3 replies to this topic

[Srikrishna Chaitanya]

Dear All
I have a problem in which naphtha and steam are coming as feed into a reformer, i have ASTM Distillation ( D-86) Assay data for naphtha from that i am able to create hypo component , and i have Molecular weight and C:H ratio( weight/weight) for Naphtha from that i calculated the approximate chemical formula and used it in creating equilibrium reaction , but its giving me a warning as unknown chemical formula. I tried with conversion reactor providing conversion value but its giving error that adiabatic solution is possible at temperature – 272.
My operating conditions of reformer are 490 oC and 27.4 kg/Cm2-g
Naphtha assay data
ASTM (D- 86)
IBP 53 oC
10 vol % 76
30 vol % 95
50 vol % 104
70 vol % 109
90 vol % 132
95 vol % 139
FBP 155
Molecular weight 98, C:H (weight : weight) =5.65
Now my questions are
1. is there any method in HYSYS so that we can find out the chemical formula with the above data
2. In hysys is it possible to carry out the reaction with out providing stoichiometry, that mean i will give reactants and products with out giving stoichiometry numbers ,. Please help me in solving the above problem and i hope my question is clear
Thanks in advance
Regards,
Satish

[Zauberberg]

Hello Satish,

Based on my 5 years experience with Aspen software, I consider modeling complex chemical reactions in HYSYS to be absolutely impossible task - or, at least not acceptable for the levels of accuracy that one will expect when simulating petrochemical or refinery reactors/reaction furnaces. For such purposes, highly specialized industrial software has to be used, with built-in moduls of different reactors and with a possibility to calibrate your reaction/separation system.

Once, while I was working in petroleum refinery, I came across such software: Petro-SIM, developed by KBC, London. Flowsheeter in Petro-SIM is actually HYSYS (I never understood how several different companies can sell the same product - Hyprotech, Aspen, KBC and, nowadays, Honeywell), but apart from standard unit operations available in HYSYS, Petro-SIM offers built-in moduls of various reaction systems: FCC, HDS, Alkylation, Catalytic Naphtha Reformer, Delayed Coker, Visbreaker, Steam Reformer etc. These models can be calibrated in extremely detailed way, using Excel-based (VB) environment. I had an opportunity to use FCC-SIM module together with my colegues, and the results were rather encouraging.

I suggest you to visit their website and look for whatever you might be interested.

http://www.petro-sim.com/index.htm
http://www.petro-sim...s/Petro-SIM.pdf

Best regards,

[Srikrishna Chaitanya]

Dear Zauberberg ,
first of all thank you very much for valuable guidance , what you said is exactly correct , these simulation software companies making separate software's for different units like reformer, hydro cracker , flare system etc. from this their intention is clear to sell more softwares . I have seen Petro-sim website , since i am in a EPC company and already we are having Aspen plus & Hysys , for me its difficult to get that software , any way i will try to do it , if not possible i have to leave the problem
i have one doubt can i do that problem with aspen plus ?

[Zauberberg]

Not possible/feasible, as far as I know. The reason is the same: level of accuracy of these models is expected to be very high, and - in my opinion - this is not possible to do by configuring complex reaction system by yourself.

Software companies are interested in selling their products, that is absolutelly correct. Each one of them has certain advantages over competitors. And, as far as industrial reactors are concerned, Petro-SIM is the best tool I have ever had opportunity to explore.

Best regards,