Wood and Lignin

Wood consists essentially of cellulose (Section 31.5), lignin (Section 32.3), hemicelluloses (Section 31.5.1), and water. The major uses of wood are for fuel and as a construction material. Also, of all the wood harvested, about one-sixth (150 million tons per year) serves as a source of cellulose for paper and pulp. For this purpose, it first has to be freed from lignin and hemicelluloses by certain digestion or disintegration methods (Section 32.3). 

A much smaller amount is transformed into chip board, particle board, and compressed wood. Chipboard or particle board is made from waste or young wood that has been mechanically disintegrated into small pieces and bonded with resins. Chipboard is cheaper than, and works as well as, wood board. Upholstered furniture and unseen components of other furniture generally consist of chipboard. 

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Sulphuric aoid reacts with great vigor upon wood and lignin, especially when heat is applied, giving rise to sulphurous, acetic, and formio acids, besides producing a black magma, from which water washes out those bodies, and leaves the carbonaceous residue to the extent of forty-three per cent, of the wood employed. 

Some general applications of TG-FTIR are evolved gas analysis, identification of polymeric materials, additive analysis, determination of residual solvents, degradation of polymers, sulphur components from oil shale and rubber, contaminants in catalysts, hydrocarbons in source rock, nitrogen species from waste oil, aldehydes in wood and lignins, nicotine in tobacco and related products, moisture in pharmaceuticals, characterisation of minerals and coal, determination of kinetic parameters and solid fuel analysis. 

Ltndberg JJ, Ratsanen S, Niemt R (1982) GC-MS studies on the pyrolysis of wood and lignin Gov Rep Announce Index (US) 1984 84 163-173 Linskens HF, Jackson JF (1986) Gas chromatography/mass spectrometry Springer, Berlin Heidelberg New York Tokyo, 304 pp... 

Kavanaugh KR, Pepper JM (1955) The alkaline nitrobenzene oxidation of aspen wood and lignin model substances Can J Chem 33 24-30... 

Nahum LS (1969) Estimation of double bond content in lignin from the results of the oxo reaction of wood and lignin model compounds Tappi 52 712-714 Pew JC, Connors WJ (1971) Color of coniferous lignin Tappi 54 245-251 Redinger L (1961) Alkali lignin, its condensation products with phenols, and preparation of curable resins Monatsber Dtsch Akad Wiss (Berl) 3 571-578 Richtzenhain H, van Hofe C (1939) A stilbene derivative from the sulfite waste liquor Chem Ber 72 1890-1892... 

Lindberg JJ, Raisancn S, Nicmi R (1982) GC-MS studies on the pyrolysis of wood and lignin. 

This investigation was extended to wood and lignin chars prepared at 400 °C to determine the effect of preexisting aromatic nuclei of lignin in the charring reactions. The permanganate oxidation analysis indicated that these chars, like cellulose chars, have considerably condensed or cross-linked aromatic structures, even at 400 C. The NMR data also showed that the chars from similar cellulose, wood. 

Smit et al. combined thioacidolysis and phosphitylation with reagent II, followed by NMR spectroscopy, to measure the total amount of condensed and uncondensed units in wood and lignin [41], Application of the method to Picea radiata wood and milled wood lignin showed that approximately 77% of the C9 units in the milled wood lignin and 71% of the C9 units in wood could be quantified. The amount of condensed structures/C9 units in MWL was determined to be as high as 8% P-5, 5% 4-0-5, and 16% 5-5 structures. 

Recently, there have been a number of studies using computational chemistry techniques to model macromolecules of kerogens (Faulon et al. 1990), coals (Carlson 1992 Nakamura 1993 Murata et al. 1993 Faulon et al. 1994), asphaltenes (Murgich et al. 1996 Kowalewski et al. 1996 Diallo et al. 1998), wood and lignin (Faulon 1994, 1995 Faulon and Hatcher 1994), and biomarkers (Peters et al. 1996 Peters 2000). Computational chemistry models have been used to predict a variety of physical and chemical properties, such as the density of coals (Nakamura et al. 1993 Murata et al. 1993), the microporosity of coals (Faulon 1994, 1995), and the self-association of asphaltenes and resins (Murgich et al. 1996 Subramanian and Sheu 1997 Zajac et al. 1997). Oil companies and petroleum research organizations are interested in compositional and structural chemistry of these macromolecules because of its potential for solving both upstream and downstream problems. 

Ranby, B., Krinstad, K.P., Cowling, E.B., Lin, S. The free radical content in wood and lignins. Acta Chem. Scand. 23, 3257-3275 (1969)... 

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