Discussion on the high proportion of C3C4 in the desorbed gas
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My unit is a catalytic device; dry gas has always been used as the medium for pre-heating the reaction stream, and C3C4 constitutes approximately 70-80% of the gases released during desorption； Earlier, in order to reduce the cooling load associated with absorption, the pre-heating medium was changed to steam; it was then found that the proportion of C3C4 in the desorbed gas increased significantly, to around 90%. Is this change in the pre-heating medium related to it? If it is necessary to reduce the proportion of C3C4 in the desorbed gas, can the temperature of the desorption tower be lowered as long as the levels of C1C2 in the liquefied gas do not exceed the specified limits?
It seems to be over-desorption; has there been any change in the amount of gas released during desorption? If it is over-desorption, the temperature can be reduced appropriately, but care should be taken as the temperature of the rectifier liquid will also be affected
If the flow rate of the desorbed gas in the desorption tower remains unchanged after the switch, the increase in the volumetric flow rate of C3 and C4 in the desorbed gas is roughly equal to the decrease in the volume of pre-heated dry gas； It can be adjusted by lowering the temperature at the bottom of the desorption tower and the temperature of the hot feed to the desorption tower, as well as by increasing the flow rate of the cold feed to the desorption tower