Municipal Solid Waste Processing Research Articles

Evaluating the emissions from the gasification processing of municipal solid waste followed by combustion

In this study, we evaluated the emissions of pollutants generated from the combustion of syngas in the gasification of Municipal Solid Waste (MSW) in Brazil using a mobile grille gasifier fed with domestic waste without any previous separation or grinding. The basic syngas composition (H2, CH4 and CO) was analyzed by gas chromatography and the Lower Calorific Value was calculated, which ranged from 1.9 to 10.2 MJ/kg. In the monitoring of combustion gases (CO2, CO, NO, NO2, SO2 and Total Hydrocarbon Content), values were found for these pollutants that were lower than the values established by the Brazilian legislation, except for SO2. Regarding the determination of the emission of metals, values lower than those permissible in the legislation were found for the most toxic metals grouped as class I (Cd, Hg, Tl). Therefore, it was evident that gasification followed by the combustion of syngas from MSW without prior segregation at source has the advantages of having fewer process steps, allowing the low emission of pollutants into the environment and it avoids that the residues are deposited in landfills, which are generators of leachate and greenhouse gas (methane).

Simulation of Combustion of Municipal Solid Waste and Coal in an Industrial-Scale Circulating Fluidized Bed Boiler

In this paper, a three-dimensional Eulerian–Lagrangian model is established to perform the full-loop simulation of the combustion process of municipal solid waste (MSW) and coal in an industrial-scale circulating fluidized bed (CFB) boiler. On the basis of the multiphase particle-in-cell (MP-PIC) scheme, the gas phase is modeled by a large eddy simulation (LES) approach and the solid phase by discrete particle method. A comprehensive reaction model including devolatilization, combustion of char and volatiles, formation and retention of acid gas, and production and reduction of NO and N2O is incorporated into the scheme. The simulated CFB boiler consists of the chamber, cyclone, loop-seal, external heat exchanger (EHE), and diplegs. The full-loop gas–solid flow behavior and combustion characteristics are obtained. Numerical results reveal that a fast fluidization regime takes place in the chamber region, while a bubbling fluidization regime appears in the EHE. Serious wall erosion takes place in the horizo...

Optimal processing route for the utilization and conversion of municipal solid waste into energy and valuable products

A systematic design of municipal solid waste (MSW) management system can lead to identify a promising and/or sustainable way of handling MSW by processing it into energy and valuable products. In this study, a systematic framework is developed for the superstructure-based optimization of MSW processing routes. The proposed superstructure includes the potential technological alternatives (such as recycling, composting, anaerobic digestion with electricity generation, gasification followed by catalytic transformation, gasification with electricity generation, plasma arc gasification with electricity generation, pyrolysis with electricity generation, incineration with electricity generation, and landfill with electricity generation) for producing valuable products from MSW. Based on the developed superstructure, a mixed integer nonlinear programming (MINLP) model is developed to identify the optimal MSW processing pathways considering two different MSW handling scenarios. For ease of the solution, the MINLP model is linearized to its equivalent MILP form, and solved in GAMS. The solution to the optimization problem provides the optimal/promising route for the synthesis of useful products from MSW under chosen economic objective function. The developed framework is applied on a case study of Abu Dhabi Emirate to find the optimal processing pathway for handling and processing of MSW into energy and value-added products. The optimization results show that an integrated pathway comprising of recycling the recyclable components of MSW along with the production of bioethanol from the rest of the waste via gasification followed by catalytic transformation can provide potential economic benefits. A sensitivity analysis is also executed to investigate the effect of key economic and technical parameters on the optimization results.

Accommodation of Interests of the State, Business and Civil Society in Environmental Projects Implemented Through Public Private Partnership in the Russian Federation

Environmental projects have a number of distinctive features, among them an increased capital/output ratio, relatively high risks, lengthy payback periods, and outcomes that are hard to evaluate using financial indicators. Public private partnership (PPP) appears to be a viable approach for the implementation of such projects; however, existing mechanisms for the accommodation of long-term interest of the state, business and civil society are inadequate to ensure their success. In this context, the author presents an algorithm of multi-criteria analysis to evaluate the social efficiency of PPP-based environmental projects, which takes into account the impact of both financial and non-financial outcomes and includes crowdsourcing public opinion into the final decision-making process. Special priority is given to the assessment of multiplicative effects, as their role and impact on the feasibility of investment are often underestimated. The author’s conclusions and recommendations are illustrated using the case study of a construction project for a municipal solid waste processing facility.
 
 Full text available at: https://doi.org/10.22215/rera.v11i2.1191

Multi-material classification of dry recyclables from municipal solid waste based on thermal imaging

There has been a significant rise in municipal solid waste (MSW) generation in the last few decades due to rapid urbanization and industrialization. Due to the lack of source segregation practice, a need for automated segregation of recyclables from MSW exists in the developing countries. This paper reports a thermal imaging based system for classifying useful recyclables from simulated MSW sample. Experimental results have demonstrated the possibility to use thermal imaging technique for classification and a robotic system for sorting of recyclables in a single process step. The reported classification system yields an accuracy in the range of 85–96% and is comparable with the existing single-material recyclable classification techniques. We believe that the reported thermal imaging based system can emerge as a viable and inexpensive large-scale classification-cum-sorting technology in recycling plants for processing MSW in developing countries.

Can the incineration of Municipal Solid Waste pose occupational and environmental radiation hazards?

An evaluation of the incineration process of municipal solid waste is made for identifying potential radiation hazards. Sources of radiation considered are the radioactive materials wrongly eliminated into municipal waste (e.g., industrial and medical waste containing radioactive sources, such as cesium-137 and technetium-99m) and also radionuclides of natural origin (e.g., radium-226, polonium-210) contained in common materials disposed as domestic waste. Through burning, radionuclides from both origins may be released as gases and radioactive particles into the atmosphere and build up in the facility and in the environment nearby. Results from model calculations indicated that naturally-occurring radionuclides released into the atmosphere likely originate a small enhancement to the natural radiation background. However, in the case of man-made radioactive sources mixed with the municipal solid waste the radioactive emissions may attain and eventually exceed the radiation dose limit for members of the public. These results support the recommendation that for natural radionuclides present in incinerated waste a careful evaluation of the risk of exposure to ionizing radiation, actually in accord to the European Directive 2013/59/EURATOM establishing the basic safety standards for radiation protection, must be performed and model calculations validated with radioactivity measurements. Regarding the potential release of radionuclides from man-made radioactive sources it is recommended the installation of portals equipped with radiation detectors to check municipal solid waste on admission in the facilities and prevent such radiological accident.

Research and demonstration results for a new “Double-Solution” technology for municipal solid waste treatment

In this paper, the pyrolysis characteristics of six typical components in municipal solid waste (MSW) were investigated through a TG-FTIR combined technique and it was concluded that the main pyrolysis process of the biomass components (including food residues, sawdust and paper) occurred at 150–600°C. The main volatiles were multi-component gas including H2O, CO2, and CO. The main pyrolysis temperatures of three artificial products (PP, PVC and leather) was ranged from 200to 500°C. The wavelength of small molecule gases (CH4, CO2 and CO) and the the chemical bonds (CO and CC) were observed in the infrared spectrum Based on the pyrolysis temperature interval and volatile constituent, a new “double-solution” process of pyrolysis and oxygen-enrichment decomposition MSW was designed. To achieve this process, a double-solution project was built for the direct treatment of MSW (10t/d). The complete setup of equipment and analysis of the byproducts has been reported in this paper to indicate the performance of this process. Energy balance and economic benefits were analysed for the process supporting. It was successfully demonstrated that the double-solution process was the environmentally friendly alternative method for MSW treatment in Chinese rural areas.

A multi-objective robust optimization model for site-selection and capacity allocation of municipal solid waste facilities: A case study in Tehran

This paper introduces a multi-objective robust optimization model for a municipal solid waste (MSW) management system consisting of customers, transfer stations, landfills, recycle plants, and waste transport vehicles. The proposed model addresses the economic, environmental, and social perspectives of this system simultaneously by minimizing the total cost, the greenhouse gas emission, and the resulting visual pollution, respectively. This model can aid decision makers to locate the optimal sites of MSW recycling and disposal facilities, optimize the capacity allocation of landfills to transfer stations and population centers, optimize the capacity allocation of transfers stations and recycle plants to population centers, determine the most suitable technology for each operation, and find the right number and type of transport vehicles based on aforementioned objectives. Comparing to prior studies, considering all three dimensions of sustainability (i.e. economic, environmental and social) simultaneously, attempting to locate all three major MSW processing and disposal facilities (namely, transfer stations, recycling plants, and landfills) at the same time, and Considering uncertainties involved in this group of facility location problems are the innovations of this study. The proposed model, which is also fully compatible with the waste segregation at source approach, was validated by the use of real data for long-term planning of Tehran's MSW management system by examining five candidate sites for the construction of new facilities. The results show the efficiency of proposed model.

Modern technologies of processing municipal solid waste: investing in the future

The problem of effective municipal solid waste (MSW) management is known to all the municipal entities of the Russian Federation. The problem is multifaceted and complex. The article analyzes the dynamics of municipal solid waste formation and its utilization within the territory of the EU and Russia. The authors of the paper suggest a project of a plant for processing municipal solid waste into a combustible gas with the help of high temperature pyrolysis. The main indicators of economic efficiency are calculated.

Municipal solid waste processing and separation employing wet torrefaction for alternative fuel production and aluminum reclamation

This study employs wet torrefaction process (also known as hydrothermal) at low temperature. This process simultaneously acts as waste processing and separation of mixed waste, for subsequent utilization as an alternative fuel. The process is also applied for the delamination and separation of non-recyclable laminated aluminum waste into separable aluminum and plastic. A 2.5-L reactor was used to examine the wet torrefaction process at temperatures below 200°C. It was observed that the processed mixed waste was converted into two different products: a mushy organic part and a bulky plastic part. Using mechanical separation, the two products can be separated into a granular organic product and a plastic bulk for further treatment. TGA analysis showed that no changes in the plastic composition and no intrusion from plastic fraction to the organic fraction. It can be proclaimed that both fractions have been completely separated by wet torrefaction. The separated plastic fraction product obtained from the wet torrefaction treatment also contained relatively high calorific value (approximately 44MJ/kg), therefore, justifying its use as an alternative fuel.The non-recyclable plastic fraction of laminated aluminum was observed to be delaminated and separated from its aluminum counterpart at a temperature of 170°C using an additional acetic acid concentration of 3%, leaving less than 25% of the plastic content in the aluminum part. Plastic products from both samples had high calorific values of more than 30MJ/kg, which is sufficient to be converted and used as a fuel.

Full-scale biodrying process of municipal solid waste

The paper presents the results obtained in the full-scale waste biodrying reactor. The studied facility includes in the biological stage a rectangular-shaped, galvanized steel reactor equipped with a module for active aeration connected with a stove and a bio-filter for removing odours. The undersize fraction (O days in the 150 m3 capasity reactor. Initial moisture content of the untreated waste was 54.65%. Moisture content was declined gradually during biodrying process. Temperature changes during 14th days of biodrying process were monitored with the maximum temperature 70°C. To assess the degree of stabilization of the biodried waste, the determination of the O2 uptake was measured. The oxygen demand of untreated waste was 53.16 mg O2 /g d.m. and after 14th days for biodried waste oxygen consumption was 19.78 mg O2 /g d.m. The results obtained in studies by respirometric dynamic method of oxygen uptake (expressed as O2 /96h parameter) had been compared to the results performed using the static method, where AT4 is the applied indicator.

Analysis of Changing Wear Assembly Screw-Engine with the use of Automatic Systems

Waste recycling in Russia merely reaches 5% to 7% versus up to 60% of MSW in the EU, and over 90% of waste in Russia is delivered to waste landfills and unauthorised dumps so that waste accumulation is increasing. This environmental situation is a national priority. The Decree of the President of the Russian Federation dated 5 January 2017 announces 2017 the Year of Ecology in Russia. Most environmental reforms stipulated by amendments to laws are enacted from 1 January 2017. These are primarily measures aimed at emissions and discharges control using best available technologies and breakthrough provisions of the Industrial and Consumer Waste law. The Clean Country, priority project of the Russian Government, will be implemented from 2017 to 2025 with the key aim of reducing the environmental footprint from municipal solid waste disposal and mitigating environmental risks of an accumulated environmental damage. The priority project involves the construction of five environment-friendly facilities for the thermal processing of municipal solid waste (waste incineration plants), four of them to be built in the Moscow Region and one facility to be built in the Republic of Tatarstan. An alternative to waste incineration is municipal waste recycling by moulding in extrusion machines to make pellets to be further used in the fuel or construction industries. The profitability of a waste recycling facility is dependent on a sound choice of extrusion equipment with the best value for money.

Incorporation of Environmental Law Requirements during Waste Management at Rubbish Recycling Plants in the Republic of Kazakhstan

Objectives: The research is aimed at improving the system of municipal solid waste handling; improving the efficiency, reliability, environmental and social acceptability of the complex of services on collection, transportation, recycling, processing and disposal of municipal solid waste; modernizing MSW sector based on advanced technologies and management practices, as well as taking measures to strictly comply with the Kazakhstan environmental law requirements. Methods: Such scientific methods as research, analysis, synthesis and substantiation were used to study this environmental problem based on the works of both domestic and foreign scholars. Findings: The authors carried out systemic legal and environmental-economic analysis of waste processing technologies and equipment enabling to assess the negative impact on the environment, as well as to study the requirements of environmental law during waste management at the rubbish recycling plants in the Republic of Kazakhstan. It has been proposed to apply life cycle assessment (LCA) in designing and selecting the best waste management option and provide support of rubbish recycling companies from the republican budget resources. Application/Improvements: Implementation of the research will improve the quality of services rendered in MSW management, increase the amount of collected and recycled secondary material resources, allow taking full advantage of the MSW energy potential and minimizing the negative environmental impact as a result of MSW treatment. Thus, it will contribute to a significant improvement in the quality and conditions of life of citizens of the Republic of Kazakhstan.

Macromodelling of fermentation process of municipal solid organic waste at biogas plants on the acidogenesis stage

In this work the task of modeling processes of anaerobic microbiological fermentation with keeping the balance on the stages of hydrolysis and acidogenesis was considered. It was proposed and justified to build the model at the stage of acidogenesis in the form of interval difference operator (IDO). The structure identification method of IDO on the principles of honey bee colony functioning in the food search process, which provides the possibility of obtaining simple IDO structures with specified prognostic properties relative to existing methods, was substantiated.

Investigation on the co-combustion of oil shale and municipal solid waste by using thermogravimetric analysis

The aim of this study is trying to reveal the thermal characteristics and kinetics of oil shale, municipal solid waste and their blends in the combustion process which are needed for efficient utilization. The combustion experiment is carried out in a thermogravimetric simultaneous thermal analyzer, where the temperature ranged from 110°C to 900°C at three different heating rates as 10°C/min, 20°C/min and 30°C/min. Their kinetics were studied by Ozawa–Flynn–Wall and Friedmen methods. According to the data analysis, combustion characteristic index increased progressively with the increase of the proportion of municipal solid waste. And it’s suggested that there was certain interaction in the combustion process of oil shale and municipal solid waste. The average activation energy of the blends reached the minimum value, 177.7927kJ/mol by Ozawa–Flynn–Wall method and 167.4234kJ/mol by Friedmen method, when the proportion of MSW was 70%.

Application of SWOT Analysis for the Selection of Technology for Processing and Disposal of MSW

Municipal solid waste management system cannot be made sustainable only with the technical end-of-pipe solutions but an integrated approach is necessary. The use of SWOT (strength & weakness and opportunity & threats) analysis technique for the selection of technology for processing and disposal of municipal solid waste will help to mitigate the uncertainties and minimise the business/project risk and will also help to identify the raw material feed mix, establish a raw material supply chain, identify the product mix and product market, business model & business risk. In this paper a systematic approach has been developed for the selection of right technology for the sustainable processing and disposal of municipal solid waste.

Municipal Solid Waste Management in Salem City, India

Salem City in Tamilnadu is an ancient city and one of the selected Smart Cities of India facing a serious environmental threat due to improper disposal of the 335 MT per day of Municipal Solid Waste (MSW) generation. The entire solid waste generated from the city has been dumped in an unscientific manner nearly for four decades in Erumapalayam land fill area (28 acres) which is located 12 km away from the city and presently it overflows with heaps of daily accumulation of MSW. Hence, in the present study an attempt has been made to convert the MSW of the city into bio-compost through vermicomposting technique and thereby aimed to implement waste to wealth practices in the city judiciously. The experimental works in the field on vermicomposting of MSW and the Cost Benefit Analysis of the same revealed that the vermicomposting process of MSW is an eco friendly, economical way of disposing the MSW of Salem City and upon implantation of the same in Salem City, it would yield a net revenue of Rs 450/MT/day over and above the routine operational expenses of Rs.706/MT/day to the Salem city municipal corporation.

Thermal behavior and kinetics of municipal solid waste during pyrolysis and combustion process

The thermal behavior of municipal solid waste (MSW) in south China during pyrolysis and combustion processes was investigated via thermogravimetric analysis. In order to investigate the effect of metal oxides in the grate ash, the pyrolysis and combustion experiments were carried out with and without additives (ZnO, Fe2O3, CuO and Al2O3). Different artificial atmospheres (O2: N2 = 1:9, O2: N2 = 3:7, O2: N2 = 5:5, O2: N2 = 7:3) were adopted to investigate the oxygen-enriched combustion characteristics. Results showed that all additives facilitated the decomposition of MSW, while the CuO prohibited the decomposition of biowaste matter. The same effort was applied on the combustion process. All additives had a catalytic effect on ignition and combustion characteristics of MSW, except for biowaste volatile combustion of MSW with CuO. The oxygen-enriched combustion conditions reduced the ignition temperature of MSW and provided more help to the combustion process of MSW. Based on several compositions parallel reaction mechanism, the kinetic parameters were obtained and confirmed that both some additives and high oxygen concentration improved MSW combustion characteristics.

Impact Of Aerobic Biostabilisation And Biodrying Process Of Municipal Solid Waste On Minimisation Of Waste Deposited In Landfills

Abstract The article discusses an innovative system used for aerobic biostabilisation and biological drying of solid municipal waste. A mechanical–biological process (MBT) of municipal solid waste (MSW) treatment were carried out and monitored in 5 bioreactors. A two-stage biological treatment process has been used in the investigation. In the first step an undersize fraction was subjected to the biological stabilisation for a period of 14 days as a result of which there was a decrease of loss on ignition, but not sufficient to fulfill the requirements of MBT technology. In the second stage of a biological treatment has been applied 7-days intensive bio-drying of MSW using sustained high temperatures in bioreactor. The article presents the results of the chemical composition analysis of the undersize fraction and waste after biological drying, and also the results of temperature changes, pH ratio, loss on ignition, moisture content, combustible and volatile matter content, heat of combustion and calorific value of wastes. The mass balance of the MBT of MSW with using the innovative aeration system showed that only 14.5% of waste need to be landfilled, 61.5% could be used for thermal treatment, and nearly 19% being lost in the process as CO2 and H2O.

The behavior of compression and degradation for municipal solid waste and combined settlement calculation method

The total compression of municipal solid waste (MSW) consists of primary, secondary, and decomposition compressions. It is usually difficult to distinguish between the three parts of compressions. In this study, the odeometer test was used to distinguish between the primary and secondary compressions to determine the primary and secondary compression coefficient. In addition, the ending time of the primary compressions were proposed based on municipal solid waste compression tests in a degradation-inhibited condition by adding vinegar. The amount of the secondary compression occurring in the primary compression stage has a relatively high percentage to either the total compression or the total secondary compression. The relationship between the degradation ratio and time was obtained from the tests independently. Furthermore, a combined compression calculation method of municipal solid waste for all three parts of compressions including considering organics degradation is proposed based on a one-dimensional compression method. The relationship between the methane generation potential L0 of LandGEM model and degradation compression index was also discussed in the paper. A special column compression apparatus system, which can be used to simulate the whole compression process of municipal solid waste in China, was designed. According to the results obtained from 197-day column compression test, the new combined calculation method for municipal solid waste compression was analyzed. The degradation compression is the main part of the compression of MSW in the medium test period.