How can you predict the pressure drop across the catalyst beds with changing operating conditions and different stages in the life cycle of the catalyst as well as for design studies?
Responding to our clients and consultants’ request, KBC has developed and implemented a pressure drop calculation in the HXX-SIM reactor models in version 6. This feature allows you to calibrate the pressure drop based on test run data, then use the model to calculate the pressure drop with respect to changes in operating conditions and reactor fouling status in the reactor catalyst life cycle. You can also use the model for design studies, for example to evaluate changes in reactor size or for catalyst evaluation.
In the following paragraph, brief steps show how to calibrate an existing hydrocracker model (Petro-SIM™ sample case “HCR_MildHCR _Sample.ksc”) for pressure drop calculation. If you have more questions on your specific plant model, please feel free to contact the KBC Software Helpdesk (firstname.lastname@example.org).
On the Home tab of the ribbon bar, click the Calibrate drop-down menu, and select Hydrocracker Calibration to activate the calibration.
Double click the hydrocracker to open the model view in the flowsheet. On the Calibration tab of the reactor in the Input Tuning Factors section, select the Miscellaneous page. Change the Pressure Drop Calculation Option to Yes.
On the Operating Data tab in the Pressure Drop Data page, the table of required parameters for pressure drop calculation is activated for user input. A sample of inputs are show as following:
After you finish inputting the data, click Calibrate in the ribbon bar to complete the calibration with pressure drop parameters.
After calibration is successful, you can go to Results tab, Reactor Conditions section and Pressure Drop page to view the results.
a) Zero liq. Flow on bed # shows the bed number on which liquid flow disappears and only vapor
flow remains. A value of 0.0000 means no such situation exists during this run.
b) Contact efficiency = 100% demonstrates that the estimated liquid flow rate was high enough
to maintain wetting of the catalyst surface.
c) Current Void Fraction shows the void fraction at the current catalyst age.
Accept the calibration factors following the calibration. Now you have the model ready to perform pressure drop case studies. Examples of charts are provided below for references.