scholarly journals Small Scale Plasma Gasification of Municipal Solid Waste

2021 ◽  
Author(s):  
◽  
Keith Male
2010 ◽  
Vol 44 (17) ◽  
pp. 6680-6684 ◽  
Author(s):  
Youngchul Byun ◽  
Won Namkung ◽  
Moohyun Cho ◽  
Jae Woo Chung ◽  
Young-Suk Kim ◽  
...  

Author(s):  
Arthur M. Omari ◽  
John P. John ◽  
Baraka Kichonge

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.


2019 ◽  
pp. 92-106
Author(s):  
Valter Silva ◽  
João Cardoso ◽  
Paulo Brito ◽  
Luís Tarelho ◽  
José Luz

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.


2019 ◽  
Vol 90 ◽  
pp. 37-45 ◽  
Author(s):  
Raquel Tavares ◽  
Ana Ramos ◽  
Abel Rouboa

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