material balance
❖ WHAT ARE BASICS OF
CALCULATION ?
❖ WHAT ARE INDEPENDENT
EQUATION ?
❖ WHAT ARE DEGREE OF
FREEDOMS ?
❖ WHAT ARE FLOW CHARTS?
❖ WHAT ARE BLOCK DIAGRAM?
, Procedure:
1. Choose a basis of calculations .if not specified in problem …..What
of calculation?
❖ is an amount or flow rate of one of the process streams on a ma
mole basis.
❖ If a stream amount or flow rate is given in the problem stateme
this as the basis of calculation (usually)
❖ If no stream amounts or flow rates are known, you can assume o
preferably a stream of known composition
❖ if mass fractions are known, choose a total mass or mass flow ra
that stream (e.g., 100 kg or 100 kg/h) as a basis
❖ if mole fractions are known, choose a total number of moles or
flow rate
,Example:
A spent sulfuric acid solution is brought up to strength for a pickling process in a mixer. Spent solution at 3% sulfuric acid (by weight) is mixed with a 50% solution (by wei
desired product concentration of 40% acid by weight. All are aqueous solutions. Determine all flow rates on the basis of 100 kg/h of product. If the actual flow of the spe
kg/h, what must the flowrates of the streams be?
2. Draw a flow chart
. What is flow chart?
A flowchart, or process flow diagram (PFD), is a convenient (actually, necessary) way of organizing process information for subsequent calculations.It is sequence of proce
by process streams .
To obtain maximum benefit from the PFD in material balance calculations, you must:
a. clearly read and understand the problem
b. convert the problem statement into process flow diagram; what are the streams in/out and what components are in each stream?
❖ WHAT ARE BASICS OF
CALCULATION ?
❖ WHAT ARE INDEPENDENT
EQUATION ?
❖ WHAT ARE DEGREE OF
FREEDOMS ?
❖ WHAT ARE FLOW CHARTS?
❖ WHAT ARE BLOCK DIAGRAM?
, Procedure:
1. Choose a basis of calculations .if not specified in problem …..What
of calculation?
❖ is an amount or flow rate of one of the process streams on a ma
mole basis.
❖ If a stream amount or flow rate is given in the problem stateme
this as the basis of calculation (usually)
❖ If no stream amounts or flow rates are known, you can assume o
preferably a stream of known composition
❖ if mass fractions are known, choose a total mass or mass flow ra
that stream (e.g., 100 kg or 100 kg/h) as a basis
❖ if mole fractions are known, choose a total number of moles or
flow rate
,Example:
A spent sulfuric acid solution is brought up to strength for a pickling process in a mixer. Spent solution at 3% sulfuric acid (by weight) is mixed with a 50% solution (by wei
desired product concentration of 40% acid by weight. All are aqueous solutions. Determine all flow rates on the basis of 100 kg/h of product. If the actual flow of the spe
kg/h, what must the flowrates of the streams be?
2. Draw a flow chart
. What is flow chart?
A flowchart, or process flow diagram (PFD), is a convenient (actually, necessary) way of organizing process information for subsequent calculations.It is sequence of proce
by process streams .
To obtain maximum benefit from the PFD in material balance calculations, you must:
a. clearly read and understand the problem
b. convert the problem statement into process flow diagram; what are the streams in/out and what components are in each stream?
