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.

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 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.

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

2003 ◽  
Author(s):  
I. Gulyurtlu ◽  
P. Abelha ◽  
D. Boavida ◽  
J. Seabra ◽  
S. Gomes ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Combustion Efficiency ◽  
Fuel Oil ◽  
Gaseous Emissions ◽  
Fluidised Bed ◽  
Heavy Fuel Oil ◽  
Heating Value ◽  
Textile Materials ◽  
Decentralized Energy ◽  
The Cost

A mixture involving wood, plastics, paper and textile materials was burned in a fluidised bed combustor to monitor the gaseous emissions and to analyse the ashes collected in different locations of the installation. The ashes collected were first analysed 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 analysed 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. The mixture could, therefore, be used as a solid fuel in industry as a substitution for coal or heavy fuel oil.

Effect of Air Distribution on Solid Fuel Bed Combustion

1997 ◽  
Vol 119 (2) ◽  
pp. 120-128 ◽  
Author(s):  
J. T. Kuo ◽  
W.-S. Hsu ◽  
T.-C. Yo
Keyword(s):  
Combustion Efficiency ◽  
Pollutant Emissions ◽  
Air Distribution ◽  
Gas Temperature ◽  
One Dimensional ◽  
Supply And Distribution ◽  
Air Supply ◽  
Burning Rates ◽  
Side Walls ◽  
Detailed Chemical

One important aspect of refuse mass-burn combustion control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g., bed height, bed voidage, bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, has the maximum combustion efficiency. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlation of combustion rate as a function of flue gas temperature and oxygen concentration. Despite the fact that the model is one-dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed-burning rates.

On Numerical Simulation of Fuel Mixed With Steam or Air to Investigate Soot and Other Emissions

2015 ◽  
Author(s):  
Ajit Patki ◽  
Xianchang Li ◽  
Daniel Chen ◽  
Helen Lou ◽  
Vijaya Damodara
Keyword(s):  
Combustion Efficiency ◽  
Combustion Mechanism ◽  
Fuel Type ◽  
Ansys Fluent ◽  
Pm 2.5 ◽  
Combustion Gases ◽  
Numerical Studies ◽  
Baseline Case ◽  
Substantial Risk ◽  
Pdf Model

Soot emissions (PM 2.5) as well as CO and NOx from industrial flares and other industrial processes or sources pose a substantial risk to human being health and the environment, and now are subject to new and tougher EPA regulations. Flaring is used widely used in many industries to dispose unwanted combustion gases by burning them as a flame. However, flaring produces significant amount of particulate matter in the form of soot, along with other harmful gas emissions. Although many experimental and numerical studies have previously been done on flames burning in a controlled condition, relatively few studies have been conducted with fuel-steam mixture. In practice, air and steam are commonly used to assist the flaring processes — control the smoke and the combustion efficiency. This study aims to investigate soot, CO and NOx emissions of turbulent diffusion methane and propane flame mixed with air or superheated steam. To study such effect numerically, the computational fluid dynamics software ANSYS Fluent 14.5 is used with non-premixed probability density function (PDF) model. The laminar flamelet is generated with automated grid refinement. For the soot generation, the Moss-Brookes soot model with Lee sub-model is considered. The combustion mechanism is developed by the authors’ research group from the combined GRI and USC mechanisms. Two types of fuel, methane and propane, are used. The amount of super-heated steam varied from four percent to twenty percent (4%, 8 %, 12%, 16%, and 20%), and the behavior of the flame is analyzed. For the baseline case, the jet has a diameter of 50.8 mm or 2 inches, and the jet velocity is kept to 1.0 m/s. A co-flow air is supplied at a velocity of 0.2 m/s. The temperature distribution of methane and propane are compared with different contents of steam or air assists. The NOx, Soot and CO yields (kg/kg) varying with steam or air percentages are also presented. The results indicate that the soot yield is dependent on fuel type strongly and the percentage of steam or air affects the soot yield differently as the fuel type varies.

scholarly journals EMISSIONS MONITORING OF HEAVY METALS AND THEIR COMPOUNDS RESULTED FROM COMBUSTION PROCESSES IN CLINKER KILNS IN ROMANIA

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
CRISTIAN CIOBANU ◽  
GHEORGHE VOICU ◽  
MAGDALENA – LAURA TOMA ◽  
PAULA TUDOR
Keyword(s):  
Heavy Metals ◽  
Wastewater Treatment ◽  
Contaminated Soil ◽  
Wastewater Treatment Plants ◽  
Raw Materials ◽  
Cement Plant ◽  
Combustion Gases ◽  
Waste Oils ◽  
Industrial Sources ◽  
Combustion Processes

<p>With the dust arising from the clinker kilns and grill coolers (the major pollution sources in a cement plant), also heavy metals and their compounds (in the form of powders and vaporous), originating from fuels and raw materials, are pumped into the air. The paper presents some aspects regarding the monitoring of heavy metals contained in the combustion gases from a Romanian cement factory. The fuels used in the incinerator varied from coal/petroleum coke, refuse oils (from waste oils and their emulsions, up to sludge, paraffin, tars, contaminated soil), rubber (including whole used tires), plastic, paper, leather, textiles, wood (including sawdust), as such or impregnated/contaminated with various substances from industrial sources or sorted household wastes, sludge (previously dried) from wastewater treatment plants. In addition, the list of over 100 types of waste that can be co-processed can be found in integrated authorizations of cement plants. However, the level of heavy metals in the combustion gases was in allowed limits.</p>

Biomass Ash - Bed Material Interactions Leading to Agglomeration in Fluidised Bed Combustion and Gasification

2008 ◽  
pp. 272-286 ◽  
Author(s):  
H.J.M. Visser ◽  
H. Hofmans ◽  
H. Huijnen ◽  
R. Kastelein ◽  
J.H.A. Kiel
Keyword(s):  
Fluidised Bed ◽  
Biomass Ash ◽  
Bed Material

scholarly journals Bubbling fluidised bed gasification of wheat straw–gasifier performance using mullite as bed material

2015 ◽  
Vol 97 ◽  
pp. 36-44 ◽  
Author(s):  
Seán T. Mac an Bhaird ◽  
Phil Hemmingway ◽  
Eilín Walsh ◽  
Amado L. Maglinao ◽  
Sergio C. Capareda ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Fluidised Bed ◽  
Bed Material

Combustion Turbine Deposition Observations From Residual and Simulated Residual Oil Studies

1982 ◽  
Author(s):  
G. A. Whitlow ◽  
S. Y. Lee ◽  
P. R. Mulik ◽  
R. A. Wenglarz ◽  
T. P. Sherlock ◽  
...  
Keyword(s):  
Vanadium Pentoxide ◽  
Field Experience ◽  
Dynamic Testing ◽  
Solid Particles ◽  
Residual Oil ◽  
Deposition Rates ◽  
Inertial Impaction ◽  
The Real ◽  
Combustion Gases ◽  
Current Utility

Burning residual oil in utility combustion turbines and the consequent deposition on blades and vanes may adversely affect reliability and operation. Corrosion and deposition data for combustion turbine materials have been obtained through dynamic testing in pressurized passages. The deposition produced by the 1900°F (1038°C) combustion gases from a simulated and a real residual oil on cooled Udimet 500 surfaces is described. Higher deposition rates for the doped fuel than for the real residual oil raised questions of whether true simulation with this approach can be achieved. Particles 4–8 μ m in dia predominated in the gas stream, with some fraction in the 0.1–12 μ m range. Deposition rates seemed to be influenced by thermophoretic delivery of small molten particles, tentatively identified as magnesium pyro and metavanadates and free vanadium pentoxide, which may act to bond the larger, solid particles arriving by inertial impaction to turbine surfaces. Estimated maintenance intervals for current utility turbines operating with washed and treated residual oil agreed well with field experience.

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