Chemical Engineering
Corrosion
catalyst
reaction kinetics
Experimental Design
19
Scopus Publications
Scopus Publications
Hot-season rise of reflux drum temperature in an atmospheric crude distillation unit: Field impacts on overhead corrosion, flare loading, and loss prevention Ahmed Qasim, Thamer Malik, Ghassan Addai, Shahd Ammar Hatem, Hameed Hussein Alwan South African Journal of Chemical Engineering, 2026 • Field study quantifies hot-season reflux-drum impacts in an atmospheric CDU. • Hotter drum shrinks condenser margin; header pressure and flare loading rise. • Off-gas shifts heavier (C 1 -C 3 down; C 4 -C 5 + up), diverting gasoline to fuel/flare. • Light naphtha gets heavier; IBP 32-40°C, EP 120-140°C; sulfur slightly higher. • Actionable window for loss prevention: 55-60°C with temp-comp neutralizer. This field study quantifies how reflux drum temperature governs the overhead risk posture of an atmospheric crude distillation unit during hot-season operation, with explicit attention to corrosion, flare loading, and economic loss. During a single summer campaign at Al-Diwaniyah Refinery, the drum temperature was stepped from 50 to 70°C and, at each set point, off gas, light naphtha, and boot water were sampled under steady operation. Hotter drum operation reduced partial condenser driving force and shifted the overhead phase split toward vapor, increasing header pressure from 0.57 to 0.82 barg and standard off gas flows from 320 to 360 and from 35 to 50 Nm 3 /h to the furnace and the flare, respectively. Concomitantly, off gas became heavier: C 1 –C 3 fraction contracted from 56.71 to 41.41 mol%, whereas C 4 rose from 25.53 to 36.72 mol% and C 5+ increased from 5.71 to 15.94 mol%. From a loss prevention perspective, this C4–C5+ enrichment, together with the higher flare rate, indicates increased diversion of gasoline-range material to the gas header and flare (avoidable hydrocarbon loss) and higher propensity for flare smoke if assist is not adjusted. Light naphtha specification drifted unfavorably (IBP from 32 to 40°C; EP from 120 to 140°C) with a modest increase in sulfur (from 300 to 312 ppm), tightening blending margins and risking reprocessing. Overhead corrosion risk increased, as boot water chemistry degraded (pH from 6.4 to 6.0; chloride from 10 to 14 ppm; dissolved iron from 0.15 to 0.44 ppm). These field resolved trends define a practical operating window that favors cooler drum targets (approximately 55–60°C), recovery of condenser effectiveness, and temperature-compensated neutralizer control to stabilize aqueous chemistry while minimizing avoidable flaring. The results provide actionable guidance for balancing product quality, energy use, environmental performance, and corrosion risk in hot-climate refining.
Nitrate removal from simulated wastewater by electrocoagulation: Impact of operating parameters on removal efficiency and energy consumption Sata Kathum Ajjam, Marwa Abd Aljaleel, Basheer Hashem Hlihl, Hameed Hussein Awlan South African Journal of Chemical Engineering, 2026 This study concerns the electrocoagulation (EG) process that is used to remove nitrate from simulated wastewater within an electrochemical cell containing a monopolar aluminium four-electrode. There are four effected parameters were chosen as a controllable variable; initial pH, applied potential, electrolysis time, and distance between electrodes, while there to responses were investigated under effect of these variables; nitrate removal efficiency and energy consumption (EC), so the new in this work is the using of four aluminium exchangeable electrodes and the investigation four operation parameters on nitrate removal and energy consumption efficiency as well as the optimization for the system. The range for the chosen studied variables is as follows: 7-11,2-10 volts,30-90 minutes, and 1-3 cm for initial pH, applied potential, electrolysis time, and distance between electrodes, respectively. The results show that nitrate removal efficiency ranged between 79.9 and 93.0 %, where the analysis variation (ANOVA) analysis shows that the electrolysis time is the most significance parameter was effect on the nitrate removal efficiency due to its highest F-value, and followed in effect by distance between electrode, applied potential, and initial pH according to their F-values 29.57, 14.38, and 3.86 for distance between electrodes, applied potential, and initial pH respectively. The energy consumption (EC) results ranged between 1.89- and 6.45 kW hr. m-3. On the other hand, the maximum nitrate removal efficiency is 94.84 % at the optimum conditions at 11, 4.66 volts, 90 minutes, and 1 cm for initial pH, applied potential, electrolysis time, and distance between electrodes correspondingly, while the minimum value for the EC is 0.0508 kW hr. m-3 at 7 initial pH solution, 4.26 volt applied potential, 30 minutes electrolysis time, and 1 cm distance between electrodes.
Synthesis of CoCrNiOx high entropy oxide catalyst and its oxidative desulfurization performance Muntasser Sahib Taha, Hameed Hussein Alwan Applied Chemical Engineering, 2025 The production of ultraclean fuel represents a big challenge for scientists and workers in the petroleum industry because the presence of sulfur in the fuel may have severe consequences for human health and the environment. Oxidative desulfurisation (ODS) is a promising technology when compared with classical hydrodesulfurisation (HDS). In this work, the production of a new catalyst for the ODS process, in which a mixed oxide catalyst was synthesised by mechanochemistry mixing of three metal chlorides (cobalt, nickel, and chromium chlorides), and the atmospheric oxygen was used as an oxidant agent for Iraqi gasoil desulfurisation in an aerobic oxidative desulfurisation (AODS). The prepared catalyst was characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy Dispersive X-ray analysis (EDX). The study included an investigation of the effect of catalyst dosage, reaction temperature, and oxidation time. Response surface methodology (RSM) was used to investigate the performance of the AODS reaction and to evaluate the main impact of the studied variables, as well as the interaction and quadratic effects, for determining the optimum condition. According to the findings obtained from the regression analysis, the experimental data were fitted to a quadratic model with a high correlation coefficient (R² 0.9839), adjusted correlation coefficient (Adj. R² 0.9419), and predicted correlation coefficient (Pred. R² 0.7419). The AODS process was applied with a maximum sulfur removal efficiency of 99% under operating conditions of 0.75 g catalyst dosage, 200 °C reaction temperature, and 60 minutes reaction time. The experimental sulfur removal efficiency was in satisfactory agreement with the predicted efficiency of 98.12%. Analysis of variation (ANOVA) shows that oxidation time is the most significant factor affecting sulfur removal efficiency, followed by reaction temperature and catalyst dosage, as indicated by their F-values.
Enhancing the vanadium recovery from heavy fuel fly ash by using Tri Sodium Citrate as a chelating agent in Alkaline Solution Basheer Hashem Hlihl, Hameed Hussein Alwan, Sata Kathum Ajjam Applied Chemical Engineering, 2025 Sodium carbonate exhibits high selectivity for vanadium and low vanadium recovery rate (43%) from the fly ash of Al-Dura thermal power plant (Baghdad, Iraq) under standard conditions (35°C , 12 hrs, 1M Na2CO3, L/S=10). The recovery increases to 57% in the presence of 0.005M KMnO4. This study explores the role of tri-sodium citrate (0.1M) as a chelating agent in enhancing recovery, achieving up to 85% recovery under the same conditions. Vanadium was precipitated as ammonium metavanadate (NH4VO3) by adjusting pH to 5 using NH4Cl and heating to 50°C for 6 hrs. The precipitate was roasted at 650°C for 2 hrs to obtain vanadium pentoxide (76% purity). The controlling step in vanadium recovery is the chemical reaction rate on the surface of fly ash, as determined by the unreacted-core model. The activation energy for the reaction is (8.47kJ/mole) at a temperature range (35-60°C).
Boosting tungsten -based catalyst activity for aerobic oxidative desulfurization of gas oil by cerium Mohammed AbdulHassan, Hameed Hussein Alwan Results in Engineering, 2024 This study is aimed at investigating the effect of tungsten-based catalysts for aerobic oxidative desulfurization (AODS) for gas oil. Two catalysts tungsten loaded on activated carbon (W/AC) and cerium-tungsten load on activated carbon (Ce–W/AC) were prepared, and they are characterized by Fourier transform infrared spectroscopy FTIR, X-ray diffraction (XRD), Scanning electronic microscopy (SEM), Energy dispersive spectroscopy EDX, and thermal behavior was examined by thermal graphometry analysis (TGA), the surface area was measure by Brunauer-Emmett-Teller (BET) method. The experiments were conducted in a lab-scale reactor. The primary investigation shows that Ce–W/AC was more active than W/AC. The second part examines the effect of reaction temperature, air flow rate, and catalyst dosage on sulfur removal efficiency by using Ce–W/AC, the ranges for the studied parameter are 150–200 °C, 20–60 mL/min, and 0.5–1 g for reaction temperature, air flow rate, and catalyst dosage respectively. The experiments were designed according to the Taguchi method. The experiments results show the sulfur removal efficiency ranged between 72.3 and 99.9. The findings demonstrate that increasing the reaction temperature leads to an increase in sulfur removal efficiency, while the increase in sulfur removal efficiency with air flow rate and catalyst dosage did not continue because it started decreasing after it reached a maximum value According to analysis variance ANOVA demonstrated that the effect of the studied variables ordered the following: reaction temperature air flow rate and finally catalyst dosage via their F-value where these values are 12.27, 4.09, and 0.16 for reaction temperature, air flow rate, and catalyst dosage respectively.
Enhancement of light Naphtha quality using calcite adsorbent from eggshells by adsorptive desulfurization Ahmed Qasim, Hameed Hussein Alwan South African Journal of Chemical Engineering, 2023 The presence of sulfur in transportation fuels has bad consequences for health and the environment, and there are many techniques used for removing or eliminating sulfur content, especially hydrodesulfurization. Hydrodesulfurization is the classical technique for desulfurization, but it is characterized by working at elevated temperatures and pressures as well as high costs. For this, there are many alternative methods, such as adsorptive, oxidative, extractive, and so on. The adsorptive desulfurization (ADS) is one of the most promising methods for sulfur reduction because of its ability to work under ambient conditions and ADS can significantly enhance the quality of light naphtha by reducing its sulfur content and improving its suitability for downstream processes such as catalyst poisoning and corrosion. The calcite prepared from eggshell was investigated here as an adsorbent for sulfur compounds from light naphtha. The adsorbent was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The investigation of adsorbent activity was done by batch adsorption, and the chosen studied variables are temperature, adsorbent dosage, and contact time with ranges of 20–40 C°, 1–3 g, and 15–45 minutes, respectively, which were designed according to the Box–Behnken experimental design and the experiment results were analyzed using Minitab software version 17. The results show that the sulfur-removing efficacy ranged between 45 and 60%, while optimum sulfur removal efficiency is 61% at the following operation conditions: 40°C, 3 grammes, and 45 minutes for temperature, adsorbent dosage, and adsorption time respectively. Adsorption isotherms Langmuir and Freundlich were examined, and the results show the Freundlich isotherm is more suitable to describe the adsorption of these sulfur compounds.
Electrocoagulation Technology for Wastewater Treatment: Mechanism and Applications Prashant Basavaraj Bhagawati, Forat Yasir AlJaberi, Shaymaa A. Ahmed, Abudukeremu Kadier, Hameed Hussein Alwan, Sata Kathum Ajjam, Chandrashekhar Basayya Shivayogimath, B. Ramesh Babu Sustainable Textiles Production Processing Manufacturing and Chemistry, 2022
Preparation, Characterization and Activity of CoMo Supported on Graphene for Heavy Naphtha Hydro-Desulfurization Reaction Iranian Journal of Catalysis, 2021
