CAIRO UNIVERSITY FACULTY OF ENGINEERING CHEMICAL ENGINEERING DEPARTMENT

1
CAIRO UNIVERSITYFACULTY OF ENGINEERINGCHEMICAL
ENGINEERING DEPARTMENT

• Organic Chemical Process Industries

Section 1
TA. Jasmine Amr Eng. Hassan El- Shimi
Wednesday, September 22nd, 2010
2
Today Agenda

• General view on Organic Industries
• Course contents
• Marks
• Review on Chemical Kinetics
• Sheet 1

3
Course Contents

• Lectures

• Sections

Laboratory

• Organic Technology (Overview)
• Nitration
• Nitrobenzene
• Dinitrobenzene
• TNB
• Aniline industry
• TNT, and .
• Sulfonation
• Intro to Petrochemical Industry

• Review on Chemical Kinetics (2 sections)
• Nitration Thermodynamics ( 2 sections)

• Peroxide value
• Saponification value
• O G Estimation
• BOD5 COD
• Dying
• Mwt. Determination

Prof. Dr. Samia Prof. Dr. Hoda Prof. Dr. Sahar
TA. Jasmine Amr Eng. Hassan El- Shimi
4
Marks (acceptable to change)

• Total marks 150 mark
• Final exam 90 mark
• Year work 60 mark
• 1st midterm 30 mark
• 2nd midterm 10 marks
• Oral exam 10 marks
• Lab 10 mark

5
(No Transcript)
6
Chemical Reaction Kinetics

• For any reaction AB ? C (product)
• Rate of reaction a no. of collisions between
  molecules A, B.
• Rate of reaction a concentration of A, B
• As rA a CA CB, hence rA k CA CB
• Where k specific rate constant
• Rate of reaction is rate of consumption or
  production of component (i)
• rA - dCA/dt - dCB/dt dCC/dt kCACB

7

• If aAbB ? cCdD (balanced equation)
• Hence, rA k CAa CBb (rate equation)
• Where, a order of reaction w.r.t. reactant (A)
  and b order of reaction w.r.t. reactant (B)
• Overall order of reaction ab
• In case of reversible reaction
• aAbB ? cCdD
• Rate eq. rA kf CAaCBb kb CCcCDd
• Order of reaction (ab) (cd)

8
Mechanism of reaction

• Elementary Reactions

• Non-elementary Reactions

• Reactions occur in a single step and the rate
  expression is suggested from the stiochiometric
  equation.
• 2AB ? RS
• rA k CA2CB

• Reactions which we observe as a single reaction,
  but in the real, its the result of a sequence of
  elementary reactions and the rate equation cant
  be detected from the stiochiometric equation.
• 2AB ? RS
• In fact AB ? AB
• ABA ? A2B S
• A2B ? R
• These 3 steps are called the reaction mechanism
• Rate eq. rate eq. of determining step (slowest
  step) ? kCA2CB

9
Arrhenius Equation

• K Ao e E/RT
• K specific rate constant
• Ao Arrhenius constant
• E activation energy
• T absolute temperature (Kelvin or oR)
• R universal gas constant 8.314 J/gmole.K or R
  0.082 lit.atm/gmole.K
  or R 1.987 cal/gmole. K 10.73 Btu/Ib. R

10

• Dependence of Rx Rate on Concentration
• r k CAn CBm n m order of
  Rx
• If B is in large excess CB constant,
  i.e. dCB/dt 0, hence
• CBm constant and rA k CA n, where
  k k CBm, and its easy to get (n).
• Molecularity
• Its the number of reactant molecules in the
  stiochiometric equation (Elementary Rx) OR number
  of molecules in the rate determining step
  (Non-elementary Rx).
• N.B. if order of Rx Molecularity, the reaction
  is called simple order reaction.

11
Sheet 1

• Problem no. 1
• A ? B, r kCAn n?
• 1) Assume zero order reaction (n0)
• Hence, r - dC/dt kCn0 k
• Get CA-CAo - kt
• Hence, CACAo kt

CA
Slope k
t
12

• 2) Assume 1st order reaction ( n1)
• r -dCA/dt kCA
• -dC/C k dt
• Hence, Ln CA- Ln CAo -kt
• Finally, ln CA ln CAo kt

Ln CA
Slope k
t
13

• 3) Assume 2nd order reaction ( n2)
• r -dCA/dt kCA2
• -dC/C2 k dt
• Hence, 1/CA- 1/CAo kt
• Finally, 1/CA 1/CAo kt

1/CA
Slope k
1/CAo
t
14

• Plot C vs t
• Plot 1/C vs t
• The order of reaction is 2nd order
• Slope k 1.415E-06 lit/gmole. Sec

15
Problem no. 2

• Given E 75000 cal
• K at 650oC and 500oC
• Hence, T1 923ok T2 773ok
• Since k Ao e-E/RT
• k1 Ao e-E/R(773) ? 1
• k2 Ao e-E/R(923) ? 2
• k1/k2

16

• k1/k2
• Since E 73000 cal R 1.987 cal/gmol .k
• Thus, k1/k2 2/3 and k1(2/3) k2
• i.e. k2 gt k1 , thus the reaction at (T2 650oC)
  is faster than the reaction at (T1 500oC).

17

• Chemical Third Year, CHE2012
• Any Question

18

• For any problem, please contact me

Eng. Hassan El- Shimi E-mail
hassanshimi_at_gmail.com Mobile [phone]
19

• Thank You