Journal of the Pakistan Institute of Chemical Engineers

Low temperature desulfurization of crude oil using ferric oxide nano catalysts: experimental optimization, performance evaluation, and techno-economic assessment

2025-04-27T01:37:17+05:00

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.

Computational and analytical investigation of date trunk biomass as a bio-adsorbent for sustainable removal of methylene blue dye from wastewater.

2025-08-25T10:16:22+05:00

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. The Gaussian 09 software package was used for Density Functional Theory (DFT) to optimize the molecular structures of guaiacol and methylene blue (MB) dye. The results revealed that date trunks have great potential as efficient bio-adsorbents for the removal of MB dye from wastewater.

Integrative water quality index (WQI) based assessment of ground water resources in Punjab, Pakistan

2025-10-10T14:55:59+05:00

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.

Tailored bimetallic Zn/Ni complex of 2, 2’-bipyridine 4,4’-dicarboxylic acid: spectral characterization and demonstrated the potential biological activities

2025-12-03T15:04:24+05:00

Bimetallic complexes have garnered significant attention in the scientific community due to their versatile applications, such as antibacterial, antifungal, antitubercular, antimalarial, antioxidant, antidiabetic, 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 in the control proves the results are valid.