Spruce wood meal

Delignification of Spruce Wood Meal on Heating with Water... 

Figure 2. Delignification on heating spruce wood meal with water at 150°C.

To test the assumption that the delignification taking place when spruce wood meal is heated with water is a result of acid catalyzed hydrolysis, wood meal samples were heated with 0.5 M phosphate buffer solution at pH 6.8 (Fig. 4). 

Figure 3. Lignins dissolved and furfural formed on heating spruce wood meal with water for 6 h at 150°C. Column Sephadex G-50. Eluent 0.5 M NaOH.

Figure 6. Delignification on heating spruce wood meal for 6 h at 150°C with 0.5 M phosphate buffer (pH 6.8) and dioxane in various volume proportions.

Figure 8. Delignification on heating (A) spruce wood meal with phosphate buffer (pH 6.8), 150°C (B) spruce wood meal with dioxane-phosphate buffer (60 40% v/v) (C) wood residue from (A) (48 h) with dioxane-phosphate buffer (60 40% v/v).

Dioxane Lignin. Spruce wood meal was extracted with a boiling solution composed of 1000 ml dioxane and 10 ml HC1 (sp. gr. = 1.19) (18). The resulting lignin was then Soxhlet-extracted with diethyl ether and fractionated by SEC (4,18) to obtain narrow fractions. 

Lignosulfonates. Samples of birch and spruce wood meal extracted with ethanol-cyclohexane (1 3) were heated from 20°C to 135°C during 1 h and then cooked for 6 h at 135°C in 150 mL reactors with sodium bisulfite liquor... 

Pepper and Supathna (1978) studies the effect on product yields of Rh-C applications ranging in amount from 1 to 30% of the original wood in the hydrogenolysis of spruce wood meal The yield of dihydroconiferyl alcohol, (9), was found to increase while the yield of 4-n-propylguaiacol, (8), decreased When the catalyst application exceeded 10%, traces of cyclohexyl derivatives were detected The maximum total yield of (8) and (9) was obtained with a 10-20% catalyst application... 

Aspen wood meal Raney nickel 195 °C, 5 h Dioxane-water (1 1) (Pepper and Steck 1963) Spruce wood meal Rhodium-C 195 °C, 5h Dioxane-water (1 1) (Pepper and Lee 1969) Birch MWL Oak MWL Copper chromite 240-260°C, 48 hDioxane (Coscia et al 1961) Spruce MWL Copper chromite 240°C, 47hDioxane (Olcay 1963)... 

The rate of 1-acetylpyrrolidine formation is followed as in the case of acetylated lignin, but the overall process is much slower and a 6-7-h reaction period may be required as illustrated in Fig. 7.2.1A for Norway spruce wood meal. 

J Gierer, O Lindeberg. Studies of the Condensation of Lignins in Alkaline Media. Part III. The Formation of StUbenes, Arylcoumarans and Diarylmethanes on Treatment of Spruce Wood Meal with Alkali and White Liquor in the Presence of Xylenols. Acta Chem Scand B33 5S0-5S2, 1979. 

In an alternative way of isolating lignin from wood, pre-extracted spruce wood meal has been treated with a commercial mono-component endoglucanase [27, 41]. Thereby, the crystalline structure of cellulose is destroyed and the now amorphous wood can be homogeneously swollen in aqueous urea. By subsequent fractionation of the material in aqueous alkali, all lignin can be recovered as various LCCs (Table 9.5). Also in this case, however, the wood... 

Types of LCC isolated from spruce wood meal after treatment with endoglucanase followed by swelling in urea and fractionation in aqueous alkali [27, 41]... 

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