Pine wood reaction

Pine-Wood Reaction.—Dip a small piece of pine-wood in concentrated hydrochloric acid and then hold it in the vapour from boiling... 

The modification of beech and pine wood with formaldehyde and tannin in a combined treatment to improve dimensional stability has been studied (Burmester, 1971a). Reaction of oak heartwood with gaseous formaldehyde did not improve dimensional stabilization, unless the heartwood was activated by pre-steaming (Burmester, 1971b). 

Rowell, R.M. and Ellis, W.D. (1979). Chemical modification of wood reaction of methyl isocyanate with southern pine. Wood Science, 12(1), 52-58. 

Pyrrole is a colorless liquid, boiling point 131°C, insoluble in water, soluble in alcohol or ether. Pyrrole dissolves slowly in dilute acids, being itself a very weak base rcsiniflcation lakes place readily, especially with more concentrated solutions of acids and on warming with acid a red precipitate is formed. Pyrrole vapor produces a pale red coloration on pine wood moistened with hydrochloric acid, which color rapidly changes to intense carmine red. Pyrrole may be made (1) by reaction of succmimide... 

Generally speaking, combustion is a heat-releasing chemical oxidation reaction, which is often accompanied by the occurrence of a flame. Flame temperatures differ widely from approx. 2000 K for an open flame to approx. 3000 K for the flame of an acetylene cutting torch. Remarkably, the heats of combustion of explosives is generally lower than those of common fuels (pine wood with 12.9% water 4.422 kcal/g, acetylene 11.923 kcal/g, dynamite 75% 1.290 kcal/g. 

The yield of glucose can be increased to 55 kg glucose per 100 kg pine wood by hydrolyzing with 3%-6% sulfuric or hydrochloric acid at 140-160 C and 6-9 bar pressure. The lignin produced is used as a fuel and burnt under the reaction pots. 

Furfurol (fural), the aldehyde of furan, was obtained by Fownes (1845, see p. 271) by distilling bran with dilute sulphuric acid. W. E. Stone and B. Tollens found that this reaction is quantitative with pentoses. Furan was discovered in pine-wood tar by Limpricht, who also obtained it by distilling barium pyromucate. He called it tetraphenor, the name furfurane being proposed by Baeyer. H. B. HilF pointed out its relation to pyromucic and maleic acids. Pyrrole was discovered, but not isolated in a pure state, by Runge (1834, see p. 184). H. Schwanert obtained it by distilling ammonium mucate, and A. C. Bell by distilling succinimide with zinc dust. 

More recent studies were carried out with coals (lignite and subbituminous), enriched with nitrogen, before carbonization and activation, by treatment with ammonia and its derivatives, mainly urea [36,37]. The ammoxidation reaction (reaction with an ammonia-air mixture) is another route to obtaining nitrogen-enriched precursors of active carbons from various carbonaceous materials, such as pine wood, peat, lignite, subbituminous coal [38], and cellulose [39]. 

Unless otherwise specified, reaction conditions were substrate (100 mg) and CrCb -OHrO (10 mg, 0.0375 mmol) were added to 2.0 g of [C4mim]Cl, followed by Ml at 400 W for the desired time. Yields of HMF from corn stalk, rice straw and pine wood were based on a hexose content of 36.1 %, 37.5% and 54%, and yields for furfural were based on a pentose content of 21.4%, 21.2% and 7.6%, respectively. [QmimJBr was used as a reaction medium. Reaction conditions were 20 mg of hydrochloric acid, 2.0 g of [OmimJCl, 30 mg of HrO, 0.1 g of pine wood, 1(X) C with an oil-bath. Reaction conditions were 10 mg of CrCb 6H2O, 2.0 g of [C4mim]Cl, 0.1 g of pine wood, 100 "C with an oil-bath. Otherwise was the same as in Entry 11 except for the reaction temperature at 200 "C. 

Chemical charge, Hquor composition, time of heatup, and time at temperature of reaction are all functions of the wood species or species mix being digested and the intended use of the pulp. A typical set of conditions for southern pine chips in the production of bleachable-grade pulp for fine papers is active alkaH, 18% sulfidity, 25% and Hquor-to-wood ratio, 4 1. Time of heatup is 90 min to 170°C time at temperature of reaction, 90 min at 170°C. Hardwoods require less vigorous conditions primarily because of the lower initial lignin content. 

---