Carbon burning intensity

The Conradson test (ASTM D-189) measures carbon residue by evaporative and destructive distillation. The sample is placed in a preweighed sample dish. The sample is heated, using a gas burner, until vapor ceases to burn and no blue smoke is observed. After cooling, the sample dish is reweighed to calculate the percent carbon residue. The test, though popular, is not a good measure of the cokeforming tendency of FCC feed because it indicates thermal, rather than catalytic, coke. In addition, the test is labor intensive and is usually not reproducible, and the procedure tends to be subjective. 

One of the most hazardous conditions a firefighter will ever encounter is a backdralt (also known as a smoke explosion). A backdraft can occur in the hot-smoldering phase of a fire when burning is incomplete and there is not enough oxygen to sustain the fire. Unburned carbon particles and other flammable products, combined with the intense heat, may cause instantaneous combustion if more oxygen reaches the fire. 

Future combustion devices may burn alternative fuels with higher carbon-to-hydrogen ratios and operate at higher pressures. The combustion of such fuels under these conditions will result in more intense turbulence, higher levels of soot formation, and the associated increase in radiative heat loss compared to more traditional fuels burned at lower pressures. Depending upon the design objectives, it may be desirable to control soot levels using predictive capabilities. 

Carbon black is another of the carbon-intensive materials. It is formed from the burning of gaseous or liquid hydrocarbons under conditions where the amount of air is limited. Such burning favors soot formation, i.e., carbon black formation. It was produced by the Chinese over 1000 years ago. Today, it is produced in excess of 1.5 million tons annually in the United States. Furnace black is the most widely used carbon black. The particle size of this raw material is relatively large, about 0.08 mm. It is soft with a Mohs scale hardness of less than one. 

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