Availability of wood

These trends are supported by a 3.3% pa growth in demand for paper and board products, with fresh wood pulp production of 167 million tonnes and recovered fibre of 141 million tonnes in 2002 (FAO, 2004). There is a reasonable correlation between per capita consumption of paper and GDP per capita (Figure 13.1). The scatter may reflect local availability of wood, the size of the literate middle class, and the diffusion of wealth within particular countries. Increasing GDP and literacy mean that the greatest growth will be seen in Asia and South America. 

The Maryland Department of Natural Resources recently completed an assessment of the availability, cost, and reliability of wood fuels on the Delmarva Peninsula (14). The study concluded that cull trees and timber harvest residue could provide over 1.9 million tons of wood fuel annually at a cost to users of 12.50 per green ton. Other studies in Minnesota, New York. Oregon, and Washington are involved in similar utilization and biomass assessments to determine the availability of wood fuels for energy. 

Wood appears to have numerous attractive advantages it is available and renewable, a "clean" fuel, and has potential positive impacts on the enhancement of good forest management practice. The availability of wood residue exists in all forested areas of the United States, including "Urban" wooded areas. It is renewable because it regenerates in a relatively short time after each harvest cycle unlike fossil fuels. Wood is a relatively "clean" fuel because it contains virtually no sulfur. 

In fact, it was this ready availability of wood that fueled the rapid industrial development of Western Europe in the eighteenth century, particularly in England. The supply of wood (in the form of char-grade timber) severely hampered the use of coal. But the timber was consumed at such a drastic rate that the woods of the English Midlands, and presumably the woods and forests in other parts of Europe, were severely decimated. Thus followed the emergence (if not the reemergence) of coal as the fuel of choice for the charcoal and carbonization industries. 

It was not until the twentieth century that furfural became important commercially. The Quaker Oats Company, in the process of looking for new and better uses for oat hulls found that acid hydrolysis resulted in the formation of furfural, and was able to develop an economical process for isolation and purification. In 1922 Quaker announced the availability of several tons per month. The first large-scale appHcation was as a solvent for the purification of wood rosin. Since then, a number of furfural plants have been built world-wide for the production of furfural and downstream products. Some plants produce as Httie as a few metric tons per year, the larger ones manufacture in excess of 20,000 metric tons. 

There is a hybrid product available which has a veneer back, a layer of PF-coated wood particles, core veneer cross-ply, another layer of wood particles, and a top veneer. This assembly is pressed into a panel, trimmed to size, and sold into the stmctural-use panel market where it competes with plywood and oriented strand board. 

Potassium Carbonate. Except for small amounts produced by obsolete processes, eg, the leaching of wood ashes and the Engel-Precht process, potassium carbonate is produced by the carbonation, ie, via reaction with carbon dioxide, of potassium hydroxide. Potassium carbonate is available commercially as a concentrated solution containing ca 47 wt % K CO or in granular crystalline form containing 99.5 wt % K CO. Impurities are small amounts of sodium and chloride plus trace amounts (<2 ppm) of heavy metals such as lead. Heavy metals are a concern because potassium carbonate is used in the production of chocolate intended for human consumption. 

A. F. Matson, R. E. Dufour, andj. E. Breen, Survey of Available Information on Ignition of Wood Exposed to Moderately Elevated Temperatures, Bulletin of Research 51, Part II, Underwriters Laboratories, Inc., 1959. 

Materials of Construction A wide variety of materials is available for tanks, as indicated earlier. Most mechanisms are made of steel however, submerged parts may be made of wood, stainless steel, rubber-covered or coated steel, or special alloys. 

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... 

The first use of lithium alloys as negative electrodes in commercial batteries to operate at ambient temperatures was the employment of Wood s metal alloys in lithium-conducting button-type cells by Matsushita in Japan. Development work on the use of these alloys started in 1983 [10], and they became commercially available somewhat later. 

Many small laboratories use kitchen cabinets, also available in wood or steel, and are quite happy with them. Normal prices of high quality kitchen cabinets are not much lower than those of the laboratory variety, but special bargains are often available. They come in far fewer types of units, which make the laboratory benches less adaptable to specific uses. Finishes are not made to resist chemicals, and the overall construction is seldom of the heavy-duty type. In a microbiological laboratory where they have been used for years, however, workers have been pleased with them. They were adequate for the light duty service and were purchased when a local dealer had a clearance sale. 

Figure 8.1 Overview of products available from wood biomass.

Available analytical methods for determining the fire resistance (or fire endurance) of wood members have been reviewed by White (8). A finite-element heat transfer model for wood-frame walls was developed by the University of California-Berkeley (9) with funding from the FPL. 

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). 

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