Pub Date : 2024-10-01DOI: 10.1016/j.sajce.2024.09.011
Dried sewage sludge is an appealing biomass fuel for industrial kilns, because of its availability, affordability and has a positive effect on improving the symbiotic sustainable circularity of liquid waste treatment plants. The study investigated the fuel characteristics (efficiency, environmental and human safety) of biochar produced from sewage sludge for utilization as heating energy and compared the fuel performance to charcoal produced from wood sources using the Water Boiling Test method and X-ray Fluorescence Spectroscopy. Biochar briquette with equal ratio of carbonized sludge and wood shavings grants a solid fuel with good quality in terms of the burning rate (10.51 g/min.), specific fuel consumption (107.13 g/l) and emission levels of CO (59.64 g kg-1 of fuel) and PM2.5 (4.76 g kg-1 of fuel). This fuel compared favourably with other biomass fuels used in Ghana. Also, no adverse impact on the environment and human health was observed in the use of the biochar with the low air quality index (35.23) recorded when the fuel is used in a well-ventilated cooking environment as well as showed low potential ecological risk (121.54) in terms of the heavy metals in the residual ash when disposed of in the soil. The positive energy balance (2.35 MJ/kg) of the production is indicative the potential carbon savings.
{"title":"Production of sustainable fuel briquettes from the co-carbonization of sewage sludge derived from wastewater treatment and wood shavings as a sustainable solid fuel for heating energy","authors":"","doi":"10.1016/j.sajce.2024.09.011","DOIUrl":"10.1016/j.sajce.2024.09.011","url":null,"abstract":"<div><div>Dried sewage sludge is an appealing biomass fuel for industrial kilns, because of its availability, affordability and has a positive effect on improving the symbiotic sustainable circularity of liquid waste treatment plants. The study investigated the fuel characteristics (efficiency, environmental and human safety) of biochar produced from sewage sludge for utilization as heating energy and compared the fuel performance to charcoal produced from wood sources using the Water Boiling Test method and X-ray Fluorescence Spectroscopy. Biochar briquette with equal ratio of carbonized sludge and wood shavings grants a solid fuel with good quality in terms of the burning rate (10.51 g/min.), specific fuel consumption (107.13 g/l) and emission levels of CO (59.64 g kg<sup>-1</sup> of fuel) and PM<sub>2.5</sub> (4.76 g kg<sup>-1</sup> of fuel). This fuel compared favourably with other biomass fuels used in Ghana. Also, no adverse impact on the environment and human health was observed in the use of the biochar with the low air quality index (35.23) recorded when the fuel is used in a well-ventilated cooking environment as well as showed low potential ecological risk (121.54) in terms of the heavy metals in the residual ash when disposed of in the soil. The positive energy balance (2.35 MJ/kg) of the production is indicative the potential carbon savings.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.sajce.2024.10.001
In the present work, artificial neural network (ANN) is applied for the estimation of acetic acid yield for 3 different species of Acetobacters like, Acetobacter pasteurianus (NCIM 2104), Acetobacter aceti (NCIM 2116) and Acetobacter xylinum (NCIM 2526). Though there is open literature mentioning acetic acid and ANN can be found, they hardly describe the usage of ANN in prediction of fermentation based acetic acid production. Indeed, a deep dearth of existing literature is felt in this area to develop a robust ANN model to predict the yield of biologically obtained acetic acid and this work is a step towards bridging that research gap. The performance of the model has been estimated with R2 (0.992, 0.988 and 0.992, respectively for the mentioned microbial species) and RMSE (0.0287, 0.034 and 0.020, respectively for the same species). The most relevant operating parameters like, temperature, agitator speed, concentrations of supplemented yeast extract and tryptone, have been considered to carry out fermentation on cheese whey permeate containing fermentable lactose (48.5 g L-1) to transform into acetic acid. Outcome datasets obtained from rigorous experimental investigations performed on the direct fermentative production of acetic acid are trained in the ANN model to predict the product yield. Such machine-learning methodology encourages reasonably accurate prediction of product generation which is extremely tough to obtain through classical analytical processes.
在本研究中，人工神经网络（ANN）被用于估算 3 种不同的醋酸菌（如巴氏醋酸杆菌（NCIM 2104）、醋酸杆菌（NCIM 2116）和木质醋酸杆菌（NCIM 2526））的醋酸产量。虽然有公开文献提到了醋酸和 ANN，但几乎没有描述 ANN 在预测发酵法醋酸生产中的应用。事实上，在这一领域，现有文献对开发一个稳健的 ANN 模型来预测从生物中获得的醋酸产量的研究十分匮乏，而本研究正是朝着弥补这一研究空白迈出的一步。该模型的性能估计值为 R2（上述微生物物种分别为 0.992、0.988 和 0.992）和 RMSE（同一物种分别为 0.0287、0.034 和 0.020）。在对含有可发酵乳糖（48.5 g L-1）的奶酪乳清渗透液进行发酵以转化为醋酸的过程中，考虑了最相关的操作参数，如温度、搅拌器速度、补充酵母提取物和胰蛋白胨的浓度。从直接发酵生产醋酸的严格实验研究中获得的结果数据集，通过在 ANN 模型中进行训练来预测产品产量。这种机器学习方法有助于合理准确地预测产品生成量，而通过传统分析过程很难获得这种预测结果。
{"title":"Application of neural network in prediction of acetic acid yield by Acetobacters","authors":"","doi":"10.1016/j.sajce.2024.10.001","DOIUrl":"10.1016/j.sajce.2024.10.001","url":null,"abstract":"<div><div>In the present work, artificial neural network (ANN) is applied for the estimation of acetic acid yield for 3 different species of <em>Acetobacters</em> like, <em>Acetobacter pasteurianus</em> (NCIM 2104), <em>Acetobacter aceti</em> (NCIM 2116) and <em>Acetobacter xylinum</em> (NCIM 2526). Though there is open literature mentioning acetic acid and ANN can be found, they hardly describe the usage of ANN in prediction of fermentation based acetic acid production. Indeed, a deep dearth of existing literature is felt in this area to develop a robust ANN model to predict the yield of biologically obtained acetic acid and this work is a step towards bridging that research gap. The performance of the model has been estimated with R<sup>2</sup> (0.992, 0.988 and 0.992, respectively for the mentioned microbial species) and RMSE (0.0287, 0.034 and 0.020, respectively for the same species). The most relevant operating parameters like, temperature, agitator speed, concentrations of supplemented yeast extract and tryptone, have been considered to carry out fermentation on cheese whey permeate containing fermentable lactose (48.5 g L<sup>-1</sup>) to transform into acetic acid. Outcome datasets obtained from rigorous experimental investigations performed on the direct fermentative production of acetic acid are trained in the ANN model to predict the product yield. Such machine-learning methodology encourages reasonably accurate prediction of product generation which is extremely tough to obtain through classical analytical processes.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.sajce.2024.10.002
To maintain the huge demand of the overgrowing population of this globe nowadays, we are extremely dependent on various synthetic plastic materials. Hence, every moment, both industries and mankind generate a huge amount of plastic waste, which has lately been recognized as a breakneck for the total environment. Therefore, to solve this particular problem, it is very crucial to replace fossil-based synthetic plastic materials with biopolymers for viable environmental protection. However, the scheming of biopolymers from their natural sources has been recognized as an immense challenge in the earlier few decades owing to the insufficiency regarding the critical understanding of the handling of starting materials. Yet, scientists have been exasperating to improve a new route of production of bioplastic and polymeric materials to solve this issue. However, in this work, we focus on the sustainable/green route of bio-nanocomposite film production from agro-waste biomass. Whereas the raw fibers and crystalline nanocellulose (CNC) were extracted from the rachis of bananas (M. oranta). Inversely, the solid polylactic acid (PLA) was purified by dissolving in a particular organic solvent (like chloroform) for better nanocomposite fabrication. Then, by employing the prominent EIPS method, the CNC-PLA bionanocomposite films were fabricated to improve their overall properties. The specimens were characterized by FTIR-ATR, TGA, DTA, DTG, SEM, XRD, and BDA analysis. The observed outcomes recommended that the newly manufactured biopolymeric CNC-PLA films have greater thermal steadiness up to 600°C, a relatively higher crystallinity index value (about 86.09±0.001%), possess considerable active binding sites like OH, COOH, C-O-C, NH, etc., and exhibit good surface morphology and biodegradability. Due to these outstanding properties, the newly produced CNC-PLA bionanocomposites would be beneficially used in bulk-scale industrial, engineering, and bio-medical sectors as a sustainable replacement for the existing fossil-based hazardous synthetic ones to develop a green and healthy environment.
{"title":"Fabrication and characterization of environmentally friendly biopolymeric nanocomposite films from cellulose nanocrystal of banana M. Oranta (Sagar kala) tree rachis fibers and poly lactic acid: A new route","authors":"","doi":"10.1016/j.sajce.2024.10.002","DOIUrl":"10.1016/j.sajce.2024.10.002","url":null,"abstract":"<div><div>To maintain the huge demand of the overgrowing population of this globe nowadays, we are extremely dependent on various synthetic plastic materials. Hence, every moment, both industries and mankind generate a huge amount of plastic waste, which has lately been recognized as a breakneck for the total environment. Therefore, to solve this particular problem, it is very crucial to replace fossil-based synthetic plastic materials with biopolymers for viable environmental protection. However, the scheming of biopolymers from their natural sources has been recognized as an immense challenge in the earlier few decades owing to the insufficiency regarding the critical understanding of the handling of starting materials. Yet, scientists have been exasperating to improve a new route of production of bioplastic and polymeric materials to solve this issue. However, in this work, we focus on the sustainable/green route of bio-nanocomposite film production from agro-waste biomass. Whereas the raw fibers and crystalline nanocellulose (CNC) were extracted from the rachis of bananas (<em>M. oranta</em>). Inversely, the solid polylactic acid (PLA) was purified by dissolving in a particular organic solvent (like chloroform) for better nanocomposite fabrication. Then, by employing the prominent EIPS method, the CNC-PLA bionanocomposite films were fabricated to improve their overall properties. The specimens were characterized by FTIR-ATR, TGA, DTA, DTG, SEM, XRD, and BDA analysis. The observed outcomes recommended that the newly manufactured biopolymeric CNC-PLA films have greater thermal steadiness up to 600°C, a relatively higher crystallinity index value (about 86.09±0.001%), possess considerable active binding sites like OH, COOH, C-O-C, NH, etc., and exhibit good surface morphology and biodegradability. Due to these outstanding properties, the newly produced CNC-PLA bionanocomposites would be beneficially used in bulk-scale industrial, engineering, and bio-medical sectors as a sustainable replacement for the existing fossil-based hazardous synthetic ones to develop a green and healthy environment.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-27DOI: 10.1016/j.sajce.2024.09.007
The progress of the Proton Exchange Membrane Fuel Cell (PEMFC) over the last few decades indicates that the cell has faced challenges in terms of commercialization and sustainability. These challenges are primarily attributed to the high cost of catalysts and durability issues. Reducing the amount of platinum is the key finding that can solve the catalyst's cost problem. The platinum load can be reduced or eliminated either by alloying with transition metals or substituting with other non-platinum metals. This review work has focused on the synthesis of catalysts using platinum metal catalysts alloyed with transition metals, as well as non-platinum metal catalysts supported on nitrogen doped carbon. It was observed that the synthesis method plays a crucial role in determining the durability and efficiency of the catalyst. From the transition metals, Pd showed excellent electrocatalytic activity similar to that of Pt metal. The study indicates that the preparation of the catalyst is challenging, resulting in rapid degradation and a short durability time. It was demonstrated that a novel synthetic strategy possesses a catalyst with strong durability, efficiency, and enhanced intrinsic activity. This review highlights the current progress of the catalyst and suggests future research directions for the scientific community.
{"title":"Comparative analysis of selected metal catalysts for oxygen reduction reaction activity: Advances in synthesis, durability, and efficiency","authors":"","doi":"10.1016/j.sajce.2024.09.007","DOIUrl":"10.1016/j.sajce.2024.09.007","url":null,"abstract":"<div><div>The progress of the Proton Exchange Membrane Fuel Cell (PEMFC) over the last few decades indicates that the cell has faced challenges in terms of commercialization and sustainability. These challenges are primarily attributed to the high cost of catalysts and durability issues. Reducing the amount of platinum is the key finding that can solve the catalyst's cost problem. The platinum load can be reduced or eliminated either by alloying with transition metals or substituting with other non-platinum metals. This review work has focused on the synthesis of catalysts using platinum metal catalysts alloyed with transition metals, as well as non-platinum metal catalysts supported on nitrogen doped carbon. It was observed that the synthesis method plays a crucial role in determining the durability and efficiency of the catalyst. From the transition metals, Pd showed excellent electrocatalytic activity similar to that of Pt metal. The study indicates that the preparation of the catalyst is challenging, resulting in rapid degradation and a short durability time. It was demonstrated that a novel synthetic strategy possesses a catalyst with strong durability, efficiency, and enhanced intrinsic activity. This review highlights the current progress of the catalyst and suggests future research directions for the scientific community.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1016/j.sajce.2024.09.003
Cationic particles are commonly used as wet-end additives in papermaking processes. This study evaluates the effects of cationic cassava starch (CCS) on the mechanical strength of paper made from bacterial cellulose (BC). Acetobacter xylinum was utilised in the production of bacterial cellulose (BC) paper, whereas 3‑chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) was employed in the etherification process of cassava starch to synthesize CCS. Papers containing CCS displayed a more compact surface structure compared to traditional wood-based papers, reaching a brightness level of 97.3 and improving thermal and mechanical characteristics, such as higher tensile strength and is suitable for use as a separator in battery fabrication processes. The results emphasise the possibility of using CCS as a sustainable option in paper production, offering enhanced environmental and mechanical efficiency.
{"title":"Improved mechanical and thermal performance of bacterial cellulose paper through cationic cassava starch addition","authors":"","doi":"10.1016/j.sajce.2024.09.003","DOIUrl":"10.1016/j.sajce.2024.09.003","url":null,"abstract":"<div><div>Cationic particles are commonly used as wet-end additives in papermaking processes. This study evaluates the effects of cationic cassava starch (CCS) on the mechanical strength of paper made from bacterial cellulose (BC). <em>Acetobacter xylinum</em> was utilised in the production of bacterial cellulose (BC) paper, whereas 3‑chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) was employed in the etherification process of cassava starch to synthesize CCS. Papers containing CCS displayed a more compact surface structure compared to traditional wood-based papers, reaching a brightness level of 97.3 and improving thermal and mechanical characteristics, such as higher tensile strength and is suitable for use as a separator in battery fabrication processes. The results emphasise the possibility of using CCS as a sustainable option in paper production, offering enhanced environmental and mechanical efficiency.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.sajce.2024.09.004
Fossil fuels continue to be the predominant source of energy globally, and with many of the world's oil reserves expected to remain productive for extended periods, there is a pressing need for enhanced oil recovery (EOR) methods to satisfy the surging demand for oil. Iran plays a pivotal role in the global oil landscape, making EOR particularly vital, as more than 50 % of oil in carbonate reservoirs remains trapped. Reservoir conformance control techniques are essential for facilitating hydrocarbon flow from the reservoir to the wellbore, especially in challenging displacement scenarios. Achieving uniform sweep efficiency and maximizing hydrocarbon production requires addressing a prevalent issue in the oil industry: excessive water production from oil wells. This phenomenon not only diminishes hydrocarbon output but also curtails reservoir productivity and economic viability while posing severe environmental risks. Among various strategies to mitigate water production, chemical solutions like polymer gel injection have emerged as effective methods for water control. Recently developed techniques, such as the injection of pH-responsive microgels, offer innovative solutions for water blocking and conformance control at reservoir depths. Microgels present several notable advantages over traditional gel injection methods. These include lower operational costs due to reduced injection pressure, which minimizes mechanical damage to the reservoir. Additionally, microgels offer lower material costs and the benefit of reversible swelling, allowing for adjustments through acid washing. However, the successful application of microgels does necessitate an initial acid pre-flush step to lower the pH of the porous medium, which can escalate operational costs. Furthermore, the effective deployment of microgels is contingent upon various factors, including the site and timing of their application, the design of the injection strategy, the parameters governing the injection process, and the microgels' performance under diverse reservoir conditions. These considerations are crucial for optimizing the efficiency and effectiveness of microgel-based interventions in EOR.
{"title":"A review of fabrication methods for biodegradable pH-Responsive nanocomposite microgels and their performance in enhanced oil recovery","authors":"","doi":"10.1016/j.sajce.2024.09.004","DOIUrl":"10.1016/j.sajce.2024.09.004","url":null,"abstract":"<div><div>Fossil fuels continue to be the predominant source of energy globally, and with many of the world's oil reserves expected to remain productive for extended periods, there is a pressing need for enhanced oil recovery (EOR) methods to satisfy the surging demand for oil. Iran plays a pivotal role in the global oil landscape, making EOR particularly vital, as more than 50 % of oil in carbonate reservoirs remains trapped. Reservoir conformance control techniques are essential for facilitating hydrocarbon flow from the reservoir to the wellbore, especially in challenging displacement scenarios. Achieving uniform sweep efficiency and maximizing hydrocarbon production requires addressing a prevalent issue in the oil industry: excessive water production from oil wells. This phenomenon not only diminishes hydrocarbon output but also curtails reservoir productivity and economic viability while posing severe environmental risks. Among various strategies to mitigate water production, chemical solutions like polymer gel injection have emerged as effective methods for water control. Recently developed techniques, such as the injection of pH-responsive microgels, offer innovative solutions for water blocking and conformance control at reservoir depths. Microgels present several notable advantages over traditional gel injection methods. These include lower operational costs due to reduced injection pressure, which minimizes mechanical damage to the reservoir. Additionally, microgels offer lower material costs and the benefit of reversible swelling, allowing for adjustments through acid washing. However, the successful application of microgels does necessitate an initial acid pre-flush step to lower the pH of the porous medium, which can escalate operational costs. Furthermore, the effective deployment of microgels is contingent upon various factors, including the site and timing of their application, the design of the injection strategy, the parameters governing the injection process, and the microgels' performance under diverse reservoir conditions. These considerations are crucial for optimizing the efficiency and effectiveness of microgel-based interventions in EOR.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1026918524001069/pdfft?md5=63b99e6a7e08b51cf454164db8c5c6f8&pid=1-s2.0-S1026918524001069-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.sajce.2024.09.008
Advances in cathode materials continue to drive the development of safer, more efficient, and sustainable lithium-ion (Li-ion) batteries for various applications, including electric vehicles (EVs) and grid storage. This review article offers insights into key elements—lithium, nickel, manganese, cobalt, and aluminium—within modern battery technology, focusing on their roles and significance in Li-ion batteries. The review paper delves into the materials comprising a Li-ion battery cell, including the cathode, anode, current concentrators, binders, additives, electrolyte, separator, and cell casing, elucidating their roles and characteristics. Additionally, it examines various cathode materials crucial to the performance and safety of Li-ion batteries, such as spinels, lithium metal oxides, and olivines, presenting their distinct advantages and challenges for battery applications. Lithium manganese (Li-Mn-O) spinels, like LiMn2O4, offer a cost-effective and environmentally friendly option with good thermal stability despite challenges such as capacity fading, which necessitate innovative approaches like dual-doping strategies. Nickel-rich lithium metal oxides like LiNixMnyCo1-x-yO2 provide high specific energy but face/encounter issues with cobalt reliance and stability, prompting research to reduce cobalt content and increase nickel content. Olivine-based cathode materials, such as lithium iron phosphate (LiFePO4), prioritize safety and stability but exhibit lower energy density, leading to exploration into isomorphous substitutions and nanostructuring to enhance performance. Safety considerations, including thermal management and rigorous testing protocols, are essential to mitigate risks of thermal runaway and short circuits. Thus, this review scrutinizes recent advancements in Li-ion battery cathode materials, delving into strategies aimed at mitigating associated drawbacks and identifying suitable electrode materials based on their electrochemical performance and capacity during operation.
{"title":"Lithium-ion battery fundamentals and exploration of cathode materials: A review","authors":"","doi":"10.1016/j.sajce.2024.09.008","DOIUrl":"10.1016/j.sajce.2024.09.008","url":null,"abstract":"<div><div>Advances in cathode materials continue to drive the development of safer, more efficient, and sustainable lithium-ion (Li-ion) batteries for various applications, including electric vehicles (EVs) and grid storage. This review article offers insights into key elements—lithium, nickel, manganese, cobalt, and aluminium—within modern battery technology, focusing on their roles and significance in Li-ion batteries. The review paper delves into the materials comprising a Li-ion battery cell, including the cathode, anode, current concentrators, binders, additives, electrolyte, separator, and cell casing, elucidating their roles and characteristics. Additionally, it examines various cathode materials crucial to the performance and safety of Li-ion batteries, such as spinels, lithium metal oxides, and olivines, presenting their distinct advantages and challenges for battery applications. Lithium manganese (Li-Mn-O) spinels, like LiMn<sub>2</sub>O<sub>4</sub>, offer a cost-effective and environmentally friendly option with good thermal stability despite challenges such as capacity fading, which necessitate innovative approaches like dual-doping strategies. Nickel-rich lithium metal oxides like LiNi<sub>x</sub>Mn<sub>y</sub>Co<sub>1-x-y</sub>O<sub>2</sub> provide high specific energy but face/encounter issues with cobalt reliance and stability, prompting research to reduce cobalt content and increase nickel content. Olivine-based cathode materials, such as lithium iron phosphate (LiFePO4), prioritize safety and stability but exhibit lower energy density, leading to exploration into isomorphous substitutions and nanostructuring to enhance performance. Safety considerations, including thermal management and rigorous testing protocols, are essential to mitigate risks of thermal runaway and short circuits. Thus, this review scrutinizes recent advancements in Li-ion battery cathode materials, delving into strategies aimed at mitigating associated drawbacks and identifying suitable electrode materials based on their electrochemical performance and capacity during operation.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1026918524001100/pdfft?md5=d8ede521e27e7b38216d3ed3ef40f20f&pid=1-s2.0-S1026918524001100-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-20DOI: 10.1016/j.sajce.2024.09.006
Regarding undeniable formation of the undesired polymer (UP) in the styrene purification process, it is of vital importance to inhibit its production. To address the mentioned issue, effects of injecting antipolymers (e.g., stable nitroxide radicals (i.e., SNRs) and antioxidants (e.g., alkylhydroxylamines (AHA)) on the controlling the UP formation have been studied through density functional theory (DFT) calculations as well as experimental method in this study. In fact, electrophilicity and growth percentage were evaluated by DFT calculations and experimental approach, correspondingly. Accordingly, it was revealed that the best antipolymers in terms of inhibiting performance were 4‑hydroxy-2,2,6,6-tetramethyl piperidine 1-Oxyl (4‑hydroxy-TEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine 1-Oxyl (4-oxo-TEMPO), and from the antioxidants, N-Ethyl-N-phenyl hydroxylamine (EPHA) and N-Benzyl-N-phenyl hydroxylamine (BPHA) exhibited the best performance. In addition, the growth percentage of 18.70, 20.55, 24.85 and 46.8, were obtained for the EPHA, BPHA, 4‑hydroxy-TEMPO, and 4-oxo-TEMPO after 4 hrs of operation, correspondingly. Besides, the synergetic effects of the used inhibitors were determined experimentally. Among the evaluated inhibitors, EPHA/4‑hydroxy-TEMPO demonstrated the best synergetic effects over the control of UP formation. Finally, the blend of 4‑hydroxy-TEMPO (40 wt.%) and EPHA (60 wt.%) was obtained to be the optimum (best) inhibitor with 7.2 % polymer growth after 4 hrs of operation.
{"title":"Combine calculation and experiment to study the undesired polymerization of styrene for screening of effective inhibitors","authors":"","doi":"10.1016/j.sajce.2024.09.006","DOIUrl":"10.1016/j.sajce.2024.09.006","url":null,"abstract":"<div><div>Regarding undeniable formation of the undesired polymer (UP) in the styrene purification process, it is of vital importance to inhibit its production. To address the mentioned issue, effects of injecting antipolymers (e.g., stable nitroxide radicals (i.e., SNRs) and antioxidants (e.g., alkylhydroxylamines (AHA)) on the controlling the UP formation have been studied through density functional theory (DFT) calculations as well as experimental method in this study. In fact, electrophilicity and growth percentage were evaluated by DFT calculations and experimental approach, correspondingly. Accordingly, it was revealed that the best antipolymers in terms of inhibiting performance were 4‑hydroxy-2,2,6,6-tetramethyl piperidine 1-Oxyl (4‑hydroxy-TEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine 1-Oxyl (4-oxo-TEMPO), and from the antioxidants, N-Ethyl-N-phenyl hydroxylamine (EPHA) and N-Benzyl-N-phenyl hydroxylamine (BPHA) exhibited the best performance. In addition, the growth percentage of 18.70, 20.55, 24.85 and 46.8, were obtained for the EPHA, BPHA, 4‑hydroxy-TEMPO, and 4-oxo-TEMPO after 4 hrs of operation, correspondingly. Besides, the synergetic effects of the used inhibitors were determined experimentally. Among the evaluated inhibitors, EPHA/4‑hydroxy-TEMPO demonstrated the best synergetic effects over the control of UP formation. Finally, the blend of 4‑hydroxy-TEMPO (40 wt.%) and EPHA (60 wt.%) was obtained to be the optimum (best) inhibitor with 7.2 % polymer growth after 4 hrs of operation.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-18DOI: 10.1016/j.sajce.2024.09.005
Chemical processes are vital in various industries but are often complex and nonlinear, making accurate modeling essential. Traditional linear approaches struggle with dynamic behaviour and changing conditions. This paper explores the advantages of the new theory of fractional neural networks (FNNs), focusing on applying fractional activation functions for continuous stirred tank reactor (CSTR) modeling. The proposed approach offers promising solutions for real-time modeling of a CSTR. Various numerical analyses demonstrate the robustness of FNNs in handling data reduction, achieving better generalization, and sensitivity to noise, which is crucial for real-world applications. The identification process is more generalized and can enhance adaptability and improve industrial plant management efficiency. This research contributes to the growing field of real-time modeling, highlighting its potential to address the complexities in chemical processes.
{"title":"System identification of a nonlinear continuously stirred tank reactor using fractional neural network","authors":"","doi":"10.1016/j.sajce.2024.09.005","DOIUrl":"10.1016/j.sajce.2024.09.005","url":null,"abstract":"<div><div>Chemical processes are vital in various industries but are often complex and nonlinear, making accurate modeling essential. Traditional linear approaches struggle with dynamic behaviour and changing conditions. This paper explores the advantages of the new theory of fractional neural networks (FNNs), focusing on applying fractional activation functions for continuous stirred tank reactor (CSTR) modeling. The proposed approach offers promising solutions for real-time modeling of a CSTR. Various numerical analyses demonstrate the robustness of FNNs in handling data reduction, achieving better generalization, and sensitivity to noise, which is crucial for real-world applications. The identification process is more generalized and can enhance adaptability and improve industrial plant management efficiency. This research contributes to the growing field of real-time modeling, highlighting its potential to address the complexities in chemical processes.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1026918524001070/pdfft?md5=f48c16e4365855aab9514acce4008efb&pid=1-s2.0-S1026918524001070-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1016/j.sajce.2024.09.002
Silver nanoparticles (AgNPs) were synthesized using a sustainable green approach utilizing deodorizer distillates of canola (CODD) and soybean oil (SODD) as both reducing and capping agents. This synthesis approach resulted in the formation of pale-yellow colored CODD-AgNPs and SODD-AgNPs, which was confirmed by distinctive absorption peaks at 420 nm and 408 nm, respectively via Ultraviolet-Visible (UV–Vis) spectroscopy. Fourier Transform Infrared (FTIR) analysis provided insights into the functional group interactions between CODD and SODD with their AgNPs. X-ray diffraction (XRD) confirmed the face-centered cubic lattice structure of both CODD-AgNPs and SODD-AgNPs. Further characterization via Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM) revealed the sizes, shapes, and surface morphologies of CODD-AgNPs and SODD-AgNPs. Assessment of antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method demonstrated superior radical scavenging efficacy by CODD-AgNPs (IC50 value 1.07±0.04 µg/mL) and SODD-AgNPs (IC50 value 1.14±0.23 µg/mL) compared to CODD and SODD. Evaluation of antibacterial properties against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) via disc diffusion method revealed potent antibacterial activities of CODD-AgNPs and SODD-AgNPs at 100 µg/mL concentration, surpassing the antibacterial efficacy of CODD and SODD. Furthermore, CODD-AgNPs and SODD-AgNPs exhibited significant anti-inflammatory potential at 500 µg/mL concentration, with IC50 values of 187.2 ± 1.28 µg/mL and 203.9 ± 2.08 µg/mL, respectively, highlighting their potential therapeutic applications. In conclusion, this study demonstrates the effective utilization of CODD and SODD in synthesizing AgNPs with enhanced biological functionalities, making them promising candidates for various biomedical applications.
{"title":"Evaluation of antioxidant, antibacterial, and anti-inflammatory activities of deodorizer distillate-derived silver nanoparticles","authors":"","doi":"10.1016/j.sajce.2024.09.002","DOIUrl":"10.1016/j.sajce.2024.09.002","url":null,"abstract":"<div><div>Silver nanoparticles (AgNPs) were synthesized using a sustainable green approach utilizing deodorizer distillates of canola (CODD) and soybean oil (SODD) as both reducing and capping agents. This synthesis approach resulted in the formation of pale-yellow colored CODD-AgNPs and SODD-AgNPs, which was confirmed by distinctive absorption peaks at 420 nm and 408 nm, respectively via Ultraviolet-Visible (UV–Vis) spectroscopy. Fourier Transform Infrared (FTIR) analysis provided insights into the functional group interactions between CODD and SODD with their AgNPs. X-ray diffraction (XRD) confirmed the face-centered cubic lattice structure of both CODD-AgNPs and SODD-AgNPs. Further characterization via Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM) revealed the sizes, shapes, and surface morphologies of CODD-AgNPs and SODD-AgNPs. Assessment of antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method demonstrated superior radical scavenging efficacy by CODD-AgNPs (IC<sub>50</sub> value 1.07±0.04 µg/mL) and SODD-AgNPs (IC<sub>50</sub> value 1.14±0.23 µg/mL) compared to CODD and SODD. Evaluation of antibacterial properties against <em>Escherichia coli (E. coli)</em> and <em>Staphylococcus aureus (S. aureus)</em> via disc diffusion method revealed potent antibacterial activities of CODD-AgNPs and SODD-AgNPs at 100 µg/mL concentration, surpassing the antibacterial efficacy of CODD and SODD. Furthermore, CODD-AgNPs and SODD-AgNPs exhibited significant anti-inflammatory potential at 500 µg/mL concentration, with IC<sub>50</sub> values of 187.2 ± 1.28 µg/mL and 203.9 ± 2.08 µg/mL, respectively, highlighting their potential therapeutic applications. In conclusion, this study demonstrates the effective utilization of CODD and SODD in synthesizing AgNPs with enhanced biological functionalities, making them promising candidates for various biomedical applications.</div></div>","PeriodicalId":21926,"journal":{"name":"South African Journal of Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1026918524001045/pdfft?md5=ca1183fbc549041d0d0b5fd74218f3dd&pid=1-s2.0-S1026918524001045-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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