Mechanisms of Bed Agglomeration during Fluidized-Bed Combustion of Biomass Fuels

2005 ◽  
Vol 19 (3) ◽  
pp. 825-832 ◽  
Author(s):  
Elisabet Brus ◽  
Marcus Öhman ◽  
Anders Nordin
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
Bed Agglomeration

Bed Agglomeration Characteristics during Fluidized Bed Combustion of Biomass Fuels

2000 ◽  
Vol 14 (1) ◽  
pp. 169-178 ◽  
Author(s):  
Marcus Öhman ◽  
Anders Nordin ◽  
Bengt-Johan Skrifvars ◽  
Rainer Backman ◽  
Mikko Hupa
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
Bed Agglomeration

Bed Agglomeration Characteristics in Fluidized-Bed Combustion of Biomass Fuels Using Olivine as Bed Material

2012 ◽  
Vol 26 (7) ◽  
pp. 4550-4559 ◽  
Author(s):  
Alejandro Grimm ◽  
Marcus Öhman ◽  
Therése Lindberg ◽  
Andreas Fredriksson ◽  
Dan Boström
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
Bed Agglomeration ◽  
Bed Material

scholarly journals Research in the fluidized bed combustion in the Laboratory for thermal engineering and energy - Part B: Achievements in technology implementation

2019 ◽  
Vol 23 (Suppl. 5) ◽  
pp. 1655-1667
Author(s):  
Borislav Grubor ◽  
Dragoljub Dakic ◽  
Stevan Nemoda ◽  
Milica Mladenovic ◽  
Milijana Paprika ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Technology Implementation ◽  
Liquid Fuels ◽  
Thermal Engineering ◽  
Fluidized Bed Combustion ◽  
Biomass Waste ◽  
Technology Application ◽  
Wide Range ◽  
Combustion Technology ◽  
Bed Agglomeration

Paper gives a review of the most important results of extensive and wide-ranging research program on R&D of fluidized bed combustion technology in the Laboratory for Thermal Engineering and Energy of the VINCA Institute of Nuclear Sciences. Paper presents detailed overview of R&D activities from the beginning in the second half of the 1970's up to present days. These activities encompass applied research achievements in the field of characterization of limestones and bed agglomeration and sintering and modeling of overall processes during fluidized bed combustion, all of which have facilitated the R&D of the fluidized bed combustion technology. Attention is also given to steady-state combustion testing of a wide-range of fuels (coals, liquid fuels, biomass, waste solid and liquid materials, etc.) in our fluidized bed combustor and development of original methodology for testing the suitability of fuels for fluidized bed combustion, as well as specific achievements in the area of technology application in Serbia.

Bed Agglomeration During the Fluidized Bed Combustion of Olive Husk

2005 ◽  
Author(s):  
Antonio Cammarota ◽  
Riccardo Chirone ◽  
Fabrizio Scala
Keyword(s):  
Fluidized Bed ◽  
Dynamic Pressure ◽  
Mediterranean Area ◽  
Operating Conditions ◽  
Pressure Gradients ◽  
Fluidized Bed Combustion ◽  
High Propensity ◽  
Olive Husk ◽  
Bed Agglomeration ◽  
High Alkali

The fluidized bed combustion of a biomass residue (olive husk) common in the Mediterranean area has been investigated in a bench scale reactor. The focus of the study was the high propensity of this fuel to give rise to bed agglomeration problems during combustion, as a consequence of the high alkali content of the ash. Bed agglomeration characteristic times as well as temperature and pressure gradients were measured at different operating conditions. In addition, a diagnostic tool based on the measurement of the dynamic pressure signal inside the bed was tested for its capability to predict the bed agglomeration onset.

Fluidized Bed Technologies for Biomass Combustion

2009 ◽  
Author(s):  
Aku Rainio ◽  
Vinod Sharma ◽  
Markus Bolha`r-Nordenkampf ◽  
Christian Brunner ◽  
Johannes Lind ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Distribution System ◽  
Circulating Fluidized Bed ◽  
Close Contact ◽  
Combustion Efficiency ◽  
Biomass Combustion ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
So2 Emissions ◽  
Gas Treatment

Biomass, a renewable fuel source for generating energy, is available in large quantities in the USA. Typical biomass consists of wood chips, construction and demolition wood, bark, residual logging debris, saw dust, paper rejects, and paper and sewage sludge. Composition and moisture content of biomass vary greatly and affect its heating value. There are several combustion technologies available to generate power from biomass. Fluidized bed boilers are preferred, because of their ability to burn a wide variety of biomass fuels while achieving high combustion efficiency and low emissions. This paper discusses basic design and operation features of bubbling (BFB) and circulating fluidized bed (CFB) boilers, both offering high fuel flexibility. In fluidized bed combustion, reactive biomass fuels are almost completely burned out because of close contact between the hot bed material and the fuel. In advanced BFB and CFB boilers, an open bottom design is used for ash and coarse material removal through the fluidizing air distribution system. This allows combustion of fuels containing large inert particles, such as rocks and metal pieces. If limestone is added to the bed, SO2 emissions are reduced. By using ammonia or urea in high temperature areas, NOx emissions are reduced. In order to achieve very low emissions, back-end flue gas treatment for SO2, NOx, HCl, HF, and Hg is required. To treat flue gases, several technologies can be used — such as activated carbon and sodium bicarbonate or Trona injection, Turbosorp® circulating dry scrubber, and SCR. Normally the preferred particulate matter cleaning device is a baghouse since the filter cake allows further reactions between pollutants and sorbents. Different fluidized bed designs are shown and recommended for various biomass fuels. This paper describes design, fuels, and emissions for an advanced BFB boiler producing steam at a rate of 230,000 lb/hr/930 psig/860°F (29.0 kg/s/64 barg/460°C).

Capture of Alkali Metals by Kaolin

2003 ◽  
Author(s):  
Khanh-Quang Tran ◽  
M. Kristiina Iisa ◽  
Britt-Marie Steenari ◽  
Oliver Lindqvist ◽  
Magnus Hagstro¨m ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Fluidized Bed ◽  
Alkali Metals ◽  
Fixed Bed ◽  
Capture Efficiency ◽  
Fixed Bed Reactor ◽  
Fluidized Bed Combustion ◽  
Biomass Fuels ◽  
Metal Source ◽  
On Line

Alkali metals present in biomass fuels may cause increased bed agglomeration during fluidized bed combustion. In worst case this may lead to complete defluidization of the bed. Other problems caused by alkali metals include increased fouling and slagging. One possibility to reduce the impact of alkali metals is to add sorbents, e.g. aluminosilicates, to the bed for the capture of alkali metals. In the current investigation, the capture of vapor phase potassium compounds by kaolin was investigated in a fixed bed reactor. The reactor consisted of an alkali metal source placed at a variable temperature from which gaseous potassium compounds were generated, a fixed bed holding the kaolin, and an on-line detector for the alkali metal concentration. The on-line alkali metal detector was based on ionization of alkali metals on hot surfaces and is capable of detecting alkali metals down to ppb levels. This makes it possible to perform experiments at alkali metal concentrations relevant to fluidized bed combustion of biomass fuels. In the experiments, KCl was used as the alkali metal source with inlet concentrations of 0.5–3.5 ppm. The experiments were performed at reactor temperatures of 800–900°C and a contact time of 0.26 s. The capture efficiencies of KCl were always above 97%. The capture efficiency was somewhat higher in oxidizing than in reducing gas atmospheres. In the oxidizing gas atmosphere, the conversion was slightly higher with H2O addition than without. The capture efficiency decreased slightly as temperature or KCl concentration was increased.

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