Experimental analysis of the addition and substitution of sub-bituminous pulverized coal in a natural gas premixed flame

This paper presents the experimental results of the addition (increasing thermal power) and substitution (constant thermal power) of a sub-bituminous pulverized coal in a natural gas flame in a laboratory-scale premixed burner. The analyzed variables include radiation intensity, temperature profile, and flame shape. It was found that with the addition of 15% and 30% coal (energy based) into the natural gas flame, the radiation intensity was increased by 37% and 65%, respectively. However, with the substitution of 15% and 30% coal for methane (energy based), the radiation intensity was reduced by 10% and 61%, respectively. Additionally, regarding the flame temperature, it was observed that 30% coal addition increased temperature by approximately 5%, while 30% coal substitution led to a reduction in flame temperature of 35%. Regarding flame shape, it was found that increased turbulence shortened the flame, while both the addition and substitution of coal into a methane flame lengthened the reaction zone.