Relationship between tar recovery rate and coal quality
Thread Content
In coking production, what is the relationship between tar recovery rate and coal quality? A low degree of coal metamorphism, as well as an excessive degree of metamorphism – such as the use of large amounts of bituminous coal and subbituminous coal – will both result in a reduced tar yield. Is this view correct?
Is the temperature in the furnace top space high? If the temperature in the furnace roof area is high, tar undergoes extensive cracking, resulting in an increase in heavy tar. Secondly, how is the operation of the primary cooler? What are the gas purification conditions, or recovery conditions?
The tar yield depends on the volatiles of the coal blend and the degree of coal metamorphism. Within the range of drying ash-free basis (DAF) volatiles Vdaf of 20% to 30% for coal blending, the tar yield X(%) can be calculated using the following formula ； X=－18.36﹢1.53Vdaf－0.026 V²daf
The formula mentioned upstairs is just a theoretical calculation; in practice, it is also necessary to take into account 1) the degree of coal metamorphism and the petrographic composition of the coal. 2. Temperature in the furnace roof space. 3. Recovery performance of the primary cooler and electrostatic precipitator.
The length of the evening period is related to the duration of interaction; a longer coking time results in a relatively higher tar yield； Depending on the furnace type, the higher the carbonization chamber, the lower the tar yield. Personal opinions are for reference only.
The yield of tar is highly correlated with coal quality, decreasing as the coal quality changes; younger coal produces more tar.
Is there a formula for calculating the tar recovery rate in the lignite coke industry? The volatiles content of the coal is over 37%, classifying it as a long-flame coal. Thank you!