Papers by Keyword: Waste Incineration

Abstract: An extensive experimental work of instrumented indentation on isolated particles of Non-Hazardous Waste Incineration bottom ash (NHWI) is presented in this paper. The aggregates studied come from the Garenne quarries at Vignoc (Brittany, France). Two spherical tungsten carbide indenters of respective 0.5 and 140 mm radius “R” were used for test series “A” and “B”. The particles studied have diameters ranging between 20 and 25 mm. With a 0.5 mm radius indenter, average reduced elastic moduli ranging from 15 to 68 GPa were found. An average reduced elastic modulus of 15 GPa was found with the 140 mm radius indenter. The experiments made it possible to highlight the particular heterogeneity that characterizes the rigidity of the types of aggregates studied.

Abstract: An original experimental campaign never conducted until now on Non-Hazardous Waste Incineration aggregates is presented in this paper. The experiments were conducted in two phases: Scanning Electron Microscopy (SEM) and instrumented indentation. A cartography followed by a series of Quantitative Chemical Microanalysis (QCM) was carried out on the 0/12.5 mm fraction of the particle size distribution. Instrumented indentation tests were carried out on isolated particles of 25 mm in diameter. Observations at the SEM yielded the exact chemical composition of the bottom ashes. It has been found that the proportions of the chemical elements composing the material are slightly different from those of other studies. This difference has made it possible to note that the zone of production of the bottom ash significantly influences their physicochemical characteristics. From the indentation curves obtained, the “Olivier and Pharr” method was used to determine the reduced modulus of elasticity “E_r”. Mean values of approximately 65 GPa and 40 GPa were obtained respectively for vitreous phases and less vitreous ones.

Abstract: Waste disposal in remote areas is a hurdle due to lack of active dumping space. Besides, improper dumping of waste on empty land can have a detrimental impact on the environment. Incineration of waste using thermal incineration (using a solar concentrator) can be utilized for mobile incineration devices to dispose of hazardous waste effectively with a limited space. The design and mobility of the solar dish for this purpose is one of the most important considerations. The modeling of the solar dish was performed on SOLIDWORKS® with APEX® for optical simulation. The simulation results showed a linear variation of flux coating to enable a more comprehensive cost benefit analysis for the design. The simulation was also used to check whether the required flux at focus (to achieve ignition) was achieved. Further work is required to validate the results.

Abstract: This paper describes the specifics of the waste incineration boiler with natural circulation fueled with municipal waste. During operation, certain parts of the boiler are exposed to corrosion and erosion due to effect of particles from the flue gas stream at high temperature. Tests have been performed which include sediment and pipe damage after one year of boiler work. Chemical analysis of sediment samples was taken from the tubes was determined presence of NaCl and Fe compounds and share from 18 % organic substances in the presence of SO₃.

Abstract: With the increasing amount of waste together with the high development of the country, the high amount of waste needed to be treated properly in order to lower the impact to the environment. Waste to Energy through incineration is considered as the appropriated technology to convert green and clean energy from discard matters, especially for the waste that has the mixing composition and has not segregate its composition in the developing country. Therefore, it is essential to simulate its combustion process to see how much of electrical power that can be generated and purpose the appropriated technic in order to improve its efficiency. This research deals with the process simulation of using incineration technology with high moisture content and low heating value in developing country. The simulation of 500 ton per day incineration technology was conducted by the unit operation in Aspen Plus^® program in order to forecast the capacity of electricity production and the contaminants in flue gas emission. It was found that, even high moisture content and low heating value of waste, incineration can be one of the solutions to dispose waste properly and can recover green and clean energy in the form of electricity ranging from 3.78-6.29 MW_e depending on waste’s quality. This green and clean energy recovery from waste could be used to reduce the using of fossil fuel in order to mitigate the emission of the greenhouse gas to atmosphere.

Abstract: With acceleration of urbanization, BOT project on waste incineration in China has been developing rapidly in recent years. Starting from present situation of waste disposal, and combining generating electricity through refuse incineration in a city, this paper analyzes content and characteristics of social risk assessment on waste incineration project and further draws the frame of social risk assessment on waste incineration BOT project. Accordingly, put forward risk response suggestions on generating electricity project through refuse incineration of urban solid waste.

Abstract: Solid waste management is commonly seen in Nigeria as simply pick up the waste and go dump it in a hole somewhere. Hence the current major solid waste management method in Nigeria is disposal at dumpsite. The solid waste management practice at the dumpsite is simple. The waste disposal trucks drive into the dumpsites through the access roads and dump their waste. Other vehicles that deliver waste to the site simply dump their waste indiscriminately by the road sides. The workers at the dumpsites use shovel to manually push the waste from the road and try to spread them as much as their strength can go. Thereafter, open air incineration without pollution control is carried out on the waste for volume reduction. This is not sustainable as it does not bring financial return at the end point of the waste. Therefore incineration with pollution control and energy recovery that will bring financial returns at the end point of the waste is ineviTable for sustainable solid waste management. In the work reported in this paper a study and preliminary design for incineration with energy recovery has been carried out. A review of solid waste component in Benin metropolis was carried out to determine the proportion of combustible material in the waste streams in the metropolis. Several conceptual designs were developed and one was selected. Detail design of a prototype for 15kW electrical power generation was done. The result obtained showed that about 43% of combustible commercial solid waste and about 16% of combustible domestic solid waste are generated in Benin metropolis. The result also showed that about 72Kg/s of combustible municipal solid waste is required for the generation of about 15kW of electrical power and the exhaust gas can be used for other process systems such as systems for drying agro-produce.

Abstract: Combustion control techniques have become a legal requirement to minimize pollution in municipal solid waste incinerators. Typically, incinerator destruction of pollutants is achieved when 2-second gas residence time at 8500 Celsius and about 6% O2 are guaranteed at exit. Performance of a fixed bed (two-stage) thermal oxidizer for solid waste is analyzed numerically using computational fluid dynamics (CFD) technique. The CFD analysis provides three-dimensional view of thermal and gas flow field inside the thermal oxidizer chamber. Localized zones of temperature and species concentration were analyzed and provided critical information for understanding the thermo-chemical processes taking place during incineration leading into design optimization and the operation strategy of the thermal oxidizer. Based on the CFD results, the original design of the thermal oxidizer was modified to optimize the flow characteristics and the residence time in the secondary chamber thereby achieving complete combustion of gases emanating from the lower chamber, hence less emissions of CO.

Abstract: An experimental system of rotating spray drying for cleaning the waste incineration flue gas has been set up on account of the particular fact, that the flue gas quantity is small and contains relatively little SO₂,but relatively much HCl. The influence, of the main parameters which could be control during design and operation, on the efficiency of desulphurization and dechlorination has been tested determined. It was showed that this method resulted in higher dechlorination efficiency and lower desulphurization efficiency. Nevertheless, considering the particularities of the waste incineration flue gas, the discharged flue gas which had been cleaned by this method can meet the restrictive demands of discharging standard of SO₂, and at the same time can warrant a higher efficiency of dechlorination. The efficiency of flue gas cleaning can be enhanced by increasing stoichiometric ratio, by injecting more water, by increasing the rotating speed of atomizer and by decreasing flue gas velocity. The efficiency of desulphurization and dechlorination could reach 78％ and 90％ at stoichiometric ratio 1.8, the amount of injection water 15L/h, rotating speed of atomizer 13500r/min and flue gas velocity 0.7m/s.

Abstract: The influence of Al and Al-Si coatings on the corrosion behaviour of HCM12 in molten KCl-ZnCl2 mixture at 650°C in air has been characterized by electrochemical impedance spectroscopy (EIS). Al and Al/Si protective coatings were developed by chemical vapour deposition in fluidized bed reactor (CVD-FBR) at moderate temperature to respect to mechanical properties of substrate. Scanning electron microscopy (SEM) was used to analyse the damage on the HCM12 electrode surface. Al-Si coating was found to be more resistant to the molten chlorides attack than Al coating; and both coatings increased the corrosion resistance of HCM12 in these conditions. The surface composition has been determined by X-ray diffraction (XRD).