Supercritical carbon dioxide extraction of onion flavour was studied using a high pressure apparatus with a 5 l extractor vessel volume. Designed experiments were carried out to map quantitative effects of extraction pressure and temperature on the extraction yield and sulphur recovery. Stagewise precipitations of the extracts were carried out using two separators in series in order to obtain essential oil rich products with a high-sulphur content. The extraction with carbon dioxide was compared to conventional steam distillation and Soxhlet extraction with hexane and ethyl alcohol.

The aim of this study was to investigate the rate of the extraction of corn germ with carbon dioxide+ethyl alcohol mixtures. The effect of the amount of ethyl alcohol entrainer on the composition of oils as well as on the nutritive value and functional properties of defatted proteins was examined. Laboratory experiments were carried out at constant pressure and temperature (300bar, 315K) with the amount of ethyl alcohol ranging from 0% to 10% by weight in CO2. Because of higher solubility of the oil with increasing alcohol concentrations the extraction time was decreased significantly. The phospholipid content of the oil samples was higher by increasing the alcohol concentration. The emulsifying, foaming and absorption properties of the isolated proteins were better when ethyl alcohol was used in the supercritical solvent mixture. Fatty acid compositions were only slightly different for oils obtained by CO2 with and without entrainer fluid extractions.

Analytical derivation for the dependence of exit reactor concentration on the Damkohler number and theological parameters of the Prandtl-Eyring fluid is given. The derivation is based on the expression of the residence time of annular elements of the fluid within the laminar flow reactor as a function of reactor length and radial position. Calculations were made for different theological parameter values.

As an example, the solubility of naphthalene in supercritical CO2 and C2H4 were chosen. Two parameter estimation criteria were compared: use of constant relative error and the maximum likelihood criterion, the latter involves the use of weights derived from the error propagation law. It was found that sigma(DELTAy)2 is very far from being proportional to y2, therefore the use of constant relative error is not justified.In the case of the given solid-fluid equilibrium examples, weights based on constant relative error assumption overemphasize the steep part of the curve where all models fail. None of the models examined were able to describe C2H4-naphthalene equilibrium. For CO2-naphthalene the BMRK model proved to be better than the other equations of state investigated.

Heat transfer coefficients to helical coils in agitated vessels have been investigated. A modified Reynolds number has been introduced into the heat tr

Experimental data on vertical baffle tube wall heat transfer in newtonian liquids obtained in a cylindrical vessel with turbines of various sizes indic

Heat transfer coefficients for vertical tube baffles in an agitated vessel have been investigated in model vessels of three different dimensions. A modified Reynolds number has been introduced into the heat transfer equation which contains the product dn representating the fluid velocity at the tube baffle and the external tube diameter do. This Reynolds number is suitable for the correlation of experimental data for tube baffles of different geometrical proportions. Experiments have been carried out with Newtonian liquids.