CHE 448 Chemical Engineering Design

1
CHE 448 Chemical Engineering Design
Spring 2006
Class Nr. 3 Tuesday January 17
Sunrise at Death Sea by Mrs B. Sorin
2
The Six Official Steps In A Project

1. Enthusiasm2. Disillusionment3. Panic4.
Search for the guilty5. Blame the innocent6.
Reward the uninvolved
Always acknowledge a fault frankly. This will
throw those in authority off their guard and give
you the opportunity to commit more. -- Mark Twain
3
Stages of a Project
Feasibility Study
Basic Engineering
Detail Engineering
Building Construction
Production
4
The Design ProcessPart I
5
The Design Project Part II
6
The Design Project Part III
7
Amount of information and stages of a project
8
Chemical Reaction Path and Molecular Structure
Design

• Chemical Reaction Path Find the optimum chemical
  reaction path to make a given molecule.
• Molecular Structure Design Design a molecule
  with prescribed properties.

9
Chemical Reaction Path

• How can we produce a given Molecule?
• Derive all alternative reaction paths,
• Using available raw materials
• Using feasible reaction mechanisms

10
What do we look for?

• What are the products and yields from a given
  chemical reaction?
• What are the reaction mechanisms?
• Do we need catalysts? Patents, Royalties?
• Do we require pressure and temperature
  excursions? Hazards (toxic, irritant)?
• Are there any difficult separation problems?
• Are all raw materials available at reasonable
  price?
• Are there any undesirable by-products?

11
Example PhenolOriginal Sulfonation Process
12
PhenolChlorobenzene Process
13
PhenolToluene Oxidation Process
14
PhenolCumene Hydroperoxide Process
15
The Phenol reaction path tree
16
Decision Model for Reaction Path Analysis I

• Cost of raw materials
• Stoichiometry
• Yield
• Cost of Utilities
• Thermochemistry
• Reaction Conditions (T, P)
• Separations
• Property differences
• Concentrations
• Percentage recovery
• Separation conditions (P, T)

17
Decision model for reaction path analysis II

• Safety- Hazards and Operability Report
• Properties of reactants and products
• Reaction and separation conditions
• Side reactions
• Reliability
• Knowledge about reaction and separations
• Flexibility-Sensitivity
• Range of conditions/yields

18
Memo
To Chief Process Engineer From J. Dilbert,
Plant Manager
Explore the possibility of making Benzene out of
our excess Toluene production in our Baton-Rouge,
LA, site. We are selling Benzene at 1.17/gal
(fob) and we sell Toluene at 0.80 /gal. Price
per gallon is 46 higher! Currently we produce
and sell about 60 106 gal/year of each (B T) (
200,000 tons/year of each). We may be able to get
additional profits of 22 M/yr!!