Combustion of Waste Fuels in Sound-Assisted Fluidized Beds

2003 ◽  
Author(s):  
A. Cammarota ◽  
R. Chirone ◽  
M. Urciuolo
Keyword(s):  
Fluidized Bed ◽  
Sound Intensity ◽  
Carbon Conversion ◽  
Fluidized Bed Combustion ◽  
Combustion Time ◽  
Fixed Carbon ◽  
Optimum Frequency ◽  
Combustion Of Solid Fuels ◽  
Minimum Intensity ◽  
Carbon Loading

In the present work, sound-assisted fluidized bed combustion has been investigated by means of a 41mm laboratory scale apparatus fed with combustible powders of different fuels: a tyre derived fuel, a lignite and a petroleum coke. The experiments aim at studying the effect of sound intensity and frequency on carbon conversion of elutriable fines generally produced during fluidized bed combustion of solid fuels. The effectiveness of sound application is evaluated in terms of effects on bed carbon loading, carbon elutriation rate, combustion time and degree of conversion of fixed carbon. Experimental data prove that application of acoustic fields of appropriate intensity and frequency may: increase bed carbon loading and combustion time, reduce elutriation of carbon fines and increase efficiency of fixed carbon conversion. The effects are different for each fuel depending on its characteristics. A simplified model of sound-assisted fluidized bed has been developed. The model has been validated by comparing the experimental optimum intensity and frequency with calculated values of minimum intensity and optimum frequency. The present formulation of the model is useful for the design of the acoustic field to be used in sound-assisted fluidized bed combustors.

Environmental Friendly Fluidized Bed Combustion of Solid Fuels: A Review About Local Scale Modeling of Char Heterogeneous Combustion

2015 ◽  
Vol 7 (2) ◽  
pp. 237-266 ◽  
Author(s):  
Germán D. Mazza ◽  
José M. Soria ◽  
Daniel Gauthier ◽  
Andrés Reyes Urrutia ◽  
Mariana Zambon ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Local Scale ◽  
Solid Fuels ◽  
Heterogeneous Combustion ◽  
Fluidized Bed Combustion ◽  
Scale Modeling ◽  
Environmental Friendly ◽  
Combustion Of Solid Fuels

Combined-Cycle Power Stations Using “Clean-Coal Technologies”: Thermodynamic Analysis of Full Gasification Versus Fluidized Bed Combustion With Partial Gasification

1996 ◽  
Vol 118 (4) ◽  
pp. 737-748 ◽  
Author(s):  
G. Lozza ◽  
P. Chiesa ◽  
L. DeVita
Keyword(s):  
Fluidized Bed ◽  
Power Plants ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Carbon Conversion ◽  
Fluidized Bed Combustion ◽  
Power Stations ◽  
Attractive Option ◽  
Partial Gasification ◽  
Partial Coal Gasification

A novel class of power plants for clean conversion of coal into power has been recently proposed, based on the concept of partial coal gasification and fluidized-bed combustion of unconverted char from gasification. This paper focuses on the thermodynamic aspects of these plants, in comparison with full gasification cycles, assessing their performance on the basis of a common advanced power plant technology level. Several plant configurations are considered, including pressurized or atmospheric fluidized-bed, air- or steam-cooled, with different carbon conversion in the gasifier. The calculation method, used for reproducing plant energy balances and for performance prediction, is described in the paper. A complete second-law analysis is carried out, pointing out the efficiency loss breakdown for both technologies. Results show that partial gasification plants can achieve efficiencies consistently higher than IGCC, depending on plant configuration and carbon conversion, making this solution a viable and attractive option for efficient coal utilization.

Emission and Combustion Characteristics of Lafia-Obi Coal in Fluidized Bed Combustor

2013 ◽  
Vol 824 ◽  
pp. 318-326 ◽  
Author(s):  
Olubunmi Tolulope Popoola ◽  
Abraham A. Asere
Keyword(s):  
Fluidized Bed ◽  
Coal Combustion ◽  
Energy Production ◽  
Volatile Matter ◽  
Matter Content ◽  
Fluidized Bed Combustion ◽  
Qualitative Information ◽  
Fixed Carbon ◽  
Fluidized Bed Combustor ◽  
Very High

The technology of fluidized bed coal combustion (FBC) and its advantages over conventional coal burning systems is now well established and is extensively reported in the literature. There is also some emphasis in literature about the suitability of Lafia-Obi coal in FBC. However, there is little quantitative or qualitative information on theperformance of Lafia-Obi in FBC. This paper reports a study of the combustion of monosized coal fractions fed continuously to the bed via an overbed feeder. Using appropriate ASTM standards, proximate and ultimate analyses of samples of Lafia-Obi coal were carried out and the coal was then combusted in a fluidized bed. Results showed that Lafia-Obi coal has low moisture, high volatile matter and very high fixed carbon content. The volatile matter content places Lafia-Obi in the medium volatile bituminous rank. The data obtained is useful in application of fluidized bed combustion for energy production using Lafia-Obi Coal

Fluidized Bed Combustion of a Biomass Fuel: Comparison Between Pilot Scale Experiments and Model Simulations

2005 ◽  
Vol 127 (2) ◽  
pp. 117-122 ◽  
Author(s):  
Francesco Miccio ◽  
Fabrizio Scala ◽  
Riccardo Chirone
Keyword(s):  
Heat Release ◽  
Fluidized Bed ◽  
Pilot Scale ◽  
Volatile Matter ◽  
High Reactivity ◽  
Operating Conditions ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Bed Temperature ◽  
Carbon Loading

In the present work the efficiency of the fluidized bed combustion (FBC) of high-volatile fuels and the extent of volatile matter post-combustion in the splashing zone and freeboard are investigated. A typical Mediterranean biomass (pine-seed shells) has been burned in a pilot-scale bubbling FB combustor (200 kWt) at different operating conditions. Both over-and under-bed fuel feeding options have been considered. A FBC model specifically developed for high-volatile fuels has been also applied to provide a comparison with bed carbon loading, in-bed heat release and splashing region temperature experimental data. Experimental results showed that the biomass combustion efficiency is always very high as a consequence of the high reactivity of the fuel. Extensive volatile post-combustion above the bed is observed, whose extent appears to be sensitive to the over/under bed feeding option and to the excess air. Approximately 80% of the total heat is released/recirculated in the bed, the remainder leading to appreciable overheating of the freeboard with respect to the nominal bed temperature. Very low bed carbon loadings have been found. Model results compare well with the experimental temperature, heat release and carbon loading trends. However, a detailed prediction of the freeboard temperature profiles requires further improvements of the model.

Sign in / Sign up

Export Citation Format

Share Document