Steam exploded wood

Cellulase system from washed steam-exploded wood (LSF, Fed-batch) 1 1.48 —- — — 40.00 36.00 ... 

Hydrolysis with 20 lU FP cellulase/g washed steam-exploded wood (10% cone) in 48 hr. 

Alkaline-extracted/steam-exploded (AESE) aspen lignin samples were prepared from steam exploded wood samples (55 s residence time at 240°C) obtained from Iotech Corp. Exploded wood pulp was treated with a series of carbon tetrachloride and alkaline extractions (12). 

Douglas fir (Pseudotsuga menziesii) was chipped and screened to a relatively homogeneous chip size of approx 3 x 3 x 0.3 cm. The chips were initially impregnated with 4.5% (w/w) gaseous S02 and then steam exploded in a 1-L steam gun in batches of 50 g of dry chips at 195°C for 4.5 min, as previously described by Boussaid et al. (14). The steam-exploded wood samples of each batch were collected, combined, washed, and finally defibrillated on a refiner to produce a homogeneous feedstock. 

Donaldson LA, Wong KKY and Mackie KL (1988) Ultrastmcture of steam-exploded wood. 

M. Tanahashi, T. Goto, F. Horii, A. Hirai, and T. Higuchi, Characterization of steam-exploded wood. III. Transformation of cellulose crystals and changes of crystallinity, Mokuzai Gakkaishi, 35 (1989) 654-662. 

A cover plate 508, for example, of stainless steel, is provided at the top of tank 501 and serves as a thermal shield as well as a support for rods 502 and for control and safety rods pivotally mounted thereunder, described infra. Above the cover plate 508 is a space 509 into which the upper ends of rods 502 project, and through which piping can be conducted. Above space 509 is a shield 509a having alternate layers of iron and Masonite brand of steam-exploded wood fiber for preventing the escape of neutrons, gamma rays, and other penetrating radiations from the top of tank 501 to the outside. 

Thermoplastic Polyesters from Steam Exploded Wood... 

Fig. 1. Typical Process Scheme for the Fractionation of Steam Exploded Wood Using Organosolv Delignification with Acetic Acid.

Table II gives a number of derived parameters used to assess the lignin s suitability as a binder. For a full binder, lignins required a minimum of three sites per average molecule for formaldehyde grafting. None of the lignins studied approach this level. At least twice the number of sites found is required for steam exploded lignins and more for the kraft lignin. PF resins have an average of eight sites per molecule, a much higher density than projected, so PF resins are excellent wood binders.

Similar conditions have been described for posthydrolysis of steam-exploded Douglas fir wood chips performed at 120°C, but longer hydrolysis time was required (15). Similar to our results, increasing catalyst also increased monosaccharide recovery and higher participation of degradation reactions. For corn cobs (36), a material similar to BSG, the posthydrolysis of OCL autohydrolysis was carried out at CS 1.66 (calculated from the reported operational conditions 125°C, 0.5% H2S04,165 min), a more severe condition than the optimal conditions determined in the present work for BSG. 

Enhanced Enzymatic Hydrolysis of Steam-Exploded Douglas Fir Wood by Alkali-Oxygen Post-treatment... 

Robert DR, Gellerstedt G, Bardet M (1986) Carbon-13 NMR analysis of lignins obtained after sulfonation of steam exploded aspen wood Nord Pulp Pap Res J 1 18-25... 

Table 9.1.5. Pyrolysis products at 51(f C of several lignins [6a], The analyzed materials were milled wood lignin (MLW), steam exploded lignin (StE.), a lignin purified by organosolv procedure (Org ), kraft lignin (Kraft), and bagasse lignin (Bag.).

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