chemical reaction engineering ppt.pptx

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another.[1] When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an energy change as new products are generated. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents. Chemical reactions are usually characterized by a chemical change, and they yield one or more products, which usually have properties different from the reactants. Reactions often consist of a sequence of individual sub-steps, the so-called elementary reactions, and the information on the precise course of action is part of the reaction mechanism. Chemical reactions are described with chemical equations, which symbolically present the starting materials, end products, and sometimes intermediate products and reaction conditions. Chemical reactions happen at a characteristic reaction rate at a given temperature and chemical concentration. Some reactions produce heat and are called exothermic reactions, while others may require heat to enable the reaction to occur, which are called endothermic reactions. Typically, reaction rates increase with increasing temperature because there is more thermal energy available to reach the activation energy necessary for breaking bonds between atoms.

A reaction may be classified as redox in which oxidation and reduction occur or non-redox in which there is no oxidation and reduction occurring. Most simple redox reactions may be classified as a combination, decomposition, or single displacement reaction.

Different chemical reactions are used during chemical synthesis in order to obtain the desired product. In biochemistry, a consecutive series of chemical reactions (where the product of one reaction is the reactant of the next reaction) form metabolic pathways. These reactions are often catalyzed by protein enzymes. Enzymes increase the rates of biochemical reactions, so that metabolic syntheses and decompositions impossible under ordinary conditions can occur at the temperature and concentrations present within a cell.

The general concept of a chemical reaction has been extended to reactions between entities smaller than atoms, including nuclear reactions, radioactive decays and reactions between elementary particles, as described by quantum field theory.

1. ChE 402: Chemical Reaction Engineering Review of the concepts of reaction kinetics- Chapter 1 Classification of chemical reactions, definition of reaction rate The general mole balance

2. CHEMICAL REACTION: A chemical reaction is a process that leads to the transformation of one set of Chemical substances to another.

3. How can we count them? Reaction

4. Batch Reactor Batch Continuous Stirred Tank Reactor (BCSTR)

5. Flow Reactor CSTR

6. Flow Reactor Continuous Stirred Tank Reactor (CSTR) Tubular Reactor

7. Plug Flow Reactor (PFR) Packed Bed Reactor (PBR) Tubular Reactor

8. Tubular Reactor Fluidized bed Reactor (FBR) Bubble Column Reactor (PBR)

9. Industrial Reactors

10. The Rate of Reaction is the study of rates of chemical reactions Chemical kinetics

11. The Rate of Reaction Independent of the type of reactor (Batch or Continuous) What factors influence the rate of a reaction? Once we specify a particular reacting system, the factors that influence the rate of a reaction are (1) temperature, (2) concentrations of reactants, (3) physical state of reactants, (4) presence of a catalyst. The rate equation (Rate Law) is an algebraic equation of a Chemical Reaction that links the Reaction Rate with concentrations or pressures of reactants and constant parameters (normally rate coefficients and partial Reaction Orders)

12. The Rate of Reaction Rate of Disappearance : Rate of Formation (Generation): Reaction in presence of Catalyst number of moles of A reacting per unit time per unit mass of catalyst (mol/s. g catalyst)

13. The Rate of Reaction

14. The Rate of Reaction Rate of reaction or Rate law may be like :

15. General Mole Balance

16. Batch Reactor Mole Balance

17. CSTR Mole Balance

18. Plug Flow (Tubular) Reactor Mole Balance PFR: The integral form is: This is the volume necessary to reduce the entering molar flow rate (mol/s) from F A0 to the exit molar flow rate of F A . or

19. Packed Bed Reactor Mole Balance PBR The integral form to find the catalyst weight is:

20. Reactor Mole Balance Summary Reactor Differential Algebraic Integral BATCH CSTR PFR PBR

21. Chemical Kinetics or Reaction Engineering Mole Balance Rate Laws Stoichiometry These topics build upon one another Mole Balance Rate Laws Stoichiometry Isothermal Design Heat Effects

22. Isothermal Reactor Design Algorithm

23. QUESTIONS ?

24. ChE 402: Chemical Reaction Engineering Review of the concepts of reaction kinetics- Chapter 1 Classification of chemical reactions, definition of reaction rate The general mole balance

25. General Mole Balance

26. Batch Reactor Mole Balance

27. CSTR Mole Balance

28. Plug Flow (Tubular) Reactor Mole Balance PFR: The integral form is: This is the volume necessary to reduce the entering molar flow rate (mol/s) from F A0 to the exit molar flow rate of F A . or

29. Packed Bed Reactor Mole Balance PBR The integral form to find the catalyst weight is:

30. Reactor Mole Balance Summary Reactor Differential Algebraic Integral BATCH CSTR PFR PBR

31. The Rate of Reaction Independent of the type of reactor (Batch or Continuous) What factors influence the rate of a reaction? Once we specify a particular reacting system, the factors that influence the rate of a reaction are (1) temperature, (2) concentrations of reactants, (3) physical state of reactants, (4) presence of a catalyst. The rate equation (Rate Law) is an algebraic equation of a Chemical Reaction that links the Reaction Rate with concentrations or pressures of reactants and constant parameters (normally rate coefficients and partial Reaction Orders)

32. The Rate of Reaction Rate of Disappearance : Rate of Formation (Generation): Reaction in presence of Catalyst number of moles of A reacting per unit time per unit mass of catalyst (mol/s. g catalyst)

33. The Rate of Reaction

34. The Rate of Reaction Rate of reaction or Rate law may be like :

35. Chemical Kinetics or Reaction Engineering Mole Balance Rate Laws Stoichiometry These topics build upon one another Mole Balance Rate Laws Stoichiometry Isothermal Design Heat Effects

36. Isothermal Reactor Design Algorithm

37. QUESTIONS ?