Why is the waste gas from coke ovens yellow in color?
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Some say it’s sulfur, while others say it’s the vaporization of tar; it’s not certain which is correct. I wonder, respected seniors, what exactly is the reason? Could you provide some references?
Was a small amount of tar carried away?
Is the tar gasified product yellow? I don’t understand.
Wastegas is gas that contains many impurities, including tar and other substances
It is the yellow smoke produced by coal combustion; this smoke is a mixture of various substances. Just like the smoke generated when bituminous coal is burned in a household stove, it results in yellow smoke. When coal burns completely, gases such as CO2, SO2, SO3, and water vapor are produced; if the combustion is incomplete, gases like CO, coal tar, and hydrocarbons may also be formed. Yellow smoke contains hydrogen sulfide, H2S. If the fans in the coking plant are not properly regulated, yellow smoke will emanate from the coke oven doors or vent pipes. It is a soot aerosol containing hydrogen sulfide; it’s essentially waste gas. It turns yellow because it contains hydrogen sulfide. Generally, the hydrogen sulfide content in the coke oven off-gas ranges from 6,000 to 8,000 mg/m3. The basis is to collect the yellow smoke at the furnace exit and analyze its components.