Semester 2 Reaction Engineering

Question 1

What are the 3 steps for a chemical reactor process

Answer 1

Mixing, reaction, separation

Question 2

What is homogenous chemical reaction

Answer 2

Single phase chemical reaction

Question 3

What is a heterogeneous chemical reaction

Answer 3

Reacting taking place with at least 2 distinct phases

Question 4

What is the function of catalyst

Answer 4

Increase ror without getting used up

Question 5

What us mass balance

Answer 5

Accounting materials entering, converting, accumulating and leaving within the reactor

Question 6

What is energy balance

Answer 6

Accounting heat entering, leaving, accumulating, forming Orr disappearing from or within g the reactor

Question 7

What is stoichiometry

Answer 7

Moles of reactant react to yield of product produced

Question 8

Rate law equation

Answer 8

-rA=kCna

Question 9

What is contacting in chemical reaction

Answer 9

How reactants are connected for the reaction to take place in a reaction plant

Question 10

What is the performance equation

Answer 10

Output=f(input,kinetics,contacting)

Question 11

Rate of reaction for the volume of reacting fluid

Answer 11

Ri= 1/v x dn/dt

Question 12

Ror of mass of solid in fluid solid system

Answer 12

Ri’=1/w x dn/dt

Question 13

Ror of the volume of solid in solid gas system

Answer 13

Ri’’=1/s x dv/dt

Question 14

Ror of solid in gas-solid system

Answer 14

Ri’’’=1/v x dn/dt

Question 15

Ror of volume of reaction, if different from the rate based on volume of fluid

Answer 15

Ri’’’’=1/vr x dn/dt

Question 16

What is rA

Answer 16

Rate of formation

Question 17

What is -rA

Answer 17

Rate of dissapearence

Question 18

What is the stoichiometric equation of aA+bB—>rR+sS

Answer 18

-rA/a=-rB/b=rR/r=rS/s

Question 19

Definition of reaction law rate

Answer 19

Algebraic equation for reaction rate as a function of properties of the reaction materials and conditions

Question 20

What is elementary reaction

Answer 20

Reaction with no intermediate, single step

Question 21

Units for 0 order

Answer 21

Mol L-1 s-1

Question 22

Unit for 1st order

Answer 22

S-1

Question 23

unites for 2nd order

Answer 23

Mol-1 L s-1

Question 24

What is the rate reaction for gas phase reaction, including simplified version (show how it is derived)

Answer 24

Pv=nRT, C=n/v
So, p=CRT, C=p/RT

-rA=kCnA
-rA=k(pA/RT)n

Where k’=k/(RT)n

So, -rA=k’Pna

Question 25

Ahrenius equation

Answer 25

K=k0e^-e/RT

Question 26

Ahrenius equation interms of y=mx+c

Answer 26

LnK=lnK0-(E/R)1/T

Question 27

Interms of what is the conversion of reactant used in batch process

Answer 27

Moles

Question 28

Signs of Fractional conversion Initial amount of moles Moles A present after certain time

Answer 28

XA NA0 NA

Question 29

2 equation of the conversion of A in time t for batch process

Answer 29

Xa=(NA0-NA)/NA0 Xa=1-(NA/NA0)

Question 30

No of moles of A interms of NA0 and XA, equation

Answer 30

NA=NA0(1-XA)

Question 31

Fractional conversion equation when volume is constant

Answer 31

XA=1-CA/CA0

Question 32

Conversion rate in continuous process

Answer 32

XA=(FA0-FA)/FA0

Question 33

What type of system batch reactor

Answer 33

Closed system, neither inflow nether outflow

Question 34

What happens to concentration over time in batch reactor

Answer 34

Changes

Question 35

What is batch reactor usually used for

Answer 35

1. Same volume prediction 2. Flexibility of multi product operation 3. Lower capital cost 4. Lab testing

Question 36

What is continuous reactors used for

Answer 36

Long production runs and products made in large scale

Question 37

What happens to conditions in continuous process over time

Answer 37

Doesn’t change

Question 38

When is CSTR used

Answer 38

Large scale, liquid phase, intense agitation

Question 39

condition of CSTR can work

Answer 39

Up to 300 degrees and 300 bar

Question 40

What about the concentration in CSTR

Answer 40

Assume perfect mixing, C is the same everywhere in the reactor

Question 41

ADV of CSTR

Answer 41

Cheap construction cost Good T control

Question 42

Disadvantage of CSTR

Answer 42

Mix might not be done properly Reactants might bypass through outlet