6 replies to this topic

[alokjaiswal]

I just read the thread of Arpit and subsequent reply of Ankur and Art. With that inspiration only, I would request all the forum members especially Ankur and Art Sir who have valuable experience, to guide me.

I am working in Ammonia Plant and I wish to design an Excel Sheet for calculating Material Balance as well as energy balance. Though models of Ammonia Plant in softwares like Aspen HYSYS are already there. But I wish to generate such model on Excel sheet which can give comparable result with that of Softwares.

Although, I do have a Excel sheet for doing material balance of Ammonia Plant, but the result are deviated (not much) from those obtained by Softwares.

So I request forum members to guide me on preparing such excel sheet.

Alok Jaiswal

[kkala]

Probably http://www.cheresour...r-bosch-process '> http://www.cheresour...r-bosch-process can be of some help, concerning mass balance only (general matter). You may need something more specific, e.g. by introducing the plant inputs / measurements at some points and have conversion, NH3 flow rate out, etc, as a result. Yet mentioned web reference can give a general idea on how to estimate flows around reactor.

[alokjaiswal]

Thanks for reply Kkala.

But this is a very priliminary step involving material balance only around NH3 Synthesis converter. I want to have deeper understanding right from Reformer to Ammonia Production which will involve some kinetics equations too for individual reactor like Reformer, Shift, Methanator etc.

Alok Jaiswal

[kkala]

I do not have knowledge to supply requested information. Having worked in a fertilizer plant, ammonia was imported, not produced.
Hopefully other members can help.

[ankur2061]

Alok,

The job of building an excel sheet is not an easy task specifically if you are building a comprehensive material and energy balance for an entire process

The complex spreadsheets that I have built have taken several revisions, corrections and re-work over a period of months. I have faced the same frustration when my excel results would not match with the software generated results. Let me tell you, even after my best efforts the results obtained from my spreadsheet and the software (HYSYS) could never match exactlly. I was happy if I could match it to the extent of +/- 10% of the software.

The main reason I believe that excel calculations are difficult to match with a professional simulation software is the exactness of the physical and thermodynamic properties in the software. Another aspect that makes software results more precise is the simultaneous iterations that the software will perform on various parmeters to converge to a solution. It would be very difficult to do such an operation in excel.

Nevertheless, I had met one excellent Venezuelan process engineer who had programmed various refinery operations (CDU, VDU, Hydrotreater, Reformer) using a combination of MATLAB and Excel and his calculations were almost a replication of results that were obtained from ProII for the same crude characteristics and throughput.

I am sure, fine tuning your spreadsheet over a period of time with ideas of improvement coming to you as your understanding of the subject increases will bring up your material and energy balance spreadsheet for ammonia to a level where the difference in results with the software is reduced to an acceptable level.

Hope this helps.

Regards,
Ankur.

Edited by ankur2061, 10 February 2012 - 02:24 PM.

[alokjaiswal]

Dear Attyub194

For our company, purchasing HYSYS or such simulation software seems worthless since jobs such as designing or checking feasibility are being done mainly our consultants such as HTAS or KBR.

Therefore, I want to prepare my own Excel sheet which can produce comparable results.

Can you guide me in preparing such an excel sheet? Or some resource where to start something like that. I am desperately seeking some guidance in this regard.

You can also contact me directly on my personal email id:

1. alokjaiswal@iffco.in
2. alok_ietl@rediffmail.com

Thanks
Alok