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Potentiality of Waste-to-Energy Sector Coupling in the MENA Region: Jordan as a Case Study

Authors:
Qahtan Thabit at University of Rostock
Qahtan Thabit
Nassour Abdallah at University of Rostock
Nassour Abdallah
Michael Nelles at Deutsches Biomasseforschungszentrum
Michael Nelles
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Population growth, urbanization, and changes in lifestyle have led to an increase in waste generation quantities. The waste management system in the Middle East and North Africa (MENA) region is still considered an adolescent system, while developed countries have made great progress in this field, including regulation, financing, administration, separation at source, recycling, and converting waste to energy. At the same time, in the MENA region, the best performance of the recycling process is around 7–10% of total waste. Nowadays, many developed countries like Germany are shifting from waste management to material flow systems, which represent the core of a circular economy. Also, it should be stated here that all countries that have a robust and integrated waste management system include waste-to-energy (W-to-E) incineration plants in their solutions for dealing with residual waste, which is still generated after passing through the entire treatment cycle (hierarchy). Therefore, this paper illustrates the potentiality of embedding waste incineration plants in the MENA region, especially in large cities, and addressing the economic and financial issues for the municipalities. Cities in these countries would like to build and operate waste treatment plants; however, municipalities do not have the sustainable investment and operating costs. The solution is to maximize the income from the output, such as energy, recycling materials, etc. In addition, the MENA region is facing another dilemma, which is water scarcity due to climate change, increasing evaporation, and reduction of precipitation. This research illustrates a simulated model for a waste incineration plant in the MENA region. The EBSILON 13.2 software package was used to achieve this process. Furthermore, the simulated plant applies the concept of waste-to-energy-to-water, so that not only is waste converted to energy but, by efficient usage of multi-stage flash (MSF) technology, this system is able to generate 23 MWe of electric power and 8500 m3/day of potable water. A cost analysis was also implemented to calculate the cost of thermal treatment of each ton of municipal solid waste (MSW) during the life span of the plant. It was found that the average cost of treatment over 30 years would be around US$39/ton.
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... First, waste will be treated within an environmental framework, as waste incineration produces far fewer emissions than landfilling, which is the main treatment process in the region. For instance, each ton of MSW to be landfilled emits 840 kg CO 2 , while each ton of MSW generates 415 kg CO 2 in the case of incineration [12,13]. Reflecting these various advantages, the MENA region constitutes a sizable economic entity and enjoys a reasonable standard of living by international standards. ...
... Overall, the rate of MSW generation ranged from 0.6 kg/capita/day in some rural areas in the region, such as in Egypt and Jordan, to 3.1 kg/capita/day in urbanized cities of the region, such as those in GCC countries. However, the normal average rate was also specified, which was stated as being around 1-1.5 kg/capita/day [12]. ...
... The main aspect of the MSW composition in the MENA region is the high portion of organic fractions, which constitutes approximately 50-60% of the waste composition. This means that MSW holds a large portion of water in its content [12,53], as indicated in Table 2. As noted previously, the variation in waste composition is due to governing parameters such as geographical and climatic conditions, population growth, economic income levels, and socio-cultural properties. ...
Facts and Figures on Aspects of Waste Management in Middle East and North Africa Region
Article
Full-text available
  • Nov 2022
The waste management field in Middle Eastern and North African countries suffers from multiple drawbacks and chronic problems that require strategic solutions and collaboration among various institutions. Due to a lack of data, a financial deficit, limited economic resources for the municipalities, and singular treatment processes, until recently, waste has been dealt with as garbage that needs to be disposed of, while, in a large number of developed countries, waste now represents a substantial economic resource and an important source of materials that can be reinserted into the industrial sector. This paper presents a review of several aspects and sectors that are directly related to waste generation and the current situation regarding the waste management system in the Middle East and North Africa (MENA) region in terms of composition, generated amount/capita, existing treatment routes, and institutional frameworks. Furthermore, gross domestic production and population growth are specified as critical factors governing the waste sector in the region. Such data and information will increase the possibility of drawing a roadmap to convert the current waste treatment stream into a material flow concept and circular economy. The energy sector (energy consumption) is also considered to illustrate the potential role of waste if incineration technology (energy recovery from waste) is realized as a radical solution for the waste system in the region. Following a review of the literature, the main challenges in the waste management sector that need to be solved are summarized. The novelty of this work is two-fold. First, it elucidates the connection between gross domestic product (GDP), waste composition, and waste generation. According to the literature, countries with a high GDP produce a greater amount of waste (around 1.5–2.7 kg/capita/day) with a lower organic share of waste composition of around 40%, as they have an increased lifestyle rate. Second, a review of energy consumption per capita illuminates the essential role of waste as a source of energy.
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... It should be mentioned here that the energy recovery efficiency of the waste incineration facility was calculated according to the R1 formula (Grosso et al., 2010). Operational properties of the furnace in the WI facility (Thabit et al., 2020 where E p implies the energy produced as heat or electricity (kW). E f is the amount of energy input into the system from fuel (kW); in this research, E f = 0 was taken since there is no assumption of supplementary fuel. ...
... This cost also varies widely and is affected by numerous aspects such as the temperature of the water intake, chemical compounds used for post-and pre-treatment, and mass flow into the unit. For real projects in different countries in the MENA region in Thabit et al. (2020) and World Bank (2019) (Thabit et al., 2020). In the literature, the operation costs ranged between 4% and 11%, and thus a value of 10% was assumed for this research. ...
... This cost also varies widely and is affected by numerous aspects such as the temperature of the water intake, chemical compounds used for post-and pre-treatment, and mass flow into the unit. For real projects in different countries in the MENA region in Thabit et al. (2020) and World Bank (2019) (Thabit et al., 2020). In the literature, the operation costs ranged between 4% and 11%, and thus a value of 10% was assumed for this research. ...
Innovative hybrid waste to energy–parabolic trough plant for power generation and water desalination in the Middle East North Africa region: Jordan as a case study
Article
Full-text available
  • Nov 2022
This research proposes a hybrid system consisting of a parabolic trough solar field coupled with a waste incineration facility to produce power and desalinated water in Jordan. To predict the performance of the proposed system, EBSILON Professional (13.02) was used to simulate the entire system and for a more realistic simulation process, a prime sample of 100 tons of municipal waste from Jordan was obtained, processed, and homogenised, after which 4 kg was brought to Germany for laboratory analysis. The laboratory results were inserted into EBSILON. Solar radiation data were adapted from meteonorms and input to EBSILON. Heat transfer between the receiver wall and the heat transfer fluid was analysed to calculate the time required to increase the temperature of the Heat Transfer Fluid from the influent temperature to the desired effluent temperature. The results show that this system can produce 34 MWe of power and 13,824 m³/d of distilled water. On the 1st January, the temperature of the heat transfer fluid in the solar field was increased by 6 °C for 20 min in an open cycle. After 5h, it reached 390 °C in a closed cycle, assuming a fixed direct normal irradiance. Economically, five scenarios were analysed to assess the impact of the cost of heat harvested to produce this amount of water on the annual cost of handling each ton of garbage which was approximately 57 US$ in the first year of operation and 19.5 US$ in the 15th year of plant operation (for the scenario in which the tariff of power sales was considered to evaluate the cost of heat for water desalination).
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... In the Middle East and North Africa (MENA) region countries, more than 95% of municipal waste goes to landfill [9][10][11]. In our previous work [12], a waste incineration plant was simulated using Ebsilon (a specific software package serving as a multi-functional engineering system analysis). Jordan was chosen for the case study, and a 4 kg sample was collected from a 52-ton heap of waste in the waste-converting station in Amman city, which receives waste from six regions, and therefore was considered a representative sample for Jordan. ...
... The total amount of thermal energy released from the furnace depends on the waste incineration plant capacity. As the capacity of the proposed system was 25 kg/s (90,000 kg/h) [12], then: the total thermal energy released from this system = 90,000 (kg/h) × 7 (MJ/kg) = 630,000 (MJ/h). The dry flue gas portion was 630,000 (MJ/h) × 0.36 (kg/MJ) = 226,800 kg/h. ...
... In our previous work [12] which used Jordan as a case study, a waste incineration plant was simulated to produce power and desalinated water, from which analysis of the MSW sample taken in Jordan was achieved. The proposed system was also analyzed economically. ...
Flue Gas Composition and Treatment Potential of a Waste Incineration Plant
Article
Full-text available
  • May 2022
Waste-to-energy (WtE) incineration is an important technique in waste management systems and waste hierarchy. It is used to treat approximately 63% of the waste in European countries. The flue gas volumetric rate and its composition are essential to determine and monitor the emissions from waste incineration plants. This paper presents two methodologies used to evaluate the emissions from incinerators during the design phase. The first consists of a set of equations applicable in Excel (calculation model), while the second is the built-in components in Ebsilon 13.2 software which simulates the emissions from a furnace. This paper also proposes a comprehensive flue gas cleaning system for a simulated waste incineration plant in Jordan. According to Ebsilon, the results showed that for a 25 kg/s loading rate, there was 258,514 mg/Nm3, 749.90 mg/Nm3, 890.20 mg/Nm3, and 717 mg/Nm3 of CO2, NO2, SO2, and HCL, respectively. It was noted that these values relate to 1.5 of excess air ratio, where the effect of excess air ratio as the main driver for any combustion process was examined. The calculation method (set of equations) evaluated the flue gas volumetric rate, the CO2 emissions, and N2O and SO2 levels. Ebsilon allows for simulation of the treatment stages and calculates the amount of materials required. Selective non-catalytic reduction (SNCR) (a built-in component in the Ebsilon library) was used to treat the NO2 emissions. For 1.5 of excess air ratio, those emissions were reduced from 749 mg/Nm3 to 180 mg/Nm3, while the Ca(OH)2 injector used to treat the SO2 and HCL emissions reduced emissions from 890.20 mg/Nm3 and 717 mg/Nm3 to 44 mg/Nm3 and 7.16 mg/Nm3, respectively. Regarding the reduction in CO2, the spherical carbon absorption concept was simulated using 9.4 kg/s of carbon which was adequate to verify a 91% reduction rate of CO2. Furthermore, the calculation model was validated and approved as a valuable model to predict the flue gas volume, the oxygen required, and flue gas emissions at the design stage.
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... Dajnak et al. [36] concluded that the concept of Waste-to-Energy-to-Water needs further study to optimize the conversion route and to evaluate the economy of the concept relative to competing desalination energy sources. Thabit et al. [37] simulated a comprehensive waste incineration plant case study in Jordan for power generation and water desalination. They found that this concept increases the affordability of the whole system. ...
Water Desalination Using the Once-through Multi-Stage Flash Concept: Design and Modeling
Article
Full-text available
  • Sep 2022
Thermal water desalination is one of the most important techniques to solve the water scarcity problem in many regions of the world. Out of around 7.8 billion people in the world, only about 6 billion of them have access to clean water; notably, climate change plays a major role in accelerating the evaporation rate of water from water bodies, which in turn increases the scarcity. Multi-stage flash, recognized to have a high rate of water production in comparison with other available technologies, accounts for 35% of water desalination facilities worldwide. This paper presents a detailed Excel model to evaluate the amount of energy required to drive 16 stages of multi-stage flash. This model aims to design and evaluate the amount of thermal energy required for such projects and optimize their performance by calibrating the governing parameters. Furthermore, the 16 stages were simulated via the Ebsilon 13.02 software package to match the results and evaluate the fulfillment of the plant requirements. The temperature drop of the brine stream was 2.34 °C/stage. The top brine temperature was 130 °C. The results show that 29.5 kg/s of superheated steam is required to desalinate 162 kg/s of 2500 kg/s influent mass flow of brine. The effect of water intake temperature was also examined by using Ebsilon. The performance ratio decreased from 5.49 to 2.66 when the water intake temperature decreased from 30 °C to 5 °C.
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... Concerning Waste-to-Energy (WtoE) plants, Gutberlet et al. (2020) suggest disincentivizing their usage by economic means, since WtoE plants show a low degree of circularity as resources are incinerated instead of being mined in landfills in Brazilian and Swedish cities. Nonetheless, WtoE plants are also incentivized in our selection, as it in the case of Thabit et al. (2020) and their research in Jordan wherein WtoE plants are also used to produce clean water. We would also include market formation as an economic policy instrument as for the case of Russia and the extended producer responsibility scheme over the import of tires, documented by Khudyakova et al. (2020), for a market for worn tires is lacking, as tends to be common for secondary resources. ...
The circular built environment toolbox: A systematic literature review of policy instruments
Article
Full-text available
  • Sep 2022
  • J CLEAN PROD
The built environment plays a central role in the transition towards the circular economy as they concentrate major consumer and polluter human activities. However, the way BEs are – and need to be – driven by policy to reach cities’ circular goals is still an under-researched aspect. Particularly, there is limited knowledge of policy instruments aimed to foster the transition towards a circular built environment. Therefore, we conduct a systematic literature search and a review of scientific publications to characterize the relation between the circular built environment and policy instruments suggesting its implementation from a circular city development perspective. We do so by answering: (1) how many publications elaborate on CBE policy instruments, (2) what type of circular actions in relation to circular city development are mentioned, and (3) what policy instruments are proposed to implement a CBE. The literature search is performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our results show that 53% of publications address policies instruments for circular built environment transitions. Although different circular actions are identified, looping actions prevail. Adapting and ecologically-regenerating actions, which are essential for circular city development, remain insufficiently researched. Finally, among policy instruments for circular built environment implementation there is a clear tendency towards regulation as means for leverage, which calls for bigger research efforts concerning the mix of policy instruments, as well as in more general challenges in governance and policy coherence.
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... According to Ohnishi et al. [65], waste utilisation in the energy system is important for promoting the transition to low-carbon cities. For the affordable implementation of waste into sector coupling, the income from the output must be maximised, as stated by Thabit et al. [66]. Energy recovery from sewage treatment can also be integrated into sector coupling approaches. ...
Beyond Traditional Energy Sector Coupling: Conserving and Efficient Use of Local Resources
Article
Full-text available
  • Jun 2022
Decentralisation and sector coupling are becoming increasingly crucial for the decarbonisation of the energy system. Resources such as waste and water have high energy recovery potential and are required as inputs for various conversion technologies; however, waste and water have not yet been considered in sector coupling approaches but only in separate examinations. In this work, an open-source sector coupling optimisation model considering all of these resources and their utilisation is developed and applied in a test-bed in an Israeli city. Our investigations include an impact assessment of energy recovery and resource utilisation in the transition to a hydrogen economy, with regard to the inclusion of greywater and consideration of emissions. Additionally, sensitivity analyses are performed in order to assess the complexity level of energy recovery. The results demonstrate that waste and water energy recovery can provide high contributions to energy generation. Furthermore, greywater use can be vital to cover the water demands in scarcity periods, thus saving potable water and enabling the use of technology. Regarding the transition to hydrogen technologies, resource energy recovery and management have an even higher effect than in the original setup. However, without appropriate resource management, a reduction in emissions cannot be achieved. Furthermore, the sensitivity analyses indicate the existence of complex relationships between energy recovery technologies and other energy system operations
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... The European Waste to Energy Plants reported that in the year 2018, Germany converted 31% of their total MSW generated into WtE, while during the same year in Sweden, Finland, Norway, and Denmark, the conversion reached more than 50% (Brenes-Peralta et al., 2020;Levaggi et al., 2020;Thabit et al., 2020). In the USA, for example, modern regulated landfills collect approximately 2.6 million tons of methane-producing heat and electricity with a capacity of up to 50 MW turbine generator (Moya et al., 2017). ...
Techno-economic feasibility of waste-to-energy technologies for investment in Ghana: A multicriteria assessment based on fuzzy TOPSIS approach
Article
  • Oct 2021
  • J CLEAN PROD
Over the years, Ghana has been challenged with erratic power cuts and load shedding, and waste-to-energy (WtE) technologies have been identified as one of the solutions to remedy the situation. In the current study, a multicriteria decision analysis (MCDA) is performed on four different WtE technologies viz anaerobic digestion, gasification, plasma arc gasification, and pyrolysis to identify the alternative with the most techno-economic advantage for investment in Ghana. The goal of the current study is achieved using a fuzzy TOPSIS approach. Five academic and field experts were employed to judge all four alternatives according to ten selected techno-economic criteria. The present study reveals that for all the alternatives under consideration, the most feasible WtE technology for investment in Ghana follows the order; gasification > anaerobic digestion > pyrolysis > plasma arc gasification. The most influential technical and economic criteria are energy generation per annum and initial investment, respectively. Sensitivity analysis shows a high degree of consistency, robustness, and stability in the obtained results. The current work recommends that the integration of anaerobic digestion and gasification should be promoted as it has the potential to offer a well-balanced WtE technology under both technical and economic conditions compared to the stand-alone systems. Findings from the current study could ease the decision-making of potential WtE technology investors in Ghana.
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... Thermal treatment in times of a pandemic is the best solution, but due to the lack of technology for managing all secondary waste, it does not fit into the circular economy as a whole [21,22]. ...
Poland’s Proposal for a Safe Solution of Waste Treatment during the COVID-19 Pandemic and Circular Economy Connection
Article
Full-text available
  • Apr 2021
The purpose of the study presented in this text is to show the influence of COVID-19 on waste management systems and circular economy stream, and their impact on circular economy, particularly the economic impact of the pandemic on the waste management sector, impact on circular economy objectives’ implementation as well as additional challenges like the need for hygienization of waste streams during different implementation efforts, such as changes in the municipal solid waste market and different waste processes of their disposal. Additionally, some methods—such as thermal treatment—which seemed to be not fully aligned with the circular economy approach have advantages not taken into account before. Incineration of higher volume of waste affects the waste structure and will change some of the circular economy objectives. The analysis was carried out on the example of the Polish market.
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... The World Energy Council reported that the WTE market is growing steadily until the year 2023 at an annual rate of 5.5% [10]. The Confederation of the European Waste to Energy Plants reported that in the year 2018, Germany diverted 31% of the total municipal solid waste generated in the country into WTE facilities, while during the same year in Sweden, Finland, Norway, and Denmark, the diversion reached more than 50% [11][12][13]. While many countries around the world are moving from a linear to circular economy, the WTE technologies became part of circular economy models [14], as shown in Figure 1 [15]. ...
Using Multi-Criteria Decision Analysis to Select Waste to Energy Technology for a Mega City: The Case of Moscow
Article
Full-text available
  • Nov 2020
Abstract: In a mega city like Moscow, both municipal solid waste management and energy systems are managed in an unsustainable way. Therefore, utilizing the municipal solid waste to generate energy will help the city in achieving sustainability by decreasing greenhouse gases emissions and the need for land to dispose the solid waste. In this study, various Waste to Energy (WTE) options were evaluated using analytical hierarchy process (AHP) to select the most appropriate technology for the Moscow region. The developed AHP model consists of 4 levels, which assessed four WTE technologies, namely landfill biogas, anaerobic digestion, incineration, and refuse derived fuel (RDF), using four criteria and nine subcriteria. The pairwise comparison was achieved by soliciting 16 experts’ opinions. The priority weights of various criteria, subcriteria, and alternatives were determined using Expert Choice Software. The developed model indicated that landfill biogas is the preferred option with a global weight of 0.448, followed by the anaerobic digestion with a weight of 0.320 and incineration with a weight of 0.138, while the least preferred technology is the RDF with a weight of 0.094. Sensitivity analysis has shown that the priorities of WTE alternatives are sensitive for the environmental and technical criteria. The developed AHP model can be used by the decision makers in Moscow in the field of WTE.
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Potential of Sustainable Concept for Handling Organic Waste in Tunisia
Article
Full-text available
  • Oct 2020
Nowadays, Tunisia is seeking to implement cost-efficient and sustainable solutions in relation to the treatment of organic waste which, at up to 65%, makes up the largest proportion of total waste generated in the country. Therefore, an efficient tool for decision makers is needed to provide a clear approach about the potential of organic waste as well as the treatment concept, which can be adapted based on technical requirements and local conditions. Results revealed that there is a high variation in terms of the nature of the collected biowaste, which affects the selection of the adopted bioprocess for each geographical zone of the study area. Three main categories of biowaste are produced along the coastline of Tunisia: food waste (FW) (102.543 t/a); green waste (GW) (1.326.930 t/a); and cattle manure (CM) (1.548.350 t/a). Based on the results of similar projects and laboratory-scale research work, anaerobic and aerobic digestion were examined. Regarding aerobic digestion, the monitoring of several physicochemical parameters ascertained that the co-composting of FW and GW at different ratios (GW: FW = 100:0, 75:25, 50:50, and 25:75) allowed the production of a stable and mature compost. A highly qualified end-product was generated from each trial categorized as a finished compost of class V with reference to German Standards of compost. Regarding the anaerobic process, different feedstock mixtures (FW:CM = 0:1, 1:1, 2:1, and 3:1) were prepared to feed semi-continuous anaerobic reactors. However, a significant improvement in the process development was recorded for digesters including a higher fraction of FW, which produced 0.846 L N /kg VS in as the maximum biogas production. Therefore, biological treatments of food waste and different co-substrates seems to be a suitable technique for Tunisia in terms of waste management, environmental, and energy aspects. However, the evaluation of the efficiency of the proposed biological treatments was also verified by a draw-up of a technical and economic feasibility analysis. Although the cost-benefit estimations proved that the profits from both the compost and biogas plants would be very modest, the feasibility of such sustainable projects should not only be evaluated on an economic basis, but also by taking into account socio-environmental considerations including decreasing environmental threats, providing work opportunities, increasing incomes, stimulating public awareness as well as reducing the operating costs linked to landfilling.
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Detecting leachate plumes and groundwater pollution at Ruseifa municipal landfill utilizing VLF-EM method
Article
Full-text available
  • Sep 2008
  • J APPL GEOPHYS
A Very Low Frequency-Electromagnetic (VLF-EM) survey was carried out in two sites of domestic waste of old and recent landfills. The landfill structures lie on a major highly fractured limestone aquifer of shallow groundwater less than 30 m, which is considered as the main source of fresh water in Amman-Zarqa region. A total of 18 VLF-EM profiles were conducted with length ranges between 250 and 1500 m. Hydrochemical and biochemical analysis of water samples, taken from wells in the region, has also been conducted. The integrated results of previous DC resistivity method of the same study area and the outcomes of the 2-D tipper inversion of VLF-EM data proved the efficiency of this method in locating shallow and deep leachate plume with resistivity less than 20 Ω m, and enabling the mapping of anomalous bodies and their extensions down to 40 m depth. The sign of groundwater contamination was noticed in many surrounding wells resulting in the high number of fecal coliform bacteria and total coliform bacteria and the increase in inorganic parameters such as chloride (Cl). The pollution of groundwater wells in the landfill area is attributed to the leachate bodies which flow through the upper part of Wadi Es Sir (A7) or Amman-Wadi Es Sir Aquifer (B2/A7). Furthermore, several structural features were detected and the direction of local groundwater movement has been determined. The structural features have been found to have critical effects on the flowing of leachate plume towards north-northeast and west-southwest of the potable aquifer in the area.
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Modelling of material recovery from waste incineration bottom ash
Article
Full-text available
  • Mar 2020
  • WASTE MANAGE
Bottom ash from municipal solid waste incineration is usually treated in order to recover valuable materials like metals and to generate a mineral material for safe utilisation in construction industry or disposal. At present, different technologies and combinations thereof are used for bottom ash treatment resulting in different quantities and qualities of the final products (metals and minerals). So far, a comparison of these technologies is hardly possible based on the available literature. Hence, present paper presents and applies a modelling approach that allows predicting the quantities and qualities (in terms of composition) of the final outputs of bottom ash treatment plants. In particular, material flow analysis models of five different bottom ash treatment plants were established on goods, material and element level and the mass and composition of the output flows of these plants were calculated based on an input of 130,000 Mg/a of bottom ash dry matter. The highest recovery of metals (up to 8,640±820 Mg/a iron, 1,530±220 Mg/a aluminium, 627±73 Mg/a stainless steel and 608±70 Mg/a heavy non-ferrous metals) can be achieved in plants that apply comminution before any ageing processes and are equipped with jiggers, inductive sorting systems and/or a high number of eddy current separators. The iron scrap fractions separated from bottom ash are contaminated by up to 114±44 mg/kg Cd and up to 9,900±3,300 mg/kg Cu, which might impair their suitability for recycling. Only minor differences in the composition of mineral material generated by different treatment plants could be observed.
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Large-Scale Screening and Machine Learning to Predict the Computation-Ready, Experimental Metal-Organic Frameworks for CO2 Capture from Air
Article
Full-text available
  • Jan 2020
The rising level of CO2 in the atmosphere has attracted attention in recent years. The technique of capturing CO2 from higher CO2 concentrations, such as power plants, has been widely studied, but capturing lower concentrations of CO2 directly from the air remains a challenge. This study uses high-throughput computer (Monte Carlo and molecular dynamics simulation) and machine learning (ML) to study 6013 computation-ready, experimental metal-organic frameworks (CoRE-MOFs) for CO2 adsorption and diffusion properties in the air with very low concentrations of CO2. First, the law influencing CO2 adsorption and diffusion in air is obtained as a structure-performance relationship, and then the law influencing the performance of CO2 adsorption and diffusion in air is further explored by four ML algorithms. Random forest (RF) was considered the optimal algorithm for prediction of CO2 selectivity, with an R value of 0.981, and this algorithm was further applied to analyze the relative importance of each metal-organic framework (MOF) descriptor quantitatively. Finally, 14 MOFs with the best properties were successfully screened out, and it was found that a key to capturing a low concentration CO2 from the air was the diffusion performance of CO2 in MOFs. When the pore-limiting diameter (PLD) of a MOF was closer to the CO2 dynamic diameter, this MOF could possess higher CO2 diffusion separation selectivity. This study could provide valuable guidance for the synthesis of new MOFs in experiments that capture directly low concentration CO2 from the air.
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Evaluation of Municipal Solid Wastes Based Energy Potential in Urban Pakistan
Article
Full-text available
  • Nov 2019
Solid waste management needs re-evaluating in developing countries like Pakistan, which currently employs landfilling as a first option. Over time, increasing population will result in decreasing space for landfill sites, ultimately increasing the cost of landfilling, while increasing accumulated waste will cause pollution. Locating and preparing a sanitary landfill includes the securing of large sectors and also everyday activity with the end goal to limit potential negative impacts. Energy production from municipal solid waste (MSW) is a perceptive idea for large cities, such as Karachi, as waste, which is an undesirable output that adds to land and air pollution, is transformed into a vital source of energy. The current study strives to provide a destination to solid waste by evaluating the energy potential that waste provides for power generation by the process of incineration. A sustainable energy generation plant based on the Rankine cycle is proposed. This study evaluates the various landfill sites in the case study area to determine their sustainability for a waste to energy (WtE) plant. The implementation of the proposed plant will not only provide an ultimate destination to waste but also generate 121.9 MW electricity at 25% plant efficiency. Thus, the generated electricity can be used to run a WtE plant and meet the energy requirements of the residents.
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Incineration of municipal solid waste in Brazil: An analysis of the economically viable energy potential
Article
Full-text available
  • Apr 2020
In Brazil, most Urban Solid Waste (USW) is disposed of in loosely controlled and low-quality dumps and landfills. One of the alternatives for improved management is incineration. This largely reduces the amount of waste in sanitary landfills, in turn enabling energy generation, which is encouraged by the Brazilian National Policy on Solid Waste (PNRS). In order to further the debate for the application of incineration plants in Brazil, the present study presents an energy and economic analysis. Calculations were carried out for different population groups in order to determine the minimum population and the respective waste generation to make an incineration plant viable. The country's energy potential was also estimated as a function of the energy tariff. The results show that the energy produced through incineration can provide power to an average of 15% of the waste generating population. The viable energy potential in the country was confirmed only for scenarios with higher energy sales tariffs than those currently applied on the Brazilian market. These results indicate the need for government intervention in order to make this technology economically viable, which would in turn reduce inadequate waste disposal throughout the country.
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Economic evaluation of 20,000 M 3 /Day seawater desalination coupling with floating reactor nuclear power plant
Article
Full-text available
  • Aug 2019
The coupling of floating nuclear reactor with different desalination processes was economically evaluated by using a desalination economic evaluation program (DEEP-5) software and a method of levelized annualized production water cost. Three desalination processes, namely, Multi-effect distillation (MED), multi-stage flash (MSF) or reverse osmosis (RO). The capacity of the plant was 20,000m3/day and its energy source was 100MWt nuclear power plant. The analysis indicated that water costs with the RO process have stronger economic competitive comparing to distillation processes, without regard to changes in water quality. The sensitivity analysis results showed that the sensitivity factors affecting the cost of desalinated water are, in order, discount rate, interest rate, Specific Construction Cost and Condensing temperature.
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Circular economy in waste management – Socio-economic effect of changes in waste management system structure
Article
  • Aug 2020
Due to the fast development, the EU economy has grown over its own raw material production. To enable future economic development, the EU is trying to develop a sustainable and resource-efficient economy. This path is emphasized through the idea of „Closing the Loop“ which is integrated into EU legislation by a Circular Economy Package and emphasizes avoidance of waste production and its recovery. New waste management goals require significant changes in the waste management system structure which introduces new problems and one of them is an increase in the costs for the system users (citizens). To assess the impact of these changes, the time-dependent Life Cycle Assessment based waste, material, and energy flow tracking framework is adapted and used to calculate material and energy production which can be monetised. As waste management plants/facilities are built with public money, to provide public service, in economic calculations annual cash flow of the system is equalized with zero, taking into account all incomes (incomes from products like energy vectors, secondary materials, and compost) and expenses (like an investment and operating costs). From these calculations, variable (volatile, time-dependent) and average system gate fee (operating cost per tonne of input waste), which is charged to the system users, are calculated. A possible increase in system cost can cause the issue of social unacceptance, which decision-makers, elected by the citizens, want to avoid. Results show that energy recovery of waste generates higher income then material recovery while overall lower system costs, and lower sensitivity of the system cost, is observed in the material recovery based scenarios. The lowest system costs are calculated for the scenario which combines material and energy recovery and avoids investments in final disposal/recovery facilities by outsourcing this service. The main problem with outsourcing the final disposal/recovery stage is the uncertainty of the cost of such service. It is found that this kind of approach has not been previously used for the assessment of the socioeconomic sustainability of the whole waste management systems and represents a good tool for decision-makers.
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Do voluntary environmental management systems improve environmental performance? Evidence from waste management by Kenyan firms
Article
  • Apr 2020
  • J CLEAN PROD
We examine whether the adoption of global voluntary environmental management systems - United Nations Global Compact and ISO 14001 - lead to more effective environmental performance. Previous studies have presented inconclusive findings of voluntary environmental management systems on environmental performances. Possible reasons for conflicting results are the influence of observable and unobservable factors that affect environmental performance as well as the use of different measures of environmental performance indicators. Using primary data from Kenyan firms in 2019, waste management defined by wastewater recycling, solid waste reusing and use of environmentally safe disposal methods, we determine the effects of voluntary environmental management systems (VEMS) on firm-level environmental performance. We conclude that the adoption of VEMS are associated with significant improvement in environmental performance in developing economies. Our conclusions provide insights to corporate management and policy makers in developing countries on decisions regarding better environmental management. VEMS forms an environmental management tool suitable in confronting wastewater and physical refuse challenges as well as conducive waste disposal methods.
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Comparative assessment of waste disposal systems and technologies with regard to greenhouse gas emissions: A case study of municipal solid waste treatment options in China
Article
  • Mar 2020
  • J CLEAN PROD
Municipal solid waste (MSW) management has shifted to include multiple functions, especially energy recovery and reduction of greenhouse gas emissions, other than sanitary treatment of waste. In China, two main MSW treatment options exist: landfill and incineration. The objective of this study was to evaluate the landfill and incineration methods in terms of two important indicators, energy balance and greenhouse gas (GHG) emissions, and to discuss the advantages as they relate to decarbonization policy. We set up two landfill cases: LF-Anaero, which adopted an anaerobic landfill structure, and LF-SAero, which adopted a semi-aerobic landfill structure. Two incineration cases were also established: INC-Non, where the MSW was not subjected to separated collection of non-burnable waste, and INC-Sep, where separated collection was conducted. Two conditions were also established. In the one-year condition, waste was assumed to entirely decompose in one year, whereas in the variable decomposition condition, the rate varied. Under the one-year condition, INC-Sep gave the best results for both energy balance and GHG emission reduction. When the decomposition rate of landfilled waste was considered, LF-SAero and INC-Sep had very similar cumulative amounts of GHG emissions after 50 years. However, in INC-Sep, the emissions all occurred in the first 20 years. In LF-SAero, about one-third of the emissions were accounted for in the last 30 years (after the landfill was out of service). Thus, this landfill method must be considered as a GHG emission source for a longer period when considering the total global warming impact. We concluded that INC-Sep is the superior technological option.
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Waste collection criticality index in African cities
Article
  • Feb 2020
The paper proposes to define a waste collection criticality index that is based on a quantified census of the current solid waste management situations of 24 African cities. The proposed index allows to compare collection efforts, to draw up a typology of cities and to highlight those where the situation is alarming. Identifying direct and indirect factors that may accentuate the specific problem of uncollected waste provides an interesting context. The exploration of the current context in different African cities has shown a growing interest in the particular issues of uncollected waste. In addition, the specificities related to the composition of waste and the problem of rapid change in lifestyle, as well as inadequate infrastructures require revisions and new perspective into public policy responses. However, decision-making in waste management still needs a dashboard with reliable indicators as well as recent data that is essential for economic analysis and for choosing an appropriate governance method adapted to each city. In this context, the criticality index applied to African cities, has revealed the impossibility of enhancing waste management without improving urban infrastructure and reducing poverty.
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