Fundamentals of Material Balance
Chapter 4
Fundamentals of Material Balances
Material Balance-Part 1
Process Classification
3 type of chemical processes: 1. Batch process
– Feed is charge to the process and product is removed when the process is completed – No mass is fed or removed from the process during the operation – Used for small scale production – Operate in unsteady state
March 31, 2009
ChE 201/shoukat@buet.ac.bd
2
Process Classification
2. Continuous process
– Input and output is continuously fed and remove from the process – Operate in steady state – Used for large scale production
3. Semibatch process
– Neither batch nor continuous – During the process a part of reactant can be fed or a part of product can be removed.
March 31, 2009
ChE 201/shoukat@buet.ac.bd
3
2 type of process operations: 1. Steady state
– All the variables (i.e. temperatures, pressure, volume, flow rate, etc) do not change with time
2. Unsteady state or transient
– Process variable change with time
March 31, 2009
ChE 201/shoukat@buet.ac.bd
4
Try This… Define type and operation of processes given: • A balloon is filled with air at steady rate of 2 g/min Semibatch and unsteady state • A bottle of milk is taken from the refrigerator and left on the kitchen Batch and unsteady state • Water is boiled in open flask Semibatch and unsteady state
March 31, 2009 ChE 201/shoukat@buet.ac.bd 5
General Balance Equation:
INPUT + GENERATION – OUTPUT – CONSUMPTION = ACCUMULATION
Balances on Continuous Steady-State Process • Steady state; accumulation = 0
INPUT + GENERATION = OUTPUT + CONSUMPTION
• If balance on steady-state non-reactive processes; generation = 0, consumption = 0 INPUT = OUTPUT
March 31, 2009 ChE 201/shoukat@buet.ac.bd 6
Steps for Material Balance Calculations:
1. Learn how to organize information about process variables - Flow Chart drawing and Labeling 2. Choose a Basis 3. Set up material balance equations 4. solve the equations
Fundamentals of Material Balances
Material Balance-Part 1
Process Classification
3 type of chemical processes: 1. Batch process
– Feed is charge to the process and product is removed when the process is completed – No mass is fed or removed from the process during the operation – Used for small scale production – Operate in unsteady state
March 31, 2009
ChE 201/shoukat@buet.ac.bd
2
Process Classification
2. Continuous process
– Input and output is continuously fed and remove from the process – Operate in steady state – Used for large scale production
3. Semibatch process
– Neither batch nor continuous – During the process a part of reactant can be fed or a part of product can be removed.
March 31, 2009
ChE 201/shoukat@buet.ac.bd
3
2 type of process operations: 1. Steady state
– All the variables (i.e. temperatures, pressure, volume, flow rate, etc) do not change with time
2. Unsteady state or transient
– Process variable change with time
March 31, 2009
ChE 201/shoukat@buet.ac.bd
4
Try This… Define type and operation of processes given: • A balloon is filled with air at steady rate of 2 g/min Semibatch and unsteady state • A bottle of milk is taken from the refrigerator and left on the kitchen Batch and unsteady state • Water is boiled in open flask Semibatch and unsteady state
March 31, 2009 ChE 201/shoukat@buet.ac.bd 5
General Balance Equation:
INPUT + GENERATION – OUTPUT – CONSUMPTION = ACCUMULATION
Balances on Continuous Steady-State Process • Steady state; accumulation = 0
INPUT + GENERATION = OUTPUT + CONSUMPTION
• If balance on steady-state non-reactive processes; generation = 0, consumption = 0 INPUT = OUTPUT
March 31, 2009 ChE 201/shoukat@buet.ac.bd 6
Steps for Material Balance Calculations:
1. Learn how to organize information about process variables - Flow Chart drawing and Labeling 2. Choose a Basis 3. Set up material balance equations 4. solve the equations