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As the different types of ARP systems, do the fluidized bed and the spray roasting process create different type of iron oxide as a by-product or would they have the same chemical characteristics?
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+ Iron oxide
+ Chemical engineering
+ Iron
+ Chemistry
+ Oxides
+ Hydrochloric acid
Posted by
Mike Singer
As the different types of ARP systems, do the fluidized bed and the spray roasting process create different type of iron oxide as a by-product or would they have the same chemical characteristics?
Circulating fluidized bed boiler NOx generally includes NO (accounting for more than 90%), NO2 and N2O.
The generation mechanism of NOx is divided into thermal generated NOx and fuel generated NOx.
Thermal-generated NOx mainly comes from the reaction of nitrogen in the combustion air with oxygen at high temperatures. When the combustion temperature is lower than 1300°C, the amount of thermal-generated NOx is sparse. As the temperature increases, the amount of NOx produced increases exponentially, and increases with the extension of the residence time in the high temperature zone and the increase of the oxygen concentration. Basically no NOx is thermal-generated in the circulating fluidized bed boiler.
Fuel-generated NOx comes from nitrogen-containing compounds in the fuel. In the combustion process, on the one hand, nitrogen compounds are decomposed and oxidized into NOx; on the other hand, the NOx generated will be reduced by the intermediate gas products of coal combustion and coke. The oxidation and reduction of fuel nitrogen are simultaneously reversible reactions. Therefore, only part of the nitrogen can be converted into fuel-generated NOx, and the amount of fuel-generated NOx decreases with the decrease of the bed temperature and the amount of oxygen during the combustion process.
Circulating fluidized bed boiler NOx generally includes NO (accounting for more than 90%), NO2 and N2O.
The generation mechanism of NOx is divided into thermal generated NOx and fuel generated NOx.
Thermal-generated NOx mainly comes from the reaction of nitrogen in the combustion air with oxygen at high temperatures. When the combustion temperature is lower than 1300°C, the amount of thermal-generated NOx is sparse. As the temperature increases, the amount of NOx produced increases exponentially, and increases with the extension of the residence time in the high temperature zone and the increase of the oxygen concentration. Basically no NOx is thermal-generated in the circulating fluidized bed boiler.
Fuel-generated NOx comes from nitrogen-containing compounds in the fuel. In the combustion process, on the one hand, nitrogen compounds are decomposed and oxidized into NOx; on the other hand, the NOx generated will be reduced by the intermediate gas products of coal combustion and coke. The oxidation and reduction of fuel nitrogen are simultaneously reversible reactions. Therefore, only part of the nitrogen can be converted into fuel-generated NOx, and the amount of fuel-generated NOx decreases with the decrease of the bed temperature and the amount of oxygen during the combustion process.
In general, spray roasted iron oxide (hematite) is very fine, has a low bulk density, and retains quite a lot of chloride (up to 5% in some cases). Fluid bed hematite is much more dense, and usually contains <1% chloride. The fluid bed system, however, consumes up to twice the amount of energy, so it really depends on what you need.
In general, spray roasted iron oxide (hematite) is very fine, has a low bulk density, and retains quite a lot of chloride (up to 5% in some cases). Fluid bed hematite is much more dense, and usually contains <1% chloride. The fluid bed system, however, consumes up to twice the amount of energy, so it really depends on what you need.
Circulating fluidized bed boiler NOx generally includes NO (accounting for more than 90%), NO2 and N2O.
The generation mechanism of NOx is divided into thermal generated NOx and fuel generated NOx.
Thermal-generated NOx mainly comes from the reaction of nitrogen in the combustion air with oxygen at high temperatures. When the combustion temperature is lower than 1300°C, the amount of thermal-generated NOx is sparse. As the temperature increases, the amount of NOx produced increases exponentially, and increases with the extension of the residence time in the high temperature zone and the increase of the oxygen concentration. Basically no NOx is thermal-generated in the circulating fluidized bed boiler.
Fuel-generated NOx comes from nitrogen-containing compounds in the fuel. In the combustion process, on the one hand, nitrogen compounds are decomposed and oxidized into NOx; on the other hand, the NOx generated will be reduced by the intermediate gas products of coal combustion and coke. The oxidation and reduction of fuel nitrogen are simultaneously reversible reactions. Therefore, only part of the nitrogen can be converted into fuel-generated NOx, and the amount of fuel-generated NOx decreases with the decrease of the bed temperature and the amount of oxygen during the combustion process.
Circulating fluidized bed boiler NOx generally includes NO (accounting for more than 90%), NO2 and N2O.
The generation mechanism of NOx is divided into thermal generated NOx and fuel generated NOx.
Thermal-generated NOx mainly comes from the reaction of nitrogen in the combustion air with oxygen at high temperatures. When the combustion temperature is lower than 1300°C, the amount of thermal-generated NOx is sparse. As the temperature increases, the amount of NOx produced increases exponentially, and increases with the extension of the residence time in the high temperature zone and the increase of the oxygen concentration. Basically no NOx is thermal-generated in the circulating fluidized bed boiler.
Fuel-generated NOx comes from nitrogen-containing compounds in the fuel. In the combustion process, on the one hand, nitrogen compounds are decomposed and oxidized into NOx; on the other hand, the NOx generated will be reduced by the intermediate gas products of coal combustion and coke. The oxidation and reduction of fuel nitrogen are simultaneously reversible reactions. Therefore, only part of the nitrogen can be converted into fuel-generated NOx, and the amount of fuel-generated NOx decreases with the decrease of the bed temperature and the amount of oxygen during the combustion process.
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In general, spray roasted iron oxide (hematite) is very fine, has a low bulk density, and retains quite a lot of chloride (up to 5% in some cases). Fluid bed hematite is much more dense, and usually contains <1% chloride. The fluid bed system, however, consumes up to twice the amount of energy, so it really depends on what you need.
In general, spray roasted iron oxide (hematite) is very fine, has a low bulk density, and retains quite a lot of chloride (up to 5% in some cases). Fluid bed hematite is much more dense, and usually contains <1% chloride. The fluid bed system, however, consumes up to twice the amount of energy, so it really depends on what you need.
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