The Study of Combustion of Municipal Waste in a Fluidized Bed Combustor

2006 ◽  
Vol 128 (2) ◽  
pp. 123-128 ◽  
Author(s):  
I. Gulyurtlu ◽  
T. Crujeira ◽  
M. H. Lopes ◽  
P. Abelha ◽  
D. Boavida ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Fluidized Bed ◽  
Combustion Efficiency ◽  
Solid Particles ◽  
Combustion Gases ◽  
Air Supply ◽  
Refuse Derived Fuel ◽  
Emission Limits ◽  
Bed Material ◽  
Fluidized Bed Combustor

The combustion behavior of municipal solid waste was studied in a pilot fluidized bed combustor. The waste was pelletized prior to its use. Both co-firing with coal and combustion of waste alone were under taken. The combustion studies were carried out on the pilot installation of INETI. The fluidized bed combustor is square in cross section with each side being 300mm long. Its height is 5000mm. There is a second air supply to the freeboard at different heights to deal with high volatile fuels. There was a continuous monitoring of the temperatures in the bed, as well as the composition of the combustion gases. The combustion gases leaving the reactor were let go through the recycling cyclone first to capture most of particulates elutriated out of the combustor. There was a second cyclone, which was employed with the aim of increasing the overall efficiency of collecting solid particles. The gaseous pollutants leaving the stack were sampled under isokinetic conditions for particulate matter, chlorine compounds, and heavy metals. The ash streams were characterized for heavy metals. The results obtained were compared with national legislation. The results obtained suggest that (i) the combustion efficiency was very high, (ii) there was an enrichment of ashes with heavy metals in the cyclones compared to the bed material, (iii) in general, the flue gas emissions were below the permited limits, and (iv) for the compliance with the new European directive for stricter emission limits adequate control devices, like bag filters, should be integrated with refuse derived fuel (RDF) combustion.

The Study of Combustion of Municipal Waste in a Fluidised Bed Combustor

2003 ◽  
Author(s):  
I. Gulyurtlu ◽  
T. Crujeira ◽  
P. Abelha ◽  
D. Boavida ◽  
J. Seabra ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Combustion Efficiency ◽  
Solid Particles ◽  
Gaseous Pollutants ◽  
Fluidised Bed ◽  
Combustion Gases ◽  
Air Supply ◽  
Control Devices ◽  
Emission Limits ◽  
Bed Material

The combustion behaviour of municipal solid waste was studied in a pilot fluidised bed combustor. The waste was pelletised prior to its use. Both co-firing with coal and combustion of waste alone were under taken. The combustion studies were carried out on the pilot installation of INETI. The fluidised bed combustor is square in cross section with each side being 300 mm long. Its height is 5000 mm. There is a second air supply to the freeboard at different heights to deal with high volatile fuels. There was a continuous monitoring of the temperatures in the bed, as well as the composition of the combustion gases. The combustion gases leaving the reactor were let go through the recycling cyclone first to capture most of particulates elutriated out of the combustor. There was a second cyclone which was employed with the aim of increasing the overall efficiency of collecting solid particles. The gaseous pollutants leaving the stack were sampled under iso-kinetic conditions for particulate matter, chlorine compounds and heavy metals. The ash streams were characterised for heavy metals. The results obtained were compared with national legislation. The results obtained suggest that i) the combustion efficiency was very high, ii) there was an enrichment of ashes with heavy metals in the cyclones compared to the bed material, iii) in general, the gaseous pollutants were below the permited limits, and iv) for the compliance with the new European Directive for stricter emission limits adequate control devices, like bag filters, should be integrated with RDF combustion.

scholarly journals Agglomeration of bed material: Influence on efficiency of biofuel fluidized bed boiler

2003 ◽  
Vol 7 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Georgy Ryabov ◽  
Dmitry Litoun ◽  
Eduard Dik
Keyword(s):  
Fluidized Bed ◽  
Chemical Compositions ◽  
Air Supply ◽  
Drain Flow ◽  
Boiler Efficiency ◽  
Successful Design ◽  
The Common ◽  
Bed Material ◽  
Fluidized Bed Combustor ◽  
Steam Drum

The successful design and operation of a fluidized bed combustor requires the ability to control and mitigate ash-related problems. The main ash-related problem of biomass filing boiler is agglomeration. The fluidized bed boiler with steam capacity of 66 t/h (4 MPa, 440 ?C) was started up at the Arkhangelsk Paper-Pi dp-Plant in 2001. This boiler was manufactured by the Russian companies "Energosofin" and "Belenergomash" and installed instead of the existing boiler with mechanical grate. Some constructional elements and steam drum of existing boiler remained unchanged. The primary air fan was installed past the common air fan, which supply part of the air into 24 secondary airports. First operating period shows that the bed material is expanded and then operator should increase the primary air rate, and the boiler efficiency dramatically decreases. Tills paper presents some results of our investigations of fuel, bed and fly ash chemical compositions and other characteristics. Special experiments were carried out to optimize the bed drain flow rate. The influence of secondly air supply improvement on mixing with the main flow and boiler efficiency are given.

scholarly journals Agglomeration of Bed Material: Influence on Efficiency of Biofuel Fluidized Bed Boiler

2003 ◽  
Author(s):  
Georgy A. Ryabov ◽  
Dmitry S. Litoun ◽  
Eduard P. Dik
Keyword(s):  
Fluidized Bed ◽  
Chemical Compositions ◽  
Air Supply ◽  
Drain Flow ◽  
Boiler Efficiency ◽  
Successful Design ◽  
The Common ◽  
Secondary Air ◽  
Bed Material ◽  
Fluidized Bed Combustor

The successful design and operation of a fluidized bed combustor requires the ability to control and mitigate ash-related problems. The main ash-related problem of biomass firing boiler is agglomeration. The fluidized bed boiler with steam capacity of 66 t/h (4 MPa, 440 °C) was started up at the Archangelsk Paper-Pulp-Plant in 2001. This boiler was manufactured by the Russian companies “Energosofin” and “Belenergomash” and installed instead of the existing boiler with mechanical grate. Some constructional elements and steam drum of existing boiler remained unchanged. The primary air fan was installed past the common air fan, which supply part of the air into 24 secondary air ports. First operating period shows that the bed material is expanded and then operator should increase the primary air rate, and the boiler efficiency dramatically decreases. This paper presents some results of our investigations of fuel, bed and fly ash chemical compositions and other characteristics. Special experiments were carried out to optimize the bed drain flow rate. The influence of secondary air supply improvement on mixing with the main flow and boiler efficiency are given.

scholarly journals Comparison of Various Fluidized Bed Combustor-Gas Turbine Systems

1985 ◽  
Author(s):  
Arthur P. Fraas
Keyword(s):  
Gas Turbine ◽  
Fluidized Bed ◽  
Thermal Efficiency ◽  
Combustion Efficiency ◽  
Capital Cost ◽  
Inlet Temperature ◽  
Extensive Experience ◽  
Helium Gas ◽  
Steam Plant ◽  
Fluidized Bed Combustor

Pressurizing a fluidized bed combustor with a gas turbine greatly improves both sulfur retention and combustion efficiency. Operating the gas turbine with a high inlet temperature (e.g. 900°C) would yield a thermal efficiency about four points higher than for an atmospheric furnace, but 40 y of experience have failed to solve problems with flyash erosion and deposits. Extensive experience such as that with fluidized bed catalytic cracking units indicates that the gas turbine blade erosion and deposit problems can be handled by dropping the turbine inlet temperature below 400°C where the turbine delivers just enough power to drive the compressor. The resulting thermal efficiency is about half a point higher than for an atmospheric bed, and the capital cost of the FBC-related components is about 40% lower. While a closed-cycle helium gas turbine might be used rather than a steam cycle, the thermal efficiency would be about four points lower and the capital cost of the FBC-related components would be roughly twice that for the corresponding steam plant.

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.

The Implications of Burning a Blend of Waste Materials in a Fluidizied Bed Combustor

2006 ◽  
Vol 128 (2) ◽  
pp. 118-122 ◽  
Author(s):  
I. Gulyurtlu ◽  
P. Abelha ◽  
D. Boavida ◽  
J. Seabra ◽  
S. Gomes ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Combustion Efficiency ◽  
Fuel Oil ◽  
Gaseous Emissions ◽  
Heavy Fuel Oil ◽  
Heating Value ◽  
Textile Materials ◽  
Decentralized Energy ◽  
The Cost ◽  
Bed Material

A mixture involving wood, plastics, paper, and textile materials was burned in a fluidized bed combustor to monitor the gaseous emissions and to analyze the ashes collected in different locations of the installation. The ashes collected were first analyzed to verify the partitioning of heavy metals in different ash streams. They were then subjected to leaching tests to verify the solubility of different components present. There is a growing interest in utilizing wastes, which cannot be recycled for further use, for energy, particularly in Europe as the amounts are great and the cost of depositing them in landfills has become very considerable. These wastes are considered renewable sources and the recent policy is to encourage their use for energy, especially for decentralized energy production. However, these wastes may be contaminated and have to be verified that their utilization for energy does not bring about any adverse consequences on the environment. Each component making up the blend to be used as fuel needs to be analyzed to determine not only its composition but also its heating value so that the final blend to be prepared could present minimum risk for emissions of pollutants, ideally less than coal and with a heating value comparable, at least, to that of coal. The results obtained suggest that (i) the combustion efficiency was very high, (ii) there was an enrichment of ashes with heavy metals in the cyclones compared to the bed material, (iii) the gaseous pollutants were below the permitted limits, and (iv) the ashes did not have tendency for leaching. Such mixtures could, therefore, be used as a solid fuel in industry as a substitution for coal or heavy fuel oil.

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