Is nitrogen oxide being generated?
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After heating the combustion furnace to 800 degrees, the material is fed in (a mixed powder of sulfur and ammonium thiocyanate, with sulfur comprising the majority), and air is added for combustion; the components involved in combustion are the mixed powder and air； The temperature inside the furnace is 1000 degrees. I would like to ask fellow sailors: does the burning furnace gas contain nitrogen oxides? Thank you
When the temperature in the combustion zone of the furnace is below 1000°C, less NO is generated; whereas when the temperature is between 1300°C and 1500°C, the NO concentration is around 500–1000 ppm.
Won’t fuel-type nitrogen oxides appear? They are generated through the high-temperature decomposition and oxidation of ammonium thiocyanate.
His furnace has a heat capacity of only 1000 degrees, so the thermal effect can be disregarded; thermal effects become significant only at temperatures above 1300 degrees
The nitrogen oxides he produces are mainly of the fuel-type; those of the thermal type are produced in small amounts since the temperature is below 1300, and there should be none of the rapid-type
It is necessary to control the oxygen level inside the furnace; the greater the excess oxygen, the more NOx is produced.
Thermic nitrogen oxides are relatively rare; they are mainly of the fuel-type, and fuel-type nitrogen oxides can be reduced through air-staged combustion.
Nitrogen is present in fuel, and the formation of fuel-derived NOx is inevitable. The processes of formation and destruction of fuel-derived NOx are related not only to the characteristics of the coal type, its structure, as well as the proportion, composition, and distribution of nitrogen in the fuel after thermal decomposition among volatiles and coke, but also to combustion conditions such as temperature, oxygen levels, and the concentrations of various components. Summarizing research conducted in recent years, the mechanisms behind the formation of fuel-derived NOx follow these general patterns: 1. Organic nitrogen compounds in the fuel are released from the fuel along with the volatiles, and this is referred to as volatile N. Nitrogen compounds that remain in coke after the volatilized N has been removed are referred to as coke N. The main nitrogen compounds in volatilized N are HCN and NH3. HCN and NH3 are oxidized to form NOx