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[tomphillips]

For my chemical engineering 3rd year design project, as part of a methanol production facility, it is my task to design a pre-reformer using glycerol as a feedstock. a pre-reformer is essentially a simple adiabatic reactor that runs the following three reactions, in an attempt to reduce the energy load and size of the main primary steam reformer.

 

C3H8O3 -> 3CO + 4H2 CO + 3H2 = CH4 + H2O CO + H2O = CO2 + H2

 

i have used excel to model this reaction as a function of mass of catalyst, to show the conversion and temperature drop. i have split the reaction into 5 reactor beds with interheating between each, to ensure that a high conversion is achieved.

 

I am now trying to calculate the pressure drop using the Ergun equation, but obviously as the density of my fluid will change throughout the reaction, with both temperature and composition, the pressure drop per unit length will also change. I was planning on calculating the pressure drop per unit length at each step of catalyst mass, and then integrating to find an exact value, but i am struggling to calculate the density at each point.

 

so my questions:

-is there a way of calculating the density of a mixture of gases if i have the composition of the mixture?

-how can i calculate the required size of my reactor vessel, from the value of total catalyst mass?

 

any help would be massively appreciated

 

Thanks

note: my spreadsheet is attached for anyone willing to look at it

Attached Files

•  glycerol pre-reformer spreadsheet.xlsx   151.54KB   30 downloads

Edited by tomphillips, 13 April 2016 - 05:22 AM.

[breizh]

hi Tomphilips ,

For the determination of the density of your gas , if you know the composition , the temperature and pressure , you can calculate the density using an EOS . I 've attached a spreadsheet to support your work .

In the data bank , last line you will have to create (name) a pseudo component with based on the composition of your gas (Mol) and your calculate pseudo MW, PC, TC , and other parameters required by the EOS choosen .

 

 

Hope this helps

 

Breizh