Pub Date : 2023-01-01DOI: 10.2298/hemind220628005l
I. Lukić, Zeljka Kesic, M. Zdujić, D. Skala
Synthesis of biodiesel from various plant oils is realized by the transesterification of triglycerides with methanol or by a reaction usually defined as methanolysis. The usage of low-quality oils, such as waste cooking oil (WCO), is followed by undesirable side reactions as a result of the increased content of free fatty acids (FFA), and water. The presence of FFA in WCO usually requires a pretreatment stage before subjecting it to methanolysis. In the present work, heterogeneously catalyzed methanolysis of WCO with and without pretreatment was investigated. Removal of FFA from WCO was conducted by using only quicklime or with the addition of a small amount of methanol (FFA to methanol = 1:3 molar ratio). The obtained results showed that pretreatment of WCO with quicklime at 30?C after 1 h reduces the FFA content by 72 %, while the adsorption capacity was determined to be 910 mg g-1. The adsorptive pretreatment, as a simple operation, using low-cost quicklime under mild conditions, had a positive effect on the transesterification rate with CaO?ZnO as a catalyst, enabling the achievement of over 96 % of biodiesel yield in only 15 min, compared to 1 h without the pretreatment. Furthermore, pretreated WCO allows an increase in repeated catalyst use and overall savings in the necessary amount of catalyst. The present study showed that quicklime is an economic, environmental-friendly, and sustainable material for FFA removal from WCO.
{"title":"Adsorptive pretreatment of waste cooking oil using quicklime for fatty acid methyl esters synthesis","authors":"I. Lukić, Zeljka Kesic, M. Zdujić, D. Skala","doi":"10.2298/hemind220628005l","DOIUrl":"https://doi.org/10.2298/hemind220628005l","url":null,"abstract":"Synthesis of biodiesel from various plant oils is realized by the transesterification of triglycerides with methanol or by a reaction usually defined as methanolysis. The usage of low-quality oils, such as waste cooking oil (WCO), is followed by undesirable side reactions as a result of the increased content of free fatty acids (FFA), and water. The presence of FFA in WCO usually requires a pretreatment stage before subjecting it to methanolysis. In the present work, heterogeneously catalyzed methanolysis of WCO with and without pretreatment was investigated. Removal of FFA from WCO was conducted by using only quicklime or with the addition of a small amount of methanol (FFA to methanol = 1:3 molar ratio). The obtained results showed that pretreatment of WCO with quicklime at 30?C after 1 h reduces the FFA content by 72 %, while the adsorption capacity was determined to be 910 mg g-1. The adsorptive pretreatment, as a simple operation, using low-cost quicklime under mild conditions, had a positive effect on the transesterification rate with CaO?ZnO as a catalyst, enabling the achievement of over 96 % of biodiesel yield in only 15 min, compared to 1 h without the pretreatment. Furthermore, pretreated WCO allows an increase in repeated catalyst use and overall savings in the necessary amount of catalyst. The present study showed that quicklime is an economic, environmental-friendly, and sustainable material for FFA removal from WCO.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73978277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind221021012p
A. Petrov, G. Čubrić, I. Salopek-Cubric
Active sportswear has certain functions that should meet the expected properties and improve the performance of athletes. In addition to functionality, an important aspect of sportswear is thermal and physiological comfort. By choosing the right clothing for athletes, the dynamic and thermal load can be significantly reduced because sports require unhindered mobility, and clothing must be adapted to the body and absorb sweat. Proper vapour and liquid flow in textile materials are important from a comfort point of view. Therefore, in this research, seven representative samples were selected that are used for clothing intended for sport and leisure. Using an infrared thermal camera, the transfer of liquid on the surface of the material was precisely monitored, until the final stage when the material is completely dry. The obtained results show that fabric made of 100 % polyester has the shortest drying time, while the highest vapour permeability was exhibited by fabric made of viscose and elastane yarn. Those fabrics should be considered as the most suitable for sportswear because they do not cause discomfort when worn. Infrared thermography is a very useful method in research because it provides reliable data, especially when it comes to the drying time of the material.
{"title":"Transfer of liquid and water vapour through knitted materials","authors":"A. Petrov, G. Čubrić, I. Salopek-Cubric","doi":"10.2298/hemind221021012p","DOIUrl":"https://doi.org/10.2298/hemind221021012p","url":null,"abstract":"Active sportswear has certain functions that should meet the expected properties and improve the performance of athletes. In addition to functionality, an important aspect of sportswear is thermal and physiological comfort. By choosing the right clothing for athletes, the dynamic and thermal load can be significantly reduced because sports require unhindered mobility, and clothing must be adapted to the body and absorb sweat. Proper vapour and liquid flow in textile materials are important from a comfort point of view. Therefore, in this research, seven representative samples were selected that are used for clothing intended for sport and leisure. Using an infrared thermal camera, the transfer of liquid on the surface of the material was precisely monitored, until the final stage when the material is completely dry. The obtained results show that fabric made of 100 % polyester has the shortest drying time, while the highest vapour permeability was exhibited by fabric made of viscose and elastane yarn. Those fabrics should be considered as the most suitable for sportswear because they do not cause discomfort when worn. Infrared thermography is a very useful method in research because it provides reliable data, especially when it comes to the drying time of the material.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90876109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind230222016m
Walid Musrati, B. Medjo, I. Cvijović-Alagić, N. Gubeljak, Primož Štefane, Z. Radosavljevic, M. Rakin
Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue pre-crack are discussed.
{"title":"Microstructure, hardness and fracture resistance of P235TR1 seam steel pipes of different diameters","authors":"Walid Musrati, B. Medjo, I. Cvijović-Alagić, N. Gubeljak, Primož Štefane, Z. Radosavljevic, M. Rakin","doi":"10.2298/hemind230222016m","DOIUrl":"https://doi.org/10.2298/hemind230222016m","url":null,"abstract":"Steel pipelines in industrial plants consist of different elements, including seamless and/or welded (seam) pipes. Properties of welded pipes, including their fracture behaviour, depend on the characteristics of both, the base metal, and the weld metal. In this work, two seam pipes are considered having different diameters and manufactured of P235TR1 steel. Hardness and microstructure were examined on the samples which contained the seam zone, to capture the influence of heterogeneity. Fracture resistance of the pipeline material, i.e. of both base metals and both seams, was determined by experimental examination of the recently proposed Pipe ring notch bending specimens with sharp stress concentrators. Differences between the two tested pipes, including the influence of the heterogeneity caused by the welded joint, were determined by comparison of the crack growth resistance curves. Effects of the initial stress concentrator shape, sharp machined notch or fatigue pre-crack are discussed.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79359166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind230403010m
Ivana Bankovic-Ilic, Marija Miladinovic
nema
{"title":"Advances in biodiesel production research","authors":"Ivana Bankovic-Ilic, Marija Miladinovic","doi":"10.2298/hemind230403010m","DOIUrl":"https://doi.org/10.2298/hemind230403010m","url":null,"abstract":"<jats:p>nema</jats:p>","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"245 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76964743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind220804007m
D. Marinković, S. Pavlović
Considering the current world crisis and definite future energy challenges, biomass-to-fuel transformation is increasingly becoming important both to the policy makers and to the industry. In this perspective, the valorisation of oils and fats via transesterification/esterification reaction is an attractive method for producing biodiesel with qualities suitable for diesel engines. The recent interest indicated a significant shift to industrial waste valorisation as another approach for achieving process eco-efficiency. In this respect, the use of zeolite-based catalysts for the production of biofuels is reviewed here, with a special emphasis on the utilization of waste raw materials following the principles of green chemistry and sustainable development. Zeolites are interesting due to their outstanding catalytic properties, including the presence of intrinsic acid sites, simple loading of base sites, shape-selectivity, and high thermal stability. Neat zeolites or modified by the loading of active species are classified into several groups following their origin. For each group, the most relevant recent results reported in the literature are reviewed together with some critical considerations on the catalyst effectiveness, stability, reusability, and economy of synthesis. As an important part required for understanding and optimization of the biodiesel production process, the mechanisms of the reaction were discussed in detail. Finally, key perspective directions for further research studies were carefully identified and elaborated.
{"title":"Recent advances in waste-based and natural zeolitic catalytic materials for biodiesel production","authors":"D. Marinković, S. Pavlović","doi":"10.2298/hemind220804007m","DOIUrl":"https://doi.org/10.2298/hemind220804007m","url":null,"abstract":"Considering the current world crisis and definite future energy challenges, biomass-to-fuel transformation is increasingly becoming important both to the policy makers and to the industry. In this perspective, the valorisation of oils and fats via transesterification/esterification reaction is an attractive method for producing biodiesel with qualities suitable for diesel engines. The recent interest indicated a significant shift to industrial waste valorisation as another approach for achieving process eco-efficiency. In this respect, the use of zeolite-based catalysts for the production of biofuels is reviewed here, with a special emphasis on the utilization of waste raw materials following the principles of green chemistry and sustainable development. Zeolites are interesting due to their outstanding catalytic properties, including the presence of intrinsic acid sites, simple loading of base sites, shape-selectivity, and high thermal stability. Neat zeolites or modified by the loading of active species are classified into several groups following their origin. For each group, the most relevant recent results reported in the literature are reviewed together with some critical considerations on the catalyst effectiveness, stability, reusability, and economy of synthesis. As an important part required for understanding and optimization of the biodiesel production process, the mechanisms of the reaction were discussed in detail. Finally, key perspective directions for further research studies were carefully identified and elaborated.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78473825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind220909002s
Danijela Stojadinović, Amelija Djordjević, I. Krstić, Jasmina Radosavljević
Technogenic risk is the result of creation and development of hazards that originate from accidents in the technosphere. It involves emissions of hazardous industrial substances into the work and natural environments, fires, radioactive contamination, and contamination by toxic substances during their transport and storage. The qualitative and quantitative technogenic risk assessment has to be performed during the use, handling, transport, and storage of hazardous substances if it is decided that specific environmental elements at a specific location are likely to become exposed to hazardous substances, leading to environmental degradation. This paper discusses vulnerability zones - specifically, the high lethality zone and the irreversible effects zone - that are formed due to hazardous events or accidents in the paints and varnishes industry. Accidents are discussed in terms of exposure to solvents classified as hazardous to ecosystem components, the biosphere, anthroposphere, and the human population during their atmospheric dispersion. The vulnerability zones are designated using the REHRA (Rapid Environmental and Health Risk Assessment) methodology and their spatial arrangement is used to perform the risk assessment for the purpose of notifying authorized institutions and the public about a potentially increased risk at the hazard location and/or the immediate vicinity.
{"title":"Atmospheric release of organic solvents due to hazardous events in the paints and varnishes industry","authors":"Danijela Stojadinović, Amelija Djordjević, I. Krstić, Jasmina Radosavljević","doi":"10.2298/hemind220909002s","DOIUrl":"https://doi.org/10.2298/hemind220909002s","url":null,"abstract":"Technogenic risk is the result of creation and development of hazards that originate from accidents in the technosphere. It involves emissions of hazardous industrial substances into the work and natural environments, fires, radioactive contamination, and contamination by toxic substances during their transport and storage. The qualitative and quantitative technogenic risk assessment has to be performed during the use, handling, transport, and storage of hazardous substances if it is decided that specific environmental elements at a specific location are likely to become exposed to hazardous substances, leading to environmental degradation. This paper discusses vulnerability zones - specifically, the high lethality zone and the irreversible effects zone - that are formed due to hazardous events or accidents in the paints and varnishes industry. Accidents are discussed in terms of exposure to solvents classified as hazardous to ecosystem components, the biosphere, anthroposphere, and the human population during their atmospheric dispersion. The vulnerability zones are designated using the REHRA (Rapid Environmental and Health Risk Assessment) methodology and their spatial arrangement is used to perform the risk assessment for the purpose of notifying authorized institutions and the public about a potentially increased risk at the hazard location and/or the immediate vicinity.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86564810","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-01DOI: 10.2298/hemind230503015b
I. Bates, Ivana Plazonić, Katja Petric-Maretic, Maja Rudolf
Paper is one of the most important materials for packaging and the demand for this material is constantly increasing. The printing and packaging industries are researching alternative sources of fibre, to produce more environmentally friendly paper without compromising quality. As a packaging material, paper must meet high strength requirements, and it has to exhibit acceptable surface properties to preserve the printing quality. This research had two objectives: to produce paper made from pulp of recycled fibre reinforced with virgin straw fibre and to evaluate the print quality on such papers. Straw pulp used for this purpose was obtained from three cereal crops: wheat, barley, and triticale. The paper produced was printed by using five printing techniques. Rubbing stability was evaluated by the difference in colour and reflectance spectra before and after performing rub tests and a comparison was made for the best interaction of paper and ink determined by the printing technique. For the prints with the highest colour difference after the rub test, the surface of the rub test receptor (uncoated recycled paper) was examined for signs of ink transfer during the test and the areas of transferred ink coverage were calculated on their processed microscopic images.
{"title":"Rubbing stability of printed innovative paper substrates containing cereal straw pulp","authors":"I. Bates, Ivana Plazonić, Katja Petric-Maretic, Maja Rudolf","doi":"10.2298/hemind230503015b","DOIUrl":"https://doi.org/10.2298/hemind230503015b","url":null,"abstract":"Paper is one of the most important materials for packaging and the demand for this material is constantly increasing. The printing and packaging industries are researching alternative sources of fibre, to produce more environmentally friendly paper without compromising quality. As a packaging material, paper must meet high strength requirements, and it has to exhibit acceptable surface properties to preserve the printing quality. This research had two objectives: to produce paper made from pulp of recycled fibre reinforced with virgin straw fibre and to evaluate the print quality on such papers. Straw pulp used for this purpose was obtained from three cereal crops: wheat, barley, and triticale. The paper produced was printed by using five printing techniques. Rubbing stability was evaluated by the difference in colour and reflectance spectra before and after performing rub tests and a comparison was made for the best interaction of paper and ink determined by the printing technique. For the prints with the highest colour difference after the rub test, the surface of the rub test receptor (uncoated recycled paper) was examined for signs of ink transfer during the test and the areas of transferred ink coverage were calculated on their processed microscopic images.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82212851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220402017n
M. Nikolic, V. Tomašević, Dragan Ugrinov
Fossil fuel depletion and soil and water pollution gave impetus to the development of a novel perspective of sustainable development. In addition to the use of plant biomass for ethanol production, plants can be used to reduce the concentration of heavy metals in soil and water. Due to tolerance to high levels of metals, many plant species, crops, non-crops, medicinal, and pharmaceutical energy plants are well-known metal hyperaccumulators. This paper focuses on studies investigating the potential of Miscanthus sp., Beta vulgaris L., Saccharum sp., Ricinus communis L. Prosopis sp. and Arundo donax L. in heavy metal removal and biofuel production. Phytoremediation employing these plants showed great potential for bioaccumulation of Co, Cr, Cu, Al, Pb, Ni, Fe, Cd, Zn, Hg, Se, etc. This review presents the potential of lignocellulose plants to remove pollutants being a valuable substrate for biofuel production. Also, pretreat-ments, dealing with toxic biomass, and biofuel production are discussed.
化石燃料枯竭和土壤和水污染推动了可持续发展新观点的发展。除了利用植物生物量生产乙醇外，植物还可用于降低土壤和水中重金属的浓度。由于对高水平金属的耐受性，许多植物物种，作物，非作物，药用和药用能源植物都是众所周知的金属超蓄积物。本文重点研究了Miscanthus sp.、Beta vulgaris L.、Saccharum sp.、Ricinus communis L. Prosopis sp.和Arundo donax L.在重金属去除和生物燃料生产方面的潜力。利用这些植物进行植物修复，对Co、Cr、Cu、Al、Pb、Ni、Fe、Cd、Zn、Hg、Se等具有较大的生物富集潜力。本文综述了木质纤维素植物去除污染物的潜力，作为生物燃料生产的有价值的基质。此外，预处理，处理有毒生物质和生物燃料的生产进行了讨论。
{"title":"Energy plants as biofuel source and as accumulators of heavy metals","authors":"M. Nikolic, V. Tomašević, Dragan Ugrinov","doi":"10.2298/hemind220402017n","DOIUrl":"https://doi.org/10.2298/hemind220402017n","url":null,"abstract":"Fossil fuel depletion and soil and water pollution gave impetus to the development of a novel perspective of sustainable development. In addition to the use of plant biomass for ethanol production, plants can be used to reduce the concentration of heavy metals in soil and water. Due to tolerance to high levels of metals, many plant species, crops, non-crops, medicinal, and pharmaceutical energy plants are well-known metal hyperaccumulators. This paper focuses on studies investigating the potential of Miscanthus sp., Beta vulgaris L., Saccharum sp., Ricinus communis L. Prosopis sp. and Arundo donax L. in heavy metal removal and biofuel production. Phytoremediation employing these plants showed great potential for bioaccumulation of Co, Cr, Cu, Al, Pb, Ni, Fe, Cd, Zn, Hg, Se, etc. This review presents the potential of lignocellulose plants to remove pollutants being a valuable substrate for biofuel production. Also, pretreat-ments, dealing with toxic biomass, and biofuel production are discussed.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75566055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220222014s
A. Sedmak, Radzeya Zaidi, Borivoje Vujicic, Ž. Šarkočević, S. Kirin, Z. Stamenic, Milos B. Djukic, G. Bakić
Corrosion effects on structural integrity and life of oil rig welded pipes are analysed by experimental, analytical, and numerical methods. Experiments were performed using standard tensile specimens and CT specimens for static loading, Charpy specimens for impact loading, and 3 Point Bending specimens for fatigue crack growth with amplitude loading. In each case new and old pipes were used to evaluate corrosion effects. Results indicated negligible corrosion effects in the case of tensile properties and impact toughness, and strong effects in the case of fracture toughness and especially fatigue crack growth rates, increasing the risk of static failure and reducing significantly structural life. Analytical expressions are used for oil rig pipe structural integrity and life assessment to quantify these effects. Recently introduced risk-based approach is applied to analyse oil rig drill pipe with a corrosion defect treated as a surface crack.
{"title":"Corrosion effects on structural integrity and life of oil rig drill pipes","authors":"A. Sedmak, Radzeya Zaidi, Borivoje Vujicic, Ž. Šarkočević, S. Kirin, Z. Stamenic, Milos B. Djukic, G. Bakić","doi":"10.2298/hemind220222014s","DOIUrl":"https://doi.org/10.2298/hemind220222014s","url":null,"abstract":"Corrosion effects on structural integrity and life of oil rig welded pipes are analysed by experimental, analytical, and numerical methods. Experiments were performed using standard tensile specimens and CT specimens for static loading, Charpy specimens for impact loading, and 3 Point Bending specimens for fatigue crack growth with amplitude loading. In each case new and old pipes were used to evaluate corrosion effects. Results indicated negligible corrosion effects in the case of tensile properties and impact toughness, and strong effects in the case of fracture toughness and especially fatigue crack growth rates, increasing the risk of static failure and reducing significantly structural life. Analytical expressions are used for oil rig pipe structural integrity and life assessment to quantify these effects. Recently introduced risk-based approach is applied to analyse oil rig drill pipe with a corrosion defect treated as a surface crack.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73948869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.2298/hemind220516019b
Maša Buljac, Nediljka Vukojević-Medvidović, Ana-Maria Sunjic, Zvonimir Jukić, Josip Radić
Composting is recognized as a sustainable waste management approach in which microorganisms treat and stabilize biodegradable waste under aerobic conditions to obtain compost as a final product. In this paper, composting of biowaste in a rotary drum composter (closed system) and an open container (open system) was compared. Temperature, pH, electrical conductivity, a carbon-to-nitrogen mass ratio (C/N ratio) and contents of moisture, carbon and dry and volatile matter, were measured during composting. Results showed decreasing profiles for moisture, volatile matter, and carbon contents, as well as for the C/N ratio, while increasing profiles for the dry matter content and electrical conductivity during composting in both systems. Leachates were formed only during the first three days of composting and were characterized with high organic loads, high ammonia concentrations, low pH, and high conductivity and turbidity. The organic matter content data during the composting process were analysed according to the first order kinetic model. Results suggested that there was a difference in the rate of organic matter decomposition, which was higher when composting in the open vessel than in the rotary drum composter.
{"title":"Biowaste composting process - comparison of a rotary drum composter and open container","authors":"Maša Buljac, Nediljka Vukojević-Medvidović, Ana-Maria Sunjic, Zvonimir Jukić, Josip Radić","doi":"10.2298/hemind220516019b","DOIUrl":"https://doi.org/10.2298/hemind220516019b","url":null,"abstract":"Composting is recognized as a sustainable waste management approach in which microorganisms treat and stabilize biodegradable waste under aerobic conditions to obtain compost as a final product. In this paper, composting of biowaste in a rotary drum composter (closed system) and an open container (open system) was compared. Temperature, pH, electrical conductivity, a carbon-to-nitrogen mass ratio (C/N ratio) and contents of moisture, carbon and dry and volatile matter, were measured during composting. Results showed decreasing profiles for moisture, volatile matter, and carbon contents, as well as for the C/N ratio, while increasing profiles for the dry matter content and electrical conductivity during composting in both systems. Leachates were formed only during the first three days of composting and were characterized with high organic loads, high ammonia concentrations, low pH, and high conductivity and turbidity. The organic matter content data during the composting process were analysed according to the first order kinetic model. Results suggested that there was a difference in the rate of organic matter decomposition, which was higher when composting in the open vessel than in the rotary drum composter.","PeriodicalId":9933,"journal":{"name":"Chemical Industry","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80373755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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