# Mass and Energy Balances

**Chemical and Biochemical Engineering**

5 ECTS; 2º Ano, 1º Semestre, 30,0 T + 30,0 TP

**Lecturer**

**Prerequisites**

**Objectives**

Develop the skills needed to solve mass and energy balances. Know how to create and interpret process diagrams, identify process variables and process relationships. Solve mass and energy balances in processes with and without reaction. Decide and define strategies for solving the balances.

**Program**

1. Material balances

1.1. Mass balances fundamentals

Felder & Rousseau chapter 4; Himmelblau & Riggs chapters 3, 6 to 8, and 12

1.1.1. Mass conservation equations.

1.1.2. Steady-state operations versus unsteady-state operations.

1.1.3. Mass balances with and without chemical reaction.

1.1.4. Basis definition and use.

1.1.5. Mass balances problems solving.

1.1.6. Systematic and non-systematic mass balances resolution.

1.1.7. Process with recycle, purge and by-pass.

1.1.8. Use of overall balances.

1.2. Definition, prevision and use of process variables

Felder & Rousseau chapters 3, 5 and 6; Himmelblau & Riggs chapters 2, 4, 5 and 13 to 18

1.2.1. Process streams composition and flow rate.

1.2.2. Calculations with solid, liquids, mixtures, solutions and suspensions.

1.2.3. Calculations with ideal gases, real gases, mixtures and vapors. Optional.

1.3. Mass balances on reactive processes

Felder & Rousseau chapter 4; Himmelblau & Riggs chapters 9 and 10

1.3.1. The chemical reaction and stoichiometry. Species and element material balances.

1.3.2. Limiting and excess reactants.

1.3.3. Conversion and degree of completion. Yield and selectivity.

2. Energy balances

2.1. Energy balances fundamentals

Felder & Rousseau chapters 7 and 8; Himmelblau & Riggs chapters 21 to 24

2.1.1. Forms of energy; Energy conservation equations.

2.1.2. Internal energy and enthalpy dependence on the pressure and temperature.

2.1.3. Heat capacity of solids, liquids and gases.

2.1.4. Energy balances in processes with phase change.

2.1.5. General strategy to solve energy balances.

2.2. Energy balances on reactive processes

Felder & Rousseau chapter 9; Himmelblau & Riggs chapters 25 and 26

2.2.1. Reaction entalpy definition and calculation. Hess´s law.

2.2.2. Combustion and formation reactions.

2.2.3. General strategy to solve energy balances on reactive processes.

3. Mass and energy balances special cases

3.1. Non-ideal mixtures effects on the mass and energy balances. Optional

3.2. Introduction to mass and energy balances for multiphase and staged processes. Optional

3.3. Non-steady state mass and energy processes. Optional

**Evaluation Methodology**

Written open-book test.

**Bibliography**

- Felder, J. (2000). *Chemical Processes Principles*. London: Springer

- Himmelblau, D. (2004). *Basic Principles and Calculations in Chemical Engineering*. New York: Prentice-Hall

- Pinho, H. (0). *Documentos de apoio de BME*. Acedido em 10 de setembro de 2018 em www.e-learning.ipt.pt

**Method of interaction**

Lectures and tutorials.

**Software used in class**

Worksheet software and free applications for solving of equations systems.