Cleaner Engineering and Technology最新文献

Considering the considerable environmental impact resulting from basic chromium sulfate, the exploration of vegetable tanning materials as an eco-friendly alternative has gained substantial interest. This study endeavors to extract tannins from Pontederia crassipes using various solvents (water, acetone, methanol, and ethanol) and evaluate their potential as a vegetable tanning agent for leather processing. Among the solvents, methanol exhibited the highest extraction efficiency at 26.34%. UV–Vis spectroscopy, FT-IR spectroscopy, and titrimetric analysis confirmed the presence of total tannins at 152.25 mg/g, which encompassed polyphenolic compounds such as epicatechin, catechin hydrate, and catechol. The antimicrobial behavior of the extracted tannin was confirmed by antimicrobial analysis. Notably, leather tanned with Pontederia crassipes tannin displayed an impressive shrinkage temperature of 83.31 °C, tensile strength 286.33 kg/cm², and elongation 63.33%. This innovative tanning approach also yielded enhanced properties such as tensile strength, Bauman tear strength, stitch tear strength, tongue tear strength, and percentage of elongation, surpassing those of traditional vegetable-tanned leather. A closer look at the surface of the tanned leathers using Scanning electron microscopy (SEM) revealed compact fiber structures and uniform surface. Moreover, the Fourier-transform infrared spectroscopy (FTIR) analysis revealed clear functional groups within the Pontederia crassipes tanned leather, as evidenced by the broad peak observed. These results collectively imply that Pontederia crassipes tannin presents promise as an eco-friendly substitute for basic chromium sulfate and a novel reservoir of vegetable tannins for the leather sector.

The conversion of agricultural waste into valuable products is a critical endeavour in the pursuit of clean and sustainable environment. Biochar has recently emerged as an effective composite filler. However, the choice of biomass for biochar production is critical in determining its properties, which in turn influence the performance of composites. This study investigates the impact of using agricultural wastes cashew nutshell and sugarcane husk for biochar production. Cashew nutshell waste and sugarcane husk waste were pyrolyzed at 400 °C for 3 h and biochar was produced, which was used as a filler in polyester matrix. The mechanical and erosive resistance properties of the resultant polyester composites were evaluated. The results revealed that both biochar-incorporated composites significantly improved the mechanical strength and erosion resistance. Notably, the sugarcane husk biochar composite has higher mechanical strength and erosion resistance. This highlights the value of sugarcane husk waste as a valuable resource for biochar production in composite materials, a significant step towards sustainable waste utilisation and the development of high-performance composites suitable for a wide range of applications.

The article investigates the development of a biomass supply chain model by studying the logistic, network optimisation, transportation and economic impact as it affects the southwest Nigeria, with a particular emphasis on the conversion of crop residues into bioproducts such as bioethanol and biodigestate for electricity generation. This model compares the energy produced from single and multiple feedstocks using simulation methods implemented in the MATLAB 2022b programming language solver with the linprog function to implement linear programming to investigate the maximum revenue and minimum production costs as they affect biomass supply chain in southwest Nigeria. The sensitivity analysis is performed to examine the impact of key parameters by measuring essential uncertainty features to show the profitability of the supply chain network while employing feedstock such as cassava peel, maize husk, rice straw, and sorghum bran. The study's findings provide insight into the optimal design and operation of the biomass supply chain in Southwest Nigeria, as well as the viability and potential of using various feedstocks for energy generation while taking into account the economic and logistical aspects of the supply chain. The optimisation framework provides decision-makers and stakeholders with practical tools to improve the sustainability of biomass utilisation and efficiency in the region, and research will help to develop a more robust and environmentally friendly energy system in the region, easing the transition to a renewable and sustainable future.

Mineral-based oil is now often used for transformer oil. Unfortunately, this kind of oil is harmful and unfriendly to the environment, necessitating the use of vegetable-based products that are both ecologically benign and biodegradable. With its properties, crude palm oil (CPO) might be a possibility for a vegetable-based insulator. Concerning it, the goal of this study was to create a method for converting CPO into an insulator that fulfilled IEC 62770 requirements. The researchers created a CPO-based insulator using degumming, filtration, distillation, and a vacuum drying technique in their work. At vacuum pressures ranging from 15% to 65% vacuum and temperatures ranging from 150 °C to 200 °C, 0.05% phosphoric acid, 5% bleaching earth, and 10% zeolite were used in the degumming process. The best measurement results showed that the values of breakdown voltage and kinematic viscosity of 60 kV and 12.7 cSt, respectively, met the requirements. The moisture content was higher than the required value, while the acid content was still relatively high, namely 1.4 mg KOH/g, thus requiring further treatment. After treatment using 2% KOH, the acidity became 0.01 mg KOH/g, and the moisture content was 176 ppm thus meeting the requirement. The color of the insulator produced was light yellow, bright, and clear. The best treatment parameter combination found was a pressure of 51.9% vacuum with a temperature of 168.7 °C. This research showed that the vacuum pressure had a significant effect on moisture, kinematic viscosity, and acidity, while temperature had a significant effect on breakdown voltage and acidity.

Gas to Liquid (GTL) fuel is considered a clean and alternative fuel and has been given much attention as a replacement for conventional fuels. This paper reviews and discusses the GTL fuel characteristics and the effects of GTL fuel on performance and emission in engines, considering previous research works. The properties of GTL fuel, such as a higher cetane number than diesel, improve its ignition and, therefore, burn more efficiently. It also helps to eliminate the knock and noise produced by the engine, resulting in lower emissions of pollutants. The energy density of GTL can potentially be higher than that of diesel, depending on its specific chemical composition and carbon cuts in the fuel, which provides more energy per unit volume, resulting in better brake-specific fuel consumption. The major finding is that the ability of GTL fuel to be implemented in existing ICE without significant modification should enhance the involvement of GTL in the automotive sector. GTL fuel has lower emissions of particulate matter, sulphur oxides, and nitrogen oxides, which are harmful pollutants that contribute to air pollution and respiratory problems. In contrast, the brake power from the usage of GTL has shown a lower value than diesel. This is caused by the lower volumetric heating value of the GTL fuel. The production process is expensive and requires significant energy, which may offset some of the environmental benefits. Additionally, the infrastructure for producing and distributing GTL fuel has yet to be widely available, which makes it difficult to adopt as a widespread replacement for conventional fuels.

Artificial ground freezing during mine shaft construction is a costly endeavor. For effective decision-making in mining operations, it's essential to establish robust control over frozen soil conditions. This control holds paramount importance for ensuring mining safety. After considering the existing approaches to the control of artificial ground freezing, we conducted an analysis of their respective advantages and disadvantages. We introduced two novel principles for controlling the freezing process. These principles mark a substantial advancement from the previously proposed freeze-on-demand concept. Subsequently, we illustrated the practical implementation of these principles by sharing our experience in controlling artificial ground freezing during the construction of two potash mine shafts in the Republic of Belarus. One of the most noteworthy outcomes of this control is the development of innovative technical solutions aimed at enhancing energy efficiency and operational safety in shaft sinking. These solutions encompass interval-based permission for mining activities, facilitating earlier shaft sinking initiation. Another significant solution pertains to swiftly responding, devising, and implementing strategies to counteract groundwater infiltration within one of the frozen soil layers.

The recovery of platinum (Pt) from electrocatalysts in spent proton exchange membrane fuel cells is promising and important for the sustainable development of such a noble metal. Conventional leaching of Pt in the aqueous phase typically requires the use of high concentration of mineral acids and the presence of strong oxidants owing to its thermodynamic stability and non-reactive properties. In the present study, the dissolution of Pt from a Pt/C fuel cell electrocatalyst was investigated using a simple and efficient process under moderate conditions in chloride media. Notably, the leachability of Pt was high ∼76% in a solution of low concentration HCl 2.0 M at 90 °C for 120 min in the absence of an oxidant. The enhancement of Pt leaching efficiency can be obtained using various oxidizing agents HNO₃, H₂O₂, NaClO and NaClO₃, and NaClO₃ shown the most effective improvement from 76% to 88%. The dissolution of Pt in a solution of 2.0 M HCl and 3.0 wt% NaClO₃ improved to 98% by the increase in leaching temperature from 50 to 90 °C. Kinetic studies indicated that Pt leaching in HCl in the presence of NaClO₃ followed a chemical-controlled mechanism with an activation energy (E_a) of 40.6 kJ/mol. Based on the findings of this study, an efficient process is proposed to recover and reuse Pt from an electrocatalyst sample of spent fuel cells, including oxidative leaching, chemical precipitation and laser reduction.

In recent years, the widespread adoption of Industry 4.0 technologies has significantly enhanced sustainability performance and addressed environmental concerns for companies. These advanced technologies are crucial in driving sustainability and reshaping organizational processes. This study investigates the relationship between Industry 4.0 technologies and Sustainable Development Goals (SDGs), specifically focusing on the United Arab Emirates (UAE). The research is considered significant and novel because of its potential to address environmental challenges, foster sustainable economic growth, guide policy decisions, promote innovation, and bridge knowledge gaps in the field. A systematic literature review was conducted utilizing the Scopus database to achieve these objectives. The review process involved defining relevant selection criteria such as SDG1 to SDG17 and Big Data and the Internet of Things (IoT), reviewing 138 articles, and employing appropriate analysis methods, including bibliometric analysis and concatenate function. Various visualizations were used to present the research outcomes effectively. The study categorized the SDGs and Industry 4.0 technologies into three levels: 17 Goals, 169 Targets, 241 Indicators, 6 Design Principles, 9 Technologies, and 37 Enablers. By analyzing the publications, the study identified the most and least utilized Industry 4.0 technologies and SDGs in the UAE context. It was discovered that addressing the UAE's food security aligns with SDG 14: Life Below Water, given the country's abundant natural resources. The study highlights key areas of concern and emphasizes the interconnection between SDGs and Industry 4.0 technologies, offering valuable insights for future investigations. Moreover, the findings benefit researchers interested in exploring specific applications within the scope of the study. This study aids in understanding and leveraging the potential role of Industry 4.0 technologies to achieve SDGs.

Brown algae are the main source of polysaccharides such as fucoidan and alginate, which can be used to develop a wide range of bioactive and polymer materials. In this study, sodium alginate and fucoidan were sequentially extracted using thermochemical, microwave, ultrasonic and sub critical water treatments of untreated and ethanol-pre-treated brown algae, Ascophyllum nodosum. Extraction was achieved using a solvent solution consisting of a 1:2 M ratio of choline chloride to glycerol (ChGl) in 70% water (w/w) for initial treatment to extract fucoidan, followed by Na₂CO₃ treatments for alginate extraction. Microwave extraction was shown to be the most advantageous treatment for alginate extraction, with the greatest biomass extracted (46.2%), purity (33.43% combined mannuronic and guluronic acid content), and molecular weight, whilst indicating an increased bioactive capacity associated with co-extracted polyphenolic content. However, using ChGl for fucoidan extraction resulted in a large fraction of the solvent remaining within the fucoidan. This is evidenced by up to 39% of the fucoidan consisting of glycerol. The extracted alginate has the potential as a bioactive polysaccharide, whilst the fucoidan would require further purification.

Biogenic synthesis of nanomaterials represents a promising alternative to traditional chemical synthesis due to its environmentally friendly nature, cost-effectiveness, low toxicity, and high biocompatibility. The primary objective of this study was to develop a novel biogenic synthesis method for titanium dioxide (TiO₂) nanoparticles using an aqueous extract of Annona muricata L. as a stabilizing and organic reducing agent. Furthermore, our aim included a comprehensive exploration of the structural, morphological, and optical properties of these nanostructures. The methodology employed in this project was grounded in the biogenic synthesis of TiO₂, utilizing the aforementioned extract as a key component. We conducted a comprehensive characterization approach to unravel the formation mechanism and validate the morphology and crystalline structure of the nanomaterial. We successfully synthesized nanoparticles with spherical morphology and an average diameter of 13.41 nm, characterized by their remarkable uniformity and high-quality crystalline structure. Additionally, we assessed the applicability of these nanoparticles in photocatalysis processes aimed at the degradation of organic dyes. Our findings indicated efficient initial activity in the kinetics of methylene blue dye degradation, with a reduction of 59.25 % within the first 30 min of exposure.