The effect of temperature on the adsorption and retention behaviors of a low molecular weight compound (phenol) on a C18-bonded silica column (C18-Sunfire, Waters) from aqueous solutions of methanol (20%) or acetonitrile (15%) was investigated. The results of the measurements were interpreted successively on the basis of the linear (i.e., overall retention factors) and the nonlinear (i.e., adso...

The pore size distribution is the most important aspect in characterization of structural heterogeneity of porous materials. Different methods have been developed and applied for the characterization of this property, and the most often used is gas adsorption [1,2], while liquid phase adsorption is seldom used [3]. A modification of the Dubinin-Radushkevich pore filling by incorporation of the ...

Batch distillation is an important separation process for small-scale production especially in pharmaceutical, specialty chemical and biochemical industries. Although batch distillation units require lower capital cost than continuous units, the unsteady state nature of the process, results in higher operating costs. Optimal control in batch distillation is a mode of operation which allows us t...

The separation of the binary mixture water-acetic acid by direct distillation is not suitable for industrial applications because of the presence of a tangent pinch on the pure water end. The problem is overcome via heterogeneous azeotropic distillation adding a third component, the entrainer, generally immiscible with water. With particular reference to terephthalic acid production process, we...

Based on the contribution of elements and chemical bonds, UNICAC (Universal Quasi-Chemical bonds Activity Coefficient) method was proposed to estimate activity coefficients nonelectrolyte liquid mixtures. The defined 10 33 as groups. calculation divided into combination term residual term. represents molecular size differences, describes interaction between molecules. energy parameters 43 group...

The separation of mixtures with close boiling points is a critical task in the petrochemical industry, and one such mixture that requires o-xylene/styrene. STED process used to separate o-xylene/styrene, which contains certain amount organic sulfur product due limitations process. In this study, underwent enhancements attain effective styrene accomplish deep desulfurization. A sulfolane (SUL) N...

Heavy crude oils are under constant investigation due to light oil exhaustion. So, its use is compulsory meet the world energy demand. present several drawbacks as high content of metals, heteroatoms, and asphaltenes, and, therefore, upgrading processes becoming essential. A deasphalting process, conventionally used for vacuum residue upgrading, can be an interesting pretreatment eliminate heav...