Reduction of the Volatile Matter Evolution Rate from a Plastic Pellet during Bubbling Fluidized Bed Pyrolysis by Using Porous Bed Material

2007 ◽  
Vol 30 (8) ◽  
pp. 1003-1009 ◽  
Author(s):  
I. N. S. Winaya ◽  
T. Shimizu
Keyword(s):  
Fluidized Bed ◽  
Volatile Matter ◽  
Evolution Rate ◽  
Porous Bed ◽  
Bubbling Fluidized Bed ◽  
Bed Material

Model of combustion and dispersion of carbon deposited on porous bed material during bubbling fluidized bed combustion

Fuel ◽  
2008 ◽  
Vol 87 (10-11) ◽  
pp. 1974-1981 ◽  
Author(s):  
I Nyoman Suprapta Winaya ◽  
Tadaaki Shimizu ◽  
Yousuke Nonaka ◽  
Kazuaki Yamagiwa
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Combustion ◽  
Porous Bed ◽  
Bubbling Fluidized Bed ◽  
Bed Material

scholarly journals Porous Bed Material-An Approach to Reduce Both Unburnt Gas Emission and NOx Emission from a Bubbling Fluidized Bed Waste Incinerator.

2001 ◽  
Vol 80 (5) ◽  
pp. 333-342 ◽  
Author(s):  
Tadaaki SHIMIZU ◽  
Hans-Jürgen FRANKE ◽  
Satoko HORI ◽  
Yasuo TAKANO ◽  
Masaru TONSHO ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Nox Emission ◽  
Waste Incinerator ◽  
Gas Emission ◽  
Porous Bed ◽  
Bubbling Fluidized Bed ◽  
Bed Material

scholarly journals Reduction of Dioxins Emission from a Bubbling Fluidized Bed Waste Incinerator by Use of Porous Bed Material.

2001 ◽  
Vol 80 (11) ◽  
pp. 1060-1063 ◽  
Author(s):  
Tadaaki SHIMIZU ◽  
Hans-Jürgen FRANKE ◽  
Satoko HORI ◽  
Yasuo TAKANO ◽  
Kazuaki YAMAGIWA ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Waste Incinerator ◽  
Porous Bed ◽  
Bubbling Fluidized Bed ◽  
Bed Material

In-Situ Hydrocarbon Capture and Reduction of Emissions of Dioxins by Porous Bed Material Under Fluidized Bed Incineration Conditions

2003 ◽  
Author(s):  
Tadaaki Shimizu ◽  
Hans-Ju¨rgen Franke ◽  
Satoko Hori ◽  
Yasuo Takano ◽  
Kazuaki Yamagiwa ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Porous Alumina ◽  
Volatile Matter ◽  
Nitrogen Atmosphere ◽  
Internal Circulation ◽  
Bubbling Fluidized Bed ◽  
Reduce Emissions ◽  
Waste Incinerators ◽  
Bed Material ◽  
Plastic Pellets

This work is intended to reduce emissions of dioxins and unburned gas from fluidized bed waste incinerators. Combustion of plastic pellets was conducted using a bench-scale bubbling fluidized bed combustor. Porous alumina was used as a bed material instead of conventional bed material (sand). First, we evaluated the effect of bed material on capture of volatile matter in the bed in a nitrogen atmosphere. Porous alumina captured volatile matter while sand did not. Feeding gas asymmetrically to enhance internal circulation of solids in the bed increased volatile capture efficiency of the porous alumina bed, whereas no improvement was found for the sand bed. Next, we performed combustion of plastic pellets by air. Emission of unburned gas was lower for the porous alumina bed than for the sand bed under a uniform gas feed condition. This is attributable to volatile matter capture by bed material that lengthens residence time of volatile matter in the combustor. However, non-uniform air feed for internal circulation was ineffective for suppressing unburned gas emissions. This may be caused by formation of an oxygen-deficient zone in the combustor. Finally, dioxin emissions were measured during PVC pellet combustion in a uniformly fluidized bed. The porous alumina bed was more effective for dioxin emission suppression than the sand bed.

scholarly journals Experimental Investigation of Radial Gas Dispersion Coefficients in a Fluidized Bed

10.14311/1568 ◽  
2012 ◽  
Vol 52 (3) ◽  
Author(s):  
Jiří Štefanica ◽  
Jan Hrdlička
Keyword(s):  
Fluidized Bed ◽  
Formation Rate ◽  
Combustion Efficiency ◽  
Tracer Gas ◽  
Cold Model ◽  
Nox Formation ◽  
Gas Dispersion ◽  
Bed Height ◽  
Bubbling Fluidized Bed ◽  
Bed Material

In a fluidized bed boiler, the combustion efficiency, the NOX formation rate, flue gas desulphurization and fluidized bed heat transfer are all ruled by the gas distribution. In this investigation, the tracer gas method is used for evaluating the radial gas dispersion coefficient. CO2 is used as a tracer gas, and the experiment is carried out in a bubbling fluidized bed cold model. Ceramic balls are used as the bed material. The effect of gas velocity, radial position and bed height is investigated.

Bed Material Agglomeration Behavior in a Bubbling Fluidized Bed (BFB) at High Temperatures using KCl and K2SO4 as Simulated Molten Ash

2017 ◽  
Vol 16 (4) ◽  
Author(s):  
Ehsan Ghiasi ◽  
Alejandro Montes ◽  
Fatemeh Ferdosian ◽  
Honghi Tran ◽  
Chunbao (Charles) Xu
Keyword(s):  
Melting Point ◽  
Fluidized Bed ◽  
Sharp Decrease ◽  
Differential Pressure ◽  
Silica Sand ◽  
Molar Ratio ◽  
Biomass Ash ◽  
Bubbling Fluidized Bed ◽  
Sand Particles ◽  
Bed Material

Abstract The agglomeration of bed material is one of the most serious problems in combustion of biomass in fluidized-bed boilers, due to the presence of some inorganic alkali elements such as K and Na in the biomass ash, which form low-melting-point alkali compounds during the process. In this study, agglomeration behaviors of bed materials (silica sand particles) were investigated in a bench-scale bubbling fluidized-bed reactor operating at 800 °C using simulated biomass ash components: KCl, K2SO4, and a mixture of KCl and K2SO4 at eutectic composition (molar ratio K2SO4/(KCl+ K2SO4)=0.26). The signals of temperature and differential pressure across the bed were monitored while heating up the fluidized bed of silica sand particles premixed with various amounts of KCl, and the KCl-K2SO4 mixture in bubbling bed regime. A sharp decrease in temperature and differential pressure was observed around 750 °C and 690 °C for 0.4–0.6 wt% loading of the low melting-point KCl and KCl-K2SO4 mixture, respectively, suggesting the formation of bed material agglomeration and even de-fluidization of the bed. Moreover, this work demonstrated the effectiveness of kaolin and aluminum sulfate to minimize agglomeration. The results indicated that these additives could successfully prevent the formation of agglomerates by forming compounds with high melting points.

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