of sulfite pulping Tappi 47 485-493... 

II. LIQUEFACTION OR DISSOLUTION OF WOOD A. Chemically Modified Wood... 

Further high quality wines are traditionally matured in oak cashs for several months. Maturation reactions are complex and like in spirit beverages, dissolution of wood components is of prime importance (8-9-10). Extracted wood components have secondary effect other than their direct flavor contribution. They appear to be necessary for correct maturation of the beverage. The effect of wood components on the maturation of beverages was clearly investigate in distilled alcoholic beverages only. The addition of oak extract to a model spirit solution reduced the extractability of ethyl esters with chain lengths of 10-20 carbons by the dichloromethane (9-10). The increase in solubility reflects a reduction in the activity of the ester in the aqueous ethanol solution, relative to the dichloromethane and indictes that an interaction between components of the wood extract and esters takes place. 

Dissolution of wood using [C mimHCl] has also been reported [127-129], Based on the same mechanism of cellulose dissolution, the dissolution of wood also requires the virtual absence of water, which necessitates extensive drying of the wood, small particle size, drying of the ionic liquid, and reaction under an inert atmosphere. Long dissolution times are usually required unless microwave heating is used. 

The first step is solvolysis and, as proposed by YU, we used phenol or phenol based solvents to perform the dissolution of wood, which should be complete, in order to avoid a difficult solid-liquid separation. So we carried out a lot of experiments in order to find the optimal conditions, i.e., a quantity of phenolic solvent as small as possible, low temperature and low pressure. Analysis of material balances of different runs shows that it is necessary to keep the weight solvent/wood above 4. To complete the dissolution of wood, the minimum amounts of water and phenol in the solvent mixture are respectively 20 wt % and 25 wt % (Figures l.a and l.b). In this case, the liquid phase is completed... 

Therefore, we can draw some partial conclusions wood can be dissolved in pure phenol or in a mixture of water and phenol with addition of sulphuric acid. Without such adition, dissolution of wood is not completed. That is of great importance from a practical point of view it is possible to use wet chips as a raw material. Water is formed during the reaction, and this formation is attributed to the condensation of carbohydrates with phenol. It seems that one molecule of glucose, the cellulose monomer, involves bonding of three molecules of phenol and formation of three molecules of water. Phenol prevents recondensation of solvolysis products, allowing stability of the oil. 

Pinosylvin (3,5-stilbenediol) ( )-form needles, insoluble in water, soluble in acetone. )- and (Z)-isomers occur together with the corresponding mono- and dimethyl ethers in pines, firs, and conifers. Pinosylvin has antifungal and antibacterial activities and protects the wood against rot, as a disinfectant it is 30-times stronger than phenol and is highly toxic for fish. As a result of condensation with lignin, pinosylvin prevents sulfite dissolution of wood. Pinosylvin monomethyl ether acts as an antifeedant for certain rabbit species. ... 

Li et al. (2010) repwrted on the dissolution of wood species in the ionic liquid [AMIMJCI. The filtrate (after separating the regenerated wood) was condensed by rotary evaporation, dried under vacuum at 40 °C overnight to recycle the IL. It was found that as the reuse cycles of the IL increased, the wood regeneration yield increased, while certain wood components enriched within the recycled IL and the efficiency of cellulase enzymatic hydrolysis on the regenerated wood decreased. 

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