Fluidized-bed combustion of coal with lime additives: catalytic sulfation of lime with iron compounds and coal ash

1978 ◽  
Vol 12 (8) ◽  
pp. 915-918 ◽  
Author(s):  
Ralph T. Yang ◽  
Ming-Shing Shen ◽  
Meyer Steinberg
Keyword(s):  
Fluidized Bed ◽  
Coal Ash ◽  
Fluidized Bed Combustion ◽  
Iron Compounds

scholarly journals Research in the fluidized bed combustion in the Laboratory for thermal engineering and energy - Part A: Achievements in targeted fundamental research

2019 ◽  
Vol 23 (Suppl. 5) ◽  
pp. 1637-1653
Author(s):  
Borislav Grubor ◽  
Dragoljub Dakic ◽  
Stevan Nemoda ◽  
Milica Mladenovic ◽  
Milijana Paprika ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Coal Ash ◽  
Thermal Engineering ◽  
Fluidized Bed Combustion ◽  
Particle Combustion ◽  
Research Activities ◽  
Energy Part ◽  
Char Particle ◽  
Fundamental Research

The paper gives a review of the most important results of extensive targeted fundamental research program on fluidized bed combustion in the Laboratory for Thermal Engineering and Energy of the VINCA Institute of Nuclear Sciences. The paper presents a detailed overview of research activities from the beginning in the second half of the 1970'' up to present days. Starting with the motives for initiating the investigations in this field, the paper highlights various phases of research and points out the main results of all research activities, not only the ones that are focused in this paper. Targeted fundamental research topics that are overviewed in this paper are heat and mass transfer, coal particle fragmentation, char particle combustion, sulfur self-retention by coal ash itself, as well as circulating fluidized bed modeling.

Fluidized bed combustion of refuse-derived fuel in presence of protective coal ash

2005 ◽  
Vol 87 (1) ◽  
pp. 33-44 ◽  
Author(s):  
Eduardo Ferrer ◽  
Martti Aho ◽  
Jaani Silvennoinen ◽  
Riku-Ville Nurminen
Keyword(s):  
Fluidized Bed ◽  
Coal Ash ◽  
Fluidized Bed Combustion ◽  
Refuse Derived Fuel

Utilization of coal ash from fluidized-bed combustion boilers as road base material

1995 ◽  
Vol 14 (2) ◽  
pp. 69-77 ◽  
Author(s):  
T. Takada ◽  
I. Hashimoto ◽  
K. Tsutsumi ◽  
Y. Shibata ◽  
S. Yamamuro ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Base Material ◽  
Coal Ash ◽  
Fluidized Bed Combustion ◽  
Road Base

An Improved Model of Sulfur Self-Retention by Coal Ash During Coal Combustion in FBC

2005 ◽  
Author(s):  
Vasilije Manovic ◽  
Borislav Grubor
Keyword(s):  
Thermal Decomposition ◽  
Fluidized Bed ◽  
Coal Ash ◽  
Sulfur Oxides ◽  
Mineral Matter ◽  
Fluidized Bed Combustion ◽  
Particle Volume ◽  
Reaction Rate Constants ◽  
Dependent Relation ◽  
Improved Model

During combustion of coal a significant amount of sulfur may be retained in ash due to the reactions between mineral matter in coal and sulfur oxides. This process is known as sulfur self-retention and its significance lies in the fact that a part of sulfur oxides, one of the main pollutants during combustion of coal, is not released in the atmosphere. Sulfur self-retention is influenced by parameters that depend on coal characteristics and combustion conditions. The interest for this process was enhanced with the introduction of fluidized bed combustion (FBC) technology since the temperatures and other conditions are favorable for sulfur self-retention. Investigation of this process, primarily modeling, is the subject of this work. The presented model is based on the previously developed model for the combustion of porous char particles under FBC conditions, along with a changing grain size model of sulfation of the CaO grains dispersed throughout the char particle volume. Incorporating the phenomena of sintering, reduction of the produced CaSO4 with CO, thermal decomposition of the produced CaSO4, as well as allowing for the different reactivity of various forms of calcium make major improvements of the model. A temperature dependent relation for the CaO grain radius takes sintering into account. Reductive and thermal decomposition were taken into account by the corresponding reaction rate constants of the Arrhenius type. The reactivity of the calcium forms in coal was considered by different initial radius of the CaO grains. The model was verified by the experimental results of sulfur self-retention of three Serbian coals during combustion in a fluidized bed combustion reactor. The comparison with the experimentally obtained results showed that the model can adequately predict the levels of the obtained values of sulfur self-retention efficiencies, as well as the influence of temperature, coal type and coal particle size.

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 Utilization of CFBC Fly Ash as a Binder to Produce In-Furnace Desulfurization Sorbent

2018 ◽  
Vol 10 (12) ◽  
pp. 4854 ◽  
Author(s):  
Chulseoung Baek ◽  
Junhyung Seo ◽  
Moonkwan Choi ◽  
Jinsang Cho ◽  
Jiwhan Ahn ◽  
...  
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Coal Ash ◽  
Limestone Powder ◽  
Fluidized Bed Combustion ◽  
High Concentration ◽  
Cfbc Fly Ash ◽  
Desulfurization Efficiency ◽  
Free Cao

Circulating fluidized bed combustion (CFBC) power generation technology is known to efficiently reduce the emission of air pollutants, such as SO2 and NO2, from coal combustion. however, CFBC coal ash contains high contents of free CaO, making it difficult to recycle. This research has been conducted to find ways to use the self-hardening property of CFBC coal ash, one of its inherent characteristics. As part of these efforts, the present study intended to investigate the properties and desulfurization efficiency of Ca-based desulfurization sorbents using CFBC fly-ash as a binder. Limestone powder was mixed with CFBC fly-ash and Ca(OH)2 to fabricate desulfurization sorbents, and it generated hydrate of cement, including portlandite, ettringite, and calcium silicate, etc. The compressive strength of the desulfurization absorbent prepared by CFBC fly ash and Ca(OH)2 was 72–92% that of the desulfurized absorbent prepared by using general cement as a binder. These absorbents were then compared in terms of desulfurization efficiency using a high-temperature fluidized bed reactor. It was confirmed that the desulfurization absorbents fabricated using CFBC fly-ash as a binder achieved the best performance in terms of absorption time, which reflects the time taken for them to remove over 90% of high-concentration SO2 gas, and the conversion ratio, which refers to the ratio of CaO turning into CaSO4.

Characterization and Use of Fluidized‐Bed‐Combustion Coal Ash

1994 ◽  
Vol 120 (6) ◽  
pp. 1488-1506 ◽  
Author(s):  
Christina B. Behr‐Andres ◽  
Neil J. Hutzler
Keyword(s):  
Fluidized Bed ◽  
Coal Ash ◽  
Fluidized Bed Combustion
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