Experimental and Kinetic Study of the Effect of using Zr- and Pt-loaded Metals on Y-zeolite-based Catalyst to Improve the Products of n-heptane Hydroisomerization Reactions

The escalating cost of Pt metal has prompted researchers to incorporate other metals into Pt/catalysts to reduce the amount of Pt. In this work, several bimetallic Pt-Zr/HY-zeolite catalysts were prepared by incorporating small amounts of the inexpensive Zr into the Pt/HY-zeolite to form an active and selective catalyst. Results showed that although half of the required platinum metal was used, the catalytic activity of the prepared Pt-Zr/HY bimetallic catalyst was higher than that of the monometallic (Pt or Zr)/HY catalysts, as a result of the improved Lewis acidity of that catalyst that resulted from the addition of the Zr metal; additionally, the branched alkanes' yield also increased. The optimum catalyst was bimetallic, containing 0.5 wt% Pt + 0.5 wt% Zr, which achieved the highest yield of isomers at 70.2 mol%, along with 82.61 and 84.98 mol% for conversion and selectivity, respectively, under 1 MPa and 250°C reaction conditions. In addition, the hydroisomerization reaction kinetic model was achieved, giving good predicted results in agreement with the experimental calculations, with an acceptable relative error. It was found that lower activation energies (about 44.5 kJ/mol) were needed for olefin hydrogenation to iso-paraffins, while higher activation energies were required for i-paraffin hydrocracking (about 138.1kJ/mol)

Effect of bore fluid flow rate on formation and properties of hollow fibers

Abstract In this work, for high performance and wide range of ultrafiltration applications, the effects of the most widely used values of internal coagulant flow rates (ICFR) (i.e., 2.6, 3.6, 4, 5, 7, 9, 11, and 13 ml/min) on the different features of the polyvinylchloride hollow fiber have been investigated. Both the idealized straight and the cylindrical pore with small effect of tortuosity were approximately obtained through the effect of ICFR. Atomic force microscope (AFM), scanning electron microscope (SEM), and ultrafiltration measurements were utilized to characterize the hollow fibers. The SEM and AFM results indicated that the cross-sectional morphology of the fibers is changed significantly with various ICFR. The structure of the inner surface was also changed from an open cellular structure to a porous structure by means of high pore density and small pore diameter. In addition, the membrane thickness was reduced by 314% with an increase in the ICFR from 2.6 to 13 ml/min. The pure water permeation flux was improved 17 times when ICFR was increased to 13 ml/min, while the BSA rejection remained within the acceptable range (from 93.4 to 90.4) when the ICFR was increased from 2.6 to 9 ml/min

Produced Water Treatment Using Ultrafiltration and Nanofiltration Membranes

The application of ultrafiltration (UF) and nanofiltration (NF) processes in the handling of raw produced water have been investigated in the present study. Experiments of both ultrafiltration and nanofiltration processes are performed in a laboratory unit, which is operated in a cross-flow pattern. Various types of hollow fiber membranes were utilized in this study such as poly vinyl chloride (PVC) UF membrane, two different polyether sulfone (PES) NF membranes, and poly phenyl sulfone PPSU NF membrane. It was found that the turbidity of the treated water is higher than 95 % by using UF and NF membranes. The chemical oxygen demand COD (160 mg/l) and Oil content (26.8 mg/l) were found after treatment according to the allowable limits set by means of world health organization WHO water quality standards. The final composition of SO4-2 (110 mg/l) and NO3 (48.4 mg/l) components within the produced water after treatment were agreed with the permissible limits of WHO, whereas Cl-1 (8900 mg/l) component is not in the allowable limits. Finally by the use of PVC, PES and PPSU hollow fiber membranes; this method is seen to be not sufficient to remove the salinity of the produced water