Environment
V. Montazeri; B. ZareNezhad; A. Ghazi
Abstract
The nanofluid-based gas hydrate formation process employing copper oxide (CuO) nanoparticles have been experimentally investigated in this work. Different concentrations of nanofluids are injected into the reactor at the operating condition of 29 bar, 274.15 K, and impeller speed of 100 rpm. It was observed ...
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The nanofluid-based gas hydrate formation process employing copper oxide (CuO) nanoparticles have been experimentally investigated in this work. Different concentrations of nanofluids are injected into the reactor at the operating condition of 29 bar, 274.15 K, and impeller speed of 100 rpm. It was observed that the kinetics of the carbon dioxide hydrate formation process was greatly affected by the nanoparticles. The remarkable point was that at a very low concentration of 20 ppm, a considerable improvement on the carbon dioxide hydrate formation kinetic without using any surfactant was obtained. At the concentration of 20 ppm, the values of the initial rate of hydrate formation, growth time, and induction time were 0.0495, 194.5, and 4.4 min, respectively, which these results can be of great importance for the use of carbon dioxide hydrate in various industries. The results indicated that the kinetics of gas hydrate formation was also severely influenced by the impeller speed and initial gas pressure. The rate of CO2 captured in the hydrate crystalline lattice is also modeled by the first-order kinetic model. It was seen that this model can be used to predict the rate of hydrate formation with considerable accuracy.
R. Alrozi; N. S. Anuar; F. Senusi; M. A. Kamaruddin
Abstract
In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption ...
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In this study, the adsorption behavior of Remazol Brilliant Blue R (RBBR) from aqueous solution by using raw and modified clinoptilolites were investigated. In the experimental work, raw clinoptilolite (R-CL) was treated with Zn(NO3)2 in ethanol and produced zinc-grafted clinoptilolite (Zn-CL).The adsorption experiments were carried out under different conditions of initial concentration (25-250 mg/L), adsorption time (0-2h), solution pH (2-12), and temperature (300-353 K) to determine optimum conditions for the highest RBBR removal. The influence of these parameters on the adsorption capacity was studied using the batch process. The results indicated that the solution pH was observed to be a key factor of the RBBR adsorption process. The maximum dye adsorption was achieved with Zn-CL adsorbent at pH~6 and the corresponding adsorption capacity was found to be 42.2 mg/g, which was higher than R-CL (12.5 mg/g). Lower adsorption capacity of RBBR was found by Zn-CL between pH 8 and 12 opposite to R-CL which showed a marginal increase in adsorption capacity within the same pH range. The results proved that Zn-CL which is a modified clinoptilolite is an effective adsorbent for the removal of RBBR from aqueous solution.
