Hasil untuk "Chemical industries"

G. Centi, E. A. Quadrelli, S. Perathoner

C. Torborg, M. Beller

F. Goodarzi, S. Zendehboudi

Subhajit Bhattacharjee, Stuart Linley, Erwin Reisner

Angelica Cardoza, Henry A. Colorado

This study shows an alkaline activated cement (AAC), also known as geopolymer, made from red brick waste with partial addition of Ordinary Portland Cement (OPC). This is a sustainable material since incorporates waste from the brick industry to make cements, therefore increasing the materials circularity and this reducing pollution. The material was cured at room temperature. The brick residue was activated with sodium hydroxide and sodium silicate in aqueous solution to form the hybrid cement. Several mixtures were made with different amounts of waste and proportions of alkaline activator. The mechanical properties of the materials were studied to determine their feasibility to be used in the construction sector. Three contents of OPC were used: 10, 20, and 30 wt%, which were added to improve the mechanical behavior and post-curing time. The activated hybrid cement was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), compression, and flexural tests. The main results show that the addition of OPC to the brick derived AAC produces an increased compressive strength of 106 MPa when 30 wt% OPC was added, a very significant result since the control sample found was 33 MPa in compression strength, an improvement for more than 3 times. The data were corroborated by statistical analysis.

Abdessamad Ettouil, Asmaa Oubihi, Hamada Imtara et al.

The extraction of gum from natural raw materials is of increasing importance in various industries, including food, pharmaceuticals, and cosmetics, particularly due to their emulsifying properties and potential applications as stabilizers and thickeners. This study presents an insight on the influence of changing parameters like reagents and operating condition on yield and some properties of the flax (Linum usitatissimum L.) seed gum. The extraction conditions were meticulously examined using a full factorial design, highlighting the significant impact of pretreatment, seed preparation, and solvent selection on the extraction yield. A response surface methodology (RSM) was then applied to optimize the water/benzoic acid ratio of the pretreatment step, the ethyl alcohol/water ratio, and the medium pH of the extraction method, resulting in a maximum yield of 14.47%. Furthermore, detailed analyses of the chemical and emulsifying properties of the gum were conducted showing emulsifying capacities over 94%, offering promising application prospects, particularly in the food industry.

Evelyn Maluleke, Maleho Annastasia Lekganyane, Kgabo L. Maureen Moganedi

Marula wine is produced from ripe fruits of the <i>Sclerocarya birrea</i> subspecies <i>caffra</i> tree through spontaneous fermentation. A few culture-based studies have shown that the fermentation is largely driven by yeasts, although, in the early stages, some lactic acid bacteria (LAB) and acetic acid bacteria may be detected. Some of the microbes may produce undesirable metabolites that lead to the spoilage and short shelf life of the wine. However, there is generally limited information on the microbial composition and its contribution to the chemical characteristics of the resultant marula wine. The aim of this study was to characterise the microbial population of marula wine from different localities in the Limpopo province, South Africa. MALDI-TOF and amplicon sequencing technique were used to identify microbial strains and to determine their diversity and changes in the different stages of fermentation. The phylogenetic relationships of LAB and <i>S. cerevisiae</i> were analysed using multilocus sequence typing. Bacterial species that were common in the different marula wines included <i>Gluconobacter oxydans</i>, <i>Lactiplantibacillus plantarum</i>, <i>Levilactobacillus brevis</i>, <i>Lacitilactobacillus nagelii</i>, <i>Lentilactobacillus kefiri</i> and <i>Lentilactobacillus parabuchneri</i>, and the yeasts were <i>Hanseniaspora guiliermondii</i>, <i>Saccharomyces cerevisiae</i>, <i>Rhodotorula mucilaginosa</i> and <i>Pichia kudriavzevii</i>. The MLST data indicated common microbiota from different marula wines with low intraspecific diversity, suggesting that the LAB and <i>S. cerevisiae</i> strains that are mainly responsible for the spontaneous fermentation of marula wine are similar irrespective of the geographical differences and production preferences.

John P. Hansen, J V Hansen, Jonathan Hansen et al.

Many oil/gas fields in Kazakhstan contain high levels of highly corrosive H2S and CO2, sometimes at very high pressures. The management of corrosion is essential in maintaining plant safety and integrity of the processing facility. This paper describes the development of a non-destructive testing (NDT) method that improves the reliability of air-cooled heat exchangers by reducing down-time related to corrosive and erosive failure of fin-fan tubes. The project goal was to maximize the output of oil and gas plants and refineries while reducing the plant operating cost. The work first identified those NDT requirements for air-cooled heat exchangers damage assessment that would provide the greatest economic benefit for Kazakhstan industry. The main objective was to develop a state-of-an-art NDT method for air-cooled heat exchanger tubes, capable to: a) detect any damage mechanism while testing from tube internal diameter, b) accurately determine the damage in terms of wall loss, c) perform inspection quickly and expediently, d) requires minimum tube cleaning. Consequently, the method specially adapted for Kazakhstan conditions was developed based on a combination of Magnetic Flux Leakage (MFL) technique for flaw detection and with Hall effect measurement of wall thickness and gradual corrosion in tubes. The method has been tested in both laboratory and field conditions and the results were compared with accurate but slow ultrasonic IRIS method. High correlation was obtained, which proved that the developed technology is capable to deliver similar results at the speed almost 10 times faster and less than half the cost.

Kongxing Huang, Guohua Chen, F. Khan et al.

Abstract Domino effects are typically high-impact low-probability (HILP) accidents, which pose a serious threat to chemical process industries. Previous researches on domino effects in chemical industries focus more on static analysis at the spatial scale. From the perspective of the spatial and temporal characteristics of the accident, this study proposed a model to analyze dynamic evolution process of domino effects by using matrix calculation coupled with Monte Carlo simulation, and the dynamic propagation of pool fire accidents is considered as the evolution of domino effects. The algorithm of the model for dynamic domino probabilities considering the synergistic effects of multiple escalation vectors from different units can be used to analyze the complex scenarios of domino effects with high-level and multiple primary accident units. Moreover, the model can be applied in chemical areas with a large number of installations due to the greatly improved calculation efficiency. The proposed model is tested and validated using earlier studied dynamic Bayesian network method, and the application of the model is demonstrated on a complex multi-unit system. The results show that domino effects have strong temporal correlation, and the scenario with multiple primary accident units is much more serious than that with only one primary accident unit, which provide important support for the implementation of emergency response. The study highlights that the proposed model serves as an important tool to evaluate strategies for prevention and control of domino effects.

Khairina Jaman, Nurjannah Amir, Mohammed Ali Musa et al.

Valorization of agro-food waste through anaerobic digestion (AD) is gaining prominence as alternative method of waste minimization and renewable energy production. The aim of this study was to identify the key parameters for digester performance subjected to kinetic study and semicontinuous operation. Biochemical methane potential (BMP) tests were conducted in two different operating conditions: without mixing (WM) and continuous mixing (CM). Three different substrates, including food waste (FW), chicken dung (CD), and codigestion of FW and CD (FWCD) were used. Further kinetic evaluation was performed to identify mixing’s effect on kinetic parameters and correlation of the kinetic parameters with digester performance (volatile solid removal (VS%) and specific methane production (SMP)). The four models applied were: modified Gompertz, logistic, first-order, and Monod. It was found that the CM mode revealed higher values of Rm and k as compared to the WM mode, and the trend was consistently observed in the modified Gompertz model. Nonetheless, the logistic model demonstrated good correlation of kinetic parameters with VS% and SMP. In the continuous systems, the optimum OLR was recorded at 4, 5, and 7 g VS/L/d for FW, CD, and FWCD respectively. Therefore, it was deduced that codigestion significantly improved digester performance. Electrical energy generation at the laboratory scale was 0.002, 0.003, and 0.006 kWh for the FW, CD, and FWCD substrates, respectively. Thus, projected electrical energy generation at the on-farm scale was 372 kWh, 382 kWh, and 518 kWh per day, respectively. Hence, the output could be used as a precursor for large-scale digester-system optimization.

Mario Linz, Jörg Exner, Tobias Nazarenus et al.

Repair instead of discard is going to be crucial in the vision of a green future, therefore we propose the powder aerosol deposition (PAD) as a promising technique to reprocess ceramic coatings at room temperature. Alumina coated copper substrates with an artificial imperfection are manufactured in a first step. In a second step, the repair of this imperfection is carried out using two different PAD apparatuses: first, a conventional PAD apparatus with a moving substrate holder and a converging slit nozzle and second, a miniaturized μPAD apparatus with a fixed substrate holder and a circular de-Laval nozzle. The different film profiles are studied using a laser scanning confocal microscope. Cross-sectional images to investigate the microstructure are taken by a scanning electron microscope. Finally, samples of both PAD apparatuses are exposed to an oxidizing atmosphere at 400 °C proving the gas-tightness as a further quality feature of the repair coating.

Farhad AZİZOV, Zarbali KHALILOV, Vefa ATAYEVA et al.

This investigation aims to study the perspectives for obtaining natural remedies and food addit­ives from raw plant materials that can be used in food, pharmaceutical, and other industries. The selection of hazelnut green leafy cover as an item is based on the fact that it is a natural organic resource that is now being discarded as waste. In the article, the results are presented about the determination of mineral elements and bioactive compounds in the bio-extracts of 70% ethyl alcohol (BE-III) and distillation water (BE-IV) obtained from the green leafy cover of the plant (Corylus avellane L.) where grow in the north-western region of Azerbaijan. According to our study, BE-III has 25 chemical elements, excluding Rb, for a total of 12.797%, while BE-IV contains 26 chemical elements for a total of 21.347%. Amounts of mac­roelements are 10.4%, and microelements are 2.69% in the content of BE-III, while amounts of macroele­ments are 17.82%, and amounts of microelements are 3.53% in the content of BE-IV. Amounts of organic compounds are 87.2% in the content of BE-III, while their amounts are 78.65% in the content of BE-IV. The amount of Zn, which has antioxidant activity, is 0.009%, and the amount of Se is 0.002% in the con­tent of BE-IV. These values vary in the content of BE-III, the amount of Zn is 0.01%, but the amount of Se is 0.001%. 15 bioactive substances were identified in the content of BE-III bio-extract; however, 5 bioact­ive substances were identified in the content of BE-IV bio-extract. According to our research results, the bio-extract obtained from hazelnut green leafy cover is abundant with antioxidants and bioactive sub­stances with antibacterial activity. For this reason, these bio-extracts can be used as both a food supple­ment and a means of treatment.

Saeid Nejati, Sajjad Keshipour, Mozhdeh Seyyedhamzeh

While one of the valuable approaches to obtaining a heterogeneous catalyst is supporting them on a high surface area supports, the strategy mainly suffers from the low number of chelating agents on most of the supports to grip the metal cations catalysts. Therefore, loading multidentate compounds susceptible to binding with metal cations is a potent strategy to improve the catalyst stability on the support. In this report, metformin as a multi-dentate ligand was bonded onto graphene quantum dots as a high aspect ratio compound to afford new support susceptible to chelating Co(II). Deposition of Co(II) on graphene quantum dots modified with metformin gave a new sustainable heterogeneous catalyst that was highly active in the oxidation of alkyl arenes. The reactions were performed in solvent-free conditions at 80 ºC with high conversions up to 96%. The organometallic compound is applicable as a recoverable heterogeneous catalyst with recyclability up to 6 times. The modification of graphene quantum dots with metformin also can gain more attention from medicinal researchers.

H. Berhe

PurposeKaizen is an umbrella concept for a management philosophy based on a set of principles and values with different tools and techniques that form part of Company-Wide Quality Control. The purpose of this study to explore the empirical evidence of Kaizen philosophy practice and its effect on Ethiopian manufacturing industries, chemical companies in particular.Design/methodology/approachAfter the literature review, an exploratory empirical research, supported on a company observation, was adopted. The eight companies visit giveaway collecting annual technical reports and Kaizen award presentations. The review structure encompassed four major approaches. The first approach is conducting extensive literature review and adopting methodologies. The second approach is examining secondary data and developing SWOT analysis. The third is exploring Kaizen practices, developing framework, identifying drivers and barriers using charts, diagrams and graphs. The final approach is proposing way forward and implications based on the findings from the investigative study to emphasize the link between Kaizen practice and its effect on manufacturing industries’ performance.FindingsThe findings indicate practice of Kaizen brought in achieving monetary, nonmonetary and qualitative results. However, results vary from company to company. The average attained improvements of productivity, production volume, machine productivity and sales volume are 2.77%, 28.69%, 10.14% and 31.53% respectively. Moreover, a total of 71,932,472.19 ETB is saved by following structured framework and practice of social and technical factors. However, companies could not sustain Kaizen activities and unable to maintain the attained substantial improvements due to less effort made on some of the Kaizen practices identified as barriers on the cause and effect diagram of this exploratory study.Research limitations/implications:A sample size of eight companies is not adequate to generalize key findings of this study. This will be put right by carrying out further surveys in the future using questionnaire and semistructured interviews.Practical implicationsThe findings of this study underlined that practice of Kaizen philosophy on chemical companies supported by structured implementation framework, full practice of drivers, eradicating barriers, sustaining practices and maintaining improvements enable in enhancing chemical companies performance through achieving quantitative (monetary and nonmonetary) and qualitative results.Originality/valueAlthough there are a number of studies published on Kaizen, currently it is found that there is lack of literature on practice and effect of Kaizen philosophy. Based on this exploratory study and assessment, the framework and circumstance of Kaizen philosophy practices are providing valuable insights for chemical companies, other manufacturing industries and organizations, which will be on board on this voyage including Ethiopian Kaizen Institute, practitioners and academicians.

J. Łapińska, Iwona Escher, Joanna Górka et al.

The use of artificial intelligence (AI) in companies is advancing rapidly. Consequently, multidisciplinary research on AI in business has developed dramatically during the last decade, moving from the focus on technological objectives towards an interest in human users’ perspective. In this article, we investigate the notion of employees’ trust in AI at the workplace (in the company), following a human-centered approach that considers AI integration in business from the employees’ perspective, taking into account the elements that facilitate human trust in AI. While employees’ trust in AI at the workplace seems critical, so far, few studies have systematically investigated its determinants. Therefore, this study is an attempt to fill the existing research gap. The research objective of the article is to examine links between employees’ trust in AI in the company and three other latent variables (general trust in technology, intra-organizational trust, and individual competence trust). A quantitative study conducted on a sample of 428 employees from companies of the energy and chemical industries in Poland allowed the hypotheses to be verified. The hypotheses were tested using structural equation modeling (SEM). The results indicate the existence of a positive relationship between general trust in technology and employees’ trust in AI in the company as well as between intra-organizational trust and employees’ trust in AI in the company in the surveyed firms.

M. Ostadi, K. Paso, Sandra Rodríguez-Fabià et al.

Integrated water electrolysis is a core principle of new process configurations for decarbonized heavy industries. Water electrolysis generates H2 and O2 and involves an exchange of thermal energy. In this manuscript, we investigate specific traditional heavy industrial processes that have previously been performed in nitrogen-rich air environments. We show that the individual process streams may be holistically integrated to establish new decarbonized industrial processes. In new process configurations, CO2 capture is facilitated by avoiding inert gases in reactant streams. The primary energy required to drive electrolysis may be obtained from emerging renewable power sources (wind, solar, etc.) which have enjoyed substantial industrial development and cost reductions over the last decade. The new industrial designs uniquely harmonize the intermittency of renewable energy, allowing chemical energy storage. We show that fully integrated electrolysis promotes the viability of decarbonized industrial processes. Specifically, new process designs uniquely exploit intermittent renewable energy for CO2 conversion, enabling thermal integration, H2 and O2 utilization, and sub-process harmonization for economic feasibility. The new designs are increasingly viable for decarbonizing ferric iron reduction, municipal waste incineration, biomass gasification, fermentation, pulp production, biogas upgrading, and calcination, and are an essential step forward in reducing anthropogenic CO2 emissions.

Yeasmin Akter Moonnee, Md Javed Foysal, Abu Hashem et al.

Abstract Background The leather industry generates huge volume of waste each year. Keratin is the principal constituents of this waste that is resistant to degradation. Some bacteria have the ability to degrade keratin through synthesis of a protease called keratinase that can be used as sources of animal feed and industrial production of biodiesel, biofertilizer, and bioplastic. Majority of the studies focused on keratin degradation using gram-positive bacteria. Not much of studies are currently available on production of keratinase from gram-negative bacteria and selection of best parameters for the maximum production of enzyme. The aim of this study was to isolate and characterize both groups of bacteria from soil for keratinase and optimize the production parameters. Results A total of 50 isolates were used for initial screening of enzyme production in skim milk, casein, and feather meal agar. Out of 50, five isolates showed significantly higher enzyme production in preliminary screening assays. Morphological and biochemical characterization revealed 60% of the isolates as gram-negative bacteria including two highest enzyme-producing isolates. The isolates were identified as Pseudomonas aeruginosa through sequencing of 16S rRNA gene. Maximum production of enzyme from P. aeruginosa YK17 was achieved with 2% chicken feather, beef extract, and ammonium nitrate as organic and inorganic nitrogen sources and glucose as a carbon source. Further analysis revealed that 3% inoculum, 40 °C growth temperature and 72-h incubation, resulted in maximum production of keratinase. Conclusion The overall results showed significant higher production of enzyme by the P. aeruginosa YK17 that can be used for the degradation of recalcitrant keratin waste and chemical dehairing in leather industries, thereby preventing environmental pollution.

Xiaochun Li, N. Wei, Z. Jiao et al.

Abstract China has emerged as a world leader in the coal chemical industry, which requires large amount of water and results in considerable CO2 emissions. This situation has led to the challenge of the CO2-Water nexus for China and particularly for the sustainable development of its coal chemical industry. CO2-enhanced water recovery (CO2-EWR) technology can provide large-scale CO2 mitigation and additional water supply in an integrated manner, especially in arid areas. Meanwhile, CO2 streams from industrial separation processes in the coal chemical industries are amenable to separation and can dramatically simplify or even dispense with the capture process. This study presents the first systematic assessment of a cost curve for onshore CO2-EWR potential using CO2 streams from industrial separation processes by an evaluation framework encompassing CO2 emission inventory, site suitability evaluation, and source–sink matching with techno-economic models. Preliminary results focused on the full capacity of several coal chemical processes as of 2015 suggest that CO2-EWR technology can mitigate 269 million tons of CO2 from industrial separation processes at relatively low cost ranging from 12 to 30 USD/t CO2 in China. Furthermore, 404 million tons of underground water could be produced for further desalination and utilization. When additional capacity under development could become fully operational, the emissions of 878 million tons of CO2 could be mitigated and provide 1318 million tons of vital water resources. Therefore, CO2-EWR technology can be essential to clean and sustainable development of the coal chemical industry and may provide low-cost opportunities to accelerate the deployment of large-scale CCUS projects in China.

Malwina Mularczyk, Izabela Michalak, Krzysztof Marycz

Bioactive compounds of natural origin are gaining increasing popularity. High biological activity and bioavailability, beneficial effects on health and safety of use are some of their most desirable features. Low production and processing costs render them even more attractive. Microorganisms have been used in the food, medicinal, cosmetic and energy industries for years. Among them, microalgae have proved to be an invaluable source of beneficial compounds. <i>Haematococcus pluvialis</i> is known as the richest source of natural carotenoid called astaxanthin. In this paper, we focus on the cultivation methods of this green microalga, its chemical composition, extraction of astaxanthin and analysis of its antioxidant, anti-inflammatory, anti–diabetic and anticancer activities. <i>H. pluvialis</i>, as well as astaxanthin can be used not only for the treatment of human and animal diseases, but also as a valuable component of diet and feed.

A. Makarova, Xuexiu Jia, Elena B. Kruchina et al.

Abstract The chemical industry is one of the typical sources of harmful pollutants and some of which are difficult to tackle. Sustainable Development Goals (SDGs) are of great concern to the performance of chemical industries regarding environmental impacts, and one of the core programs is the global voluntary Responsible Care® Program (RCP), aiming to encourage the industries to voluntarily report environmental performance data. Due to the voluntary reporting system, the collected datasets are huge while often heterogeneous, which makes it difficult to analyse the performance and evaluate the difference before and after the launch of the program. Direct comparison of actual indicators may fail to provide an accurate estimation of the implementing efficiency of the RCP. In this study, an original algorithm is developed to analyse the environmental KPIs of chemical companies involved in the RCP, in order to investigate the efficiency of the program and provide insightful suggestions for further development of the data reporting, as well as to provide advice for the further application of the program. The results showed that most of the environmental impacts of the chemical industries in the RF, e.g. soil pollution and water pollution, has been decreasing after the launching of the program. However, for both the companies involved in the RCP and the entire chemical industrial sector of the RF chemical industry, the GHG emissions maintained an increase. A major insightful conclusion is more energy has been used for improving more direct environmental impact, while the attention for impacts with longer harm potential, e.g. GHG emissions, has been shifted. Further policies and regulations should be targeted at the impact of the chemical industry on climate change, and new technologies should be encouraged to improve the efficiency of energy use and thus decrease GHG emissions.