Wood Distillation

WOOD DISTILLATION, the decomposition of wood by subjecting it to high temperatures in the absence of air. Larger enterprises for wood distillation have emerged in the USSR only in the last few years, and this industry is almost completely unaddressed in professional-hygienic literature. The production process consists of the following: birch firewood, loaded into retorts, is subjected to a temperature of 400°, and as the heating temperature increases, various products of wood decomposition are released in the following order: water, wood alcohol and acetic acid (280°), methane, carbon dioxide, and other gaseous products (350°), resinous products (350–430°). As a result of wood decomposition, 20–30% charcoal, 35–45% wood vinegar, water, alcohols, etc., 3–9% resin, and 20–35% gaseous products are obtained. The latter are transferred to the furnace and burned; the distillate is processed to obtain acetic acid separately (in the form of powdered calcium acetate, from which acetone is then released when heated to 400°) and alcohol (the latter undergoes rectification). The main occupational hazards vary depending on the department; for example, the retort operator is exposed to radiant energy, coal dust, vapors of acetic acid, acetone, wood alcohol, etc.; the operator of the three-vat department is exposed to excessive humidity and the same vapors; the powder dryer is exposed to radiant energy, vapors of acetic acid, acetone, and resinous substances; the alcohol worker and the alcohol transfer worker are exposed to the release of allyl alcohol and allyl oils into the air. The latter factor deserves special attention—the release of allyl oils often occurs unexpectedly, and workers are subjected to acute exposure to its vapors, resulting in severe photophobia, intense burning in the eyes, and lacrimation. These symptoms last for about two days. A study of 74 workers in the main departments of the "Methyl" plant (Vilensky and Loginov) conducted in 1926 revealed nothing characteristic; as for eye injuries, in individuals exposed to allyl vapors, no ophthalmological changes to the fundus were found, but they develop persistent chronic conjunctivitis. -Prophylaxis-the diversion of allyl compounds through pipes into a hermetically sealed tank with subsequent transfer into cylinders, or the installation of a chemical absorber along the path of their discharge; the latter is more radical but economically disadvantageous, as allyl alcohol is used in the cinematographic industry. In the plate-drying department-the installation of fume hoods.