Regarding the hydrocracker: when the purity of recycle hydrogen decreases and the flow rate of mixed hydrogen appears to increase, I would appreciate some guidance on the potential impacts this has on the reaction system
Thread Content
As the title suggests, in the paraffin oil hydrocracking unit, where centrifuges are used, if the purity of the system’s recycle hydrogen decreases, the flow rate indicated by the hydrogen mixture meter will definitely increase. We all know this is due to the characteristics of the orifice flow meter; it’s just that the displayed value increases. But why does an increase in the hydrogen mixing flow rate caused by a decrease in the purity of the recycled hydrogen also result in a better heat transfer effect by the recycled hydrogen? Some experienced teachers say it’s due to the effect of specific heat. Could everyone please explain this? Thank you!
However, under normal circumstances, it shouldn’t be the case that merely adjusting the turbine speed or closing the anti-surge valve increases the amount of hydrogen mixed in, thereby causing both the inlet temperature of the hot high-pressure separator and the inlet temperature of the first reactor to decrease. Then why does an increase in the hydrogen mixture flow rate resulting from changes in purity have the same effect, causing both temperatures to decrease as well?
The experienced teacher is right: at the same volume flow rate, the molar specific heat capacity of hydrogen with lower purity is definitely greater than that of hydrogen with higher purity. Since the molar specific heat capacity is higher in the case of lower purity, less temperature increase occurs when the same amount of heat is absorbed