Issue of changes in fuel gas composition in the pyrolyzer
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When the fuel gas composition in the pyrolyzer becomes lighter, and with a stable feed rate, what adjustments are needed to the fuel gas in order to stabilize the outlet temperature of the pyrolyzer? I hope to get a reply from the expert. Thank you.
I think it’s still necessary to refer to the specific changes in calorific value in order to make adjustments.
After the fuel gas becomes lighter, reducing the oxygen content and negative pressure appropriately can control the gas flow rate in the pyrolysis furnace, thereby stabilizing the temperature at the furnace outlet.
Is such an adjustment made because its calorific value has decreased? Can I increase the pressure of the fuel gas?
As the fuel gas becomes lighter, its calorific value will decrease. With a constant amount of raw material, stabilizing the COT can be achieved by: increasing the pressure of the fuel gas, that is, by increasing its supply. 2. Reduce the air damper to allow the overall heat of the furnace to move downward. Attention must be paid to the furnace oxygen level in both methods
For mixed light hydrocarbons, the calorific value is positively correlated with density; as the density decreases, the calorific value drops, which in turn results in a slightly reduced amount of air required. It is best to install an online calorimeter to continuously monitor the calorific value of the gas, or use an online chromatograph to continuously measure the gas composition, thereby optimizing the supply of gas and the amount of combustion air; this will basically prevent significant fluctuations in the heat output of the pyrolysis furnace. Currently, the cracking furnaces in large-scale ethylene cracking units are generally equipped with online calorific value analysis systems to monitor changes in the calorific value of the gas, thereby allowing for timely adjustment of the amounts of fuel gas and air supplied.