PLANT DESIGN & FEASIBILITY STUDY

MATERIAL BALANCE USING EXCEL WORKSHEET : EXERCISE 1

Ahmad Muzammil Bin Idris55201113653

BACH. CHEM ENG TECH PROCESS

1

Material balance Reconciliation Using Spread Sheet

In this exercise you are required to set up a spreadsheet to solve the mass balance for the following flow sheet of a gas phase reaction

The feed stream consists of:

Compound (kmols/hr)CO2 360CH4 192CO 876H2 4520

H2O 6CH3OH 0

N2 446

The following equations should used

MixerStream 6 is mixed with stream 1

Purge15% of stream 5 is purged in stream 7

Separator Assume all CO2, CH4, CO, H2 and N2 go into stream 5. It is assumed that 99% of H2O and 93% of CH3OH go into the product stream

Mixer Reactor

Gas Liquid Separator

Purge

Feed

1 23

4

5

Product

6

7

2

a) For a first pass calculation assume that there is no recycle in stream 6. Using spreadsheet calculate the

composition of stream 6. Using the spreadsheet calculate the composition of stream 6 (Since the

spreadsheet does not allow circular references is will be necessary to have two columns for stream 6, one

with all zeros and one calculated by the spreadsheet) This is equivalent to ‘tearing’ stream 6.

b) Substitute the values you obtained for stream 6 by the spreadsheet calculation in place of the column of

zeros. Give the new set of values for the torn stream

c) Continue substituting the values until those you substitute are the same as those calculated. What is the

final solution for the product stream (4), purge stream (7), and the torn stream (6)?

This is roughly how sequential modular flowsheeting packages work although they have a more efficient

convergence routine (usually a Newton-Raphson type method) requiring fewer interactions. Your report

should include a brief introduction to the problem, the answers to parts a, b, and c and two copies of your

final spreadsheet along with a short outline describing what information you are presenting. Of the two copies

of the spreadsheet one should show the numbers and the other the formulae (try using the Display equation

option in the Option menu). Marks will be given for presentation so try and use the formatting capabilities of

the spreadsheet to produce a clear document without handwritten additions.

3