scholarly journals Industrial Composting of Commingled Municipal Solid Waste: A Case Study of Shiraz City, Iran

2020 ◽  
Vol 8 (4) ◽  
pp. 1292-1303 ◽  
Author(s):  
Sama Azadi ◽  
Ayoub Karimi-Jashni ◽  
Nasser Talebbeydokhti ◽  
Rouhollah Khoshbakht ◽  
Azadeh Binaee Haghighi
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Public Awareness ◽  
Co2 Production ◽  
Small Scale ◽  
Lack Of Information ◽  
Clean Index ◽  
Economic Analyses ◽  
Performance Results ◽  
Industrial Composting

Composting is a preferable treatment option for putrescible waste disposal. In the small-scale composting, the control of the process is easy and high quality compost is usually produced while the conditions of industrial composting and small-scale composting are so different especially in developing country that municipal solid waste (MSW) is collected as commingled. Unfortunately, there is still a lack of information and experiences regarding the successful industrial composting from commingled municipal solid waste (CMSW). Therefore, this study was conducted on the compost production from CMSW in Shiraz City, Iran, with the composting capacity of 100 tonnes per day. The common process of windrow composting was modified for industrial composting in Shiraz City. The efficiency of the modified process was assessed using physical, chemical, and economic analyses. In addition, the maturity and stability of produced compost was evaluated using different indices such as fertilizing index (FI), clean index (CI), static respiration index (SRI), cumulative respiration index (CRI), and C-CO2 production index (C-CO2 Index). Finally, solutions and suggestions were presented to improve the system performance. Results showed that although the input putrescible waste to composting site has low homogeneity, produced compost in Shiraz City has a “good” quality. The produced compost with FI and CI of about 4.2 and 3.6, respectively, has high fertilizing potential and medium heavy metal content and can be sold without any restriction. Based on the economic analysis, poor marketing, strategies of bad marketing, lack of public awareness, and visible impurities, in spite of complying with the required standards, are the main reasons for the low sale price. The results of this study can be valuable for industrial composting in the cities where wastes are not separated at source.

scholarly journals Municipal Waste Disposal Strategy by Fuzzy TOPSIS Method

2019 ◽  
Vol 8 (6) ◽  
pp. 3497-3499
Keyword(s):  
Waste Management ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Public Awareness ◽  
Fuzzy Topsis ◽  
Decision Makers ◽  
Municipal Waste ◽  
Topsis Method ◽  
Municipal Waste Management ◽  
The City

Municipal solid waste is a major challenge for the metropolitan city. Improper handling of municipal solid waste will create the city unsuitable for living.in this paper, we are discussing about the Indore Municipal Corporation strategy to make the city, one of the cleanest city in India. For this purpose, the 5 selected methods are assigned ranks using Fuzzy TOPSIS method by taking opinion from decision makers and averaged for further analysis. On the basis of reviews 6 main problems created in the city due to municipal waste management ( Dust, Fouling, Emission level, Spreading of Diseases, Open defecation ad Improper segregation) are taken into considerations and 20 decision maker’s opinion is taken on measures taken by Indore municipal corporation for reducing problems created in the city due to municipal waste management are Abolishing cattle, Making more number of urinals, D2D garbage collection, General public awareness, Mechanized road sweeping n jet washing and Using twin bins for source segregation. In this paper the Evaluation shows that open defecations ranking one among all the problems which is greatly reduced by various measures taken by the Indore municipal corporation followed by spreading of disease and improper segregation

scholarly journals Simulation and Optimization of Municipal Solid Waste Combustion: A Case Study of a Fixed Bed Incinerator

2020 ◽  
pp. 5-19
Author(s):  
Arthur M. Omari ◽  
John P. John ◽  
Baraka Kichonge
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Fixed Bed ◽  
Small Scale ◽  
Waste Incinerator ◽  
Simulation And Optimization

In this study, a Computational Fluid Dynamics (CFD) technique was used to develop a model for the simulation and flow conditions of the incinerator. The CFD technique are based on subdividing the volume of interest, i.e., the combustion chamber (or other parts of the plant) into a grid of elementary volumes. The relevant equations of conservation (mass, momentum, energy) are then applied to each of those elements, after defining all inputs, outputs and boundary conditions. The resulting system is then integrated from start to finish, after introducing momentum, mass and heat transfer. The objective of the study was to evaluate and optimize the performance of locally available incinerators in Tanzania. The small scale municipal solid waste incinerator modelling was done by using a fluent solver. The case study of the existing incinerator at a Bagamoyo hospital in Tanzania was used as a model and the obtained values were compared with simulated results and other publications for validation. The design optimization using CFD techniques to predict the performance of incinerator showed the deviation of input air by 14%, the mass flow rate by 26.5%, the mass fraction of carbon dioxide by 10.4% and slight deviation of nitrogen dioxide and carbon monoxide. The study suggested removing the ash during the incineration process by using a moving grate mechanism to minimize the possibility of formation of NOX. The study found the maximum mass flow rate capacity of incinerator to be 68kg/h with input air A1 as 0.03639 kg/s, input air A2 as 0.03046 kg/s and input air A3 as 0.03409 kg/s. The findings indicated that as capacity is scaled up, the available momentum declines relative to the dimensions of the furnace.

scholarly journals Municipal Solid Waste as a valuable recycled asset for small-scale electricity production in rural communities

2019 ◽  
pp. 92-106
Author(s):  
Valter Silva ◽  
João Cardoso ◽  
Paulo Brito ◽  
Luís Tarelho ◽  
José Luz
Keyword(s):  
Rural Communities ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Economic Model ◽  
Electricity Generation ◽  
Integrated System ◽  
Waste To Energy ◽  
Electricity Production ◽  
Small Scale ◽  
Biomass Supply

Municipal solid waste provides an opportunity for electricity production. This strategy provides the rural communities a potential waste-to-energy opportunity to manage its costly residues problem, turning them into a valuable recycled asset. To address this issue, a techno-economic study of an integrated system comprising gasification of Acacia residues and Portuguese Municipal Solid Waste (PMSW) with an Internal Combustion Engine-Generator (ICEG) for electricity generation at small-scale (100 kW) was developed. Current studies only devote attention to biomass residues and do not explore MSW potential to eschew biomass supply shortage. Conventional systems are generally part of biomass supply chains, limiting flexibility and all year operation for their operators. Experimental data was gathered at a downdraft gasifier to provide a clear assessment of particle and tar concentration in the syngas and levers conditioning a satisfactory ICE operation. Once the potential of using Acacia residues and PMSW has been proven during gasification runs testing, and validation, a set of new conditions was also explored through a high-fidelity CFD model. We find that residues blends have the highest potential to generate high-quality syngas and smallest exposure to supply disruption. Despite both substrates showing potential at specific conditions, they also present individual drawbacks which will be best mitigated by executing a hybrid supply comprising the mix of substrates. An economic model coupling the financial indicators of net present value (NPV), internal rate of return (IRR) and the payback period (PBP) considering a project lifetime of 25 years was developed. Cost factors include expenses with electricity generation, initial investment, amortizations and operation and maintenance (containing fuels costs). Revenues were estimated from electricity generated and sales to the national grid. A sensitivity analysis based on the Monte Carlo method was used to measure the economic model performance and to determine the risk in investing in such venture. The risk appraisal yielded favorable investment projections, with an NPV reaching positive values, an IRR superior to the discount rate and PBP lower than the project life span. This work allowed to confirm the positive effect of the generation of energy from downdraft gasification plants on a small-scale. Regardless of the project’s feasibility, the economic performance depended to a large extent on the electricity prices which present considerable variability and are subject to political decisions.

scholarly journals Thermo-economic Analysis of a Retrofit Small Scale Municipal Solid Waste Power Plant

2018 ◽  
Vol 3 (3) ◽  
pp. 1
Author(s):  
Barinyima Nkoi ◽  
Confidence Koate ◽  
Howells Idaerefagha Hart
Keyword(s):  
Power Plant ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Saturation Pressure ◽  
Design Parameters ◽  
Economic Evaluations ◽  
Small Scale ◽  
Software Modeling ◽  
Port Harcourt ◽  
Rivers State

This paper evaluates the thermo-economics of a retrofit small scale municipal solid waste (MSW)-fueled power plant in Port Harcourt, Rivers State, Nigeria. The design parameters for the combustion chamber which utilizes mass combustion in stoker crate furnace is operated at steam saturation pressure of 38.2bar, with fuel consumption rate of 41.3tonnes/hr (11.88kg/s) and was selected for the amount of MSW generated in Port Harcourt metropolis. The data used to assess the availability of the fuel (MSW) were obtained from waste dumpsites controlled by Rivers State Waste Management Agency (RIWAMA). MATLAB Software modeling was used for the thermodynamic analysis to appropriately retrofit a steam turbine to the selected combustor and the result show that the optimal performance of the proposed MSW plant gives a net power output of 5.23MW.  The result further shows that heat in the steam entering the turbine is equivalent to 0.71MWh per tonnes of waste. Therefore, at 17.3% thermal efficiency of the proposed MSW plant, 0.13 MWh of electricity will be produced per tonnes of waste combusted. However, it is estimated that the plant may consume 15% of the electricity, which implies that 0.11MWh/tonne will be exported to the grid. Thus, as the plant is expected to process 340770.3tonnes/yr of MSW, the net electricity output of the proposed plant is estimated at 37.48GWh per year. The economic evaluations have shown that the Net present worth of the plant is $6395107.07 with a payback period of 7years for a 20years life cycle. This work thus indicates huge potentials in generating electrical energy and wealth from MSW in Port Harcourt and beyond with the use of cheap and readily available fuel from municipal solid waste.

scholarly journals EVALUATION OF NEW SMALL-SCALE COMPOSTING PRACTICES WITH ENERGY RECOVERY

Detritus ◽  
2020 ◽  
pp. 3-10
Author(s):  
Roberto Guião de Souza Lima Jr. ◽  
Claudio Fernando Mahler
Keyword(s):  
Solid Waste ◽  
Energy Recovery ◽  
Gas Production ◽  
Small Scale ◽  
Shopping Malls ◽  
Organic Solid Waste ◽  
Organic Solid ◽  
Water Recirculation ◽  
Composting Systems ◽  
Industrial Composting

This study involves the evaluation of new composting systems for the treatment of organic solid waste that has low environmental impact. Two composting devices were developed, with four types of management. Their behavior was analyzed regarding temperature, gas production, moisture, leachate and percolated water production, compost maturation, nutrient presence, pH and water heating, which can be seen as an energy gain in addition to the economic viability of the process. The proposed composting techniques kept the waste at thermophilic temperatures for more than 20 days, with no significant emission of CH4, under aerobic conditions by passive aeration, without leachate generation. These results can be partially attributed to the suspension of the compost on pallets, the residue composition chosen in the experiments and the boundary conditions of the compartments. The energy recovery test, through water recirculation inside the compost, presented temperatures that reached 51°C after 24 h of recirculation, and were maintained throughout the process, 20 days, demonstrating its effectiveness. The proposed models are environmentally viable, minimizing gas emissions and leachate generation compared to landfill or industrial composting plants. They can be used in industrial kitchens, residential complexes, shopping malls and other small and medium solid waste generators. In addition, the solution presented in this study avoids the transportation of waste over medium and long distances, which also brings a significant reduction in energy expenses, and in the case of landfills, it avoids occupation for long periods, thus reducing emissions of gases and leachate, whose control and treatment are expensive.

Analysis of the Barrier Factors of Municipal Solid Waste Classification Recycling

2013 ◽  
Vol 726-731 ◽  
pp. 2618-2621 ◽  
Author(s):  
Yong Chun Wu ◽  
Lian Feng Xu
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Public Awareness ◽  
Waste Reduction ◽  
Scientific Management ◽  
Waste Classification ◽  
Theoretical Issues ◽  
Laws And Regulations ◽  
Recycling Facilities

Many cities in China are facing a "junk siege" dilemma, municipal solid waste classified recycling is one of the effective disposal methods of garbage scientific management, and is also the best way to waste reduction, recycling and harmless, However our municipal solid waste classification recycling remain stagnant, This paper argues that it is because of many obstacles that municipal solid waste classification recycling face makes municipal solid waste classification recycling have little effect, which include public awareness needs to be improved, the limitations of traditional garbage classification, lack of corresponding laws and regulations, garbage recycling facilities not complete and the corresponding theoretical issues remain to be explored etc.

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