6 replies to this topic

[sharkyurui]

Hello everyone,

I wonder how to get the RON of a stream in Hysys. There is a property called RON(clear) in Properties tab of a stream. BUT it is empty! So what could I do?

[Technical Bard]

HYSYS can't do Octane number, unless you have all real components, or pseudocomponents that have a blending octane number defined. If you are using boiling point curves, you can't do it.

This is because octane number is not reliably correlated with boiling point and specific gravity alone - it is far too dependent on molecular structure.

[Robert Montoya]

Dear Sharkyurui, HYSYS can give a preliminary octane number as follow:

Utilities THEN cold properties and you can read in "Research Octane Number"
I have used cold properties for estimate some properties. I think that this number is a good approach.
Regards.

[sharkyurui]

HYSYS can't do Octane number, unless you have all real components, or pseudocomponents that have a blending octane number defined. If you are using boiling point curves, you can't do it.

This is because octane number is not reliably correlated with boiling point and specific gravity alone - it is far too dependent on molecular structure.

Dear Bard, I do know the exactly composition of the stream. It consists of C7~C10 Aromatics and Paraffin whose pure octane numbers all above 100. Is these info enough for HYSYS to calculate stream R.O.N.?

[sharkyurui]

Dear Sharkyurui, HYSYS can give a preliminary octane number as follow:

Utilities THEN cold properties and you can read in "Research Octane Number"
I have used cold properties for estimate some properties. I think that this number is a good approach.
Regards.

Dear roberdani12, thankyou for your solution, I get the R.O.N. of the stream, but the result seems not right. I'm using Hysys to simulate Continuous Cata Reforming and the product stream consists of C7~C10 Aromatics and Paraffin whose pure octane numbers all above 100, but the R.O.N. is only about 76. I read the help, it says, the Range of Validity of Research Octane Number is "D86 50% ~420°F". So, how could I get a relatively trusty R.O.N. of the product whose D86 50% is 138°C(280°F)?

[muazkrc]

Dear Sharkyurui, HYSYS can give a preliminary octane number as follow:

Utilities THEN cold properties and you can read in "Research Octane Number"
I have used cold properties for estimate some properties. I think that this number is a good approach.
Regards.

Dear roberdani12, thankyou for your solution, I get the R.O.N. of the stream, but the result seems not right. I'm using Hysys to simulate Continuous Cata Reforming and the product stream consists of C7~C10 Aromatics and Paraffin whose pure octane numbers all above 100, but the R.O.N. is only about 76. I read the help, it says, the Range of Validity of Research Octane Number is "D86 50% ~420°F". So, how could I get a relatively trusty R.O.N. of the product whose D86 50% is 138°C(280°F)?

Dear Sharkyurui
I'm doing the same research to model a reformer reactor(CCR one) but many problems faced me like how to get reaction sets,what kind of equation that i have to use ,and where can i find the parameter.
so if you know something that can help me please send it to me in (muazkrc@hotmail.com)
regards

[Padmakar Katre]

HYSYS can't do Octane number, unless you have all real components, or pseudocomponents that have a blending octane number defined. If you are using boiling point curves, you can't do it. This is because octane number is not reliably correlated with boiling point and specific gravity alone - it is far too dependent on molecular structure.

Dear Bard, I do know the exactly composition of the stream. It consists of C7~C10 Aromatics and Paraffin whose pure octane numbers all above 100. Is these info enough for HYSYS to calculate stream R.O.N.?

Hi,
When you have the C7-C10 aromatics and paraffins compositions and then you can do an excersize to calculate the RON outside the simulator i.e. with EXCEL. Any commerical simulator will predict RON of a stream based on it's assiged RON values to idividaul components, in absence of which in case of psuedo-components, the results will be either not diplayed or wrong what " Technical Bard" has already stated in his post.
If you have different streams with D86 distillation data, gravity curves. For every psudo component in each blend, Hysys will assign a RON value which will be used to caluclate the RON of any stream with said composition in flowsheet.