Journal of the Pakistan Institute of Chemical Engineers

Mathematical modeling of membrane system for hydrocarbon gas (C1 – C3) recovery in polyethylene plant

Olalekan Adeloye — 2025-04-22

This study proffers a solution to the issue of hydrocarbon loss in petrochemical plants. Three sections were identified as locations where the loss occurred during the polyethylene production operations within the Indorama polyethylene plant facility. This study focused on developing a hollow-fiber membrane system designed to enhance the recovery of methane, ethylene, and propylene within polyethylene production plants. The membrane model was developed and analyzed for use in the Indorama polyethylene plant to predict the recovery of hydrocarbon gas at designated points of loss. Comprehensive modeling showed that the system was described by eleven coupled ordinary differential equations accounting for mass, energy, and momentum. The model equations were discretized into a set of algebraic equations using the orthogonal collocation method, and the solution to these equations was obtained using the Newton-Raphson method. The results showed a remarkable recovery of methane (~86%), ethylene (~80%), and propylene (~91%) on the shell side while capturing about 82% of carbon dioxide on the fiber side. These results were achieved using the spirobisindane-based ladder polymer (PIM-1) membrane material under 90 bar and 2 bar pressure on the shell and fiber side, respectively, with a membrane area of 6900 m². These findings were instrumental in assessing the effectiveness of the PIM-1 for recovering these hydrocarbon gases.

Fabrication of anions exchange membrane (AEM) using Polyvinylidene Fluoride(PVDF) to separate glycine via electrodialysis

Munir Ahmad — 2025-05-24

Enormous industrial waste is being produced while manufacturing food supplements, beverages, desserts, medicaments, bakery items, energy, and tonics containing varying quantities of foodstuff like organic acids, vitamins, and amino acids from feedstocks due to operational flaws which is discharged in water or thrown away at open spaces where it is piling up as environmental load besides adding millions of revenue loss annually to the national exchequer in the form of foreign reserve enhancing import bill. These important food items must be restored by separating them from waste at war footings to improve the economy and quality of life regarding environmental cleanliness. Anion exchange membrane-based electrodialysis has emerged as one of the finest techniques to get rid of this unavoidable process flaws besides carrying out technologically matchless and cheap separation of such food items from industrial waste and from the reaction broths where such products are being ruined due to heat and discharging exuberantly with accuracy without further damaging them and polluting the environment. Polyvinylidene fluoride (PVDF) based IEMs were synthesized by introducing varying amounts of ion exchange resin applying the solution blending technique with Methyl 2-pyrrolidone being its compatible organic solvent whereas, a single-step phase inversion opted for pore formation in deionized water-ethanol solution. Subsequently, each membrane was modified with PANI coating to enhance its conductivity. Bubbles were removed from the casting solution by continuous stirring and uniform composite membranes were fabricated. Every membrane showed enhanced conductivity, IEC, superhydrophilicity, and better anion exchange capability. The effect of PANI and varying quantities of ion exchange resin incorporated while fabricating ion exchange membrane in the matrix of PVDF was studied in terms of its separation efficiency of glycine via electrodialysis in feed and glycine product solutions as glycinate ions quantifying with acid-based titration and subsequently verified with HPLCMSMS which is instrumental in designing and developing efficient, most modern anion-exchange membrane (AEM) system on an industrial scale for commercial applications

Removal of malachite green from aqueous solution using chemically treated activated carbon

Muaz Zahid — 2025-07-26

The increasing discharge of dye waste water from Pakistan textile industries causes serious environmental problems. This study focus to explore an efficient method to remove malachite green dye through chemically treated activate carbon derived with (coal waste and calcium silicate).This study examines the effectiveness of activated carbon under controlled conditions and looks into how acid and alkali modifications affect the material adsorption capabilities. Several Batch adsorption experiments have been conducted by varying factors like adsorbent type and contact time. Langmuir and Freundlich model isotherms have been used to access the adsorbents performance, and pseudo first order and second order have been used to investigate adsorption. The acid treated activated carbon gives the highest dye removal efficiency attaining 80% removal efficiency in a short period of time. While the kinetic data more closely matched the pseudo-second-order model, indicating that chemisorption is the predominant process, the equilibrium data better fit the Langmuir isotherm, indicating monolayer adsorption onto a homogenous surface. Because of its increased surface area and pore structure, these data demonstrate how well acid-treated activated carbon adsorbs dye molecules. This study helps to develop cost-effective and environmentally friendly wastewater treatment strategies in dye-intensive industries. In conclusion, acid-treated activated carbon offers a promising, sustainable solution for industrial dye wastewater treatment. Its high removal efficiency and rapid adsorption kinetics make it a suitable candidate for large-scale applications.

Effect of grit blasting on electrochemical behavior of anodized AZ31B magnesium alloy

Faraz Hussain — 2025-08-01

Magnesium (Mg) alloys as biodegradable materials, are attracting significant importance for implant applications due to their suitability as biodegradable material. In the present research, An AZ31B Magnesium alloy was grit blasted with quartz and alumina particles with different blasting pressures and anodized in KOH solution for different durations to develop an anodized film on the different substrates. The surface morphology of the anodization layer was analyzed by scanning electron microscopy. The nature, coverage, and effectiveness of the anodized layer were investigated with potentiodynamic polarization (PD) scans and electrochemical impedance spectroscopy (EIS) in a simulated body fluid (SBF) solution. The results show an increase in surface coverage with an increase in anodization time. It is also revealed that a capacitive anodized layer with a dense inner layer having full coverage was obtained at 40 minutes anodization time for quartz and alumina blasted samples at 1000 kPa blasting pressure. The outcomes of this study help in developing a protective anodized film on the surface of Mg alloys for bone fixation implants.