Iranian Journal of Chemical Engineering (IJChE)

Abstract In this research, the metal-organic framework of HKUST-1 (Hong Koung University of Science and Technology) was synthesized for use in modern drug delivery systems by the thermal solvent method. It was activated in two conditions: under vacuum pressure and by a freeze-drying method. The synthesized HKUST-1 Metal-Organic Framework was analyzed by IR, XRD, BET, and SEM. In order to examine and compare the results, the IR sample was synthesized using the sample before and after the activation of the sample. Regarding the XRD pattern, the peak area of 2θ = 11.760 showed the highest intensity. The SEM images showed an octagonal morphology in which the particle size was in the range of 5-65 μm. Furthermore, by using the BET method, the surface area of 1306 m²/g was calculated.

Abstract Essential oil of Valeriana officinialis L. cultivated in Iran was extracted using steam distillation technique and then analyzed by gas chromatography and gas chromatography-mass spectrometry. Optimization of extraction of essential oil was
performed using this technique. The extraction yield results for steam flow rates of 4, 7 and 9 L/min for a packed bed of 100 gram of plant were found to be 0.60, 0.52 and 0.47 percent, respectively. For bed heights of 35, 47.5 and 65 cm and a steam flow rate of 4 L/min the extraction yield was found to be 0.60, 0.36 and 0.24 percent. The results of multistage column for a total of 100 g packed bed and 4 L/min steam flow rate were 0.65, 0.65 and 0.6 for three, two and one stage distillation column, respectively. The oil yield was increased from 0.6 for standard roots to 0.7 for crushing roots.

Abstract In this work, a new process design and clean production to increase the yield of steam distillation of rosemary essential oil was studied. For extraction of essential oil, a packed bed of rosemary was exposed to the steam flow. For improving the total yield, multistage bed column was used. The effects of steam flow rate, height of plant bed, multistage beds and time of extraction on yield and composition of the oil were studied. Also, trend of three major components of the oil during different extraction times and conditions were observed. We determined minimum steam to be passed through the packed bed so that there is minimum water in the distillation and hence, steam channeling phenomenon was overcome. Furthermore, we obtained optimum steam flow rate and time for extraction of the oil. Using a multistage column with suitable steam redistributors results in reduction of pressure drop, and steam channeling in the
column, hence, increacing the yield of extraction. This research revealed different behaviors of the main components of rosemary oil; α-pinene, 1,8-cineole and camphor in treating with amount of steam flow rate.

Abstract An experimental study of the phase inversion phenomenon was carried out in a rotating disc contactor (9.3 cm diameter). The effect of energy input via agitation and physical properties of the liquids upon inversion holdup and also delay time (time of inversion) was investigated at the constant input flow rate of the dispersed phase under no mass transfer conditions. Water was chosen as the continuous phase, and it was kept stagnant inside the column. The critical dispersed phase holdup was found to be decreased by increasing the energy input via agitation. It was observed that the lower
both the interfacial tension and the density difference of two phases, the greater the resistance of the system to inversion. Moreover, a reduction in delay time was observed by increasing the energy input via agitation.

Abstract In this research, the effect ofmixed salts together with mixed ionic surfactants on dropinterface coalescence time was studied for the system of water (d) / toluene(c) as a model system. Sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) as anionic and cationic surfactants were used. Sodium chloride (NaCl) and magnesium sulfate were used as salts. In the first stage of experiments, the system of water and toluene was influenced separately with SDS+NaCl, SDS+MgSO4, CTAB+NaCl and CTAB+MgSO4. It was observed that drop size increased with SDS+NaCl and also with SDS+MgSO4. Partial coalescence times increased for all systems. Overall, this increase of coalescence time was more obvious when CTAB was applied. Also reduction in drop size was observed. In the case ofmixed surfactants with single salt, it was observed that partial coalescence was suppressed for the system with (SDS+CTAB)+MgSO4. On the other hand, drop size decreased and total coalescence time increased. This may be due to the difference between the anions and cations ofthe two salts. For the case ofmixed surfactants with mixed salts, drop size and coalescence time decreased.

Abstract "> Phase inversion phenomenon occurs in many industrial processes including liquidliquid dispersions. Some parameters such as energy input or the presence of mineral compounds in the system affect this phenomenon. The aim of this research is to study the speed of rotation or energy input at a range of 400 to 800 rpm in a batch liquid-liquid system containing toluene and water. The presence of sodium chloride and magnesium sulphate in the system was also studied. It was shown that the increase of energy input had a more obvious effect on oil in water (O/W ) dispersion at lower values of holdup. It was also shown that the ambivalence (o/w → w/o) region of the phase inversion curve shifted downward and became wider as a result of the decrease in interfacial tension. It was observed that inorganic salt, used in both single and dual (mixed) shapes, enhanced phase inversion for O/W dispersion. Therefore, the greater the ionic strength of salt, the greater the tendency to phase inversion is.