In the Netherlands about 40% of the electricity is generated by coal nowadays. Only imported bitu... more In the Netherlands about 40% of the electricity is generated by coal nowadays. Only imported bituminous coal is fired. Typical values for this coal are a calorific value of 27 MJ/kg, an ash content of about 11% and a sulfur content of 0.7%. Pulverised coal-fired dry bottom boilers are installed exclusively in the Netherlands. The flue gases are cleaned by high-efficiency cold-side electrostatic precipitators (ESPs) and nowadays they are also cleaned by flue-gas desulfurisation (FGD) installations of the lime(stone)/gypsum process in all large coal-fired power plants.
Employees of coal-fired power stations and people living nearby as well as those involved in the ... more Employees of coal-fired power stations and people living nearby as well as those involved in the shipment and processing of coal fly ash can be exposed to coal fly ash (pulverised fuel ash or “PFA”). An extensive research program was carried out in order to map such exposure and its effects. Particle size distribution, chemical composition, quartz, radioactivity, emission factors and fugitive dust modelling were studied.
SUMMARY Employees of coal-fired power stations and people living nearby as well as those involved... more SUMMARY Employees of coal-fired power stations and people living nearby as well as those involved in the shipment and processing of coal fly ash can be exposed to coal fly ash (pulverised fuel ash or “PFA”). An extensive research program was carried out in order to map such exposure and its effects. Particle size distribution, chemical composition, quartz, radioactivity, emission factors and fugitive dust modelling were studied. PFA is a combustion aerosol, which means that the elements which volatilise during combustion are found mostly on the outside of the particles. Particle size is thus dependent on the concentration of these elements. Occupational limits (TLV’s or PELs) generally refer to the inhalable fraction (PM50). Based on more than twenty years of research at Dutch coal-fired power stations, it appears that there exists a relationship, the so called RE factor, between fuel composition and ash composition. For all the elements studied RE factors have been determined: for ...
SUMMARY In the Netherlands building materials must comply with leaching limits as laid down in th... more SUMMARY In the Netherlands building materials must comply with leaching limits as laid down in the Buildings Materials Decree. The leaching behaviour of the building materials has to be determined by standardised tests at the laboratory. The results of these tests are used as input in formulas that calculate the cumulative emissions over 100 years. The question arises whether this approach is a good prediction of what will happen in the field. At KEMA a major research item is to investigate leaching behaviour under field conditions. This paper presents the results of field leaching of two types of bricks for five and a half years and of concrete for two years. For these three types of building material two forms are tested, one ordinary form and one in which 20% coal fly ash (CFA) is used. The results are compared between the different types of clay, between materials with and without CFA and between prolonged field tests and brief laboratory leaching tests. The use of CFA as a raw ...
ABSTRACT An agreement was made between the Dutch government and the electricity producing compa-n... more ABSTRACT An agreement was made between the Dutch government and the electricity producing compa-nies for reducing the CO2-emissions with 3 million ton in 2008. In practice this means that about 13% of the coal by energy or about 20% by dry mass will be replaced by secondary fuel. Since 1993 KEMA has researched the effect of direct co-combustion in 39 test series. In these test series secondary fuels are co-combusted in proportions up to 42% by dry mass. All by-products in the Netherlands have to be used. The quality of the by products was an important issue in these test. The technical properties, the environmental properties and the health aspects were investigated in detail. New standards for the application in cement and concrete were established on the results of these test series. The KEMA TRACE MODEL®. predicts the composition of the ashes and establishes whether the ashes are hazardous or not according to the definitions of the European Waste Catalogue of the European Union.
Concentraties van gasvormig As, B, Br, Sb, Se, Hg en I in de buitenlucht van Arnhem Kwlk In de pe... more Concentraties van gasvormig As, B, Br, Sb, Se, Hg en I in de buitenlucht van Arnhem Kwlk In de periode van 90-02-02 tot 91-03-29 is in Arnhem een meetpunt voor het bemonsteren van buitenlucht in werking geweest, waarbij de concentraties van de gasvormige spoorelementen arsenicum, borium, bromium, antimoon, selenium, kwik en jodium zijn bepaald. De gemiddelde concentraties waren; As 1,2, B 60, Br 50, Sb 0,4, Se 0,8, Hg 1,4 en I 6 ng.m3.
Nuisance from dust caused by the handling and blowing away of coal and ash could be a problem at ... more Nuisance from dust caused by the handling and blowing away of coal and ash could be a problem at coal-fired power stations. A research programme was initiated in order to establish the exposure levels as well as the effects on workers and people living in the vicinity. This programme investigated the following aspects: exposure, particle size distribution, chemical composition, emission factors and fugitive dust cal-culations (Meij, 2000). Due to the different standards applied to the general population and to workers, the exposure to three dust fractions had to be established. For the general population this was the fine dust fraction (PM10) and for the workers these were the inhalable fraction (PM50) and the respirable fraction (PM4). The particle size distribution is therefore an important parameter. However, different measure-ments provide different answers.
ABSTRACT The element concentrations and distributions in coal, bottom ash, pulverized-fuealsh (PF... more ABSTRACT The element concentrations and distributions in coal, bottom ash, pulverized-fuealsh (PFA, ash collected in the ESPs) and fly ash (as present in the flue gases downstream of the ESP) of coal-fired power plants in the Netherlands were studied. Also, special attention was given to minor and trace elements present in the vapor phase in the flue gases downstream of the ESP (As. B, Br, Cl, F, Hg, I, Se). An important goal of this research programme is to establish the relationship between the elements in the different process streams. For this purpose mass balances were determined to obtain a good understanding of the accuracy of the measurements. A total of 16 test series were performed. The research established the collection efficiency ofthe new generation of high-efficiency cold-side electrostatic precipitators (ESPs) in relation to their collection both of total particulate matter and of each individual element. In an ESP hardly any gaseous inorganic trace elements are removed. All large coal-fired power plants in the Netherlands are equipped with wet flue gas desulfurization (FGD) plants. In one test series the fate of (trace)elements in such an installation was studied in detail. It appeared that 90% of the total particulate matter in the FGD plant was removed, but that the fly dust emitted consisted of about 40% fly ash and l0% gypsum particles 5:0% of the fly dust emitted originates in evaporated droplets( saturated with gypsum). Hence, the demisters are of vital importance to minimize emissions. In a wet FGD plant the gaseous inorganic trace elements are also removed. The removal of these elements was measured at all FGD plants in the Netherlands. The heavy metals are introduced in the FGD plant partly by the flue gases but primarily by the limestone. The gaseous elements are mainly introduced by the flue gases. The (heavy)metals leave the FGD through the following media, in order of decreasing importance: gypsum, sludge, wastewater effluent (the majority of the gaseous elements) and flue gases (only a few gaseous elements).
Abstract In the Netherlands the elemental compositions of the various streams of coal-fired power... more Abstract In the Netherlands the elemental compositions of the various streams of coal-fired power plants are well recorded. The information of these studies is used to calculate enrichment factors for the trace elements in ash, the vaporization percentage of minor and ...
Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may b... more Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may be sent to landfills for their disposal. In this work, leaching and speciation of mercury in fly ashes and gypsum from a modern co-combustion power plant equipped with a selective catalytic reduction (SCR) unit in the Netherlands were studied. The mercury leachable contents were checked against different regulations, including Dutch, German and the Council Directive 2003/33/EC. The speciation of mercury in coal combustion products is essential not only to determine the risk when the wastes are finally disposed but also to understand the behaviour of mercury during combustion and therefore to select the appropriate mercury removal technology. A temperature-programmed decomposition technique was used in order to identify and quantify which mercury species are associated with coal combustion products. The main mercury species identified in fly ash samples was mercury sulphate, whereas in the gypsum sample the mercury present was mercury chloride. The quantitative mercury results carried out using the thermal desorption method may be considered accurate. The results obtained show that fly ash and gypsum samples from this power plant can be acceptable at landfills as a non-hazardous waste.
In the Netherlands about 40% of the electricity is generated by coal nowadays. Only imported bitu... more In the Netherlands about 40% of the electricity is generated by coal nowadays. Only imported bituminous coal is fired. Typical values for this coal are a calorific value of 27 MJ/kg, an ash content of about 11% and a sulfur content of 0.7%. Pulverised coal-fired dry bottom boilers are installed exclusively in the Netherlands. The flue gases are cleaned by high-efficiency cold-side electrostatic precipitators (ESPs) and nowadays they are also cleaned by flue-gas desulfurisation (FGD) installations of the lime(stone)/gypsum process in all large coal-fired power plants.
Employees of coal-fired power stations and people living nearby as well as those involved in the ... more Employees of coal-fired power stations and people living nearby as well as those involved in the shipment and processing of coal fly ash can be exposed to coal fly ash (pulverised fuel ash or “PFA”). An extensive research program was carried out in order to map such exposure and its effects. Particle size distribution, chemical composition, quartz, radioactivity, emission factors and fugitive dust modelling were studied.
SUMMARY Employees of coal-fired power stations and people living nearby as well as those involved... more SUMMARY Employees of coal-fired power stations and people living nearby as well as those involved in the shipment and processing of coal fly ash can be exposed to coal fly ash (pulverised fuel ash or “PFA”). An extensive research program was carried out in order to map such exposure and its effects. Particle size distribution, chemical composition, quartz, radioactivity, emission factors and fugitive dust modelling were studied. PFA is a combustion aerosol, which means that the elements which volatilise during combustion are found mostly on the outside of the particles. Particle size is thus dependent on the concentration of these elements. Occupational limits (TLV’s or PELs) generally refer to the inhalable fraction (PM50). Based on more than twenty years of research at Dutch coal-fired power stations, it appears that there exists a relationship, the so called RE factor, between fuel composition and ash composition. For all the elements studied RE factors have been determined: for ...
SUMMARY In the Netherlands building materials must comply with leaching limits as laid down in th... more SUMMARY In the Netherlands building materials must comply with leaching limits as laid down in the Buildings Materials Decree. The leaching behaviour of the building materials has to be determined by standardised tests at the laboratory. The results of these tests are used as input in formulas that calculate the cumulative emissions over 100 years. The question arises whether this approach is a good prediction of what will happen in the field. At KEMA a major research item is to investigate leaching behaviour under field conditions. This paper presents the results of field leaching of two types of bricks for five and a half years and of concrete for two years. For these three types of building material two forms are tested, one ordinary form and one in which 20% coal fly ash (CFA) is used. The results are compared between the different types of clay, between materials with and without CFA and between prolonged field tests and brief laboratory leaching tests. The use of CFA as a raw ...
ABSTRACT An agreement was made between the Dutch government and the electricity producing compa-n... more ABSTRACT An agreement was made between the Dutch government and the electricity producing compa-nies for reducing the CO2-emissions with 3 million ton in 2008. In practice this means that about 13% of the coal by energy or about 20% by dry mass will be replaced by secondary fuel. Since 1993 KEMA has researched the effect of direct co-combustion in 39 test series. In these test series secondary fuels are co-combusted in proportions up to 42% by dry mass. All by-products in the Netherlands have to be used. The quality of the by products was an important issue in these test. The technical properties, the environmental properties and the health aspects were investigated in detail. New standards for the application in cement and concrete were established on the results of these test series. The KEMA TRACE MODEL®. predicts the composition of the ashes and establishes whether the ashes are hazardous or not according to the definitions of the European Waste Catalogue of the European Union.
Concentraties van gasvormig As, B, Br, Sb, Se, Hg en I in de buitenlucht van Arnhem Kwlk In de pe... more Concentraties van gasvormig As, B, Br, Sb, Se, Hg en I in de buitenlucht van Arnhem Kwlk In de periode van 90-02-02 tot 91-03-29 is in Arnhem een meetpunt voor het bemonsteren van buitenlucht in werking geweest, waarbij de concentraties van de gasvormige spoorelementen arsenicum, borium, bromium, antimoon, selenium, kwik en jodium zijn bepaald. De gemiddelde concentraties waren; As 1,2, B 60, Br 50, Sb 0,4, Se 0,8, Hg 1,4 en I 6 ng.m3.
Nuisance from dust caused by the handling and blowing away of coal and ash could be a problem at ... more Nuisance from dust caused by the handling and blowing away of coal and ash could be a problem at coal-fired power stations. A research programme was initiated in order to establish the exposure levels as well as the effects on workers and people living in the vicinity. This programme investigated the following aspects: exposure, particle size distribution, chemical composition, emission factors and fugitive dust cal-culations (Meij, 2000). Due to the different standards applied to the general population and to workers, the exposure to three dust fractions had to be established. For the general population this was the fine dust fraction (PM10) and for the workers these were the inhalable fraction (PM50) and the respirable fraction (PM4). The particle size distribution is therefore an important parameter. However, different measure-ments provide different answers.
ABSTRACT The element concentrations and distributions in coal, bottom ash, pulverized-fuealsh (PF... more ABSTRACT The element concentrations and distributions in coal, bottom ash, pulverized-fuealsh (PFA, ash collected in the ESPs) and fly ash (as present in the flue gases downstream of the ESP) of coal-fired power plants in the Netherlands were studied. Also, special attention was given to minor and trace elements present in the vapor phase in the flue gases downstream of the ESP (As. B, Br, Cl, F, Hg, I, Se). An important goal of this research programme is to establish the relationship between the elements in the different process streams. For this purpose mass balances were determined to obtain a good understanding of the accuracy of the measurements. A total of 16 test series were performed. The research established the collection efficiency ofthe new generation of high-efficiency cold-side electrostatic precipitators (ESPs) in relation to their collection both of total particulate matter and of each individual element. In an ESP hardly any gaseous inorganic trace elements are removed. All large coal-fired power plants in the Netherlands are equipped with wet flue gas desulfurization (FGD) plants. In one test series the fate of (trace)elements in such an installation was studied in detail. It appeared that 90% of the total particulate matter in the FGD plant was removed, but that the fly dust emitted consisted of about 40% fly ash and l0% gypsum particles 5:0% of the fly dust emitted originates in evaporated droplets( saturated with gypsum). Hence, the demisters are of vital importance to minimize emissions. In a wet FGD plant the gaseous inorganic trace elements are also removed. The removal of these elements was measured at all FGD plants in the Netherlands. The heavy metals are introduced in the FGD plant partly by the flue gases but primarily by the limestone. The gaseous elements are mainly introduced by the flue gases. The (heavy)metals leave the FGD through the following media, in order of decreasing importance: gypsum, sludge, wastewater effluent (the majority of the gaseous elements) and flue gases (only a few gaseous elements).
Abstract In the Netherlands the elemental compositions of the various streams of coal-fired power... more Abstract In the Netherlands the elemental compositions of the various streams of coal-fired power plants are well recorded. The information of these studies is used to calculate enrichment factors for the trace elements in ash, the vaporization percentage of minor and ...
Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may b... more Fly ashes and gypsum are one of the main wastes produced in coal-fired power stations which may be sent to landfills for their disposal. In this work, leaching and speciation of mercury in fly ashes and gypsum from a modern co-combustion power plant equipped with a selective catalytic reduction (SCR) unit in the Netherlands were studied. The mercury leachable contents were checked against different regulations, including Dutch, German and the Council Directive 2003/33/EC. The speciation of mercury in coal combustion products is essential not only to determine the risk when the wastes are finally disposed but also to understand the behaviour of mercury during combustion and therefore to select the appropriate mercury removal technology. A temperature-programmed decomposition technique was used in order to identify and quantify which mercury species are associated with coal combustion products. The main mercury species identified in fly ash samples was mercury sulphate, whereas in the gypsum sample the mercury present was mercury chloride. The quantitative mercury results carried out using the thermal desorption method may be considered accurate. The results obtained show that fly ash and gypsum samples from this power plant can be acceptable at landfills as a non-hazardous waste.
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