Chemical Process Design
Volume:2 Issue: 2, Dec 2023

Separation of binary amalgamation of Acetone and Chloroform is not possible by ordinary distillation methods due to the existence of maximum boiling azeotrope. In this study, Pressure swing distillation (PSD) and Extractive distillation (ED) have been employed to separate this mixture. The trouble is the considerable energy consumption by distillation towers. In this article, feed splitting approach has been used for heat integration of the process. In addition, exergy analysis has been used in order to achieve a more precise evaluation and more appropriate comparison between the processes. The results have demonstrated that PSD is not a practical and effective approach to separate this mixture, since the azeotropic point does not change with the pressure fluctuations exerted in this process. Furthermore, according to the obtained results, ED process which is including feed splitting approach has abated the amount of hot utility, cold utility and exergy loss by 19.28%, 19.62% and 65% respectively.

The 10th Refinery of the South Pars Gas Complex in Iran experienced a notable decrease in gas production due to the formation of deposits in the cold box. To tackle this issue, a comparison of data was conducted before and after the refinery's annual turnaround. After extensive investigations, it was determined that the Xylene solvent wash was the most suitable solution to address the cold box pressure drop in the ethane recovery unit. The scale of the cold box studied in this article is significant in terms of dimensions and flow rate. The Phase 19 gas plant encountered the issue in interesting way according to limitations such as large-scale continuous production. A chemical wash procedure was designed and implemented during the refinery shutdown, which resulted in a successful reduction in the cold box pressure drop and an increase in production rate by approximately 188 tons/hour. This led to a yearly revenue increase of approximately 387 million USD, emphasizing the significance of addressing deposit buildup in cold boxes to maintain optimal gas production and achieve substantial financial gains.

An extremely sensitive and selective electrochemical sensor based on anatase TiO2 nanosheet hierarchical spheres (TiO2NSHSs), Pt nanoparticles (PtNPs), carbon paste electrode (CPE) and 2,3-dihydro-2-(3,4-dihydroxyphenyl) quinazolin-4(1H)-one (DHP) for determination of isoprenaline (IP) in the presence of phenobarbital (PB) was developed. The excellent synergistic effect of TiO2NSHSs, PtNPs and DHP showed significantly enhanced electrocatalytic activity for IP and PB. In order to characterize the developed nanosensor, the scanning electron microscope (SEM), electrochemical impedance spectroscopy (EIS) and voltammetry were used. Electrochemical behavior of the DHP/PtNPs/TiO2NSHSs/CPE sensor studied using differential pulse voltammetry (DPV), cyclic voltammetry (CV) and EIS. Several effective parameters were investigated and optimized on the nanosensor response. The proposed sensor, under the optimized conditions, showed two linear dynamic ranges from 0.05- 20.0 µM and 20.0-900.0 µM with a low detection limit of 7.0 nmol.L −1 for IP determination. Finally, the modified sensor was employed to determine the analytes in human blood plasma with ±0.3% error. Validation of the proposed method was performed using high-performance liquid chromatography (HPLC).

In this work, the structure of a poly ether block amide (PEBA) polymeric membrane was investigated using molecular simulation study. This membrane performance for the separation of CO2 from N2 was evaluated. In this regard, the density and fractional free volume (FFV) for this membrane were calculated and compared with experimental data. The results showed the conformity of the molecular simulation results with experimental work results. In addition, the mobility of PEBA chains and its polyether and polyamide parts were measured on a molecular scale which cannot be measured on a laboratory scale. Then the diffusion and solubility coefficients of gases were determined for this membrane and the permeability of CO2 and CO2/N2 selectivity were calculated. The performance properties of the simulated membrane showed that, solubility has a greater role in CO2/N2 selectivity than diffusivity in this membrane, so that CO2 permeability and CO2/N2 selectivity were 116.9 and 130 Barrer, respectively.

Produced water (PW) is the largest by-product of oil and gas production, which has a serious impact on water pollution in the offshore oil and gas industry. In industrial processes, it is necessary to separate hydrocarbons and oil along with water by methods such as gravity sedimentation, enhanced gravity sedimentation, and hydrocyclones from produced water. However, conventional technologies cannot achieve optimal separation requirements in a compact space under extreme conditions, such as emulsions and large volumes of PW. The PW treatment system must be green and efficient in order to benefit from the extensive exploration, production of offshore oil and gas in the future. Therefore, factors such as improving the purification efficiency, reducing the space occupation and the cost of practical use of a PW purification process on an offshore operational scale along with the new method of Combined fibers coalescence were investigated according to the operational works that have been don successfully.

This study focuses on the synthesis and characterization of hematite nanoparticles using the ball milling process. The research investigates the changes in microstructure and magnetic properties of the powders during the milling process using XRD, SEM, TEM, and VSM techniques. The crystallite size is determined through XRD patterns using Scherer methods. It is found that the particle size decreases and lattice parameters with extended milling times. XRD and TEM analysis estimate the average particle size of the hematite nanoparticles to be around 30 nm and 12 nm, respectively. The SEM image shows uniform dispersion and a spherical morphology. The magnetic saturation increases as a result of the ball milling process, and the VSM results indicate that the saturation magnetic value increases with longer milling times. The morphology of the particles is predominantly spherical or semi-spherical. The study concludes that the shape and size of the synthesized particles are influenced by the milling time parameter. Both SEM and XRD results highlight the significant influence of milling time on the shape and size of the synthesized particles.