Aspen wood chips

During water immersion, 1 kg of mixed spruce and aspen wood chips at an average 50% water content would pick up an additional 0.51 kg of water and reach a terminal moisture level of about 67%. Water uptake is quick even after immersion for 3 h moisture levels exceed 63%. This is similar to the findings of Brebner (4) and Wasp et al. (6), who reported saturated wood values of 65%. We conducted two experiments with straw and found that moisture level rose from 14% as received to >80% after exposure of 3 h. This is similar to the findings of Jenkins et al. (9) for rice straw from California. 

During oil immersion for 48 h, 1 kg of mixed conifer and aspen wood chips at an average 50% water content would pick up an additional 0.45 kg of oil and reach an oil level of 31 %. Comparable figures for 124 hours are an uptake of 0.52 kg to reach a oil level of 34%. Direct combusting wood chips delivered in a heavy gas oil can be thought of as cofiring a mix of about two / thirds oil and one/third wood on a thermal basis. Pipeline cost would increase because of additional pumping the increase would depend on the viscosity of the oil fraction that was selected as the transport carrier fluid. 

Aspen wood chips were kindly supplied by the USDA Forest Products Laboratory (Madison, WI) and corn stover by the National Renewable... 

Schell, D. J., Torget, R., Power, A., Walter, P. J., Grohmann, K., and Hinman, N. D., A technical and economic-analysis of acid-catalyzed steam explosion and dilute sulfuric-acid pretreatments using wheat straw or aspen wood chips. Appl Biochem Biotechnol 1991, 28-9, 87-97. 

Torget, R., Hiimnel, M Wright, J.D., and Grolimann, K, (1988) Initial Design of a Dilute Sulfiiric Acid Pretreatment Process for Aspen Wood Chips. Applied Biochemistry and Biotechnology, 17, 89-104. 

FIGURE 15.4 Pretreatment of aspen wood chips with three strains of Ceriporiopsis subver-mispora lowered the energy reqnired to refine to 100 mL CSF and increased the tensile strength of the pulp. (Data redrawn from Akhtar, M., Holrforschung, 48,199-202,1994. With permission.)... 

M Akhtar. Biomechanical pulping of aspen wood chips with three strains of Ceriporiopsis subvermispora. Holzforschung 48 199-202, 1994. 

Air-dried com stover provided by the Agricultural Utilization Research Institute was milled and then screened, and only the fraction less than 2-mm sieve was used in this research. Aspen pulping wood chips (Populus tremuloides) with a pretreatment, which were the intermediates of a biorefinery process, were provided by the Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, Minnesota. Aspen wood chips that passed through a 1 -in. sieve but not through a 0.5-inch sieve were used. Aspen wood chips were pretreated with dilute sulfuric acid to remove partial hemicellulose. 

The aspen wood chips were pretreated with 1 % dilute sulfuric acid at 160°C for 4 h to remove partial hemicellulose. 

Swedish aspen wood chips (AC) were obtained from Rockhammar s Bruk, Frovi, Sweden. The carbohydrate composition of the wood chips was analysed according to section 2.9. The starting material composition is summarised in Table 1. 

Aspen wood chips Populus tremula) were obtained from Rockhammars Bruk (Frovi, Sweden) and ground in an 8-inch Sprout Waldron 105-A refiner. 

Wood Delignijication. The production of wood pulp (qv) for the paper (qv) industry consists of removing lignin (qv) from wood chips, thus freeing the ceUulose fibers. An aqueous solution containing 30—70 wt % sulfolane efficiently extracts the lignin from aspen. Western hemlock, and Southern pine wood chips. Pulp yields are from 50—75% (43,44). 

Ramos, L. P., Breuil, C., and Saddler, J. N. 1992. Comparison of steam pretreatment of Eucalyptus, Aspen, and spruce wood chips and their enzymatic hydrolysis. Appl. Biochem. Biotechnol., 34/35, 37—47. 

A very facile dip acetylation procedure was developed for wood chips and fibers. The wood is dried at 105°C and then dipped in acetic anhydride for 1 min and drained. Then the sample is placed in a preheated (120°C) reactor for different lengths of time, depending on the degree of substitution of acetyl groups desired in the sample.29 The swelling of aspen flake-board made from such chemically modified flakes is dramatically reduced. For example, while unmodified flakeboard swelled by over 60 percent after immersion in water for 5 days, the modified material swelled by only about 8-22 percent, depending on the extent of chemical modification. 

Conductometric titrimetry can be applied to a wide range of pulp types with a wide range of sulfonate contents. The method has been applied to softwood chips treated with sulfite, softwood sulfite mechanical pulps, high-yield bisulfite pulps, low-yield acid sulfite pulp (Katz et al. 1984, Gummerus 1985, Heitner and Hattula 1988) and sulfite treated aspen wood (Beatson et al. 1985) with sulfonate contents ranging from 20 to 300 mmol kg-1. In addition, the method has been adapted to measure sulfonate content of sulfonated kraft lignin (Oster et al. 1988). 

Pyrolysis under vacuum of aspen poplar wood chips exhibited an active zone of decomposition occurring between 240 and 300 C . A 58 % by wt, yield of pyrolytic oil was obtained at 350°C which contained miscellaneous compounds such as phenols, carboxylic acids, alcohols and esters. The vacuum process removes the reaction products before they are further decomposed. The yield of relatively volatile phenols (monolignols in this paper) depends on the pyrolysis materials. The yield of phenols varied from 1 to 3.7 % when different biomass samples were subjected to vacuum pyrolysis. ... 

The major factor which enters into variable operating costs is wood, here taken as 25.00 per dry ton, a reasonable current price for aspen chips in several locations in Canada. Under some special circumstances this can be reduced considerably waste aspen chips, for example, would cost 18.00 per ton. If available in adequate quantity, such chips would cut the cost of ethanol by... 

Figure 1. Induction of xylanases in Trichoderma harzianum. The ratios of xylanase to endocellulase activities were determined in the culture filtrates of T. harzianum grown on steam treated aspenwood. Aspen chips were steam treated from 20 to 240 s at 240° C to produce a series of samples with a variable content of xylan and cellulose. The specific content of these carbohydrates were expressed as the ratio of xylan to glucan. Enzyme activities were determined on culture filtrates of 300 mL batch cultures of T. harzianum grown on these wood samples at a loading of 1% (w/v) as described by Saddler and Mes-Hartree (66). Enzyme activities were also determined in culture filtrates of T. harzianum grown on Avicel, Solka Floe and oat spelts xylan.

Red Oak is the wood most used for the production of irradiated acrylic-wood parquet flooring,however acrylic Aspen chip board and acrylic particle board are finding their way into the flooring market. Smaller amounts of maple, ash and black walnut have been used. The polymer loading of red oak is about 40% which makes the acrylic-wood flooring quite expensive, approximately three times that of ordinary red oak parquet flooring. 

MJ Rocheleau, BB Sithole, LH Allen, S Iverson, R Earrell, Y Noel. Eungal treatment of aspen chips for wood resin reduction A laboratory evaluation. J Pulp Pap Sci 24(2) 37-42, 1998. 

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