Pag-asa D. Gaspillo

Kinetic study on the dehydration of tert‐butyl alcohol catalyzed by ion exchange resins

The dehydration of tert-butyl alcohol (TBA) in the liquid phase was studied by using an ion exchange resin, Amberlyst 15 (A15) in the H+ form. Experiments were carried out both in a semi-batch reactor and in a continuous stirred tank reactor (CSTR) with wet or dry resins. The results with the dry resin in the semi-batch reactor were different from those with the wet resin due to the swelling of resin in the presence of water. However, the results in CSTR agreed well with those in the semi-batch reactor using the wet resin. A rate equation that considered the inhibition of water was formulated. The experimental results agreed well with the calculated ones.

Selective transport of Li–Na and Li–K binary systems across a cation exchange membrane under an electric field

Abstract The selective transport for Li–Na and Li–K systems through cation exchange membranes under an electric field was measured as a function of voltage, feed concentration, and the number of membranes used in the chamber. The transfer rate of metal ions and permeation selectivity were evaluated by conducting experiments both in a single and multistage continuous one-pass flow mode of operation. The results are analyzed on the basis of the concentration of alkali metal ions from the feed and recovery side overflows. A comparison of the results obtained from both the single stage and multistage experiments showed that higher selectivity was obtained for the Li–K system compared to the Li–Na system. For the multistage operation, the permeation and selectivity of Li + and K + through five and 11 membranes were examined. A high separation factor was obtained when 11 membranes were used. The efficiency of the recovery of metal ions using membranes may be expressed by the calculation of the separation factor and the metal ion concentration obtained from the recovery solution and further enhanced by increasing the number of membranes used.

Modeling of Moringa Oleifera Oil Solubility in Supercritical Carbon Dioxide

Moringa oleifera (MO) oil solubility behavior in supercritical carbon dioxide (SC-CO2) was investigated at temperature rang e from 35 to 60°C and pressure from 15 to 30MPa. It was observed that pressure played key role on solubility while temperature has minor effect on solubility relative to that of pressure. Solubility was covariant with pressure. Solubility effect with temperature shifted to opposite behavior when pressure has reached the crossover pressure point at 26.38MPa. At p < 26.38MPa, an increased temperature has reduced the solubility. While at p ≥ 26.38MPa, the increased temperature led to an enhanced solubility. Fractionation of the oil during extraction period was observed too. Short chain fatty acids (C14:0, C16:0, C16:1) reduced by 21.87, 7.94 and 9.49% while long chain fatty acids (C20:0, C20:1, C22:0, C24:0) increased by 22.43, 11.42, 21.76 and 35.71% respectively. All C18 fatty acids (stearic, oleic, linoleic, linolenic) were not fractionated significantly during extraction period. However, the effect of the fractionation on the solubility was insignificant. Furthermore, modeling of MO oil solubility in SC-CO2was conducted. Del Valle-Aguilera model with root mean square percentage deviation of 6.18% is recommended for high oleic oil solubility in SC-CO2.