Journal of the Pakistan Institute of Chemical Engineers
Journal of the Pakistan Institute of Chemical Engineers (JPIChE) is the publication of the Pakistan Institute of Chemical Engineers (PIChE). The journal has been approved by HEC. The Journal publishes articles covering wide range of fields of chemical and process engineering.
Pakistan Institute of Chemical Engineers
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Novel approaches to wastewater treatment processes: Synchronizing advanced oxidation processes with nanostructured catalysts: A review
The rising pollution of water resources by recalcitrant organic pollutants provides the necessity to develop the new advanced treatment technologies along with the traditional pattern of treatment processes. Advanced Oxidation Processes (AOPs) have gained popularity as they can be used to degrade stubborn pollutants as they generate highly reactive oxygen species (ROS), primarily, hydroxyl radical (OH). Nanostructured catalysts have been incorporated to revolutionize AOP, making them much more efficient, selective and cost-effective. The review provides an in-depth discussion of the synergy between engineered nanomaterials and a number of AOPs (photocatalysis, Fenton based processes, ozonation, and persulphate activation). We discuss the fundamentals of action of nanostructured catalysts including metal oxides, carbon-based nanomaterial and single atom catalysts that promote the generation of ROS in detail. Recent achievements in designing materials toward improvement of the light absorption, charge separation and catalytic stability are discussed. In addition, the review addresses such critical issues as catalyst recovery, potential nanotoxicity, scale up to real-world solutions in industry. Taking into account the latest studies (up to the year 2026), the article at hand underlines the potential of nanocatalyst-based AOPs integration as transformative and suggests the research pathways to reach sustainable and efficient wastewater treatment.
Copyright (c) 2026 Journal of the Pakistan Institute of Chemical Engineers
Integrated biodiesel production and DES-based purification from animal fats: comparative effects of feedstock, alcohol and catalyst
Biodiesel is a sustainable alternative to fossil fuels; however, the high cost of feedstock and downstream purification processes remains a significant challenge. This work presents an integrated approach for biodiesel production from chicken and beef fats using an alkali-catalyzed transesterification process followed by purification with a deep eutectic solvent (DES) composed of tetrabutylammonium bromide (TBABr) and oxalic acid. The effects of feedstock type, alcohols (methanol and ethanol), and catalysts (KOH, NaOH, and Ca(OH)2) were comparatively evaluated. The highest biodiesel yield, 91 ± 1%, was achieved using chicken fat, methanol, and NaOH under optimized conditions (60 oC, 1 hour, 400 rpm, a 6:1 alcohol-to-oil molar ratio). DES purification reduced acid value by ~37%, demonstrating effective impurity removal. Product quality was further validated through FT-IR, GC-FID, and physicochemical property analysis based on ASTM standards. The study demonstrates that the selection of feedstock, alcohol, and catalyst significantly influences reaction kinetics, phase separation, and mass transfer during process performance. The proposed integrated approach provides an efficient and environmentally friendly strategy for biodiesel production and purification.
Comprehensive chemical profiling and biological activities of Tinospora malabarica: Implications for herbal drug development and quality control
This study investigates the chemical composition and biological activities of a significant medicinal plant species, Tinospora malabarica, Sindh region of Pakistan. Initially, the determination of physicochemical parameters was carried out to understand the general properties of plant. Phenolic compounds were identified using HPLC-PDA and 6 phenolics were detected in this species. Essential oils and volatile compounds were extracted through steam distillation. Analysis of each volatile constituent was done through GC-MS and 75 compounds were identified. Fatty acid profiling was conducted via GC-FID, and identified 19 fatty acids in T. malabarica. To evaluate the antioxidant capacity, BHT was used as control in DPPH assay. Antibacterial activity was evaluated by testing the extracts against five bacterial strains: Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhimurium, Staphylococcus aureus. The results provide a comprehensive understanding of this plant species' chemical composition and biological activities, highlighting its potential for the development of herbal drug formulations. Furthermore, the findings contribute to establishing quality control protocols for use of T. malabarica which is a raw materials used in herbal drug production.
AI-Driven prediction of sulfide removal from wastewater through aeration and iron dosing
Wastewater containing sulfide needs to be segregated to save the environment and preserve the quality of water. Precise prediction of sulfide is important to monitor the environment, the exploration of minerals, and industrial operations. In this study, five widely used machine learning (ML) models namely, XGBoost, Artificial Neural Networks (ANN), Support Vector Regression (SVR), Random Forest (RF), and AdaBoost, using the published data of suldife removal by aeration and iron salts. XGBoost was selected as the best model (RMSE: 160.86, R2: 0.973) and was much better than others due to hyper parameter optimization and extensive analysis (RMSE, MAE, R2). The correlation study of features indicated that there are fundamental input relationships that dictate the behavior of sulfide. The optimized XGBoost structure achieves highest predictive accuracy. The results explain the potential application of machine learning models to optimize waste water treatment parameters and increase efficiency.
Optimization model for transmission and distribution a natural gas: A case study of the gas pipeline network system
With increasing demand of natural gas, Pakistan is trying to import it from neighbor countries. In this respect, new pipeline networks will be constructed to import gas from Russia or Iran. The construction of pipeline network is a capital intensive process. Therefore, it is important to minimize the total life investment cost for an optimum design of pipeline network. The total life cost of a pipeline network depends on various factors such as pipeline diameter, thickness, compressor powers or operating conditions. In this study, a comprehensive optimization model has been developed to evaluate the optimum total life cost of natural gas pipeline network. The pipeline network contains both transmission and distribution pipelines. The transmission pipeline diameter, thickness and number of compressors are selected as the decision variables. The technical constraints are also considered in the optimization model to ensure safety, economics, and stability of pipeline network. These constraints are studied for different input variables. The optimization problem is mixed integer nonlinear programming type because it contains both discrete and continuous variables along with nonlinear equations. Therefore, rank optimization technique is used in this study. The developed optimization model is implemented on the case study using MATLAB software. The optimum total life cost of the case study has been investigated for different parameters.
Synthesis, spectral characterization, and antimicrobial evaluation of a Zn/Ni bimetallic complex derived from 2,2′-Bipyridine-4,4′-Dicarboxylic Acid
Bimetallic complexes have garnered significant attention in the scientific community due to their versatile applications, such as antibacterial, antifungal, antitubercular, antimalarial, antioxidant, antibiotic, anti-inflammatory, and anticancer activities. This study reports the synthesis and characterization of a bimetallic Zn/Ni complex derived from 2,2’-bipyridine-4,4’-dicarboxylic acid (BPyCOOH) as a multifunctional coordination compound with effective antimicrobial impact. This complex ensured efficient coordination of the ligand with both Zn(II) and Ni(II) ions due to its bifunctional groups in a single ligand structure. Structural elucidation was achieved through UV–Vis, FTIR, and elemental analyses. The UV–Vis spectrum displayed two distinct absorption bands at approximately 280 nm and 400 nm, attributed to π–π* transitions and metal-to-ligand charge transfer (MLCT), confirming the successful formation of the bimetallic coordination framework. The Zn/Ni(BPyCOOH)₂ complex was evaluated for its antimicrobial potential against selected Gram-positive and Gram-negative bacterial strains, also demonstrating minimum inhibitory concentration (MIC) activity. The Gram-positive bacteria, P. mirabilis, showed the highest zones of inhibition (27.7±0.9) at (20 mg/ml) of Zn/Ni(BPyCOOH)₂ complex. Therefore, Zn/Ni(BPyCOOH)₂ complex shows concentration (dose) dependent antimicrobial activity. It is most effective against Proteus mirabilis (P. mirabilis), gram-negative, and least in Staphylococcus aureus (S. aureus), gram-positive, by calculating the diameter of the zone of inhibition. No inhibition observed in the control, which proves the results are valid.
Kinetic and thermodynamic evaluation of plastic waste degradation for energy recovery
Plastic consumption with effective recycling is essential for sustainable life-cycle management. In recent years, energy recovery and value-added product generation from plastic waste have gained increasing attention, with pyrolysis emerging as a promising thermochemical pathway for plastic degradation. This study investigates the thermokinetics of two waste plastic streams: mechanically recycled plastics, high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and landfill-dumped mixed waste plastic (MWP) and multilayer plastic (MLP), to evaluate operational parameters for pyrolysis and hydrothermal liquefaction (HTL) to optimize their conversion into valuable products. Thermogravimetric analysis (TGA), conducted at a heating rate of 10 °C/min, revealed that HDPE exhibited the highest weight loss (98%) at a peak temperature of 494 °C with a degradation time of 13 minutes. PET has a low conversion rate (80.53%) than HDPE, LDPE, and PP, resulting in a larger residue. The Coats-Redfern model-fitting method, applied with various models, was used to calculate the kinetic triplet and thermodynamic properties. Among the tested models, F1 (First-order) and F2 (Second-order) reaction models were identified as the most suitable for recycled plastics, while D2 (two-dimensional diffusion) was found to be appropriate for dumped plastics. The activation energies of mechanically recycled plastics were estimated to range from 154 to 295 kJ/mol, whereas landfill-dumped plastics ranged from 117 to 171 kJ/mol. Analysis of degradation temperature, duration, and weight loss (%) obtained from TGA provided a reference point for determining the optimal operating parameters (reaction time and temperature) for pyrolysis, thereby minimizing solid residue and enhancing the efficiency of plastic conversion into oil and gases.
Optimizing design and process parameters to improve thermal efficiency and emission reduction of domestic gas stove burners
The purpose of this experimental study is to optimize the process and design parameter for burners commonly used in domestic gas stoves. We observed the effect of four parameters; design of burner (swirl or radial), loading height, primary aeration, and semi-confinement of combustion flame on the overall thermal efficiency and emissions from burner used in domestic gas stoves using natural gas as a fuel. Experimental results showed that swirling motion of the flame prolonged the residence time of the combustion products under loading vessel and hence increased the thermal efficiency with slight increase in CO emission. Additionally, swirl improved the mixing of fuel and air which facilitated the combustion reaction to completion. Flame confinement with a metallic shield was another factor which improved efficiency due to a delay in dispersion of flue gases into atmosphere. However, it might slightly increase CO emissions because of the limited supply of secondary air. Combined effect of both the swirling motion and flame confinement with a metallic shield decreased gas consumption up to 9%. Loading height was found to be an important factor for efficiency enhancement and emissions control but its value was very sensitive to change in burner diameter, amount of primary and secondary aeration, gas supply pressure and flow rate, velocity of fuel air mixture and loading vessel dimensions. Required amount of primary aeration decreased CO emissions through complete combustion and enhanced efficiency by producing strong blue flame. Without primary aeration, flame temperature was low as compared to the primary aeration flame indicated by the color of flame.
Integrative water quality index (WQI) based assessment of ground water resources in Punjab, Pakistan
The needs of more than 70% of Punjab’s residents for domestic use, agriculture and industry are met by groundwater. Today, its quality and sustainability have significantly deteriorated by fast urban growth, factory outflows, runoff from farms and unchecked water usage. The most prevalent human activity involving the subsurface of the Earth is groundwater extraction, 982 km3 of groundwater were extracted annually worldwide. Water scarcity and a reduced supply of drinking water are the results of excessive groundwater pumping. Pakistan is among the nations that, by 2030, will have fewer renewable water resources than the estimated threshold value of 1500 m3 per capita annually. A complete evaluation of groundwater quality was conducted in 36 districts of Punjab using 5,319 water samples collected from groundwater sources from both urban and rural areas. Empirical experiments involving Physical, Chemical and Bacteriological analysis were done in the laboratories. Key findings reveal alarming contamination levels, with 61.9 % of samples deemed unfit for drinking due to elevated concentrations of Total Dissolved Solids (TDS), heavy metals, and microbial pathogens. The WQI classification highlighted that over 10 districts in Punjab fall into "unsuitable for drinking" category (WQI ≥ 300), posing significant public health risks, including cancer, fluorosis, and waterborne diseases. The results emphasize to develop integrated water management plans, strengthen law enforcement, inform the public and use modern resources of Geographical Information Systems for decision making and adopt lower cost water purification systems to improve the water quality of Punjab. Actions should include developing institutions, updating water quality guidelines, and encouraging rainwater collection as well as aquifer refilling. This research follows SDG 6.1, helping policymakers build policies that reduce groundwater risks and secure safe drinking water across Punjab.
Photocatalytic ozonation of deltamethrin: A 3D response surface methodology approach
Deltamethrin is a persistent, toxic, and synthetic pyrethroid widely used in agriculture. Its environmental persistence leads to significant ecological consequences, necessitating effective removal strategies. While various Advanced Oxidation Processes (AOPs) — such as UV / H2O2, ozone-based methods, and photo-Fenton processes-are used to manage deltamethrin concentrations, photocatalytic ozonation has gained prominence. By combining a photocatalyst with ozone, this method achieves a higher degradation rate through the enhanced generation of reactive species. This study focuses on the degradation of deltamethrin via photocatalytic ozonation using a TiO2/WO3 composite photocatalyst prepared via the sol-gel method. To optimize the process, the research investigates several key variables, such as: pH, catalyst amount, and initial deltamethrin concentration. The interaction between these variables and their impact on the degradation rate was investigated using 3D Response Surface Methodology (RSM). The results demonstrate that photocatalytic ozonation is a viable method for the degradation of deltamethrin, achieving a 26% degradation rate within one hour of reaction time. Despite the potential of this process, further research should focus on three key areas: developing more efficient heterogeneous catalysts, improving catalyst recyclability, and addressing the technical challenges of scaling photocatalytic ozonation for industrial applications.
Sustainable hybrid activated carbon derived from food waste and scrap tire for synergistic CO2 and NOx adsorption
Worldwide, food and tires waste (a substantial fraction of municipal solid waste) are dramatically increasing due to population growth and economic development, mostly in developing countries. In current research, food and tire waste material were validated in the flow tube furnace to synthesize biochar, then resulting biochar was subsequently subjected to chemical activation using Ferrous Ammonium Sulfate Hexahydrate ((NH4)2Fe(SO4)2·6H2O). Activation was carried out at different biochar and activating agent ratios (1:0.5, 1:1, 1:1.5, 1:2) and pyrolysis temperatures (500℃, 600℃, 700℃, and 800℃) to prepared activated carbon. As illustrated by the proposed reaction pathways, that carboxyl group and hydroxyl group on the surface of biochar play a key role in interacting with Fe+2 ions released from activating agents. The activated carbon was evaluated for CO2 and NOx adsorption under ambient conditions (25±2℃ & 1 atm), typical of coal-fired flue gas. Analysis demonstrated highest removal efficiencies of CO2 and NOx was observed to be 93% (282 mg g-1) and 90% (1.16 mg g-1), respectively, achieved at the activation temperature of 500℃ after 120 minutes of treatment. Functional groups identify by FTIR including C=O, O-H and N-H contributing to CO2 and NOx adsorption from flue gases. SEM revealed a rough, well developed porous surface with interconnected fine particles, produced cavities to adsorb CO2 and NOx. This study reveals that activated carbon derived from food waste and scrap tires is effective for removing CO2 and NOx gases released from coal combustion.
Computational and analytical investigation of date trunk biomass as a bio-adsorbent for sustainable removal of methylene blue dye from wastewater.
The Industrial release of synthetic dyes, such as methylene blue (MB), into water has created significant environmental concerns. The use of date trunk as a bio-adsorbent was investigated for the removal of MB dye from wastewater. The effects of several experimental parameters, such as MB dye concentration, contact time, and adsorbent dosage, were studied using a batch-laboratory operational setup. Fourier Transform Infrared (FTIR) spectroscopy was performed to reveal the presence of functional groups in the bio-adsorbent. This study evaluated the adsorption capacity of a green bio-adsorbent for the removal of MB dye from wastewater. The maximum adsorption of MB was obtained for the bio-adsorbent dosage of 0.4 gram for 50 min, achieving a maximum removal efficiency of 92.4%. The Gaussian 09 software package was used for Density Functional Theory (DFT) to optimize the molecular structures of guaiacol and methylene blue (MB) dye, , with the calculated adsorption energy (Eads = -1.43 Hartree) confirming a thermodynamically favorable interaction. The results revealed that date trunks have great potential as efficient bio-adsorbents for the removal of MB dye from wastewater.
Comparative analysis on isotherm and kinetic modelling for the adsorption of carcinogenic pollutants onto modified graphite intercalation compounds
Industrial, agricultural, and domestic activities have been generating various carcinogenic pollutants and imparting toxic, nonbiodegradable, and long-enduring impacts on both humans and animals, even at low concentrations. This article has been reported for the first time to investigate the kinetics and isotherms models of carcinogenic pollutants including Acid violet 17 (AV17), Mercaptan 1, Humic acid, Phenol and Methylene Blue (MB), which were adsorbed on the surface of NYEX® 1000. The effects of adsorbent dosage and contact time for AV 17 (8.2-70 ppm), contact time (0–180 min), Marcaptan 1 (11.7–100 ppm), contact time (0–180 min), Ethane Thiol (7.5-50 ppm), contact time (0–180 min), Humic acid (21.7-60 ppm), contact time (0–120 min), Phenol (8.8-70 ppm), contact time (0–180 min) and MB (11.7-100 ppm), contact time (0–180 min) were investigated against NYEX® 1000 respectively. The kinetics findings showed the adsorption of Humic acid (R2=0.99908), AV 17 (R2=0.9977), Mercaptan 1 (R2=0.9982), Phenol (R2=0.9989) and MB (R2=0.9966) on the surface of NYEX® 1000 were well described by Pseudo-second order kinetics. The Pseudo-1st order kinetics revealed lower regression coefficient values for all pollutants, confirming it to be least followed. The Isotherm models such as Halsey (R2=0.9971, R2=0.9485) showed the good agreement to describe the equilibrium of AV 17 and Phenol adsorption respectively. On the contrary, equilibrium adsorption of Mercaptan 1, Humic acid and MB on the surface of NYEX® 1000 was found to be well described by Dubinin-Radushkevich with R2= 0.984, 0.9331 and 0.9766 respectively. It would be undoubtedly valuable for achieving a comprehensive explanation of the adsorption process and ultimately enhancing the removal performance.
Copyright (c) 2025 Journal of the Pakistan Institute of Chemical Engineers
Removal of malachite green from aqueous solution using chemically treated activated carbon
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.
Low temperature desulfurization of crude oil using ferric oxide nano catalysts: experimental optimization, performance evaluation, and techno-economic assessment
The present study investigates the desulfurization of heavy and light crude oils using ferric-oxide (Fe₂O₃) nano-catalysts under mild operating conditions, with the goal of developing an energy-efficient, hydrogen-free alternative to conventional hydrodesulfurization (HDS). Laboratory experiments were conducted in a fixed-bed catalytic reactor, evaluating the effects of temperature (35–75 °C), pressure (1.0–1.9 bar), catalyst particle diameter (54–91 nm), and catalytic-bed diameter (1–2.5 cm) on sulfur-removal efficiency. Optimal desulfurization occurred at 55 °C, 1.6 bar, and a bed diameter of 2.5 cm, with 58 nm and 77 nm nanoparticles showing the best performance for heavy and light crudes, respectively. A quadratic regression model developed through analysis of variance (ANOVA) yielded an excellent fit (R² = 0.9997, Adj-R² = 0.9899), validating the model’s predictive capability. Compared with conventional HDS, the Fe₂O₃ nano-catalyst achieved 70–90 % sulfur removal without hydrogen consumption and at less than one-tenth of the energy intensity. A preliminary techno-economic analysis indicated that the heating energy accounts for ~45 k USD yr⁻¹ (≈0.1 kWh kg⁻¹ S removed) for a 1,000 bbl day⁻¹ pilot system. Benchmarking against HDS, oxidative desulfurization (ODS), and bio-desulfurization (BDS) demonstrated the potential of the nano-catalyst process for decentralized or small-scale refinery units. The findings provide a foundation for scaling up low-pressure, low-temperature catalytic desulfurization systems and integrating them with sustainable refining operations.
Effect of grit blasting on electrochemical behavior of anodized AZ31B magnesium alloy
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.
Fabrication of anions exchange membrane (AEM) using Polyvinylidene Fluoride(PVDF) to separate glycine via electrodialysis
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
Effect of Dextrin content in alcohol-based Zircon coating for sand mold applications
Three alcohol-based zircon coating compositions were developed using a variation of dextrin binder for high-temperature steel castings in silica sand molds. The average particle size of zircon sand used in formulating the coatings was measured as 40 microns. The coatings were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), thermal stability testing, surface roughness and permeability measurement. The results demonstrated that increasing the dextrin content principally improved the mold and casting surface finish. There was a significant improvement in an average surface roughness reduction of the mold and by 25% of the casting. The permeability number of the sand mold with coating was reduced by more than 20% of that of the sand mold without coating, which greatly influenced in enhancing the mold-metal interface protection and reducing the casting surface defects. The thermal stability of the coating was observed from 200oC to 1600oC and no cracks and delamination were observed. The findings highlight the potential of dextrin as an effective binder in zircon coatings, optimizing performance for steel casting applications.
China's strategic response to climate change: policies, challenges, and pathways to carbon neutrality
Climate change, driven by greenhouse gas (GHG) emissions, poses a significant threat to China's environment, economy, and society. This review paper examines China's evolving response to this challenge. It explores China's international commitments, including the Paris Agreement and its Nationally Determined Contributions (NDCs) aiming for carbon neutrality by 2060. Additionally, the paper analyzes domestic policies like the 1+N Climate Policy framework, the 14th Five-Year Plan (FYP) for Energy, and the National Emissions Trading Scheme. These policies highlight China's multi-pronged approach, focusing on GHG reduction and a comprehensive energy sector transformation. The paper emphasizes the importance of evaluating these policies for effectiveness and acknowledges the challenges China faces, such as balancing climate goals with economic growth. Ultimately, the paper argues that China's strategic approach signifies a growing recognition of the need for climate action. The success of this approach, coupled with continued advancements in clean energy technologies and international collaboration, will be paramount in achieving carbon neutrality and securing a sustainable future.
Hydrodynamic and thermal analysis of water slugs in super-hydrophobic T-Junction microchannel
Due to the unrealized potential of microfluidic devices and the advancement of computational approaches to examine the design and flow behaviour of these devices, microfluidics has gotten a lot of attention in recent years. The goal of this research was to look at how air-water bubbles passing through a microchannel with a T-junction. To produce different degrees of wettability, the contact angle was changed. The importance of slug flow in micro-channels was highlighted in this study since it was critical for many microfluidic device applications. Micro reactors, microchannel heat sinks, and other similar devices are examples. To explore the production of slugs, a multiphase model was used to follow the air-water interface. First, it was performed a rigorous mesh independence analysis to determine the best ideal mesh for present research without sacrificing accuracy while conserving computational resources. As a result, it was decided on a mesh size of 0.1mm for present research. The 8850 W/m2 continuous heat flux utilized on the walls caused the temperature of the wall to vary along its length. The heat transfer enhancement was measured to cool the wall and increased Nu number due to slug flow. In two-phase settings, slug flow was compared to single phase flow to control the temperature of heated wall and Nusselt number augmentation. Comparison of single-phase flows, slug flow induced a greater fall in wall temperature and an increase in Nusselt number.
Silver doped CeO2 nanocomposites for photo degradation of selected azo dyes
The sol-gel approach was employed to synthesize silver-doped CeO2 nanoparticles exhibiting superior photocatalytic activity under solar light irradiation. The produced catalysts were characterized using techniques such as Fourier transform infrared spectrophotometer (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Dynamic light scattering (DLS) and UV-vis spectrometer. These approaches were also usefulness for analyzing the absorption spectra and the concentration of azo dyes in water at variance of concentrations during the photodegradation experiment. Research results indicated that anatase phase nanoparticles of pure CeO2 and silver (Ag) doped CeO2 have crystallite sizes that range between 15 and 18 nm. The doping was found that Ag/ CeO2 catalyst enhance the performance and light absorption capabilities towards nanoparticles as compared to pure CeO2. Ag/CeO2 nanoparticles are an attractive option for photocatalytic purification of other organic-based wastewater exposed to sun light because of their significant photocatalytic efficacy in visible light, deep catalytic constancy, and reusability for dye photocatalysis.
Mathematical modeling of membrane system for hydrocarbon gas (C1 – C3) recovery in polyethylene plant
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.
Effect of grit blasting on electrochemical behavior of hydroxyapatite coated AZ31B magnesium alloy
Magnesium (Mg) alloys have garnered considerable interest as biodegradable materials for bone fixation implants. In this study, AZ31B Mg alloy substrates were grit-blasted with quartz and alumina particles at varying pressures and subsequently coated with hydroxyapatite via electrodeposition for different durations. Scanning electron microscopy was employed to examine the surface morphology of the hydroxyapatite layer, while potentiodynamic polarization and electrochemical impedance spectroscopy were conducted to assess the layer's nature, coverage, and effectiveness in a simulated body fluid. The findings indicate that longer deposition times led to increased surface coverage. Notably, a capacitive hydroxyapatite layer with a dense inner structure and complete surface coverage was achieved after 40 minutes of deposition on quartz- and alumina-blasted samples at a blasting pressure of 1000 kPa. The findings of this study aid in developing biocompatible coatings on magnesium alloys for bone fixation implants.
Ethylene vinyl acetate (EVA) film reinforced with transparent zirconium oxide (ZrO2) nanoparticles to enhance the durability of solar cells
Solar cells must be more efficient, durable, and long-lasting. In the present work a new approach to improve the EVA films commonly used in solar cells, with transparent Zirconium Oxide (ZrO2) nanoparticles is reported. EVA films were surface modified with transparent Zirconium Oxide (ZrO2) nanoparticles using different techniques: ATR-FTIR, TG, DSC, visual degradation comparison, degradation upon exposure to UVB radiation and thermal stability. This meant the EVA films filled with ZrO2 nanoparticles showed more thermal stability, lesser yellowing, and fewer cracks compared to conventional EVA films. It suggests that reinforcing EVA films by ZrO2 nanoparticles imparts durability and long life in solar cells.
A study of boiling heat transfer via an aqueous solution of commercial-grade engine coolant and pure water
Commercial grade motor radiator coolant is a mixture of glycol, corrosion inhibitors, inorganic compounds, and water. These type of radiator coolants formulations are used to enhance the thermal efficiency and lifespan of internal combustion engines. In this study we added a radiator coolant solution in a distilled water to investigate potential improvements in the heat transfer rate during boiling. Thus, the heat dissipation from a coiled Nichrome wire (electrically operated) was analyzed in open air, pure water, and various concentrations of aqueous coolant solutions. The boiling of coolant aqueous solution at concentrations of 5% wt./wt., 10% wt./wt., 15% wt./wt., and 20% wt./wt. were compared with pure water. In general, a heat transfer coefficient values increases with coolant concentration. For example, at 5% wt./wt., the heat transfer coefficient is 40 W/m²·K, whereas at 20% wt./wt. concentration, it rises to 140 W/m²·K. Moreover, qualitatively the bubble size in pure water is significantly larger than that of bubbles of the coolant solutions. Turbidity and total dissolved solids increase with coolant concentrations, whereas at a 20% wt./wt. concentration, the surface tension decreases to 68.8 mN/m. This study suggests that adding an engine coolant solution into standard boiler feed water or similar cooling system devices will improve the overall heat transfer rate and hence reduces the operational fuel expenses.
Copyright (c) 2024 Journal of the Pakistan Institute of Chemical Engineers
Enhancement of mechanical properties of nano TiO2 epoxy-silicon blend
Polymeric materials are significantly affected by epoxy-based thermosets. Epoxies have a high crosslink density, making them brittle and prone to break. A commercial process known as "polymer blending" creates a new material by combining two or more polymers in varying proportions that have specific desired properties. In this study, the mechanical properties of polymer blends were enhanced by the addition of TiO2 nanoparticles with different parentages, and mechanical and characterization tests were conducted to investigate the changes in the mechanical properties. FTIR spectroscopy showed that the nanomaterial did not cause a chemical change in the polymeric mixture, whereas the mechanical properties improved to a certain extent at low percentages. When the percentage increased, agglomeration occurred in the nanomaterial, leading to a decrease in the mechanical properties, as observed in the SEM tests.
Magnesium extraction from serpentine for carbon capture and storage
This study aims to enhance availability of feedstock for mineral carbonation (MC) and evaluate viability of lizardite found in Pakistan as lizardite has a high reactivity compared to other ultramafic rocks. Leaching experiments were conducted to extract magnesium from heat-activated lizardite. Sulfuric acid (2% solution), hydrochloric acid (2% solution), and nitric acid (2% solution) were used in leaching experiments. The results showed that 71.8%, 65.2%, and 59% magnesium were extracted using H2SO4, HCl, and HNO3 acids, respectively. Mg extraction was highest in H2SO4 dissolution as compared to HCl and HNO3 dissolution. The leaching process was conducted at 25°C with 6 grams of solids using 2% acid solution for 5 hours. Similarly, silicon and iron were also extracted from heat activated lizardite. The findings suggest that lizardite can be a promising raw material for MC, though further studies on reaction kinetics and scaling potential are necessary.
Effect of grit blasting on in-vitro bio-assessment of anodized and electrodeposited HA-Coated AZ31B Magnesium alloy
In this study, AZ31B Magnesium alloy samples were grit blasted with quartz and alumina particles at 1000 kPa blasting pressure to achieve sample roughness. The blasted samples were anodized and electrodeposited HA-coated for 40 minutes to improve the corrosion resistance and biocompatibility. The coating characteristics and composition of the coatings were studied by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis respectively. The thickness of the coatings was measured using optical microscope. The corrosion behavior of the coatings was determined by open circuit potential (OCP) in a simulated body fluid (SBF) solution. The biocompatibility of the coatings was analyzed by bio-assessment using MTT assay. The results revealed that the electrodeposition of HA coating on alumina blasted samples results in best surface morphology, yielding lowest corrosion rate and best biocompatibility with a cell viability about 80% even after 7 days treatment.
Optimizing the operational parameters of nanographene-based cathode electrode in Electro-Fenton process for treatment of textile industry wastewater containing a mixture of dyes
This study aimed to evaluate the effectiveness of the electro-Fenton process in the treatment of textile wastewater using carbon felt modified with graphene nanoparticles as the cathode and a thin film of platinum as the anode. The primary characteristics of wastewater, including COD, color, BOD5, pH, electrical conductivity (EC), and chlorides, were measured. Factors affecting the efficiency of the electro-Fenton process were studied. The optimum conditions were determined as follows: the inlet airflow of 1 (L/min), pH=2.5, the current intensity of 200 mA, and ferrous ion concentration of 1.5 mM. Based on the results maximum system decolorization and COD removal rates were 94.31% in 120 minutes and 57.47% in 30 minutes of reaction respectively. Dye removal efficiency increases due to graphene particles on the carbon felt and increasing surface area. Also, the application of the platinum electrode and the role of this electrode in anode oxidation causes an increase in the efficiency of dye removal. Because the electro-Fenton process is carried out at acidic pH, it is necessary to conduct pH modification on the final effluent of this process.
Tailored polyether sulfone/cellulose acetate based mixed matrix membranes for enhanced crude glycerin purification
Membrane based purification of crude glycerin is of unique importance due to its vast applications in pharmaceutical, polymer and food industries. Polyether Sulfone/Cellulose Acetate Based Mixed Matrix Membranes being reinforced with modified activated carbon has shown enough capability to purify crude glycerin. The membrane is synthesized by phase inversion method by using N-Methyl-2-pyrrolidone (NMP) as solvent and aminopropyl-triethoxycyclene as crosslinker. After adding modified activated carbon as a filler, the membrane is characterized using Fourier Transform Infrared (FTIR) spectroscopy and Thermal Gravimetric Analysis (TGA) to determine the chemistry and mechanical strength of the created membrane, respectively. All membranes' glycerin rejection is investigated using dead end filtration apparatus operating at two bar pressure. The impact of modified activated carbon is also examined by adjusting the filler concentration in a pure mixed matrix membrane solution. As a result, it is noted that the greatest glycerin rejection of 72.7% is achieved at 0.6% weight percentage of activated carbon. Nonetheless, at 0.8% weight of filler, a maximum water flux of 17.8 kg/hr.m2 was attained.