The amount of gas bypassing in catalytic cracking
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This post was last edited by percy on 2015-10-3 at 17:38. I would like to ask the experts: is the differential pressure of the slide valve equal to the pressure reading at the regenerator end minus the pressure reading at the rear end? Is its value normally controlled to be positive? If it is a positive value, how can the amount of flue gas carried to the riser by the catalyst be estimated? Is the differential pressure of the check valve the pressure reading at the settler end minus the pressure reading at the rear end? Is its value normally controlled to be positive? If it is a positive value, how is the amount of oil and gas carried to the regenerator by the catalyst estimated? Thank you to all the experts
I would like to ask the experts: is the differential pressure of the slide valve the pressure reading at the regenerator end minus the pressure reading at the rear end? Is its value normally controlled to be positive? Answer: The pressure difference across the slide valve – for the slide valve in question, such as the regeneration slide valve – is calculated by subtracting the pressure at the lower part of the slide valve (on the lift pipe side) from the pressure at the upper part of the slide valve (on the regenerator side). This value should be positive under normal conditions. The pressure difference across the slide valve serves as an important indicator for daily monitoring, as it reflects the fluidization condition of the catalyst in that area. It is recommended to use the same method for calculations, namely by subtracting the pressure at the lower part from that at the upper part of the slide valve. The reason is that the inclined tubes in which each slide valve is located are used for dense-phase transportation; analogously to water, its static pressure must be taken into account. If it is a positive value, how can the amount of flue gas carried to the riser by the catalyst be estimated? Answer: The amount of flue gas carried by the catalyst to the riser is usually estimated, based on the circulation rate of the catalyst; the amount of flue gas per ton of catalyst is calculated at 1 Nm3/h. For example, if the catalyst circulation rate is 900 t/h, then the amount of flue gas entrained is 900 Nm3/h; is the differential pressure across the plug valve equal to the pressure reading at the settler end minus the pressure reading at the rear end? Is its value normally controlled to be positive? Answer: I haven’t done it, so I’m not sure. If it is a positive value, how is the amount of oil and gas carried to the regenerator by the catalyst estimated? Thank you to the experts for your answers. As for the amount of oil and gas, I believe it is determined by calculating the H/C ratio in coke using the data on flue gas, and estimates are then made based on this H/C ratio.