Waste Energy Conversion Research Articles

Efficient High Heating Value estimation using Latin Hypercube Sampling and Artificial Neural Network-based approach.

To maximize energy recovery in waste-to-energy (WTE) systems, the High Heating Value (HHV) of municipal solid waste (MSW) must be accurately estimated. To forecast the HHV of MSW, this study proposes a unique method that combines an Artificial Neural Network (ANN) model with Latin Hypercube Sampling (LHS), with a focus on Solan City, Himachal Pradesh, India. In the present study, the elemental characteristics of waste have been used to deal with uncertainty and to find the suitable parameters responsible for the HHV of the MSW. Initially, Latin Hypercube Sampling (LHS) has been used to deal with uncertainty in the elemental composition of MSW, which includes carbon (C), hydrogen (H), nitrogen (N), sulfur (S), and oxygen (O) content. This elemental composition has been used as input parameters to the ANN model for predicting the HHV of MSW. The network 5-28-5-1 offered a minimum MAPE value of 2.18%, MSE, RMSE and R2 values are 0.012, 0.107 and 0.767, respectively. Thereafter, a synaptic weight approach was used to find the most significant parameters responsible for HHV in MSW. It was observed that carbon is the most suitable parameter for HHV of MSW. By dealing with the uncertainty in MSW characteristics, the integration of LHS strengthens the robustness of the model. The results offer an accurate and economical approach for HHV estimation, which will be useful for improving the MSW management and WTE conversion procedures.

Operational optimization of a rural multi-energy system supported by a joint biomass-solid-waste-energy conversion system and supply chain

Biomass, as one of the most accessible renewable resources, could reduce dependency on fossil fuels and mitigate associated environmental impacts. With economic development and improved living standards, biomass in rural areas is converted into various forms of energy to meet high energy demands. However, existing studies on rural multi-energy system operations assume energy production from biomass is a given input parameter and consider it to be a fixed constant or subject to upper and lower bounds, independent of the biomass supply chain. Indeed, biomass energy production is significantly influenced by the collection, transportation, storage, and other processes within the supply chain. This work proposes a mixed integer linear program (MILP) for the joint optimization of an integrated rural multi-biomass-solid waste energy conversion system with a source-grid-demand-based biomass-solid waste supply chain (IRMBS-BSC system). The IRMBS-BSC system encompasses three sub-systems: the biomass-solid waste source sub-system, the biomass-solid waste grid sub-system, and the biomass-solid waste demand sub-system. Various biomass-solid wastes are classified, and a source model is established to evaluate their availability. Subsequently, a supply chain model is developed within the biomass-solid waste grid sub-system. Based on the available and transported quantity from the biomass-solid waste source sub-system and grid sub-system, a multi-energy system operation model, considering refined biomass conversion processes, is proposed. A case study involving a multi-energy system that integrates multiple rural community biomass-solid waste supplies is conducted. The results demonstrate that the proposed MILP, which considers the biomass-solid waste supply chain, can reduce energy imports during the load peak periods and can also decrease the overall operational costs of the multi-energy system.

Current and emerging waste-to-energy technologies: A comparative study with multi-criteria decision analysis

In response to the rise in waste crisis and the possibility of energy utilization from waste, there has been increasing interest in waste-to-energy (WtE) conversion technologies, which requires intense scientific attention. There are diverse WtE technologies that apply to different waste types and require multidisciplinary decision support. The paper applies a Multi-criteria Decision Analysis (MCDA) tool to compare their economic, technological, socio-cultural, and environmental aspects to help identify the most promising choice. The comparison used in this study concerns four widely used technologies: Incineration (INC), Anaerobic Digestion (AD), Gasification (GAS), and Pyrolysis (PYR), and one emerging WtE conversion technology, Hydro-thermal Carbonization (HTC). The Comparison criteria are divided into four main criteria and fifteen sub-criteria. The Analytical Hierarchy Process (AHP) model was implemented using ’SuperDecisions’ software to make pairwise comparisons of identified criteria and to rank the WtE technology alternatives. Thirty-two international studies were shortlisted to gather data and provide input into the AHP model. The results show that the environmental factors are prioritized with a priority vector of 0.56. Further, the study concludes that the most suitable WtE technology, based on chosen parameters, is AD, followed by HTC, INC, and PYR with the priority vectors of 0.348, 0.201, 0.162, and 0.148, respectively, provided applicability. The emerging technology, HTC, is found to be the second most suitable technology. Further, the results represent the hierarchy structure arranged so that the main components are divided into sub-components with alternatives at the structure’s base, and the ’SuperDecisions’ model based on this hierarchy can be used in the future to find suitable WtE technology for a specific city with the necessary input for identified main and sub-criteria. This research not only provides a structured comparison of WtE technologies but also offers a scalable AHP framework that can be adapted for specific municipal contexts in future studies. By addressing the diverse needs of decision-makers across different regions, our model contributes to a more nuanced understanding of WtE technology selection and lays the groundwork for incorporating local policies and regulations in subsequent research phases.

Al-doped Bi2Se3 nanoparticulate semiconductors with controlled resonance states for enhanced thermoelectric efficiency

The generally lower thermoelectric figure of merit (zT < 0.1) of eco-friendly Bi2Se3 semiconductors constrains the waste energy conversion efficiency in the resulting devices compared to a relatively toxic Bi2Te3. We strategically introduce an aluminium (Al) dopant to create resonance states near the Fermi level and obtain Al–Bi2Se3 nanoparticulate semiconductors with enhanced zT. As an electron feeder, these resonance states significantly improve transport properties within the Al–Bi2Se3 semiconductors. The theoretical calculation shows the creation of the resonance states by hybridizing the dopant's s-orbitals with the host's p-orbitals near the Fermi level. The Al–Bi2Se3 semiconductors effectively moderate electron concentration and the Seebeck-dependent effective mass, resulting in an ultrahigh zT of 0.57 over a broad temperature range of 300–473 K. The nanoparticle size (20 nm) efficiently impedes the propagation of lattice vibration, leading to an ultralow total thermal conductivity of 0.399 Wm−1/K. In contrast to conventional doping approaches, our strategic resonance doping is pivotal to enhancing the thermoelectric performance of the Bi2Se3 semiconductors and providing a pathway for synthesizing other semiconductor materials.

GENERATION OF ELECTRICITY FROM WASTE MATERIALS USING Node MCU AND IOT

Nowadays, electricity is considered one of the major commodities in our lives. Due to the increase in demand for electricity, the supply also needs to be increased. There are many effective methods like hydroelectricity, solar power, nuclear power etc, one such method is the generation of electricity from waste materials which is eco-friendly and cost-effective, about 75% of waste in India is reduced by waste-to-energy conversion plants which decrease the number of pollutants like CO, SO2 , NO2 to a huge number. With India's substantial population and the corresponding waste generation, implementing such solutions can significantly alleviate environmental concerns while meeting energy demands. To ensure effectiveness and sustainability, it's crucial to address any drawbacks associated with waste-toenergy conversion. This might involve optimizing technology to maximize energy output while minimizing emissions, ensuring proper waste management practices to handle various types of waste safely, and conducting thorough environmental assessments to mitigate any potential negative impacts. Collaborating with experts in renewable energy, waste management, and environmental science can provide valuable insights and guidance for our project. Additionally, engaging with local communities and stakeholders can help garner support and ensure the project aligns with their needs and concerns. Overall, we focus on reducing pollutants and promoting renewable energy production through innovative waste-to-energy solutions is commendable and holds great potential for a sustainable future.

Electrocatalytic Ni-Co Metal Organic Framework for Efficient Urea Oxidation Reaction

Energy shortage and environmental pollution have become the most serious problems faced by human beings in the 21st century. Looking for advanced clean energy technology to achieve sustainable development of the ecological environment has become a hot spot for researchers. Nitrogen-based substances represented by urea are environmental pollutants but ideal energy substances. The efficiency of urea-based energy conversion technology mainly depends on the choice of catalyst. The development of new catalysts for urea oxidation reaction (UOR) has important application value in the field of waste energy conversion and pollution remediation based on UOR. In this work, four metal–organic framework materials (MOFs) were synthesized using ultrasound (NiCo-UMOFs) and hydrothermal (NiCo-MOFs, Ni-MOFs and Co-MOFs) methods to testify the activity toward UOR. Materials prepared using the hydrothermal method mostly form large and unevenly stacked block structures, while material prepared using ultrasound forms a layer-by-layer two-dimensional and thinner structure. Electrochemical characterization shows NiCo-UMOFs has the best electrocatalytic performance with an onset potential of 0.32 V (vs. Ag/AgCl), a Tafel slope of 51 mV dec−1, and a current density of 13 mA cm−2 at 0.5 V in a 1 M KOH electrolyte with 0.7 M urea. A prolonged urea electrolysis test demonstrates that 45.4% of urea is removed after 24 h.

Emission of Per- and Polyfluoroalkyl Substances from a Waste-to-Energy Plant─Occurrence in Ashes, Treated Process Water, and First Observation in Flue Gas.

Per- and polyfluoroalkyl substances (PFASs) are a large group of compounds commonly used as industrial chemicals and constituents of consumer products, e.g., as surfactants and surface protectors. When products containing PFASs reach their end of life, some end up in waste streams sent to waste-to-energy (WtE) plants. However, the fate of PFASs in WtE processes is largely unknown, as is their potential to enter the environment via ash, gypsum, treated process water, and flue gas. This study forms part of a comprehensive investigation of the occurrence and distribution of PFASs in WtE residues. Sampling was performed during incineration of two different waste mixes: normal municipal solid waste incineration (MSWI) and incineration of a waste mix with 5-8 wt % sewage sludge added to the MSWI (referred to as Sludge:MSWI). PFASs were identified in all examined residues, with short-chain (C4-C7) perfluorocarboxylic acids being the most abundant. Total levels of extractable PFASs were higher during Sludge:MSWI than during MSWI, with the total annual release estimated to be 47 and 13 g, respectively. Furthermore, PFASs were detected in flue gas for the first time (4.0-5.6 ng m-3). Our results demonstrate that some PFASs are not fully degraded by the high temperatures during WtE conversion and can be emitted from the plant via ash, gypsum, treated process water, and flue gas.

Robust optimal dispatching model and a benefit allocation strategy for rural novel virtual power plants incorporating biomass waste energy conversion and carbon cycle utilization

To optimize the utilization of rural biomass waste resources (e.g., straw and solid waste), biomass waste energy conversion (BWEC) and carbon cycle utilization (CCU) are integrated into a traditional virtual power plant, i.e., a rural BWEC-CCU-based virtual power plant. Furthermore, a fuzzy robust two-stage dispatching optimal model for the BWEC-CCU-based virtual power plant is established considering the non-determinacy from a wind power plant (WPP) and photovoltaic (PV) power. The scheduling model includes the day-ahead deterministic dispatching model and real-time uncertainty dispatching model. Among them, in the day-ahead dispatching phase, the dispatching plan is formulated with minimum operating cost and carbon emission targets. In the real-time dispatching phase, the optimal dispatching strategy is formulated aiming at minimum deviation adjustment cost by applying the Latin hypercube sampling method. The robust stochastic theory is used to describe the uncertainty. Third, in order to achieve optimal distribution of multi-agent cooperation benefits, a benefit distribution strategy based on Nash negotiation is designed considering the three-dimensional interfering factor of the marginal benefit contribution, carbon emission contribution, and deviation risk. Finally, a rural distribution network in Jiangsu province, China, is selected for case analysis, and the results show that 1) the synergistic optimal effect of BWEC and CCU is obvious, and the operation cost and deviation adjustment cost could decrease by 26.21% and 39.78%, respectively. While the capacity ratio of WPP + PV, BWEC, and CCU is 5:3:2, the dispatching scheme is optimum. 2) This scheduling model can be used to formulate the optimal scheduling scheme. Compared with the robust coefficient Γ = 0, when Γ = 1, the WPP and PV output decreased by 15.72% and 15.12%, and the output of BWEC and CCU increased by 30.7% and 188.19%, respectively. When Γ∈ (0.3, 0.9), the growth of Γ has the most direct impact on the dispatching scheme. 3) The proposed benefit equilibrium allocation strategy can formulate the most reasonable benefit allocation plan. Compared with the traditional benefit allocation strategy, when the proposed method is used, the benefit share of the WPP and PV reduces by 5.2%, and the benefit share of a small hydropower station, BWEC, and CCU increases by 1.7%, 9.7%, and 3.8%, respectively. Overall, the proposed optimal dispatching and benefit allocation strategy could improve the aggregated utilization of rural biomass waste resources and distributed energy resources while balancing the benefit appeal of different agents.

Robust Multi-objective optimal dispatching model for a novel island micro energy grid incorporating biomass waste energy conversion system, desalination and power-to-hydrogen devices

To realize renewable and self-sustainable energy supply in island region, based on geographical characteristics with abundant renewable resources, an optimal model for island micro energy grid (MEG) is designed incorporating biomass waste energy conversion system (ECS), desalination, and power-to-hydrogen (BSP-MEG) Firstly, the mathematical model is designed, including models of power generators, ECS, desalination and power-to-hydrogen (P2H) devices, etc. Next, the multi-objective scheduling optimization model is designed, containing conventional scheduling model (Scheduling optimization objectives and constraints established with minimum operation and environment costs) and stochastic scheduling model (Minimum Conditional Value-at-Risk objective specific to volatility and uncertainty of renewable generations based on robust stochastic optimization method). Then, to solve the multi-objective optimization problem (MOP), a hybrid differential evolution algorithm is proposed based on local optimal and external archiving strategies. Finally, the MEG of YongXing Island is selected as an example. The results show (1) BSP-MEG effectively realized multi-energy cooperative optimization, and promote intra-day peak shaving. (2) BSP-MEG reduced operating costs, environmental costs and Conditional Value-at-Risk (CVaR) by 78.2%, 61.8% and 77.9% respectively, while curtailment rate by 25.6 to 0.9%. (3) Whether in general scenario or worst, BSP-MEG can realize self-production and self-sale of energy and material, of which risk resistance ability is better. (4) By designing local optimal and external archiving strategies, hybrid differential evolution algorithm performs better in solving complex MOP. In general, the optimization model proposed in this paper can improve the utilization of renewable resources, alleviate the shortage of fresh water, and help realize renewable and sustainable energy supply.

A multi-time scale dispatching optimal model for rural biomass waste energy conversion system-based micro-energy grid considering multi-energy demand response

Aiming at utilizing straw, garbage, domestic sewage and other biomass waste resources in rural areas, this study designed a rural biomass wastes energy conversion system (BWs)-based micro energy grid (BWs-MEG), and the mathematical modeling of BWs-MEG is carried out including multi-energy transforms system (METS) and multi-energy demand response (MEDR). Then, a two-stage optimal framework for rural BWs-MEG multi-time scale dispatching is designed. In the day-ahead stage, a multi-objective dispatching optimal model was constructed with the objectives of minimum operating costs and maximum eco-environment benefits. In the intra-day stage, the robust optimization theory was utilized to characterize the uncertainties of wind power plant (WPP) and photovoltaic power generation (PV) and a rolling dispatching optimal model was constructed with the objective of minimum deviation costs. After that, the above dispatching model was fuzzified and linearized, and then converted into a mixed integer linear programming model. Finally, a micro-energy grid in northern China was selected as an example for case study. The results showed: (1) BWs can utilize rural biomass waste resources for pyrolysis power generation (PG) and gas production to achieve energy utilization and provide power, heating and gas output. In the islanded operation mode and grid-connected operation mode, when MEG is configured with BWs, the deviation costs decrease by 25.6 % and 26.33 %, while the operating costs increases only by 7.60 % and 13.52 %, respectively. The power output of WPP and PV increase by 1.03 % and 2.19 % in the grid-connected operation mode, indicating that BWs is conducive to realizing the multi-dimension supply and demand balance of power, heating and gas loads. (2) Multi-time scale dispatching model can give play to the regulation ability of BWs, METS and MEDR and connect the day-ahead dispatching plan with the intra-day dispatching strategy to formulate the optimal dispatching strategy. When there is deviation in the day-ahead dispatching strategy, METS and MEDR could maintain the supply and demand balance of power load. AHP can change the heating period and BWs could maintain the supply and balance of heating and gas loads. Compared with the day-ahead dispatching plan, the output of PG and power-to-gas device in intra-day dispatching strategy increase by 21.22 % and 9.78 %. (3) Robust stochastic optimization method can characterize the uncertainties of WPP and PV and formulate the dispatching decision schemes with different risk attitudes. With the robust coefficient Г increasing, MEG operating costs and eco-environment benefits increase and deviation adjustment costs decreases, but the robustness of the dispatching scheme is improved. When 0.25≤Г≤0.75, the increase of the uncertainty parameter will have a direct impact on the formulation of dispatching scheme. And the decision maker belongs to risk preference type, who is willing to take certain risks to win excess benefits. Besides, if MEG operates in the grid-connected mode, the uncertainty risks will be weakened and the operation mode shall be reasonably selected according to the demand for dispatching decision. Overall, the proposed optimization model can promote the energy utilization of rural biomass waste resources, which is conducive to the realization of a clean and low-carbon transformation of the overall energy structure.

Selection of Waste to Energy Technologies for Municipal Solid Waste Management—Towards Achieving Sustainable Development Goals

The Sustainable Development Goals (SDGs) play an essential role, emphasizing responsible resource use, production, and consumption, including waste management. In addition, SDG 3, 7, 11, 12, and 13 are directly/indirectly related to waste management. This study aims to determine a suitable waste-to-energy (WtE) technology in Chittagong City, Bangladesh, focusing on cleaner technology. Anaerobic digestion, gasification, incineration, and landfill gas (LFG) recovery were considered as possible alternatives. Technical, economic, environmental, and social issues have been considered as necessary criteria for evaluation. An analytical hierarchy process was applied to rank these technologies based on stakeholders’ perceptions. The study found that anaerobic digestion (AD) ranked first, receiving 38% of overall weight. The second preferred technology is LFG (27%). Gasification and incineration stood at third and fourth, respectively (21% and 14%). According to a sensitivity study, the decision is only sensitive to the economy. LFG will become the most favoured solution for WtE conversion if the economy prioritizes more than 38%. Subsequently, this study’s findings will help achieve Bangladesh’s SDG agenda.

Waste cooking oil biodiesel with FeO nanoparticle – A viable alternative fuel source

Latest trend in determination of alternate fuels have made waste energy conversion as the hot topics. In this present paper, waste cooking oil is converted into biodiesel which is used as an alternate for diesel fuel and to influence the performance parameters iron oxide nano particles was considered for DI diesel engine and its impacts on engine performance and emission characteristics were studied. The process used for the conversion of waste cooking oil into biodiesel in this paper is transesterification process. Experimental tests were conducted in a CI engine using waste cooking oil biodiesel with iron oxide nanoparticles. A CI engine at constant speed of 1500 rpm was used for doing the tests. The combination of obtained biodiesel from waste cooking oil and commercially available iron oxide nanoparticles were used in this research work. The obtained results shows that Brake thermal efficiency is increased marginally and Brake specific fuel consumption is reduced in the blend WCB FeO75 when compared to other blends.

Potential of Waste to Energy Conversion in Egypt

This paper proposes a study on the potential of waste-to-energy (WTE) possibility in the Arab Republic of Egypt. WTE is a viable option for municipal solid waste (MSW) management and a renewable energy source. The issue of waste spread is a chronic environmental challenge in the Arab Republic of Egypt. The MSW practices in Egypt are simply done by collecting the waste and dumping it in open landfill sites. This research aims to assess the potential contribution of the WTE facility to meet electricity demand in Cairo City, which is Egypt’s capital and the biggest city in population as a sample, and then apply the results to all of Egypt. The paper introduced a step-by-step calculation for the electrical power that can be generated from Cairo MSW. Four scenarios for WTE utilization were developed: Mass Burn without any waste processing, Mass Burn with 25% recycling, Mass Burn excluding 50% of organic material, and Mass Burn excluding 50% of organic material with 25% recycling. The Mass Burn scenario implies full MSW stream incineration; the Mass Burn with recycling scenario considers a partial separation of reusable materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material scenario considers a partial separation of organic materials and the waste leftover for incineration; the Mass Burn with excluding 50% of organic material with 25% recycling scenario considers a partial separation of organic materials and partial separation of reusable materials and the waste leftover for incineration. The analyses were done for the period 2011–2031 for Cairo with a total population of about 10 million in Nov 2021. The results show the huge potential of WTE conversion as a source of renewable energy, which is a key factor in Egypt’s sustainable development strategy 2030. Available data have been theoretically processed to show the decision-makers in Egypt the amount of electrical power that can be generated by using the WTE options to manage the MSW in Egypt.

Estimating the Energy Recovery Potential from Municipal Solid Waste in Ha’il Region (Kingdom of Saudi Arabia)

In the Kingdom of Saudi Arabia (KSA), the need of an agile solid waste management (SWM) system is vital to control safely the rapid growth of its municipal solid waste (MSW) with minimal environment toll. Further, the domestic energy production in KSA is thriving and putting a tremendous pressure on its reserves of fossil oil. Waste-to-energy (WTE) plants provides an excellent opportunity, even if MSW mitigation and energy production are usually considered separately. Energy recovery (ER) from waste is not a new field of study; however, its implementation remains a challenge in KSA. Although there is abundance of useful waste in the urban markets, practices aiming at WTE conversion are still negligible. In the KSA, so-called green markets are abundant with renewable energy potential, yet the practical implementation of this potential is missing. This work aims to present the worldwide SWM methods, the classification and the characteristics of solid waste in KSA especially in Ha’il region. In addition, the present research deals with the evaluation of waste generation in Ha’il region for the ER purpose and depicts that WTE is not only environmentally friendly but also financially rewarding. Data were collected regarding solid waste in Ha’il region and the calculations of ER potential from solid waste were conducted. The obtained results show that ER from solid waste can save energy consumption in Ha’il region; the saving factor was estimated to be 18%.

Financial and Socio-economic Study of Modular Pyrolysis Facilities as Waste-to-Energy Technology: a Case Study in Metropolitan Manila, Philippines

Industrial, medical, and electronic residual wastes can potentially be an important source of energy with the use of waste-to-energy (WtE) conversion technology. In Metropolitan Manila, Philippines, about 144,000 kg/d of residual wastes were being generated by the hospitals, industrial sectors, and electronic companies. Hence, imploring high potential benefits can be achieved through utilizing these wastes as feedstock for any WtE conversion facility. A technical and financial costing was performed to evaluate the feasibility of putting up a conventional pyrolysis system in Metropolitan Manila. Various modular-type scenarios of a pyrolysis system in the WtE facility were identified based on the geographical attributes of the sectoral residual wastes generators. Results showed that a 10 tons/d pyrolysis plant facility, with Brayton power set-up, can eventually produce 800 kW and generate an annual net income of PHP 83.63 M after a 2-yr breakeven period. In addition, this facility can accommodate at most 11 tons/d of residual wastes for processing. In contrast, a smaller footprint of pyrolysis-Brayton set-up consisting of three tons per day, with 1,000 kg of daily wastes and a power generation of 65 kW, can potentially produce a net income of PHP 18.06 M following a 3-yr breakeven period. The WtE business models of putting up conventional pyrolysis facilities, by presenting both the maximum and minimum scenarios in terms of plant capacity and income when intended for operation and adoption, were computed to be feasible.

Application of Fuzzy Control Technology in Aerobic Compost Heat Recovery Device

The technology of aerobic composting of organic solid wastes has been mature, but the technology of energy recovery and utilization generated by aerobic composting is backward. This paper investigates the status quo of organic solid waste energy conversion and fuzzy control technology. Based on reality, the principle of energy recovery of aerobic composting technology is introduced, the characteristics and advantages of fuzzy control technology are analyzed, and the design of fuzzy control technology for heat recovery device of aerobic composting has improved the utilization rate of energy recovery of aerobic composting. Practice has proved that the introduction of intelligent control technology such as fuzzy control into the control technology of biomass energy recovery is an inevitable trend in the development of new energy field.

Scaling-up defect-free asymmetric hollow fiber membranes to produce oxygen-enriched gas for integration into municipal solid waste gasification process

Municipal solid waste (MSW) gasification is an attractive waste-to-energy (WTE) technology with promise for future solid waste management, owing to the production of syngas which can be used as an alternative energy resource. However, quality of produced syngas is not meeting expectation. One promising solution is to use oxygen-enriched gas (OEG) to elevate produced syngas quality but producing OEG is costly. Herein, we demonstrated an asymmetric defect-free hollow fiber membrane made up of Matrimid® 5218 polyimide for scaling-up to 2-inch membrane modules. Our modules have an effective surface area up to 2.6 m2 with a packing density of up to 44% to produce OEG of 45% O2 purity. The 2-inch membrane module was integrated into a lab-scale gasification process to produce syngas using refuse derived fuel (RDF) generated from MSWs collected from the university campus. Prior to this, the lab-scale gasification was first optimized by tuning the gasification temperature, O2 purity and equivalence ratio (ER). Then, MSW gasification using membrane-based OEG was carried out, and compared against air gasification and synthetic OEG of the same O2 purity. Our results showed that, at O2 purity of 45%, gasification temperature of 900 °C and ER of 0.15, the quality of produced syngas was elevated with a lower heating value (LHV) of 9.15 MJ/m3 and H2/CO ratio of 1.43, which was substantially higher than air gasification with LHV and H2/CO ratio reported at 5.38 MJ/m3 and 0.81, respectively. Gasification results for membrane-based OEG and synthetic OEG were also comparable, while process simulation evidence suggested that membrane-based separation was at least 2-fold less energy-intensive than cryogenic distillation and pressure swing adsorption. Overall, this proof-of-concept successfully demonstrates the viability and competitiveness of membrane process for producing OEG at medium O2 purity (i.e., 40–50%) to support MSW gasification for WTE conversion.

Estimation of energy content in municipal solid waste of Bhutan and its potential as alternate powers source

Conversion of Solid waste into energy is the most resourceful process to combat landfill saturation and environmental impression. Bhutan, with an exponential rise in the waste production, Waste to Energy (WTE) conversion is an alternative solution for municipal solid waste management (MSW). The study for MSW composition and its energy potential analysis for Memelakha (Thimphu) and Pekarshing (Phuntsholing) landfills was done to resolve the waste management challenges in the country. The standard number of samples from two dumpsites were used to analyze for the waste characterization (waste composition, proximate analysis, chemical analysis) and high heating value (HHV) of MSW. MSW of two landfills showed that the main elemental constituents were Carbon and Oxygen with 17.26% and 9.97% by mass respectively for Pekarshing and 16.52% (Carbon) and 11.07% (Oxygen) by mass for Memelakha landfill. Based on the physio-chemical analysis of MSW, the average calorific HHV of MSW obtained were 10.028 MJ/kg (26.04% of coal energy) for Pekarshing dumpsite and 9.6 MJ/kg (24.94% of coal energy) for Memelakha. The analysis showed that by the year 2050 Memelakha landfill has the potential to generate the power of 8.85 Megawatt (MW) and 1.44 Megawatt (MW) for Pekarshing. For (WTE) conversion, incineration, pyrolysis, and gasification technologies are found suitable based on the current composition MSW of Bhutan. Furthermore, in terms of energy efficiency and percentage of wastage, the gasification process was the most feasible method for WTE conversion at two locations with a waste volume reduction of 80 to 90 percent at the landfill.

Evolution of kinetic and hydrothermal study of refused derived fuels: Thermo-gravimetric analysis

With the increase in municipal-solid-waste (MSW) production, energy usage, and the curb of the landfill, it has developed the need of our society to use local MSW under the vision of waste-to-energy (WTE). WTE conversion is an environment-friendly way for disposing of MSW around the globe, in this study examining the usage of plastic, wood, and cloth for the refused derived fuels (RDFs) production. RDF is solitary of MSW energy yields, whose reliability and superiority are analysed in the current work. Three different RDFs had been assumed from diverse waste streams accessible at the plant site to propose the best RDF based on energy-efficiency. Plastics, wood, and cloth are the principal constituents in the method of occupied RDFs like RDF-I, RDF-II and RDF-III, respectively. The results demonstrated that the RDF-I holds a high amount of carbon as-well-as hydrogen content and adequate calorific value, which leads to a better fuel-quality and have better activation energy. Thermogravimetric analysis had shown, with the increase in the volatile matter fraction of RDFs, the retention time under the combustion atmosphere has remained increased accordingly and kinetic analysis showed the great activation energy value as compared to the other samples. Regarding all results, RDF-I was recommended to be a good option for energy applications and can be used as a fuel for numerous combustion reactions.

An optimization‐based analysis of waste to energy options for different income level countries

Utilizing waste-to-energy (WtE) technologies is becoming crucial in today's world where energy sources are scarce. Despite the fact that WtE technologies (incineration, gasification, pyrolysis, anaerobic digestion, and landfill gas recovery) have been analyzed thoroughly in the literature regarding their efficiency rates in treating waste, the applicability of each method to different waste compositions and in various economic environments has not been considered before. In this study, this issue is investigated by modeling and solving a mixed integer programming model. The model is illustrated in three settings, namely Turkey, Brazil, and Germany, each of which is an example of a lower middle income, upper middle income, and a high income country, respectively. The findings of the optimization model suggest that plasma-arc gasification and advanced incineration stand out as the most efficient technologies to create the WtE conversion, provided that there are sufficient funds to build and run these facilities. If there are economic restraints, anaerobic digestion could be a more cost-effective way to create energy from waste. However, the solutions can be highly dependent on the parameters of the problem, as indicated in the results of the sensitivity analysis performed. In particular, if CO2 emissions are a big concern, the optimization model favors more of plasma-arc and pyrolysis technologies. Novelty Statement Despite a wide range of previous studies involving technical analysis of WtE technologies, an economic perspective involving facility building decisions comparing different income level countries has not been performed before. This study examines all waste-to-energy methods in the literature not only regarding their efficiency rates in treating waste but also selecting the most appropriate methodology in different settings. In this manner, considering different income level countries brings a proper perspective and novelty to the study.