The activation of trihydrate bauxites at temperatures up to 1600°F. has been studied with particular reference to the production of a highly efficient drying adsorbent. Data are presented to show the relationship between activation temperature, residual volatile matter content, surface area, dry gas capacity, and equilibrium capacity. The mechanism of the thermal decomposition of bauxite is discussed with reference to the results of differential thermal and x-ray diffraction analyses. The maximum dry gas capacity is attained by activation at 700-750°F. This treatment reduces the volatile matter content of the mineral from about 28-30 to 6-8%. Under optimum activating and operating conditions bauxite will adsorb 11-16% by weight of water before any moisture is detectable in the effluent. Activated bauxite may be regenerated repeatedly by heating at 300-500°F. The various other factors which influence drying efficiency are discussed. INDUSTRIAL AND ENGINEERING CHEMISTRY Vol. 36, No. 2 reaction is characteristic of gibbsite (12, 22, SO, SI);

Bauxite, a naturally occurring hydrated oxide of aluminum, has been thermally activated to produce a highly efficient adsorbent for the refining oi sugar sirups and liquors. Laboratory data indicate that the percolation of defecated solutions through activated bauxites raises the apparent purity 3-10 per cent in the case of sirups and up to 2 per cent for high-purity liquors. The invert content of the solution is decreased 4-34 per cent. Decreases of 20-80 per cent in the ash content are observed following filtration through activated

THE industrial utilizationof rosin includes processes in which the rosin is heated at various temperatures up to the distillation point at atmospheric pressures-e. g., in the preparation of metallic rosinates and rosin esters, the blending of rosin with synthetic resins, the purification of rosin by vacuum distillation, and the production of rosin oil. Since abietic acid is remarkably labile at temperatures above its melting point, the problem of the effect of temperature on rosin (and abietic acid) is of obvious importance in technical operations, where the acid function or the characteristic physical properties of rosin are of primary interest, and in the study of the chemistry of the resin acids. The progressive changes which occur as the acid is heated involve, as the temperature rises to the distillation point: isomerization, evidenced by the sharp decrease in melting point and change in optical rotatory power without change in acid or saponification number; loss of water; decarboxylation, with loss of carbon dioxide and monoxide; and finally complex decomposition yielding a large variety of open-chain and ring compounds. Although a considerable amount of data on both phases of the pyrolysis of the acid has accumulated from both industrial research (5) and purely scientific investigation (8), the information on the predistillation phenomena is especially difficult to correlate because of the unsystematic variation in the experimental conditions and the difference in properties of the rosins or acids used. The present article is offered as a systematic and more complete study of the decarboxylation, dehydration, and isomerization of Z-abietic acid from American wood rosin between its melting point and distillation temperature during arbitrarily chosen time and temperature intervals. All the experiments were carried out in pure nitrogen to avoid the more complex phenomena associated with the presence of oxygen.Preparation of Materials and Experimental Method Abietic acid was prepared according to the directions of Steele (11) from American wood rosin (I grade). The rosin was crystallized three times from 98 per cent acetic acid and then freed of the residual acid in va-.uo over solid sodium hydroxide. This product was

For the first time a method for the preparation of furfural acetal from the aldehyde and ethanol has been described.The effect of the ratio of reactants upon the extent of the reaction of benzaldehyde with ethanol, butanol and propanol-2 and of furfural with ethanol has been determined when the ratio of aldehyde to alcohol is varied from 1 to 2 to 1 to 10. The equilibrium constant for the first two of these reactions was found to be identical for the two alcohols but to decrease slightly with increase in ratio of alcohol to aldehyde.9 The equilibrium constant for the reaction of benzaldehyde with propanol-2 and of furfuraldehyde with ethanol appeared to be independent of the concentration of reactants. The equilibrium constant for the reaction of furfuraldehyde and methanol has been redetermined.

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