Pub Date : 2023-09-21DOI: 10.3390/recycling8050072
Chi Nghia Chung, Christian Marschik, Jakub Klimosek, Juraj Kosek, Mohamad Hassan Akhras, Georg Steinbichler
One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of which often depends on the diffusion coefficient—a measure of the mass transport of volatile components in polymeric phases. The aim of this study was to develop a practically feasible experimental approach using thermogravimetric analysis (TGA) to determine the average diffusion coefficient of volatile components in polymer waste materials. First, the TGA method was validated with a pressure decay apparatus (PDA) using predefined binary material mixtures: Thin sheets were pressed from virgin high-density polyethylene (HDPE) and polypropylene (PP) and deliberately saturated with toluene in a sorption experiment. These saturated samples were then used in TGA and PDA desorption experiments at 60 °C, 80 °C and 100 °C, which yielded similar results with an average difference of 7.4% for the HDPE-toluene system and 14.7% for the PP-toluene system. When validated, TGA was employed to determine the diffusion coefficient of volatile components in post-industrial plastic waste melt at a temperature of 220 °C. The proposed method contributes to the understanding of diffusion-based mass transport in polymer waste materials and provides a key parameter for model-based process control and optimization. In practice, the diffusion coefficient results can be used to predict the degassing performance of an extrusion process in the mechanical recycling of plastic waste.
{"title":"An Experimental Approach to Determining the Average Diffusion Coefficient of Volatile Components in Polymer Waste Materials","authors":"Chi Nghia Chung, Christian Marschik, Jakub Klimosek, Juraj Kosek, Mohamad Hassan Akhras, Georg Steinbichler","doi":"10.3390/recycling8050072","DOIUrl":"https://doi.org/10.3390/recycling8050072","url":null,"abstract":"One of the major challenges in recycling plastics is the removal of undesired volatile components from the polymeric phase, which may reduce process efficiency and negatively affect product quality. Accordingly, the recycling industry employs a broad range of degassing techniques, the efficiency of which often depends on the diffusion coefficient—a measure of the mass transport of volatile components in polymeric phases. The aim of this study was to develop a practically feasible experimental approach using thermogravimetric analysis (TGA) to determine the average diffusion coefficient of volatile components in polymer waste materials. First, the TGA method was validated with a pressure decay apparatus (PDA) using predefined binary material mixtures: Thin sheets were pressed from virgin high-density polyethylene (HDPE) and polypropylene (PP) and deliberately saturated with toluene in a sorption experiment. These saturated samples were then used in TGA and PDA desorption experiments at 60 °C, 80 °C and 100 °C, which yielded similar results with an average difference of 7.4% for the HDPE-toluene system and 14.7% for the PP-toluene system. When validated, TGA was employed to determine the diffusion coefficient of volatile components in post-industrial plastic waste melt at a temperature of 220 °C. The proposed method contributes to the understanding of diffusion-based mass transport in polymer waste materials and provides a key parameter for model-based process control and optimization. In practice, the diffusion coefficient results can be used to predict the degassing performance of an extrusion process in the mechanical recycling of plastic waste.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136237547","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 : 2023-09-15DOI: 10.3390/recycling8050071
Cecilia Chaine, Andrew S. Hursthouse, Iain McLellan, Evi Viza, Jan Miller
Countries with emerging legislation on the waste electrical and electric equipment (WEEE), but limited infrastructure, may find in other, more robust, systems the tools to develop adaptable and socioeconomically viable management schemes. Additives found in the plastics in electronic goods, such as brominated flame retardants (BFRs), are components of a safety system, but introduce characteristics that result in their waste being hazardous. Established and emerging regulatory systems need to implement legislation that impacts the management of WEEE, to reduce risks to human health and the environment, while maximising opportunities for resource recovery from widely varying materials. To assess the context of developed and emerging regulatory systems, a baseline study was undertaken of WEEE plastics in Scotland and Uruguay. For the identification of BFRs in plastics, an internationally validated screening methodology using X-ray fluorescence was adopted at different processing operations. It was observed that, using a threshold of 830 mg/kg for Br as a BFR tracer, in Scotland, more than 70% of the plastics would be recyclable, while, in Uruguay, that fraction dropped to 50%. These results, and the wider literature discussion, highlight the impact that regulatory frameworks have on the quality and recyclability of recovered material. We identify future actions to be considered by policy-makers for a more sustainable regulatory approach.
{"title":"The Challenge of Plastic Management for Waste Electrical and Electric Equipment Recycling in the Global South: A Case Comparison between Europe and Latin America","authors":"Cecilia Chaine, Andrew S. Hursthouse, Iain McLellan, Evi Viza, Jan Miller","doi":"10.3390/recycling8050071","DOIUrl":"https://doi.org/10.3390/recycling8050071","url":null,"abstract":"Countries with emerging legislation on the waste electrical and electric equipment (WEEE), but limited infrastructure, may find in other, more robust, systems the tools to develop adaptable and socioeconomically viable management schemes. Additives found in the plastics in electronic goods, such as brominated flame retardants (BFRs), are components of a safety system, but introduce characteristics that result in their waste being hazardous. Established and emerging regulatory systems need to implement legislation that impacts the management of WEEE, to reduce risks to human health and the environment, while maximising opportunities for resource recovery from widely varying materials. To assess the context of developed and emerging regulatory systems, a baseline study was undertaken of WEEE plastics in Scotland and Uruguay. For the identification of BFRs in plastics, an internationally validated screening methodology using X-ray fluorescence was adopted at different processing operations. It was observed that, using a threshold of 830 mg/kg for Br as a BFR tracer, in Scotland, more than 70% of the plastics would be recyclable, while, in Uruguay, that fraction dropped to 50%. These results, and the wider literature discussion, highlight the impact that regulatory frameworks have on the quality and recyclability of recovered material. We identify future actions to be considered by policy-makers for a more sustainable regulatory approach.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135437442","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 : 2023-09-12DOI: 10.3390/recycling8050070
Ketija Bumbiere, Maksims Feofilovs, Pauls Asaris, Dagnija Blumberga
As an integral part of the EU’s Green Deal, the purpose of the bioeconomy is to ensure an effective transition to meet people’s needs based on renewable resources while maintaining economic growth. This study undertakes the modeling of bioresource value scenarios in the agricultural sector and proposes a methodology to evaluate the possibilities of reaching a higher added value of bioresource products. The main objective of the study is the adaptation of the market allocation–energy flow optimization model system (TIMES) for analysis of high-value-added product production capacities in the livestock sector to reach an increase in added value for 2030 with the introduction of new technologies. The developed model is tested in a case study of the animal husbandry sector in Latvia. The results show which pathways are economically feasible to achieve value-added targets set for 2030. Although not all of the available resources are used due to local market limitations, there is significant potential for the use of animal husbandry resource waste, and it is possible to achieve about 62% higher cumulative added value from 2023 to 2030 with the production of new products (protein powder, wool pellets, and gelatin) in comparison with the base scenario.
{"title":"Application of TIMES for Bioresource Flow Optimization—Case Study of Animal Husbandry in Latvia, Europe","authors":"Ketija Bumbiere, Maksims Feofilovs, Pauls Asaris, Dagnija Blumberga","doi":"10.3390/recycling8050070","DOIUrl":"https://doi.org/10.3390/recycling8050070","url":null,"abstract":"As an integral part of the EU’s Green Deal, the purpose of the bioeconomy is to ensure an effective transition to meet people’s needs based on renewable resources while maintaining economic growth. This study undertakes the modeling of bioresource value scenarios in the agricultural sector and proposes a methodology to evaluate the possibilities of reaching a higher added value of bioresource products. The main objective of the study is the adaptation of the market allocation–energy flow optimization model system (TIMES) for analysis of high-value-added product production capacities in the livestock sector to reach an increase in added value for 2030 with the introduction of new technologies. The developed model is tested in a case study of the animal husbandry sector in Latvia. The results show which pathways are economically feasible to achieve value-added targets set for 2030. Although not all of the available resources are used due to local market limitations, there is significant potential for the use of animal husbandry resource waste, and it is possible to achieve about 62% higher cumulative added value from 2023 to 2030 with the production of new products (protein powder, wool pellets, and gelatin) in comparison with the base scenario.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135887584","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 : 2023-09-11DOI: 10.3390/recycling8050069
Izabella-Eva Gherman, Elena-Simina Lakatos, Sorin Dan Clinci, Florin Lungu, Vladut Vasile Constandoiu, Lucian Ionel Cioca, Elena Cristina Rada
This study provides a comprehensive view of the research field of construction and demolition waste (CDW) management in the circular economy based on a literature review. The increased intensity of interest is due to the need to create frameworks, mechanisms, and tools for the process of mind-shifting towards circularity. Research topics, researched life cycle stages, strategies for CDW management, sustainability assessment, building stock quantification, assessment tools and forecast methods, materials with CDW content, waste treatment solutions, and the barriers and drivers for efficient waste management in the construction industry are identified as the main concerns in the analyzed research field. The results show that a major concern in the academic field directs research to the path of innovative strategy elaboration, identifying the enablers and barriers in CDW management, computational tool creation for design and assessment, building stock modeling, and circular building material development. The environmental approach prevails, leaving economic and social assessments in CDW management uncovered. Although stakeholders’ involvement is stressed in most cases, strategies for awareness-raising and education for a sustainable circular activity in the field are lacking. The circularity of CDW management being a multifaceted and multi-disciplinary complex challenge, it is approached on different levels. This study introduces the novelty of structuring the trends of existing knowledge in a holistic view, identifying the research directions, dimensions, specific aspects, and instruments.
{"title":"Circularity Outlines in the Construction and Demolition Waste Management: A Literature Review","authors":"Izabella-Eva Gherman, Elena-Simina Lakatos, Sorin Dan Clinci, Florin Lungu, Vladut Vasile Constandoiu, Lucian Ionel Cioca, Elena Cristina Rada","doi":"10.3390/recycling8050069","DOIUrl":"https://doi.org/10.3390/recycling8050069","url":null,"abstract":"This study provides a comprehensive view of the research field of construction and demolition waste (CDW) management in the circular economy based on a literature review. The increased intensity of interest is due to the need to create frameworks, mechanisms, and tools for the process of mind-shifting towards circularity. Research topics, researched life cycle stages, strategies for CDW management, sustainability assessment, building stock quantification, assessment tools and forecast methods, materials with CDW content, waste treatment solutions, and the barriers and drivers for efficient waste management in the construction industry are identified as the main concerns in the analyzed research field. The results show that a major concern in the academic field directs research to the path of innovative strategy elaboration, identifying the enablers and barriers in CDW management, computational tool creation for design and assessment, building stock modeling, and circular building material development. The environmental approach prevails, leaving economic and social assessments in CDW management uncovered. Although stakeholders’ involvement is stressed in most cases, strategies for awareness-raising and education for a sustainable circular activity in the field are lacking. The circularity of CDW management being a multifaceted and multi-disciplinary complex challenge, it is approached on different levels. This study introduces the novelty of structuring the trends of existing knowledge in a holistic view, identifying the research directions, dimensions, specific aspects, and instruments.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135980643","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 : 2023-09-09DOI: 10.3390/recycling8050068
Austen Rowell, Tewodros Ghebrab, Randall Jeter
Microbial treatment of recycled concrete aggregate (RCA) may improve the quality of the aggregate, and enhance its use in the production of structural concrete and promote the recycling of concrete waste. The mortar phase of the RCA is responsible for the poor performance of the aggregate. Treating the old adhered mortar or removing it from the natural aggregate (NA) is an option to make RCA beneficial for the production of quality recycled aggregate concrete (RAC). Removing the adhered mortar from recycled concrete aggregate using silicate-solubilizing bacteria was investigated. The bacteria could synthesize the silicates in the calcium silicate hydrate phase of the cement paste leading to the breakdown of the old adhered mortar. Four SSB strains were tested for survivability and activity in an alkaline medium to simulate the concrete environment. The Serratia marcescens bacterial strain, which survived the environment, was inoculated into screw-cap glass vials containing recycled concrete aggregate fragments and glucose-enhanced nutrient broth and then incubated for 14 days. Partial removal of the old adhered mortar was observed based on the weight lost from the RCA. The S. marcescens bacterial strain could survive the alkaline concrete environment and solubilize the silicates present in cement paste resulting in the removal of the old adhered mortar.
{"title":"Bacterial Treatment of Recycled Concrete Aggregate","authors":"Austen Rowell, Tewodros Ghebrab, Randall Jeter","doi":"10.3390/recycling8050068","DOIUrl":"https://doi.org/10.3390/recycling8050068","url":null,"abstract":"Microbial treatment of recycled concrete aggregate (RCA) may improve the quality of the aggregate, and enhance its use in the production of structural concrete and promote the recycling of concrete waste. The mortar phase of the RCA is responsible for the poor performance of the aggregate. Treating the old adhered mortar or removing it from the natural aggregate (NA) is an option to make RCA beneficial for the production of quality recycled aggregate concrete (RAC). Removing the adhered mortar from recycled concrete aggregate using silicate-solubilizing bacteria was investigated. The bacteria could synthesize the silicates in the calcium silicate hydrate phase of the cement paste leading to the breakdown of the old adhered mortar. Four SSB strains were tested for survivability and activity in an alkaline medium to simulate the concrete environment. The Serratia marcescens bacterial strain, which survived the environment, was inoculated into screw-cap glass vials containing recycled concrete aggregate fragments and glucose-enhanced nutrient broth and then incubated for 14 days. Partial removal of the old adhered mortar was observed based on the weight lost from the RCA. The S. marcescens bacterial strain could survive the alkaline concrete environment and solubilize the silicates present in cement paste resulting in the removal of the old adhered mortar.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136192671","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 : 2023-08-30DOI: 10.3390/recycling8050067
Y. Shigematsu, S. Inazumi, S. Chaiprakaikeow, S. Nontananandh
This paper focuses on the development of high-flowability liquefied stabilized soils (HFLSS) made of recycled construction sludge (RCS) to enhance their application in construction work. Liquefied stabilized soils (LSSs) have already found widespread use in construction sites, particularly for filling long-distance structures and dealing with complex underground spaces. However, to further optimize their performance, the development of high-flowability liquefied stabilized soils (HFLSSs) with superior flowability is required. This study experimentally investigates the basic properties, including mechanical characteristics and flowability performance, of the newly developed HFLSS made of RCS. The results confirm that the developed HFLSS made of RCS meets the quality requirements expected from LSSs and exhibits enhanced flowability, making it a promising material for construction applications. The advanced development of LSSs in this paper expects to promote recycling construction-generated soils, including construction-generated sludges in the construction industry.
{"title":"Properties of High-Flowability Liquefied Stabilized Soil Made of Recycled Construction Sludge","authors":"Y. Shigematsu, S. Inazumi, S. Chaiprakaikeow, S. Nontananandh","doi":"10.3390/recycling8050067","DOIUrl":"https://doi.org/10.3390/recycling8050067","url":null,"abstract":"This paper focuses on the development of high-flowability liquefied stabilized soils (HFLSS) made of recycled construction sludge (RCS) to enhance their application in construction work. Liquefied stabilized soils (LSSs) have already found widespread use in construction sites, particularly for filling long-distance structures and dealing with complex underground spaces. However, to further optimize their performance, the development of high-flowability liquefied stabilized soils (HFLSSs) with superior flowability is required. This study experimentally investigates the basic properties, including mechanical characteristics and flowability performance, of the newly developed HFLSS made of RCS. The results confirm that the developed HFLSS made of RCS meets the quality requirements expected from LSSs and exhibits enhanced flowability, making it a promising material for construction applications. The advanced development of LSSs in this paper expects to promote recycling construction-generated soils, including construction-generated sludges in the construction industry.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47242474","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 : 2023-08-27DOI: 10.3390/recycling8050066
Xiaoming Liu, Si Li, Wenhao Chen, Huizhou Yuan, Yiguan Ma, Muhammad Ahmar Siddiqui, Asad Iqbal
Food waste (FW) increases with urbanization and population growth, which puts pressure on the treatment system, causing a variety of harmful impacts on the environment. Proper FW treatment is imperative for ecological integrity and public health. Even though FW treatment is an extensively studied topic, the sustainable FW treatment considering holistic-lifecycle-based environmental impacts has rarely been evaluated. This study addresses this gap through a comprehensive analysis of various FW treatment methods, including co-treatment with sewage, anaerobic digestion, incineration, and aerobic composting. The impacts of greenhouse gas (GHG) emission and energy use efficiency are assessed by analyzing diverse FW treatment methods in Shenzhen, China. The study indicates that FW addition to sewage does not adversely affect the current sewage treatment plant, but benefits GHG avoidance and energy recovery. Compared with the other FW treatment methods, FW anaerobic digestion avoids the most GHG emissions with −71.3 kg CO2 eq/FU and recovers the most energy with −223 kWh/FU, followed by FW co-treated with sewage. The energy conversion efficiency of the combined heat and power (CHP) unit greatly affects FW incineration, while energy consumption in incineration and anaerobic digestion (AD) process is relatively minor. Perturbation analysis pinpoints key parameters influencing outcomes, including CHP efficiency, GHG emission factor of local electricity, and chemical oxygen demand (COD) in FW with ratios of −13~−0.942, −0.518~0.22, and −13~1.01, respectively, that should be given special attention. This study sheds light on sustainable FW management strategies, not only in China but also transferrable to regions confronting similar challenges. Advocating ecologically balanced and resource-efficient approaches, the study aligns with broader aims of fostering sustainable development.
食物垃圾（FW）随着城市化和人口增长而增加，这给处理系统带来了压力，对环境造成了各种有害影响。适当的FW处理对生态完整性和公众健康至关重要。尽管FW处理是一个广泛研究的主题，但考虑到基于生命周期的整体环境影响的可持续FW处理很少得到评估。本研究通过对各种FW处理方法的综合分析，解决了这一差距，包括与污水共处理、厌氧消化、焚烧和好氧堆肥。通过对深圳市不同FW处理方法的分析，评估了温室气体排放和能源利用效率的影响。研究表明，在污水中添加FW不会对目前的污水处理厂产生不利影响，但有利于避免温室气体排放和能源回收。与其他FW处理方法相比，FW厌氧消化以−71.3 kg CO2 eq/FU避免了最多的GHG排放，并以−223 kWh/FU回收了最多的能量，其次是与污水共同处理的FW。热电联产（CHP）机组的能量转换效率对FW焚烧的影响很大，而焚烧和厌氧消化（AD）过程的能耗相对较小。扰动分析确定了影响结果的关键参数，包括CHP效率、当地电力的GHG排放因子和FW中的化学需氧量（COD），其比值分别为−13～−0.942、−0.518～0.22和−13～1.01，应特别注意。本研究揭示了可持续FW管理策略，不仅在中国，而且可以转移到面临类似挑战的地区。该研究倡导生态平衡和资源高效的方法，符合促进可持续发展的更广泛目标。
{"title":"Assessing Greenhouse Gas Emissions and Energy Efficiency of Four Treatment Methods for Sustainable Food Waste Management","authors":"Xiaoming Liu, Si Li, Wenhao Chen, Huizhou Yuan, Yiguan Ma, Muhammad Ahmar Siddiqui, Asad Iqbal","doi":"10.3390/recycling8050066","DOIUrl":"https://doi.org/10.3390/recycling8050066","url":null,"abstract":"Food waste (FW) increases with urbanization and population growth, which puts pressure on the treatment system, causing a variety of harmful impacts on the environment. Proper FW treatment is imperative for ecological integrity and public health. Even though FW treatment is an extensively studied topic, the sustainable FW treatment considering holistic-lifecycle-based environmental impacts has rarely been evaluated. This study addresses this gap through a comprehensive analysis of various FW treatment methods, including co-treatment with sewage, anaerobic digestion, incineration, and aerobic composting. The impacts of greenhouse gas (GHG) emission and energy use efficiency are assessed by analyzing diverse FW treatment methods in Shenzhen, China. The study indicates that FW addition to sewage does not adversely affect the current sewage treatment plant, but benefits GHG avoidance and energy recovery. Compared with the other FW treatment methods, FW anaerobic digestion avoids the most GHG emissions with −71.3 kg CO2 eq/FU and recovers the most energy with −223 kWh/FU, followed by FW co-treated with sewage. The energy conversion efficiency of the combined heat and power (CHP) unit greatly affects FW incineration, while energy consumption in incineration and anaerobic digestion (AD) process is relatively minor. Perturbation analysis pinpoints key parameters influencing outcomes, including CHP efficiency, GHG emission factor of local electricity, and chemical oxygen demand (COD) in FW with ratios of −13~−0.942, −0.518~0.22, and −13~1.01, respectively, that should be given special attention. This study sheds light on sustainable FW management strategies, not only in China but also transferrable to regions confronting similar challenges. Advocating ecologically balanced and resource-efficient approaches, the study aligns with broader aims of fostering sustainable development.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42610463","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 : 2023-08-26DOI: 10.3390/recycling8050065
K. Owaid, Raghed Y. Ghazal, M. A. Avdelzaher
This study focuses on producing asphalt with improved rheological properties that differ from the original asphalt and are less affected by aging conditions. The rheological properties of Qayara asphalt were enhanced by modifying the asphalt using spent rubber tire (SRT) with different percentages of anhydrous aluminum chloride. Percentages ranging from 1.0% by weight of the spent tire rubber were added after proceeding with the thermal crushing process. The percentages of anhydrous aluminum chloride catalyst were 0.4 and 0.8%, respectively. This mixture was microwaved at 270 watt of power for 4, 8, and 12 min, respectively. The measurements performed are plasticity, penetration, softening point, and penetration index. The previously mentioned measurements were also made on the modified asphalt one year after the modification process to understand the effect of aging conditions. The microstructure and thermodynamics have been characterized by FE-SEM and EDX measurements. This study provides good rheological properties of the modified bitumen binder that is aging-resistant.
{"title":"Study of the Effect of Modification of Asphalt on the Rheological Properties Employing Microwave Radiation—An Aging Study","authors":"K. Owaid, Raghed Y. Ghazal, M. A. Avdelzaher","doi":"10.3390/recycling8050065","DOIUrl":"https://doi.org/10.3390/recycling8050065","url":null,"abstract":"This study focuses on producing asphalt with improved rheological properties that differ from the original asphalt and are less affected by aging conditions. The rheological properties of Qayara asphalt were enhanced by modifying the asphalt using spent rubber tire (SRT) with different percentages of anhydrous aluminum chloride. Percentages ranging from 1.0% by weight of the spent tire rubber were added after proceeding with the thermal crushing process. The percentages of anhydrous aluminum chloride catalyst were 0.4 and 0.8%, respectively. This mixture was microwaved at 270 watt of power for 4, 8, and 12 min, respectively. The measurements performed are plasticity, penetration, softening point, and penetration index. The previously mentioned measurements were also made on the modified asphalt one year after the modification process to understand the effect of aging conditions. The microstructure and thermodynamics have been characterized by FE-SEM and EDX measurements. This study provides good rheological properties of the modified bitumen binder that is aging-resistant.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46220533","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 : 2023-08-20DOI: 10.3390/recycling8040064
G. De Feo, C. Ferrara, L. Giordano, L. S. Ossèo
The management of waste cooking oil (WCO) often poses significant challenges. The improper disposal of WCO results in negative environmental impacts and economic losses. However, from a circular economy perspective, WCO can be recycled and used as a sustainable feedstock for numerous industrial products, replacing virgin vegetable oils. This approach enables the recovery of resources while simultaneously addressing the problem of WCO disposal. By employing a multi-criteria decision analysis (MCDA) approach, the study assesses three alternative recycling pathways for WCO used as a feedstock in the production of (A1) biodiesel, (A2) biolubricant, and (A3) biosurfactant. The aim is to identify the optimal alternative, taking into account environmental, economic, and technical factors. The procedure involved a team of chemical engineers working in the WCO recycling sector who were selected as decision makers. The ‘priority scale’ combined with the Paired Comparison Technique was employed as a weighting method to evaluate the selected criteria. The results revealed that the decision makers considered environmental sustainability as the most crucial evaluation criterion, followed by the economic criterion. In contrast, the aspect of process management was deemed less significant. Among the compared alternatives, utilizing WCO as a feedstock for biosurfactant production was assessed as the optimal WCO recycling solution. This alternative not only demonstrated the lowest coefficient variation but was also deemed the most favourable option. Biolubricant production was determined to be the second-best alternative. The adopted MCDA approach proved to be a reliable and effective tool, enabling the clear identification of the preferred WCO recycling alternative among those assessed. This was achieved through the utilization of the decision makers’ expertise and knowledge.
{"title":"Assessment of Three Recycling Pathways for Waste Cooking Oil as Feedstock in the Production of Biodiesel, Biolubricant, and Biosurfactant: A Multi-Criteria Decision Analysis Approach","authors":"G. De Feo, C. Ferrara, L. Giordano, L. S. Ossèo","doi":"10.3390/recycling8040064","DOIUrl":"https://doi.org/10.3390/recycling8040064","url":null,"abstract":"The management of waste cooking oil (WCO) often poses significant challenges. The improper disposal of WCO results in negative environmental impacts and economic losses. However, from a circular economy perspective, WCO can be recycled and used as a sustainable feedstock for numerous industrial products, replacing virgin vegetable oils. This approach enables the recovery of resources while simultaneously addressing the problem of WCO disposal. By employing a multi-criteria decision analysis (MCDA) approach, the study assesses three alternative recycling pathways for WCO used as a feedstock in the production of (A1) biodiesel, (A2) biolubricant, and (A3) biosurfactant. The aim is to identify the optimal alternative, taking into account environmental, economic, and technical factors. The procedure involved a team of chemical engineers working in the WCO recycling sector who were selected as decision makers. The ‘priority scale’ combined with the Paired Comparison Technique was employed as a weighting method to evaluate the selected criteria. The results revealed that the decision makers considered environmental sustainability as the most crucial evaluation criterion, followed by the economic criterion. In contrast, the aspect of process management was deemed less significant. Among the compared alternatives, utilizing WCO as a feedstock for biosurfactant production was assessed as the optimal WCO recycling solution. This alternative not only demonstrated the lowest coefficient variation but was also deemed the most favourable option. Biolubricant production was determined to be the second-best alternative. The adopted MCDA approach proved to be a reliable and effective tool, enabling the clear identification of the preferred WCO recycling alternative among those assessed. This was achieved through the utilization of the decision makers’ expertise and knowledge.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2023-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46135287","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 : 2023-08-16DOI: 10.3390/recycling8040063
K. Rajan, I. Mustafa, Aravinthan Gopanna, Selvin P. Thomas
The present investigation reports the results of experiments related to the conversion of low-density polyethylene (LDPE) waste carry bags to fuel through an economic catalytic pyrolysis method in a batch reactor using zinc oxide (ZnO) as the catalyst. Plastics are highly beneficial for the day-to-day activities of human beings; however, their decomposition is limited due to their strong covalent bonding. Degradation of these big molecules into smaller ones or monomers has been attempted by several researchers in recent decades, with limited success. Pyrolysis is one of the ideas used to convert plastics, with the crowded structure of polymers, into fuel rather than small molecules. Among these plastics, LDPE is widely used as carry bags throughout the world, and, herein, the results of catalytic pyrolysis of the conversion of LDPE into fuel are reported. A compact laboratory-scale batch reactor, specially designed at our laboratory, was used to carry out the pyrolysis process. Different dosages of ZnO were used as a catalyst to carry out the pyrolysis at a specific temperature. The optimal dosage of ZnO for a 50 g waste LDPE batch was found to be 0.6 g to get the maximum oil yield. The yielded oil was analyzed chemically through Fourier transform infrared spectroscopy (FTIR) and a Reformulyzer M4 Hydrocarbon Group Type Analyzer. Evaluation of physical and chemical exergy along with exergetic efficiency of the process was carried out. The described experiments and the results represent a small but significant step toward curbing the menace of plastic solid wastes, which are degrading the environment and human life worryingly, and allowing them to be utilized for generating low-cost fuel for transportation and other applications.
{"title":"Catalytic Pyrolysis of Waste Low-Density Polyethylene (LDPE) Carry Bags to Fuels: Experimental and Exergy Analyses","authors":"K. Rajan, I. Mustafa, Aravinthan Gopanna, Selvin P. Thomas","doi":"10.3390/recycling8040063","DOIUrl":"https://doi.org/10.3390/recycling8040063","url":null,"abstract":"The present investigation reports the results of experiments related to the conversion of low-density polyethylene (LDPE) waste carry bags to fuel through an economic catalytic pyrolysis method in a batch reactor using zinc oxide (ZnO) as the catalyst. Plastics are highly beneficial for the day-to-day activities of human beings; however, their decomposition is limited due to their strong covalent bonding. Degradation of these big molecules into smaller ones or monomers has been attempted by several researchers in recent decades, with limited success. Pyrolysis is one of the ideas used to convert plastics, with the crowded structure of polymers, into fuel rather than small molecules. Among these plastics, LDPE is widely used as carry bags throughout the world, and, herein, the results of catalytic pyrolysis of the conversion of LDPE into fuel are reported. A compact laboratory-scale batch reactor, specially designed at our laboratory, was used to carry out the pyrolysis process. Different dosages of ZnO were used as a catalyst to carry out the pyrolysis at a specific temperature. The optimal dosage of ZnO for a 50 g waste LDPE batch was found to be 0.6 g to get the maximum oil yield. The yielded oil was analyzed chemically through Fourier transform infrared spectroscopy (FTIR) and a Reformulyzer M4 Hydrocarbon Group Type Analyzer. Evaluation of physical and chemical exergy along with exergetic efficiency of the process was carried out. The described experiments and the results represent a small but significant step toward curbing the menace of plastic solid wastes, which are degrading the environment and human life worryingly, and allowing them to be utilized for generating low-cost fuel for transportation and other applications.","PeriodicalId":36729,"journal":{"name":"Recycling","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2023-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44133921","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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