Wood processing

Wood Residuals. Chips, sawdust, and other residuals such as planar shavings are used as a primary source of fiber for some pulp mills. Chips are screened and placed in a purchased chip pile. Sawdust and other residuals obtained from wood processing plants must be cooked separately and requite special digesters and handling equipment. These materials may also be burned as hog fuel. 

Component, wt % Wood Process Chlorite holoceUulose Kraft... 

Although the hydrolysis of wood to produce simple sugars has not proved to be economically feasible, by-product sugars from sulfite pulping are used to produce ethanol and to feed yeast (107). Furthermore, a hemiceUulose molasses, obtained as a by-product in hardboard manufacture, can be used in catde feeds instead of blackstrap molasses (108). Furfural can be produced from a variety of wood processing byproducts, such as spent sulfite Hquor, bquors from the prehydrolysis of wood for kraft pulping, hardboard plants, and hardwood wastes (109). 

Charcoal is produced commercially from primary wood-processing residues and low quaUty roundwood in either kilns or continuous furnaces. A kiln is used if the raw material is in the form of roundwood, sawmill slabs, or edgings. In the United States, most kilns are constmcted of poured concrete with a capacity of 40 to 100 cords of wood and operating on a 7- to 12-d cycle. Sawdust, shavings, or milled wood and bark are converted to charcoal in a continuous multiple-hearth furnace commonly referred to as a Herreshoff furnace. The capacity is usually at least 1 ton of charcoal per hour. The yield is - 25% by weight on a dry basis. 

The rubber polyisoprene is a natural polymer. So, too, are cellulose and lignin, the main components of wood and straw, and so are proteins like wool or silk. We use cellulose in vast quantities as paper and (by treating it with nitric acid) we make celluloid and cellophane out of it. But the vast surplus of lignin left from wood processing, or available in straw, cannot be processed to give a useful polymer. If it could, it... 

Wastes from wood processing and the production of paper, cardboard, pulp, panels and furniture Wastes from the leather and textile industries... 

Carlson, F.E., Phillips, E.K., Tenhaeff, S.C. and Detlefsen, W.D., Measuring and Controlling Volatile Organic Compound and Paniculate Emissions from Wood Processing Operations and Wood-Based Products. Forest Products Society, Madison WI, 1995, pp. 52-61. 

In one reported incident sodium sulphide was incorporated into residuary waters from some pulp wood processing, which contained sodium carbonate. This produced an unexplained explosion. 

Activated sludge from a plant treating wood-processing-industry wastewater Glucose 2 100 300 [18]... 

In bulk fermentation and sponge batter processes the bonds are broken by the action of enzymes and flour improvers. In the Chorley-wood process the bonds are broken by intense mechanical input and the action of the improver. Similarly, in an ADD process the effect is... 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

Goldstein, I.S., Dreher, W.A. and Jeroski, E.B. (1959). Wood processing inhibition against swelling and decay. Industrial and Engineering Chemistry, 51(10), 1313-1317. 

Shimizu, K., Sudo, H. and Fijii, T. (1989). Total utilisation of wood components by steam explosion pre-treatment. In Wood Processing and Utilization, Kennedy, J.F., Phillips, G.O. and Williams, P.A. (Eds.). Ellis Harwood, Chichester, UK, pp. 407 12. 

Walker, J.C. (1994). Primary Wood Processing Principles and Practice. Chapman and Hall, USA. 

Westin, M., Lande, S. and Schneider, M. (2003). Eurfurylation of wood— process, properties and commercial production. In Proceedings of the First European Conference on Wood Modification, Ghent, Belgium, Van Acker, J. and Hill, C.A.S. (Eds.), pp. 289-306. 

Morohoshi, N. In, Wood Processing and Utilization, Kennedy, J.F., Ed. Ellis Horwood Limited West Sussex, England, 1989 pp 341-346. 

Wood debarking and Solid Bark, wood processing residues... 

Wood chips are preheated in steam before passage through disc refiners. Heating is meant for softening the lignin portion of wood and to promote fiber separation. This pulp is stronger than that produced by the ground-wood process. 

Primary irritant dermatitis caused by wood contact consists of erythema and blistering, which may be accompanied by erosions and secondary infections. Irritant chemicals typically are found in the bark or the sap of the outer part of the tree. Therefore, loggers and persons involved in initial wood processing are most affected. In most reports of contact dermatitis, hardwoods of tropical origin have been implicated, although other woods, including pine, spruce, western red cedar, elm, and alder, have been cited. 

A UV/ozone Ultrox system was used to treat wastewater contaminated with phenol and polychlorophenol (PCP) at a wood processing facility in Denver, Colorado. The capital cost for the Ultrox system was 200,000. Operation and maintenance costs for the entire remediation system were 10.92 per 1000 gal of treated wastewater. This cost estimate excludes the expenses associated with site preparation, permitting and regulatory compliance, startup, analysis, effluent disposal, and demobilization (D205505, p. C-1). 

Equipment and instrumentation developments in automotive, electronics, and wood-processing industries... 

The steam explosion process is a recent development in wood processing (1,2). Much attention has been paid to this process from the viewpoint of total wood utilization. Cellulose and hemicellulose from this process can be converted into sugars of commercial value by enzymatic methods (3). However, the conversion of lignin from this process (steam explosion lignin) into useful materials continues to present difficulties. Preparation of adhesives from it is considered to be a feasible way to solve this problem. 

Turning to the detonation of condensed EM we note that in this case the study of the equation of state of a dense gas in which repulsion of molecules is more important than their thermal motion turned out to be non-trivial (see the fundamental work by L. D. Landau and K. P. Stanyukovich).29 Water-filled EM were studied by Yu. B. Khariton.30 At present A. N. Dremin is developing ideas on the specific influence of a shock wave on the kinetics of reaction in an EM.31 For gas-dispersion systems the structure of detonation waves has become the subject of numerous studies related to explosions of coal dust husks in grain elevators, gas suspensions of dust in wood processing, etc.32,33 34 5 Works on gas suspensions have also been published abroad.36,37 In gas suspensions we may expect that the reaction rate is determined by diffusion and depends weakly on the temperature. 

Residues. Residues from the forest such as twigs, from the agricultural industry, from wood processing (wood dust), as well as from animal farming (manure) are good examples of residue biomass. 

In Ukraine forests cover only 15.6% of the territory, at that nearly half of them have environmental value. The country lacks for merchantable wood that is why timber is imported. The main forest areas are located in the Carpathians and Polissia (Forest Land) were more than 90% of wood is harvested. Wood potentially available for energy production makes up 1.6 mill m3/year of felling residues, 2.1 mill m3/year of wood processing waste, 3.8 mill m3/year of firewood that in sum is equivalent to 16 TWh/year. 

Lignocellulosics are the most abundant renewable organic materials in the biosphere. They account for approx 50% of the total biomass in the world, with an estimated annual production of 1-50 x 1091 (4). Lignocellu-losic materials, particularly the residues obtained from wood processing, are usually much cheaper than sugar- and/or starch-derived feedstock, such as sugarcane and corn. They also have no competitive use as human or animal foodstuffs. 

Table II. Sinmary of effluent standards for selected segments of the wood processing industry...

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