J. F. Mathews

Factors affecting the desolventization of canola meal

Factors affecting the level of residual solvent in hexane-extracted canola meal included the moisture content of the crushed seed and the temperature of the hexane at the time of extraction, the duration of the extraction process and the severity of the cooking procedure prior to extraction. Low moisture, low temperature extraction, short exposure to excess hexane and mild cooking procedures all contribute to minimizing the levels of sorbed hexane after desolventization was complete. Dry heat could drive off only part of the residual hexane. Moist heat, as steam, was more effective.

Liquefaction of Aspen Poplar to Produce an Oil and Chemicals

In a period when fossil hydrocarbons are likely to become scarcer, methods to convert renewable biomass to useful fuels and chemical feedstocks are increasingly attractive. Such methods would permit the conversion of the very large solar energy reserves trapped as lignocellulosic materials into a form which would have the advantages of being initially sulfur-free and readily portable. All such biomass is composed of two vastly chemically different components: the carbohydrate-based holocellulose (cellulose and hemicelluloses) and the aromatic based lignin, which together have a much lower heating value than fossil fuel due to their high oxygen content. The production of a fuel compatible with natural oil must therefore involve significant oxygen removal. Any one such process may not be suitable for conversion of both the holocellulose and the lignin and an optimization of reaction conditions may be required.

Effect of ultrasonic waves on the catalytic activity of silica gel

Abstract It has been found that silica gel, prepared in the presence of ultrasonic waves (90 kHz), is more active as a catalyst in the decomposition of hydrogen peroxide (0.3 wt % aqueous solution) than silica gel prepared with only the usual stirring techniques. The reaction studies carried out at 37, 44, 54 and 63 °C in a batch reactor showed that both the activation energy and the frequency factor were higher for the insonated gel than the uninsonated gel. The increase in activation energy and the catalytic activity has been explained in terms of the compensation effect. Surface area, pore volume, and pore-size distributions were also measured. The existing kinetic data on the catalytic decomposition of hydrogen peroxide (using various catalysts) has been correlated in terms of the “isokinetic temperature” and a “characteristic frequency factor.” This correlation enables the kinetic parameters of a new catalyst (for H 2 O 2 decomposition) to be determined with a minimum of experimental work.

Studies on the mechanism of formation of the products of liquefaction of cellulose and aspen poplar wood

Abstract Studies are reported on the chemical nature and mechanism of formation of the components of the oil fraction obtained by the alkali-catalyzed liquefaction of aspen poplar wood and separately of cellulose. Along with the smaller molecular weight compounds reported earlier (5) evidence has been obtained for the presence of polymeric fractions involving ether linkages and which show a bimodal pattern of molecular weights. Using appropriate model substances, some evidence ha3 been obtained for the production and involvement of one- and two-carbon fragments as well as ketene-type intermediates in the liquefaction process. Examination of the role of pH during the conversion process suggests that the initially alkaline medium is required to degrade the cellulose to smaller fragments, including possible saccharinic acids, with a corresponding decrease in pH. Then at an appropriate pH (now acidic) and temperature the resulting degradation products are converted to components of the final oil.