Characterization of Solid Wastes From Circulating Fluidized Bed Combustion

1995 ◽  
Vol 117 (1) ◽  
pp. 18-23 ◽  
Author(s):  
E. J. Anthony ◽  
G. G. Ross ◽  
E. E. Berry ◽  
R. T. Hemings ◽  
R. K. Kissel
Keyword(s):  
New Brunswick ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Full Scale ◽  
Operating Conditions ◽  
Solid Wastes ◽  
Fluidized Bed Combustion ◽  
Scale Unit

The characterization of solid wastes from full-scale circulating fluidized bed combustors (CFBC) is necessary to ensure that disposal procedures or utilization strategies for the waste solids are successful. Pilot plants are extremely useful in providing hydrodynamic heat and mass transfer data that can be used to design and predict the performance of larger units. Combustion studies indicate that data from pilot-scale units can be used to approximate the behavior of a full-scale plant for different fuels and operating conditions, even when the pilot plant is not designed to properly scale the commercial unit. However, the same does not seem to be true for the determination of reduced sulphur, the other is species and geotechnical or physical properties of the solid wastes generated from pilot plants. The results of analyses of samples generated from two units are discussed. One is a 150 by 150 mm square, 7.3 m high pilot-scale CFBC located at the University of British Columbia and 22 MWe CFBC located at Chatham, New Brunswick. This unit is operated by the New Brunswick Electric Power Commission (NBEPC). Both used the same New Brunswick coal containing 7 percent sulphur. The data presented indicate that the pilot-scale unit can significantly overpredict the formation of sulphides, and compared with the full-scale unit, produces residues with much less promise for either disposal or utilization in low-strength concretes. The results strongly suggest that further work is necessary to understand better the phenomena that produce sulphides and affect the geotechnical properties of wastes.

scholarly journals Characterization of solid wastes from circulating fluidized bed combustion

1989 ◽  
Author(s):  
E J Anthony ◽  
G G Ross ◽  
E E Berry ◽  
R T Hemings ◽  
R K Kissel ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Solid Wastes ◽  
Fluidized Bed Combustion ◽  
Circulating Fluidized Bed Combustion

Combustion Characteristics of Natural Gas in a Circulating Fluidized Bed

2003 ◽  
Author(s):  
Dennis Y. Lu ◽  
Edward J. Anthony
Keyword(s):  
Natural Gas ◽  
Gas Phase ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Combustion Characteristics ◽  
Air Pollutant ◽  
Operating Conditions ◽  
Fluidized Bed Combustion ◽  
Gas Combustion

Recently there has been interest in extending the application of fluidized bed combustors (FBCs) to fuels with difficult handling properties or ones that are associated with non-conventional air pollutant problems. These fuels, such as biomass, plastic wastes, black liquors and heavy liquid fuels, have very high volatiles contents and, because they are often treated as easily-burned materials, they have received much less attention than has been given say to the combustion processes for char in FBCs. Understanding their gas-phase chemistry is helpful in optimizing their combustion. This paper describes the study of natural gas combustion in a fluidized bed as a simple model for studying gas-phase reactions involving C/H/N/O chemistry in the absence of char. The experimental work was conducted using a pilot-scale CFBC unit. Combustion characteristics and emissions were investigated by varying the operating conditions and in particular the combustion temperature, fluidizing velocity and bed material. The results indicated that fluidized bed combustion chemistry is associated with superequilibrium free radical processes, similar to high-temperature flame systems. In this system, prompt-NO mechanisms are the only routes for NO formation and this work shows that they can lead to significant NOx production.

Attrition Behavior of Coal Ash Under Circulating Fluidized Bed Combustion Conditions

2003 ◽  
Author(s):  
Franz Winter ◽  
Xin Liu
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Coal Ash ◽  
Operating Conditions ◽  
Laboratory Scale ◽  
Silica Sand ◽  
Electrical Heating ◽  
Fluidized Bed Combustion ◽  
Bed Temperature ◽  
Wide Range

The attrition behavior of ash produced from two bituminous and one anthracite coal was studied under laboratory-scale circulating fluidized bed combustor (CFBC) conditions. After the ash was produced in the oven, the ash sample with a size range from 0.1 to 1 mm was fed into the hot CFBC, which was heated by electrical heating shells and fluidized by air. The laboratory-scale CFBC was operated with using fine silica sand (40 to 80 μm) as bed material. After a certain time the operation was stopped, all particles were collected and sieving analysis was performed to obtain the actual particle size distribution (PSD) of the coal ash. The operating conditions were changed in a wide range, i.e. the bed temperature from 600 to 850°C, the fluidizing velocity from 1.2 to 2 m/s, the residence time from 60 to 120 min and the design of the cyclone. The effects of operating conditions and coal type were studied and their relative importance is discussed. Elemental analysis of the coal ashes showed that Si and Ca may play an important role during attrition.

scholarly journals N2O and NO Emissions from CFBC Cofiring Dried Sewage Sludge, Wet Sewage Sludge with Coal and PE

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Zhiwei Li ◽  
Hongzhou He
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Conversion Ratio ◽  
Fluidized Bed Combustion ◽  
Mixed Fuel ◽  
Higher Temperature ◽  
Circulating Fluidized Bed Combustion ◽  
No Emissions

Experiments on cofiring dried sewage sludge, wet sewage sludge with coal and polyethylene (PE) were carried out on a pilot scale 0.15MWt circulating fluidized bed combustion (CFBC) plant, and the influence of furnace temperatures, cofiring rates on N2O and NO emissions was investigated. Temperature is an effective parameter influencing N2O emission, and higher temperature leads to significant N2O reduction and decrease of conversion ratio of fuel-N to N2O. Increasing in cofiring rates leads to higher nitrogen content in the mixed fuel, which could result in higher NO and N2O emissions from combustion. With more sewage sludge addition, higher NO but lower N2O emissions are observed. N2O emission from cofiring wet sewage sludge with coal is higher than that from cofiring dried sewage sludge with coal and PE, and fuel-N conversion ratio to N2O and NO is much higher in cofiring wet sewage sludge with coal than that in cofiring dried sewage sludge with coal and PE.

Characterization of ashes from a 100kWth pilot-scale circulating fluidized bed with oxy-fuel combustion

2011 ◽  
Vol 88 (9) ◽  
pp. 2940-2948 ◽  
Author(s):  
Yinghai Wu ◽  
Chunbo Wang ◽  
Yewen Tan ◽  
Lufei Jia ◽  
Edward J. Anthony
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Fuel Combustion

Oxy-fuel circulating fluidized bed combustion in a small pilot-scale test rig

2010 ◽  
Vol 91 (11) ◽  
pp. 1617-1623 ◽  
Author(s):  
T. Czakiert ◽  
K. Sztekler ◽  
S. Karski ◽  
D. Markiewicz ◽  
W. Nowak
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Fluidized Bed Combustion ◽  
Test Rig ◽  
Scale Test ◽  
Circulating Fluidized Bed Combustion ◽  
Pilot Scale Test

scholarly journals Fluidized bed combustion with the use of Greek solid fuels

2003 ◽  
Vol 7 (2) ◽  
pp. 33-42
Author(s):  
Emmanuel Kakaras ◽  
Panagiotis Grammelis ◽  
George Skodras ◽  
Panagiotis Vourliotis
Keyword(s):  
Fluidized Bed ◽  
Brown Coal ◽  
Circulating Fluidized Bed ◽  
Pilot Scale ◽  
Thermal Capacity ◽  
Low Rank ◽  
Fluidized Bed Combustion ◽  
Bubbling Fluidized Bed ◽  
Combustion Technology ◽  
Combustion Tests

The paper is an overview of the results obtained up to date from the combustion and co-combustion activities with Greek brown coal in different installations, both in semi-industrial and laboratory scale. Combustion tests with Greek lignite were realized in three different Circulating Fluidized Bed Combustion (CFBC) facilities. Low rank lignite was burned in a pilot scale facility of approx. 100kW thermal capacity, located in Athens (NTUA) and a semi-industrial scale of 1.2 MW thermal capacity, located at RWE's power station Niederaussem in Germany. Co-combustion tests with Greek xylitic lignite and waste wood were carried out in the 1 MWth CFBC installation of AE&E, in Austria. Lab-scale co-combustion tests of Greek pre-dried lignite with biomass were accomplished in a bubbling fluidized bed in order to investigate ash melting problems. The obtained results of all aforementioned activities showed that fluidized bed is the appropriate combustion technology to efficiently exploit the low quality Greek brown coal either alone or in conjunction with biomass species.

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