Atmospheric Crude Tower
Atmospheric Crude Tower
(OP)
I have started atmospheric crude tower simulation using hysys. I have the laboratory data of boiling points and the mass% recovered determined by ASTM D86 method.
My question is regarding inputing these values to the simulator. In the assay type data of the simulator I have entered ASTM D86 and this data type accepts only liq vol% as assay basis. But I have mass% recovered, do I need to convert it to vol% and input the values? I am a beginner and I need lots of information. Please help with this.
Thank you.
My question is regarding inputing these values to the simulator. In the assay type data of the simulator I have entered ASTM D86 and this data type accepts only liq vol% as assay basis. But I have mass% recovered, do I need to convert it to vol% and input the values? I am a beginner and I need lots of information. Please help with this.
Thank you.





RE: Atmospheric Crude Tower
RE: Atmospheric Crude Tower
RE: Atmospheric Crude Tower
RE: Atmospheric Crude Tower
RE: Atmospheric Crude Tower
I have a lot of experience in modeling CDU towers, and what I can recommend you is definitely NOT to use D86 results as model input. Standard crude assay should contain TBP distillation, density and viscosity curves - at least. This is your Oil Manager input.
Best regards,
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Atmospheric Crude Tower
RE: Atmospheric Crude Tower
If model input is wrong (incorrect assay/blend characterization), converging the column is as bad as not running the model at all: simply you cannot rely on such results, and product yields/qualities will show there's something wrong with the simulation approach, regardless of the number of theoretical/actual plates and their efficiency. Ensure your input data are completely valid, and later you can tune them if necessary.
Afte this step, try to relax your model by specifying ranges of convergence parameters instead of fixed values, and later you can narrow these to a single value. Try to think as "distillation tower", structure your specifications in order to leave a place for the model to breathe. For example, do not specify flowrate and duty (delta T) for all pumparounds, leave at least one free. Do not overspecify side draws (by fixing tray temperature and product draw rate), and alway fix the tower top temperature. If you model the column as refluxed absorber template, you have to assume/predict overhead reflux rate as well.
Best of luck,
http://antwrp.gsfc.nasa.gov/apod/astropix.html
RE: Atmospheric Crude Tower
What specification did you select on Monitoring tab in Hysys? For the first step, flow rate on each draw and pumparound and reflux flow would be proper to get converged, and then you can try to get products on draw-off, which meet property targets such as flash point, with adjusting those flow rates. You should remember that all the flows and properties will not be matched with your actual data and lab result but be made closely with them. Hopely you can get beautiful modeling as you want.
Best wishes..