A. Boukhiar, S. Benamara, Yougourthane Bouchal, Kahina Touderte, Siham Messouidi
Olive leaves (OLs) are well known for being rich in oleuropein, their main bioactive molecule which has recently been attracting great interest from the scientific community due to its antiviral properties, including Covid-19 disease. Furthermore, the high-temperature/short-time drying process has found applications for various plants and food processing, which might be also implemented for the drying of OLs. This study focuses on: 1. the mathematical modeling of thin-layer high-temperature-drying (HTD) kinetic of olive (var. Chemlal and Oleaster) leaves, and 2. the determination of HTD effect on some physicochemical properties (oleuropein, chlorophylls, and CIELab color parameters) of the dried olive leaves (DOLs). For this, four drying temperatures (100, 120, 140, and 160 °C) were applied. For comparison purposes, low-temperature DOL samples were also prepared. The obtained data have shown that among the tens tested mathematical models, the Midilli et al. model describes more correctly experimental data for all drying temperatures and for both olive leaf varieties (R2 = 0.9960, SEE = 0.0085, RMSE = 0.0165 and χ2 = 0.0006). Moreover, the results show that the HTD at 120 and 160 °C does not differ from freeze-drying in terms of oleuropein retention (p < 0.05), highlighting the technological interest in the high-temperature/short-time drying process. Considering the biological value of oleuropein, in particular its antiviral activity, the study deserves further investigation in order to elucidate certain questions such as the storability of DOLs, and their valorization as fortification ingredient in food and pharmaceutical formulations, evaluation in vitro of their biological activities, etc.
{"title":"High-temperature Thin-layer Drying Kinetic of Cultivated and Wild Algerian Olive Leaves","authors":"A. Boukhiar, S. Benamara, Yougourthane Bouchal, Kahina Touderte, Siham Messouidi","doi":"10.3311/ppch.20264","DOIUrl":"https://doi.org/10.3311/ppch.20264","url":null,"abstract":"Olive leaves (OLs) are well known for being rich in oleuropein, their main bioactive molecule which has recently been attracting great interest from the scientific community due to its antiviral properties, including Covid-19 disease. Furthermore, the high-temperature/short-time drying process has found applications for various plants and food processing, which might be also implemented for the drying of OLs. This study focuses on: 1. the mathematical modeling of thin-layer high-temperature-drying (HTD) kinetic of olive (var. Chemlal and Oleaster) leaves, and 2. the determination of HTD effect on some physicochemical properties (oleuropein, chlorophylls, and CIELab color parameters) of the dried olive leaves (DOLs). For this, four drying temperatures (100, 120, 140, and 160 °C) were applied. For comparison purposes, low-temperature DOL samples were also prepared. The obtained data have shown that among the tens tested mathematical models, the Midilli et al. model describes more correctly experimental data for all drying temperatures and for both olive leaf varieties (R2 = 0.9960, SEE = 0.0085, RMSE = 0.0165 and χ2 = 0.0006). Moreover, the results show that the HTD at 120 and 160 °C does not differ from freeze-drying in terms of oleuropein retention (p < 0.05), highlighting the technological interest in the high-temperature/short-time drying process. Considering the biological value of oleuropein, in particular its antiviral activity, the study deserves further investigation in order to elucidate certain questions such as the storability of DOLs, and their valorization as fortification ingredient in food and pharmaceutical formulations, evaluation in vitro of their biological activities, etc.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90109372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zsuzsanna Szokol, Károly Lozsi, A. Virág, A. Dancsó, L. Szlávik, G. Simig, Balázs Volk
Blarcamesine is a promising investigational drug for the treatment of Alzheimer's disease. The international nonproprietary name blarcamesine refers to a racemic compound, although it seems likely that it will be marketed in an enantiopure form. A resolution process has been described in the literature, but the absolute configurations of the enantiomers have not yet been disclosed. In the present study, crystals of (R)-(-)- and (S)-(+)-mandelate salts of (+)- and (-)-blarcamesine and also that of (R)-(+)-blarcamesine itself, suitable for single-crystal X-ray diffraction measurement were prepared and the absolute configurations of (+)- and (-)-blarcamesine have been determined.
{"title":"Assignment of Absolute Configuration to Enantiomers of Anti-Alzheimer Drug Candidate Blarcamesine","authors":"Zsuzsanna Szokol, Károly Lozsi, A. Virág, A. Dancsó, L. Szlávik, G. Simig, Balázs Volk","doi":"10.3311/ppch.20662","DOIUrl":"https://doi.org/10.3311/ppch.20662","url":null,"abstract":"Blarcamesine is a promising investigational drug for the treatment of Alzheimer's disease. The international nonproprietary name blarcamesine refers to a racemic compound, although it seems likely that it will be marketed in an enantiopure form. A resolution process has been described in the literature, but the absolute configurations of the enantiomers have not yet been disclosed. In the present study, crystals of (R)-(-)- and (S)-(+)-mandelate salts of (+)- and (-)-blarcamesine and also that of (R)-(+)-blarcamesine itself, suitable for single-crystal X-ray diffraction measurement were prepared and the absolute configurations of (+)- and (-)-blarcamesine have been determined.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78674631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Due to the efforts of reducing greenhouse gas emissions, nearly two-thirds of the installed electric capacity worldwide will come from renewables in 2050 (EIA 2021), making frequency control without energy storage impossible. Power-to-Methane (PtM) technology allows electricity to be stored in the form of methane. The storage efficiency of PtM may be increased either by maximizing the recovery of the stored electricity, which is a common method, or by reducing the amount of electricity the PtM has to be charged with for a given amount of stored energy. In this paper, a case study is presented for the latter by directly integrating an Organic Rankine Cycle into the PtM technology by recycling the waste heat from water electrolysis and biological methanation back to electrolysis. With this method, total storage efficiency can be increased by approximately two percentage points.
{"title":"Efficiency Increase of Biological Methanation based Power-to-Methane Technology Using Waste Heat Recovery with Organic Rankine Cycle","authors":"A. Groniewsky, Réka Kustán, A. Imre","doi":"10.3311/ppch.20428","DOIUrl":"https://doi.org/10.3311/ppch.20428","url":null,"abstract":"Due to the efforts of reducing greenhouse gas emissions, nearly two-thirds of the installed electric capacity worldwide will come from renewables in 2050 (EIA 2021), making frequency control without energy storage impossible. Power-to-Methane (PtM) technology allows electricity to be stored in the form of methane. The storage efficiency of PtM may be increased either by maximizing the recovery of the stored electricity, which is a common method, or by reducing the amount of electricity the PtM has to be charged with for a given amount of stored energy. In this paper, a case study is presented for the latter by directly integrating an Organic Rankine Cycle into the PtM technology by recycling the waste heat from water electrolysis and biological methanation back to electrolysis. With this method, total storage efficiency can be increased by approximately two percentage points.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86726482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper emphasizes the importance of isotope studies as a unique tool for detecting groundwater contamination with the landfill leachate. The aim of the study was to present an additional and useful method for detecting groundwater contamination, based on stable isotope analysis. The proposed method relies on the interpretation of measured δ13CDIC and δ18O levels (in precipitated carbonates during preparation of a water sample). According to this method, two zones with different isotope composition of groundwater were identified: the first zone with natural groundwater and with low δ13CDIC levels (from −20.6 to −12.4‰) and high δ18O levels (from −13.6 to −8.0‰), and the second zone with leachate-contaminated groundwater rich in δ13CDIC (from −10.9 to + 3.6‰) and high level of δ18O (from −9.8 to −7.1‰). Measuring the isotopic composition of oxygen alone, is insufficient to delimit the contaminated zone due a partial overlap of natural levels with those of the contaminated with groundwater leachates. Determination of δ13CDIC and δ18O in the landfill leachate-contaminated water can provide an effective tool to detect groundwater contamination near municipal landfills, and it can help to minimize the number of samples collected for the analysis of conventional parameters. This proven method may offer an easy-to-use solution for detecting groundwater contamination.
{"title":"Precipitation Method for Determination of Carbon and Oxygen Isotopes to Detect Groundwater Contamination Near a Municipal Landfill","authors":"D. Porowska","doi":"10.3311/ppch.20266","DOIUrl":"https://doi.org/10.3311/ppch.20266","url":null,"abstract":"The paper emphasizes the importance of isotope studies as a unique tool for detecting groundwater contamination with the landfill leachate. The aim of the study was to present an additional and useful method for detecting groundwater contamination, based on stable isotope analysis. The proposed method relies on the interpretation of measured δ13CDIC and δ18O levels (in precipitated carbonates during preparation of a water sample). According to this method, two zones with different isotope composition of groundwater were identified: the first zone with natural groundwater and with low δ13CDIC levels (from −20.6 to −12.4‰) and high δ18O levels (from −13.6 to −8.0‰), and the second zone with leachate-contaminated groundwater rich in δ13CDIC (from −10.9 to + 3.6‰) and high level of δ18O (from −9.8 to −7.1‰). Measuring the isotopic composition of oxygen alone, is insufficient to delimit the contaminated zone due a partial overlap of natural levels with those of the contaminated with groundwater leachates. Determination of δ13CDIC and δ18O in the landfill leachate-contaminated water can provide an effective tool to detect groundwater contamination near municipal landfills, and it can help to minimize the number of samples collected for the analysis of conventional parameters. This proven method may offer an easy-to-use solution for detecting groundwater contamination.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84820854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Balázs Szemenyei, Marianna Firisz, P. Baranyai, Péter Bagi, L. Drahos, Ildikó Móczár, P. Huszthy
(R,R)- and (S,S)-enantiomers of anthracene-containing pyridino-18-crown-6 ether having tert-butyl groups at the stereogenic centers were prepared with the aim of achieving higher enantioselectivity than for the reported (S,S)-analogue having isobutyl groups. The enantiomeric recognition abilities of the new sensor molecules toward chiral protonated primary amines and amino acid esters were studied in acetonitrile by UV–vis and fluorescence spectroscopies. The pKa values of these pyridino-crown ethers and their reported (S,S)-analogues having methyl or isobutyl groups have also been determined in acetonitrile.
{"title":"Larger Groups, Smaller Enantioselectivity? Two Anthracene-Containing, Pyridino-Crown Ether-Based Fluorescent Sensor Molecules","authors":"Balázs Szemenyei, Marianna Firisz, P. Baranyai, Péter Bagi, L. Drahos, Ildikó Móczár, P. Huszthy","doi":"10.3311/ppch.20468","DOIUrl":"https://doi.org/10.3311/ppch.20468","url":null,"abstract":"(R,R)- and (S,S)-enantiomers of anthracene-containing pyridino-18-crown-6 ether having tert-butyl groups at the stereogenic centers were prepared with the aim of achieving higher enantioselectivity than for the reported (S,S)-analogue having isobutyl groups. The enantiomeric recognition abilities of the new sensor molecules toward chiral protonated primary amines and amino acid esters were studied in acetonitrile by UV–vis and fluorescence spectroscopies. The pKa values of these pyridino-crown ethers and their reported (S,S)-analogues having methyl or isobutyl groups have also been determined in acetonitrile.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82262734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Filipović, J. Filipović, B. Lončar, V. Knežević, M. Nićetin, V. Vujačić
The effects of the osmodehydration pretreatment parameters on successive lyophilization mass transfer kinetics of the peaches, dehydrated in the combined dehydration process, were investigated and mathematically modelled. The obtained results showed the statistically significant effect of osmotic dehydration pretreatment and its parameters on the final dry matter content and water activity values of the dehydrated peaches. The maximum dry matter content and minimal water activity values of dehydrated peach samples were 84.60 % and 0.423, respectively, produced in osmodehydration pretreatment in molasses of 80 % concentration, at 50 °C, during a 5-hour process and subsequent 6-hour lyophilization. With the increase of all osmodehydration pretreatment parameters it is possible to reduce the duration of the lyophilization process, reducing the high energy demand of the dehydration method (lyophilization) and substituting it with low energy demanding dehydration method (osmodehydration) without compromising the quality of the final product, regarding the dry matter content and water activity values. Mathematical models describing the effect of the duration of the lyophilization on the dry matter content and water activity values of the fresh and dehydrated peaches were developed. They showed a good correlation between calculated and experimental values, allowing a good prediction of the investigated responses. In the combined method, protein, sugar, K and Fe content of the dehydrated peach samples were enriched and further enhanced in prolonged lyophilization stages.
{"title":"Modeling the Effects of Osmotic Dehydration Pretreatment Parameters and Lyophilization Kinetics on Mass Transfer and Selected Nutritive Parameters of Peaches","authors":"V. Filipović, J. Filipović, B. Lončar, V. Knežević, M. Nićetin, V. Vujačić","doi":"10.3311/ppch.20242","DOIUrl":"https://doi.org/10.3311/ppch.20242","url":null,"abstract":"The effects of the osmodehydration pretreatment parameters on successive lyophilization mass transfer kinetics of the peaches, dehydrated in the combined dehydration process, were investigated and mathematically modelled. The obtained results showed the statistically significant effect of osmotic dehydration pretreatment and its parameters on the final dry matter content and water activity values of the dehydrated peaches. The maximum dry matter content and minimal water activity values of dehydrated peach samples were 84.60 % and 0.423, respectively, produced in osmodehydration pretreatment in molasses of 80 % concentration, at 50 °C, during a 5-hour process and subsequent 6-hour lyophilization. With the increase of all osmodehydration pretreatment parameters it is possible to reduce the duration of the lyophilization process, reducing the high energy demand of the dehydration method (lyophilization) and substituting it with low energy demanding dehydration method (osmodehydration) without compromising the quality of the final product, regarding the dry matter content and water activity values. Mathematical models describing the effect of the duration of the lyophilization on the dry matter content and water activity values of the fresh and dehydrated peaches were developed. They showed a good correlation between calculated and experimental values, allowing a good prediction of the investigated responses. In the combined method, protein, sugar, K and Fe content of the dehydrated peach samples were enriched and further enhanced in prolonged lyophilization stages.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85816537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Power industry needs make-up water in power plant processes to compensate for the constant water loss during work. Mediterranean Seawater samples are studied to obtain pretreated water to use as a feed for the desalination stage. A comparison of coagulation with two coagulants, namely Poly aluminum chloride and ferric chloride in a one wt% stock solution, followed by microfiltration, was evaluated to obtain an efficient pre-treatment method. The lowest dosage of PACl positively affected all the measured parameters, especially the total suspended solid content was reduced to below 10 mg/L. The addition of FeCl3 resulted in 2.5-times higher total suspended solid content (23.5±4.58 mg/L) than the initial value measured for seawater (10.8±1.03 mg/L). Considering the flux values, two-steps of microfiltration and the lowest dosage of PACl followed by microfiltration resulted in the same high flux (3500 L /(m2 h) at the initial stage and 2500 L/(m2 h) at the 90% recovery rate). The flux after FeCl3 dosage seemed to be the highest, but it should be emphasized that the flocs were filtered via two consecutive 5–13 μm microfiltration stages, so this flux is not entirely comparable with those measured in other cases. Considering the chloride concentration, after microfiltration without coagulation, it remained constant; using coagulants it showed a slight reduction (~4%). From environmental point of view, the two-steps of microfiltration is recommended to be used since no chemicals are required for the operation; it can provide a steady flux of the cleanest pretreated water based on total suspended solid content.
{"title":"The Role of Coagulation and Microfiltration in Seawater Pre-treatment","authors":"Reem Shaheen, Edit Cséfalvay","doi":"10.3311/ppch.20025","DOIUrl":"https://doi.org/10.3311/ppch.20025","url":null,"abstract":"Power industry needs make-up water in power plant processes to compensate for the constant water loss during work. Mediterranean Seawater samples are studied to obtain pretreated water to use as a feed for the desalination stage. A comparison of coagulation with two coagulants, namely Poly aluminum chloride and ferric chloride in a one wt% stock solution, followed by microfiltration, was evaluated to obtain an efficient pre-treatment method. The lowest dosage of PACl positively affected all the measured parameters, especially the total suspended solid content was reduced to below 10 mg/L. The addition of FeCl3 resulted in 2.5-times higher total suspended solid content (23.5±4.58 mg/L) than the initial value measured for seawater (10.8±1.03 mg/L). Considering the flux values, two-steps of microfiltration and the lowest dosage of PACl followed by microfiltration resulted in the same high flux (3500 L /(m2 h) at the initial stage and 2500 L/(m2 h) at the 90% recovery rate). The flux after FeCl3 dosage seemed to be the highest, but it should be emphasized that the flocs were filtered via two consecutive 5–13 μm microfiltration stages, so this flux is not entirely comparable with those measured in other cases. Considering the chloride concentration, after microfiltration without coagulation, it remained constant; using coagulants it showed a slight reduction (~4%). From environmental point of view, the two-steps of microfiltration is recommended to be used since no chemicals are required for the operation; it can provide a steady flux of the cleanest pretreated water based on total suspended solid content.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90927132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lanthanum supported on 4Å molecular sieves proved to be an efficient heterogeneous catalyst for the one-pot three-component synthesis of 1,2,3,4-tetrahydroisoquinolinone-4-carboxylic acid derivatives from homophthalic anhydride, aromatic aldehydes and an amine component, ammonium acetate or aralkyl amines, with good to excellent yields. The catalyst could be recovered easily and reused without significant loss of its initial activity.
{"title":"Heterogeneous Catalytic Method for the One-pot Three-component Synthesis of Isoquinolonic Acid Derivatives Catalyzed by a 4Å Molecular Sieves Supported Lanthanum Catalyst","authors":"Ágnes Magyar, Zoltán Hell","doi":"10.3311/ppch.20094","DOIUrl":"https://doi.org/10.3311/ppch.20094","url":null,"abstract":"Lanthanum supported on 4Å molecular sieves proved to be an efficient heterogeneous catalyst for the one-pot three-component synthesis of 1,2,3,4-tetrahydroisoquinolinone-4-carboxylic acid derivatives from homophthalic anhydride, aromatic aldehydes and an amine component, ammonium acetate or aralkyl amines, with good to excellent yields. The catalyst could be recovered easily and reused without significant loss of its initial activity.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91278548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article examines results of the thermodynamic modeling of interaction of the briquetted tailings obtained at hydrometallurgical leaching of the vanadium-containing quartzites (black shales) with carbon and iron, determination of Si, V, Fe, C equilibrium distribution and optimal conditions for the formation of various grades of ferrosilicon, as well as the electric melting to produce silicon alloys. The research techniques were the method of thermodynamic modeling using the HSC-6.0 software package (Outokumpu), the second-order rotatable designs (Box-Hunter plans) and electrofusion in an arc furnace. It was established that an increase in the amount of iron from 11 to 39% makes it possible to increase the extraction degree of silicon into an alloy up to 72–73% in the temperature of 1800–2000 °C, in the process the silicon concentration in the alloy decreases from 57–65.7 to 40.5–40.9%; FS45-grade ferrosilicon at the extraction degree of silicon in the alloy of 70–72.6% can be formed in the temperature of 1750–2000 °C in the presence of 29–39% Fe, FS50 ferrosilicon is formed at 25.5–35.0% Fe and 1870–2000 °C, and FS65 ferrosilicon – in the temperature of 1895–2000 °C in the presence of 11–12.7% Fe. The FS45-grade ferrosilicon was formed during electric smelting of a charge containing 57% of the briquettes, 21% of coke, 22% of steel chips, and the FS50-grade ferrosilicon – using a charge consisting of 61% of the briquettes, 22% of coke and 17% of steel chips; the silicon extraction degree into the alloys is 73–79%.
{"title":"Comprehensive Processing of Vanadium-Containing Black Shale Tailings","authors":"V. Shevko, D. Aitkulov, A. Badikova","doi":"10.3311/ppch.20050","DOIUrl":"https://doi.org/10.3311/ppch.20050","url":null,"abstract":"This article examines results of the thermodynamic modeling of interaction of the briquetted tailings obtained at hydrometallurgical leaching of the vanadium-containing quartzites (black shales) with carbon and iron, determination of Si, V, Fe, C equilibrium distribution and optimal conditions for the formation of various grades of ferrosilicon, as well as the electric melting to produce silicon alloys. The research techniques were the method of thermodynamic modeling using the HSC-6.0 software package (Outokumpu), the second-order rotatable designs (Box-Hunter plans) and electrofusion in an arc furnace. It was established that an increase in the amount of iron from 11 to 39% makes it possible to increase the extraction degree of silicon into an alloy up to 72–73% in the temperature of 1800–2000 °C, in the process the silicon concentration in the alloy decreases from 57–65.7 to 40.5–40.9%; FS45-grade ferrosilicon at the extraction degree of silicon in the alloy of 70–72.6% can be formed in the temperature of 1750–2000 °C in the presence of 29–39% Fe, FS50 ferrosilicon is formed at 25.5–35.0% Fe and 1870–2000 °C, and FS65 ferrosilicon – in the temperature of 1895–2000 °C in the presence of 11–12.7% Fe. The FS45-grade ferrosilicon was formed during electric smelting of a charge containing 57% of the briquettes, 21% of coke, 22% of steel chips, and the FS50-grade ferrosilicon – using a charge consisting of 61% of the briquettes, 22% of coke and 17% of steel chips; the silicon extraction degree into the alloys is 73–79%.","PeriodicalId":19922,"journal":{"name":"Periodica Polytechnica Chemical Engineering","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2022-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83764038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ida Zahović, J. Dodić, J. Grahovac, Aleksandra Ranitović, M. Grahovac, Ivana Pajčin, Zorana Trivunović
In this study, the effect of cultivation time on xanthan biosynthesis by different Xanthomonas campestris and Xanthomonas euvesicatoria strains, isolated from crucifers and pepper leaves, respectively, was examined. Xanthan was produced by submerged cultivation on crude glycerol-based medium at a laboratory level under aerobic conditions at 30 °C and 150 rpm for 168 h and 240 h. Bioprocess efficacy was estimated based on the xanthan concentration in media at the end of bioprocess and its average molecular weight. According to the obtained results, Xanthomonas strains have statistically significant effect on xanthan concentration in cultivation media when biosynthesis is performed by X. euvesicatoria strains, and cultivation time has significant effect on this parameter only when bioprocess is performed by X.campestris strains. The combination of Xanthomonas strains and cultivation time has a statistically significant effect on xanthan concentration in medium for both groups of isolates. The obtained results show that all applied Xanthomonas strains and cultivation time as well as their combination have statistically significant effect on average molecular weight of xanthan produced in applied experimental conditions. It is found that X. euvesicatoria strains produce higher amount of xanthan in a shorter period of time (168 h) when compared to the X.campestris strains. Xanthan of higher average molecular weight was produced when cultivation of both groups of isolates was performed for 240 h in applied experimental conditions. Results obtained in this research suggest that X. euvesicatoria strains have the greatest potential for application in biotechnological production of xanthan on crude glycerol-based medium.
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