South African Journal of Chemical Engineering最新文献

{"title":"A comprehensive review on natural convection in various shaped enclosures by FEM: Engineering applications","authors":"Asif Hasan,&nbsp;Mohammad Mokaddes Ali,&nbsp;Shakhawat Hossain,&nbsp;Neamul Haque Siam,&nbsp;Asaduzzaman Rony,&nbsp;Al-Amin Shohan","doi":"10.1016/j.sajce.2025.08.009","DOIUrl":"10.1016/j.sajce.2025.08.009","url":null,"abstract":"<div><div>Natural convection within enclosed cavities plays a critical role in heat and mass transfer across a wide range of engineering applications. Buoyancy flows are a fundamental aspect of many optimized systems currently deployed, including passive cooling of electronic devices, thermoregulation of solar collectors, and insulation of buildings to store energy used by aerospace systems. Recent advancements in nanofluids, magnetohydrodynamics (MHD), and smart materials have increased the functional applicability of natural-convection-based systems, and modern forms of the Finite Element Method (FEM) have become essential in the accurate modelling of heat and fluid flow in geometrically complex enclosures. The review explores the dynamic fields in detail but with particular focus on how they are applicable in heat exchangers in industry, microfluidic devices, biomedical incubators, and environmental ventilation systems. The review further explores localized heat sources, vortex formation due to embedded obstacles, porous media effects, and the synergistic influence of thermal and magnetic fields. This review investigates how integrating the Finite Element Method (FEM) with artificial intelligence, entropy-based optimization, and experimental validation can transform the design and advancement of next-generation thermal management systems. The findings underscore FEM’s utility as a multi-physics simulation tool for real-world thermal challenges, with particular relevance to South Africa’s growing demand for energy-efficient buildings, renewable energy solutions, and sustainable manufacturing technologies.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 308-334"},"PeriodicalIF":0.0,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water hyacinth derived activated carbon electrode materials for water defluoridation using capacitive deionization technology","authors":"Hassan Johnson Kalilo ,&nbsp;Joyce Elisadiki ,&nbsp;Maheswara Rao Vegi ,&nbsp;Said Ali Hamad Vuai","doi":"10.1016/j.sajce.2025.08.013","DOIUrl":"10.1016/j.sajce.2025.08.013","url":null,"abstract":"<div><div>Safe water is a vital component of human life that requires purification to reduce the concentration of ionic pollutants using appropriate water treatment techniques, such as capacitive deionization (CDI) water treatment technology. The porous activated carbon electrode materials have prepared via the carbonization of water hyacinth plants followed by chemical activation using KOH at different temperatures (400-700°C with an increment of 100°C) labeled as CWH-400, WHAC-500, WHAC-600 and WHAC-700 all being activated for 1 h where CWH represents carbonized water hyacinths and WHAC represents water hyacinths activated carbon. The activation temperature has a significant effect on the specific surface area of the porous carbon prepared, as it increases from 464.67 m²/g for CWH-400 to 1020.01 m²/g for WHAC-700. The defluoridation experiments were done using water samples with initial fluoride concentrations of 4.21, 4.61 and 3.51 mg/L for water samples from Arusha (A), Manyara (B) and Shinyanga (C) respectively when the 2 V was supplied to the cell with 10 mL/min flow rate at 3 hours charging time. The defluoridation results were 1.28, 1.37, and 1.15 mg/L for water samples A, B, and C, respectively. The WHAC-700 electrode was found to possess a capacitance of 501.89 F/g, exhibiting removal efficiencies of 69.60%, 70.28%, and 67.24% for water samples from Arusha (A), Manyara (B), and Shinyanga (C), respectively, at a potential of 2 V with a charging time of 3 hours. Therefore, the water hyacinth plants are suitable precursors for preparing porous activated carbon electrodes to be used in a CDI cell for the defluoridation of any water sample.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 357-370"},"PeriodicalIF":0.0,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The potential of the Bland-Altman method in chemical engineering","authors":"Mrs.Cecilia M. Botha ,&nbsp;Shawn C. Liebenberg ,&nbsp;Frederik H. Conradie ,&nbsp;Mr.Abraham F. van der Merwe","doi":"10.1016/j.sajce.2025.08.012","DOIUrl":"10.1016/j.sajce.2025.08.012","url":null,"abstract":"<div><div>Statistical methods play a crucial role in the analysis and interpretation of complex data in chemical engineering research. However, parametric statistical approaches may not always suffice in addressing the intricacies of data analysis within design, process modelling and process development. This paper explores the application potential of less conventional statistical methods in the context of chemical engineering. The application potential of these methods will be demonstrated using recent findings from a study conducted on a low-flux flue gas desulphurisation circulating fluidised bed (FGD-CFB). We analysed the solids flux measurements in a novel, low-flux CFB system by using a less conventional statistical technique, the Bland-Altman method, and verifying the findings using the Kruskal-Wallis test. This statistical analysis validated a non-isokinetic solids sampling technique for low-flux dry and semi-dry FGD-CFBs. This case study demonstrates the applicability of this statistical method within chemical engineering, highlighting its potential beyond its traditional use in medical research. Importantly, the focus of this contribution lies not on the specific findings of the case study, but on the methodologies employed therein. This paper aims to be an educational piece to inform the chemical engineering researcher on how and why this less-used-within-engineering statistical method may be applied. It highlights the potential of utilising statistical approaches that are typically used outside the context of engineering in addressing practical engineering challenges. This paper emphasises the applicability of this statistical method in providing valuable insights into complex engineering systems. It is guided by a systematic inquiry aimed at assessing the statistical methods’ suitability for different types of data sets. By embracing this method, chemical engineers can potentially unlock new insights for research and development, facilitating innovation, sustainability, and advancement in the field.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 348-356"},"PeriodicalIF":0.0,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Life cycle assessment of facile applicable biodiesel production","authors":"Mohamed A. Hanafy ,&nbsp;Rehab M. Ali ,&nbsp;Abdallah S. Elgharbawy ,&nbsp;Ahmed I. Osman ,&nbsp;Mohamed A. Farrag ,&nbsp;Abdulaziz H. Al-Anazi","doi":"10.1016/j.sajce.2025.08.011","DOIUrl":"10.1016/j.sajce.2025.08.011","url":null,"abstract":"<div><div>Biodiesel is crucial for mitigating fossil fuel depletion and reducing environmental impacts. Herein, this approach represents a life cycle assessment (LCA) of biodiesel production from waste cooking oil (WCO) utilizing potassium carbonate (K₂CO₃) as a heterogeneous catalyst instead of potassium hydroxide (KOH), which is the most used catalyst in industry. However, KOH requires a 20% methanol and a 66% reaction time, higher than K₂CO₃. Besides, KOH is used once, and produces impure biodiesel and glycerol. While K₂CO₃ can be used, recovered and reused twice, which decreases the net required catalyst amount without a significant decrease in biodiesel production yield, decreases the environmental burdens, and produces purer products. When using WCO or high free fatty acid (FFA) oils, K₂CO₃ has the advantage of effective direct transesterification, while KOH requires post-treatment process (esterification), which means extra usage of methanol besides the acid catalyst, which is commonly H₂SO₄, to decrease the FFA content and avoid the saponification reaction. Therefore, this research aims to quantify the environmental burdens of biodiesel production and compare the performance of K₂CO₃ with that of conventional KOH. Using the ReCiPe method in SimaPro 9.5 software, the LCA adheres to ISO 14040 and 14044 standards. Key findings indicate significant impacts in climate change (0.274 kg CO_2,eq), human non-carcinogenic toxicity (0.12 kg 14-DCB_eq), terrestrial ecotoxicity (0.536 kg 14-DCB_eq), and fossil resource scarcity (0.183 kg oil_eq). Methanol and K₂CO₃ are identified as major contributors to environmental burdens. In contrast, KOH demonstrates a less environmental impact compared to K₂CO₃. The economic study revealed that, for producing 250 thousand tons of biodiesel per year, the total CAPEX needed to build up the plant is around 12 M$ for both catalysts. The results proved that using K₂CO₃ leads to higher net profits. The study revealed that the biodiesel plant would achieve a remarkable net profit using any type of catalyst, with an advantageous economic indicator for K₂CO₃ over KOH, proving the high profitability of using K₂CO₃ as a catalyst.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 291-307"},"PeriodicalIF":0.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green synthesis, characterization, antibacterial, and antifungal activity investigation of zinc oxide nanoparticles using Verbascum Sinaiticum leaf extract","authors":"Berie Kumie ,&nbsp;Walelign Wubet ,&nbsp;Tadesse Bizuayehu ,&nbsp;Hailemichael Tegenu ,&nbsp;Melesse Ababay ,&nbsp;Aklilu Melese","doi":"10.1016/j.sajce.2025.08.007","DOIUrl":"10.1016/j.sajce.2025.08.007","url":null,"abstract":"<div><div>In this study, zinc oxide nanoparticles (ZnO NPs) were eco-friendly synthesized using <em>Verbascum sinaiticum</em> leaf extract (VSPLE). The amount effects such as pH adjusted at (4, 6, 7, 8, 10 and 12), zinc acetate concentration (0.1, 0.2, 0.3, 0.05, and 0.025 M), reaction temperature (20, 40, 60, 80 and 100 °C), reaction time (20,40, 60, 80, 100, 120, and 140 min), and plant extract volume(1, 2, 3, 4, and 5 mL). The synthesized nanoparticles were characterized by using SEM, TGA/DTA, XRD, UV-Vis, and FT-IR spectroscopic techniques. The SEM analysis revealed that the synthesized ZnO NPs exhibited a rod-shaped morphology, and a total weight loss of 15.29 % observed at 24-544 °C in the TGA/DTA analysis, with no further weight loss above 544 °C, confirmed the high thermal stability of ZnO NPs. The XRD analysis confirmed the formation of small sized ZnO NPs with an average crystal size of 52.9 nm. The UV-Vis analysis revealed the absorption of ZnO NPs at 400 nm, and the characteristic band observed in FT-IR analysis at 635 cm⁻¹ for Zn-O stretching confirmed the formation of ZnO NPs. The biosynthesized ZnO NPs demonstrated a significant in vitro antimicrobial activity as evidenced by the inhibition zone sizes against one Gram-positive <em>S. aureus</em> (17.10 ± 0.17) and two Gram-negative bacteria <em>K. pneumoniae</em> (14.17 ± 0.29), and <em>E. coli(12.83 ± 0.29</em>) at 10 mg/mL using the disc diffusion method. It also showed good antifungal activity against <em>Candida ethanolica (</em>6.90 ± 0.10) and <em>Saccharomyces cerevisiae (</em>6.00 ± 0.10), support the potential of plant-mediated nanoparticle synthesis as a promising route for developing biocompatible antimicrobial agents.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 277-290"},"PeriodicalIF":0.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144885854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical characterization and antimicrobial potential of purified aceh patchouli oil (Pogostemon cablin Benth.) residue for floor cleaning product innovation","authors":"Syaifullah Muhammad ,&nbsp;Nadia Isnaini ,&nbsp;Binawati Ginting ,&nbsp;Hanifa Rifdah Aiman ,&nbsp;Ernawati ,&nbsp;Vicky Prajaputra ,&nbsp;Elly Sufriadi","doi":"10.1016/j.sajce.2025.08.010","DOIUrl":"10.1016/j.sajce.2025.08.010","url":null,"abstract":"<div><div>Patchouli oil residue, a by-product of vacuum distillation, remains underutilized despite its bioactive compound content. This study aimed to characterize the residue using Gas Chromatography–Mass Spectrometry (GC-MS), purify iron (Fe) contamination using activated carbon, evaluate its antimicrobial and antifungal activities, and formulate it into a floor-cleaning soap. GC-MS analysis identified patchouli alcohol (57.19%) as the dominant compound. Purification using 5 g of activated carbon for 3 hours reduced Fe content from 10.351 mg/L to 4.062 mg/L (60.7% reduction), improved residue clarity, and eliminated naphthalene, a potential contaminant. The purified residue exhibited strong antibacterial activity against <em>Staphylococcus aureus</em> (13.28 mm ± 1.38) and moderate activity against <em>Escherichia coli</em> (7.02 mm ± 0.23), as well as strong antifungal activity against <em>Candida albicans</em> (14.88 mm ± 2.88). The formulated floor-cleaning soap met Indonesian National Standard (SNI 1842:2019) for pH, viscosity, specific gravity, foam stability, and homogeneity. It retained bioactivity with inhibition zones of 15.89 mm (<em>S. aureus</em>), 6.00 mm (<em>E. coli</em>), and 10.89 mm (<em>C. albicans</em>), showing enhanced antibacterial activity against <em>S. aureus</em> compared to the purified residue, but slightly lower activity against <em>E. coli</em> and <em>C. albicans</em>. These findings confirm that the formulated product not only meets national standards but also offers antimicrobial functionality. This study contributes a sustainable and scientific approach to valorizing agro-industrial waste into a value-added floor-cleaning product with confirmed antimicrobial and antifungal efficacy, aligning with green chemistry and circular economy principles.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 335-347"},"PeriodicalIF":0.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Removal of sulfur compounds from sour gas using metal nano-absorbents: Process optimization","authors":"Mehdi Sedaghat,&nbsp;Farshad Farahbod","doi":"10.1016/j.sajce.2025.08.008","DOIUrl":"10.1016/j.sajce.2025.08.008","url":null,"abstract":"<div><div>Sour gas, a natural gas laden with significant quantities of the highly toxic and corrosive hydrogen sulfide (H2S), presents substantial environmental and economic challenges due to its sulfur content. This study explores the potential of nanotechnology to enhance hydrogen sulfide removal from sour gas. The corrosive nature of sulfur compounds necessitates substantial investments in equipment maintenance and protection, particularly within gas pipelines and storage facilities. The removal or reduction of sulfur compounds, including H2S, associated with oil and gas operations offers significant economic, environmental, and health benefits. A hybrid adsorption and magnetic field approach was employed to capture H2S from natural sour gas. The application of a magnetic field elevated the operating temperature, influencing the mobility of carbon nanotubes within the nanofluid and the nanofluid layer. Consequently, a current of 1.5 amperes resulted in a 4.8 % increase in mass transfer coefficient and a 3.6 % increase in mass flow rate. Based on the results of the analysis of variance (ANOVA), as well as the comparison of predicted and experimental data and residual plots, the degree of validity of the predicted model is considered satisfactory. This research demonstrates that the R² coefficient is 0.9972 and the Adjusted R² coefficient is 0.9948.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 266-276"},"PeriodicalIF":0.0,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum mechanical investigation of polypyrrole-MXene nanocomposite as an electrode material for magnesium-ion batteries","authors":"Anthony Chidi Ezika ,&nbsp;Williams Kehinde Kupolati ,&nbsp;Emmanuel Rotimi Sadiku ,&nbsp;Gbolahan Joseph Adekoya","doi":"10.1016/j.sajce.2025.08.006","DOIUrl":"10.1016/j.sajce.2025.08.006","url":null,"abstract":"<div><div>The current challenge in energy storage technologies lies in identifying efficient electrode materials for Magnesium-ion (Mg-ion) batteries, motivating the exploration of the energy storage capabilities of Polypyrrole-MXene (Ti₂CO₂) nanocomposites as a potential solution to enhance battery performance. Hence, in this paper, quantum mechanical simulations were employed to examine the capability of energy storage of Polypyrrole-MXene (Ti₂CO₂) filled nanocomposite. The electronic structures, adsorption energies, and adsorption site of Mg@PPy/MXene (Ti₂CO₂) nanocomposite were investigated. The results reveal that Mg-ions on MXene/PPy nanocomposite have a very high adsorption energy of -0.84 eV. The distance of Mg-ion adsorption from the MXene’s surface at the bridge site is 2.75 Å. However, its distance from the PPy is considerably farther at 2.83 Å. The electron difference study, using the charge transfer analysis, revealed that physisorption is the dominating adsorption mechanism for the Mg-ion in the system. The electrode's propensity to transport electrons during the electrochemical reaction is shown by the projected density of state (PDOS), and its energy bandgap is 0.05. Consequently, the MXene (Ti₂CO₂) /PPy nanocomposite might be used as an Mg-ion electrode in battery applications.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 501-505"},"PeriodicalIF":0.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review of the co-pyrolysis of low-rank coals and microalgae biomass for fuel production","authors":"Hope Baloyi ,&nbsp;Bilal Patel","doi":"10.1016/j.sajce.2025.08.005","DOIUrl":"10.1016/j.sajce.2025.08.005","url":null,"abstract":"<div><div>This review comprehensively examines recent advancements in the co-pyrolysis of low-rank coal and microalgae biomass. The co-pyrolysis process aims to improve coal conversion efficiency and enhance the quality of pyrolysis products while integrating renewable biomass to facilitate cleaner fuel production. The article highlights significant research progress in coal-microalgae pyrolysis studies, concentrating on pyrolysis reactions and the underlying reaction mechanisms involving low-rank coals and various microalgae species. Key factors influencing product yield distribution, such as feedstock composition, pyrolysis temperature, heating rate, catalyst use, and reaction time, are analysed in detail. The findings indicate that optimising the blend ratio between coal and biomass substantially enhances bio-oil yield, while pyrolysis temperature significantly impacts product distribution. The heating rate is crucial for promoting pyrolysis reactions, and catalysts play a vital role in improving the efficiency of the co-pyrolysis process, particularly by increasing oil yield and improving its quality. Furthermore, the combined effect of pyrolysis temperature and blend ratio greatly influences char properties. The review concludes by emphasizing both the challenges and opportunities in implementing co-pyrolysis technology for low-rank coal and microalgae biomass, while also offering future perspectives on the practical application of this novel process.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 216-230"},"PeriodicalIF":0.0,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144829900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freeze- and oven-drying of red ginger juice (Zingiber officinale var. Rubrum): A comparative study on physicochemical properties, bioactive retention, and microstructural characteristics","authors":"Maisaroh ,&nbsp;Lusiana Kresnawati Hartono ,&nbsp;Olivia Bunga Pongtuluran ,&nbsp;Priyo Atmaji ,&nbsp;Sri Yuliani ,&nbsp;Wahyu Bahari Setianto ,&nbsp;Elvi Restiawaty ,&nbsp;Yazid Bindar","doi":"10.1016/j.sajce.2025.08.004","DOIUrl":"10.1016/j.sajce.2025.08.004","url":null,"abstract":"<div><div>This study evaluates the influence of drying methods and oven drying temperatures on the physicochemical properties, bioactive compounds, and microstructure of red ginger (<em>Zingiber officinale</em> var. <em>Rubrum</em>) juice powder. Two drying techniques were applied, freeze-drying (FD) and oven-drying (OD) at 40 °C to 80 °C. FD preserved the highest levels of bioactive compounds, particularly 6-gingerol, but required prolonged drying (63.0-72.0 hours) and yielded lower product mass. In contrast, OD at 50 °C provided the best compromise between processing efficiency (9.3-10.0 hours) and quality retention, maintaining high levels of total phenolic content (TPC), 6-gingerol, and antioxidant activity. Drying at ≥ 60 °C caused 6-gingerol degradation into 6-shogaol, reducing antioxidant capacity and altering color due to Maillard reactions. Scanning electron microscopy (SEM) revealed that FD retained intact microstructures, whereas OD at higher temperatures induced porosity and fragmentation. Overall, OD at 50 °C is recommended as a practical and effective method for producing high-quality red ginger juice powder on an industrial scale.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":"54 ","pages":"Pages 254-265"},"PeriodicalIF":0.0,"publicationDate":"2025-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144865146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}