6 replies to this topic

[ebth]

hi all 

am doing  research on formaldehyde simulation using hysys 7.3, from methanol .. 

now am on the first unit the packed bed reactor , an i dont know how to do it

[ebth]

help me plz    

[Bobby Strain]

Maybe you are a student?

 

Bobby

[ebth]

Yes i am a student .. an this is my final research

[Saml]

You should post in the student forum.

 

That said, It seems that you are falling in what most of the students fall: thinking that Simulators can provide all the design answers

 

Simulators are basically a thermodynamic properties calculator. On this, they are very strong.

 - a Valve is an adiabatic expansion, together with some Cv calculation in some cases.

 - a Compressor is a polytropic or adiabatic pressure evolution

 - a heat exchanger is heating one stream and coolint the other.

 - a distillation column is solving the n stages equilibriums.

-  a separator is an L-V calculation

 

Then, there are some modules where they calculate transfer phenomena.

-  Can calculate the U of a heat exchanger

-  Can calculate the pressure drop in a pipe, packed beds or trays.

- There are a few models of mass transfer, like rate distillation

 

And regarding reaction kinetics, almost all of them requires the user to provide the kinetic. It can be a custom module built on any programming language, where you take into account all the catalyst factors (size, porosity, tortuosity, composition, dispersion, BET area or whatever) or can be a pseudo homogeneus kinetic. But the point is that there is no database of kinetics. Only of thermodynamic properties.

 

So from the simulator you can get the free energy of the reaction, the equilibrium (if there is any), the temperature vs conversion evolution. But you cannot get the size of the reactor if you don't have the kinetic of the reaction over the catalyst you are using. HINT: probably you won't have it. Catalyst manufacturers keep this information as a secret. May be research data, or general information like typical LHSV (liquid hourly space velocity).

[ebth]

First of all am sorry am not Familiar with forms ... an thank u so much sir for the informations

[Padmakar Katre]

hi all 

am doing  research on formaldehyde simulation using hysys 7.3, from methanol .. 

now am on the first unit the packed bed reactor , an i dont know how to do it

 

Get in touch with Aspen Tech technical support team, know which thermo model is suitable for your flowsheet, do they have any standard case of the same flowsheet if not entire at least the reactor model. This will surely help you in setting up your flowsheet.