Influence of the interaction on NOx emission during co-combustion of combustible solid waste components

Chen, Yumeng; Ma, Xiaoqian; Liao, Yanfen; Hu, Zhifeng; Lin, Yousheng

doi:10.1016/j.joei.2015.05.009

Cited by 7 publications

(3 citation statements)

References 25 publications

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“…Nitrogen content in plastics and rubbers is lower than miscanthus, so the effect of NO x formation is lesser (test of 60% and 40% polymeric waste). The formation of NO x is related to the time that the products remain in the gas phase inside the boiler, with the increase in the residence time of the gas in the boiler, there is an interaction with hydrocarbon radicals that are in the flame zone, increased in NO x production [60]. This tendency is in agreement with that of polymeric combustion by Baron [61] et al who referred that NO x concentration depends on the nitrogen the content of the fuel and is not prejudiced by irregular feeding interval.…”

Section: Combustion Testsmentioning

confidence: 99%

Co-Combustion of Waste Tires and Plastic-Rubber Wastes with Biomass Technical and Environmental Analysis

et al. 2020

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The present work studies the possibility of energy recovery by thermal conversion of combustible residual materials, namely tires and rubber-plastic, plastic waste from outdoor luminaires. The waste has great potential for energy recovery (HHV: 38.6 MJ/kg for tires and 31.6 MJ/kg for plastic). Considering the thermal conversion difficulties of these residues, four co-combustion tests with mixtures of tires/plastics + pelletized Miscanthus, and an additional test with 100% Miscanthus were performed. The temperature was increased to the maximum allowed by the equipment, about 500 °C. The water temperature at the boiler outlet and the water flow were controlled (60 °C and 11 L/min). Different mixtures of residues (0–60% tires/plastics) were tested and compared in terms of power and gaseous emissions. Results indicate that energy production increased with the increase of tire residue in the mixture, reaching a maximum of 157 kW for 40% of miscanthus and 60% of tires. However, the automatic feeding difficulties of the boiler also increased, requiring constant operator intervention. As for plastic and rubber waste, fuel consumption generally decreased with increasing percentages of these materials in the blend, with temperatures ranging from 383 °C to 411 °C. Power also decreased by including such wastes (66–100 kW) due to feeding difficulties and cinder-fusing problems related to ash melting. From the study, it can be concluded that co-combustion is a suitable technology for the recovery of waste tires, but operational problems arise with high levels of residues in the mixture. Increasing pollutant emissions and the need for pre-treatments are other limiting factors. In this sense, the thermal gasification process was tested with the same residues and the same percentages of mixtures used in the co-combustion tests. The gasification tests were performed in a downdraft reactor at temperatures above 800 °C. Each test started with 100% acacia chip for reference (like the previous miscanthus), and then with mixtures of 0–60% of tires and blends of plastics and rubbers. Results obtained for the two residues demonstrated the viability of the technology, however, with mixtures higher than 40% it was very difficult to develop a process under stable conditions. The optimum condition for producing a synthesis gas with a substantial heating value occurred with mixtures of 20% of polymeric wastes, which resulted in gases with a calorific value of 3.64 MJ/Nm3 for tires and 3.09 MJ/Nm3 for plastics and rubbers.

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Section: Combustion Testsmentioning

confidence: 99%

Co-Combustion of Waste Tires and Plastic-Rubber Wastes with Biomass Technical and Environmental Analysis

et al. 2020

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Section: Mass Fraction Of No 2 Emission (Ppm)mentioning

confidence: 99%

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

Omari

John

Kichonge

2020

JERR

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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%,

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“…This may be due to the high temperature of ash and excess air enters to the primary chamber during filling the waste while the combustion process continues. The ash concentration and the filling of waste during second and other higher cycles of operation may cause this excess temperature and excess air to form thermal NOx which was not considered during the practical experiments (Chen et al, 2016). 77 for residence time such as Canadian standards which set the standard residence time to be not less than 1 second at a temperature not less than 1000°C (CCME, 1989).…”

Section: The Cfd Output Simulation Resultsmentioning

confidence: 99%

Optimization of incineration process

Omari

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Municipal solid waste management has become a challenge in many cities in the developing countries due to the poor methods of waste disposal, which increase the risk of the spread of diseases, leach and increase the demand of land for waste disposal. Characterization study of waste samples from Arusha shows that the combustible fraction is about 87% and biodegradable is 80%. The Thermal gravimetric analyser and Bomb calorimeter show the energy value of about 12.5 MJ/kg and the degradation of about 85%. The study shows that the municipal solid waste disposal method can be thermal, biological or physical. However, thermal method by incineration process is the most preferred and convenient because it destroys pathogens and reduces waste volume in the fastest way. The waste flow analysis of Arusha city shows that the waste has the annual recoverable potential of 128GWh. The case study used an existing incinerator as showed the variation of effluents with operating conditions. The design optimization using computational fluid dynamic 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 research suggested removing the ash during the incineration process by using a moving grate mechanism to minimize the possibility of formation of NOX. To feed the incinerator by using mechanical means without direct opening the door, it suggested to incorporating moving grate mechanism. The operating conditions of the incinerator designed should have the optimum values for input air one A1-1 as 0.036 39 kg/s, the input air two A2-1 as 0.030 46 kg/s, the input air three A3-1 as 0.034 09 kg/s, the input fuel value as 19.6 kg/h and the maximum capacity of incinerator as 68 kg/h.

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Influence of the interaction on NOx emission during co-combustion of combustible solid waste components

Cited by 7 publications

References 25 publications

Co-Combustion of Waste Tires and Plastic-Rubber Wastes with Biomass Technical and Environmental Analysis

Co-Combustion of Waste Tires and Plastic-Rubber Wastes with Biomass Technical and Environmental Analysis

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

Optimization of incineration process

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