Canadian Journal of Chemical Engineering最新文献

Methylparaben, commonly found as an emerging contaminant in personal care products and pharmaceuticals, have raised concerns due to their potential endocrine-disrupting effects on humans and male fish. Nano-filtration presents a viable alternative for mitigating this contamination. In this paper, the first part explores advances in various methods, each of which facilitates the separation of paraben from aqueous media. In the later experimental segment, the flat sheet membrane module is used for nano-filtration, for different operating parameters. The two NF300 & NF100 membranes are employed to see the efficiency of removal of nethylparaben from synthetic wastewater. The removal efficiency of methylparaben by NF300 membrane is 32.64%, while the removal efficiency by NF100 membrane is 70.46%. The efficiency of the membrane increases with the increase in pressure and decrease in the concentration. The outcome shows nano-filtration is a promising technology for addressing the emerging contaminant methylparaben in waste water.

This study aimed to determine the optimum conditions for the lipolysis of tengkawang fat using lipase derived from frangipani resin to produce free fatty acids, which, particularly stearic acid, serve as key intermediates in various industrial applications. A 2^(4–1) fractional factorial design was used to screen the effects of pH, temperature, enzyme concentration, and buffer-to-fat ratio on the degree of lipolysis. The 5-h reaction yielded a reaction mass of 43.35% of free fatty acids. ANOVA results revealed that pH, enzyme concentration, and their interaction were significant, with curvature present at the centre point. Optimization was then conducted using response surface methodology (RSM) with a face-centred central composite design (FCCCD). The highest degree of lipolysis achieved was 89.54% under the conditions of pH 7, temperature 27°C, enzyme concentration 10%, and a buffer-to-fat ratio of 2:1. Time profile observations showed that the lipolysis reaction proceeded slowly, reaching 89.53% at the end of 24 h.

The fluidization behaviour was investigated using a cold flow bubbling fluidized bed setup with a column of 8 cm inner diameter. Minimum fluidization velocities (U_mf) were experimentally determined for both mono-component (rice husk or coal) and binary mixtures of rice husk and coal, using air as the fluidizing medium. For the binary mixtures, U_mf,m was measured by varying the weight fraction and particle size of coal. It was observed that fluidization performance improved significantly with an increase in the coal weight fraction. Conversely, higher proportions of rice husk led to deteriorated fluidization behaviour due to its low bulk density and irregular particle shape. To predict the U_mf,m for specific mixtures, two empirical correlations were developed for rice husk weight fractions of 20% and 40%. These correlations showed good agreement with experimental results, with relative errors within 7%.

This study presents a hydrogen transfer reaction of 1,2-butanediol (BDO) to nitrobenzene for the simultaneous production of 1-hydroxy butanone and aniline over Cu/SiO₂ catalysts. A series of Cu supported SiO₂ catalysts with Cu loading up to 25 wt.% were prepared by the wet impregnation method. The prepared catalysts were further characterized by various characterization techniques such as X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area, Fourier transform infrared (FTIR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR). The transfer hydrogenation of nitrobenzene through the dehydrogenation of BDO was effectively accomplished rather than hydrogenation of nitrobenzene via external hydrogen due to well dispersed copper nanoparticle on the surface of SiO₂. The present strategy enables the production of two industrially important chemicals in a single step with stoichiometric amount of hydrogen source. Among the series of catalysts, 20 wt.% Cu/SiO₂ catalyst exhibited excellent catalytic performance (89% conversion of BDO and 85% conversion of nitrobenzene). The catalyst also shows very good stability for 9 h during the time-on-stream.

The present study focuses on the production of biodiesel through the transesterification process and investigates the physicochemical properties of grape seed and Kusum oils methyl ester. Optimization of key process parameters, including molar ratio, catalyst concentration, reaction time, and temperature, was conducted for both oils. The effects of these factors on biodiesel production and conversion efficiency were analyzed. A 3 × 3 × 3 completely randomized design asymmetrical factorial approach was used to optimize reaction conditions. A total of 54 experiments were conducted to assess the effect of various parameters on ester recovery efficiency and kinematic viscosity. For grape seed oil methyl ester, optimal conditions were determined to be 0.5 wt.% KOH catalyst, 4:1 molar ratio, a reaction temperature of 60°C, and a reaction time of 60 min, resulting in a yield of 99% grape seed oil methyl ester with a viscosity of 4.25 cSt. In contrast, the optimal conditions for Kusum oil methyl ester included an 8:1 molar ratio, 1.5 wt.% KOH catalyst, a reaction temperature of 60°C, and 60-min reaction time, achieving 95.58% yield of Kusum oil methyl ester with a viscosity of 9.53 cSt. The results indicate that grape seed oil methyl ester is a superior choice compared to Kusum oil methyl ester in terms of biodiesel yield and kinematic viscosity. The physicochemical properties of both esters, including kinematic viscosity, density, flash and fire points, cloud and pour points, and calorific value, met the ASTM D6751 and EN 14214 standards, confirming their suitability as alternative fuels for diesel engines.

This study investigates the impact of incorporating an internal vortex finder in the hydrocyclone overflow to enhance performance in terms of oil concentration using computational fluid dynamics (CFD) techniques. A three-factor Box–Behnken design was employed to evaluate the influence of the internal overflow pipe diameter and the external overflow and underflow diameters. The optimal hydrocyclone configuration, designated as HC-05, features an internal overflow diameter of 10 mm, an external overflow diameter of 17.5 mm, and an underflow diameter of 20 mm. This configuration achieves an overall total efficiency ($��E_T^{\prime }�$) of 90.4% while producing a more concentrated volumetric oil stream from the internal overflow and capturing 99.9% of all sand particles in the underflow.

Numerical simulations were employed to investigate the gas–liquid two-phase flow within a recycling cyclone and the impact of key structural parameters on its separation performance. Using a coupled Reynolds stress model (RSM) for the gas phase and a discrete phase model (DPM) with a discrete random walk (DRW) for liquid droplets, this study analyzed the effects of the recycle line, gap width, baffle plate size, and entrance geometry. Results show that the recycle line significantly enhances separation efficiency, especially at lower inlet velocities. Optimal gap width and baffle plate size are crucial for balancing separation efficiency and operational reliability. While rectangular entrances offer slightly higher separation efficiency than circular ones, they also increase pressure drop. These findings offer valuable guidance for optimizing recycling cyclone design to improve particle separation in industrial settings.

This study investigated the usefulness of measurements from an agitator torque sensor in monitoring the dynamics of suspension polymerization. The main focus was to estimate the viscosity of the reaction mass during polymerization using the agitator torque as a secondary variable. Viscosity is a crucial parameter that plays a vital role in determining the efficiency of the process and the quality of the final product. Accurate viscosity monitoring is essential as it provides valuable insights into the progression of the polymerization process and its dynamic behaviour. This study developed a combined Kalman filter (KF) and fuzzy logic (FL) model to estimate viscosity in real time, addressing the challenges of noise in torque measurements. Experimental validation showed that the KF-fuzzy model improved the accuracy and stability of viscosity predictions, particularly during the critical stages of polymerization. This approach enables better monitoring of reaction dynamics, thereby supporting process optimization and control.