Colza oil bleaching through optimized acid activation of bentonite. A comparative study

Response surface modeling of acid activation of raw diatomite using in sunflower oil bleaching by: Box–Behnken experimental design

“…These values suggest that the different parameters studied have a direct relationship on the bleaching efficiency, except solid to liquid ratio the effect of quadratic term of x 3 2 (p =0.0016) are slightly higher than the first-order effect of x 3 (p =0.0038). Didi et al (2008) observed similar phenomenon of acid concentration, activation time and solid to liquid ratio in an optimization based on a 3 3 full-factorial design conducted to optimize bleaching efficiency of colza oil by bentonite. As seen in Tables 5 and 6, the most significant component of the regression model was found as the acid concentration (x 1 ) for the present application (t =15.4597, p =2.06E-5, F =239).…”

Acid activation of Bentonite for use as a vegetable oil bleaching agent

“…The occurrence of optimal activation parameters (Didi et al, 2009), beyond which a decay of the bleaching capacity takes place, is clear evidence that activation improves the surface area, porosity and acidity of the clay material, but only up to a certain level. The fact that dealumination of the clay minerals and protonation of the ion-exchange sites occur inevitably upon acid-activation reveals that high bleaching capacities require acid sites stronger than silanol groups and the remaining protonated ]H) sites.…”

“…The present study comes to pursue a previous work dealing with the optimisation of the bleaching capacity (Didi et al, 2009). Therefore, based on a series of 27 attempts made according to a 3 3 experiment factorial design, by varying the acid concentration (X 1 ), the contact time (X 2 ) and the temperature (X 3 ) in suitable parameter ranges, calculations were made in order to assess the estimated standard deviation of the model as a response-function.…”

“…Although it seems to be a good alternative, the use of factorial experimental designs has scarcely been envisaged in this regard, most of the experiments being dedicated only to the optimization of clay activation (Didi et al, 2009;Kirali and Laçin, 2006). So far, no statistical approach has been considered so as to correlate parameters that control clay activation for effective oil bleaching processes and neither factors, interactions or synergy have been discussed.…”

“…So far, no statistical approach has been considered so as to correlate parameters that control clay activation for effective oil bleaching processes and neither factors, interactions or synergy have been discussed. To such an end, based on the results obtained in a previous work using a factorial 3 3 experimental design (Didi et al, 2009), calculation attempts were made to assess and simulate the effects of the following three key parameters on the bleaching capacity of an Algerian bentonite in the colza oil processing: acid concentration, contact time and temperature.…”