1. TESTING/PERFORMANCE EVALUATION OF CATALYSTS
Presentation to
Nagarjuna Fertilizers Team
National Centre for Catalysis Research
Indian Institute of Technology
Chennai
20th Sept.2009

2. Outline Objectives Performance of catalysts
Laboratory scale evaluation
Pilot scale evaluation
Industrial reactors
Catalyst Testing- Essentials

3. Objectives Checking performance of new catalysts
Comparison of different catalysts/selection
Optimize process parameters
Effect of feedstock, impurities
Assessment of catalyst life, regenerability
Generation of kinetics data
To establish the key performance parameters

4. Catalysts-Performance materials
Expected to display specific space time yield- yield per unit wt. of catalyst per unit time
Better process economics
Reasonable life and regenerability/re-use
Cost effective
Process economics- Key driver for catalyst selection/regeneration

5. Parameters for evaluation
Activity % Conversion per pass
Selectivity - Extent of formation of desired product
Minimum side products
Yield Based on activity & selectivity
Life Duration for which desired activity &
selectivity are maintained (Cycle/Total)
Regenerability- Ability to regain activity after one
life- cycle
Key performance parameters

6. Stages of evaluation Laboratory scale Pilot scale
A number of catalyst recipes are tested & the most promising ones are examined further
Pilot scale
Establishing long term stability & process parameters optimization for selected catalysts
Semi-commercial/Demonstration
Establishing commercial viability of the final catalyst/process
Development of catalytic process technology

7. Laboratory data- Criteria
Fast screening of catalysts
Evaluation of activity & selectivity under different process conditions
Effect of pressure, temperature, feed composition, H2/HC ratios
Effect of alternative / variations / impurities in feedstocks, moisture etc.

8. Laboratory reactors Pulse micro reactor
Small amount of catalyst (mg) / reactants (µl)
Reactants are injected as liquid/gas pulses
Carrier gas (CG) takes the reactant vapors to the catalyst bed
Reactor effluent directly enters GC for analysis
The reaction takes place under non- steady
state conditions
Useful for fast screening of catalysts CG 
Liquid
GSV R GC
Preliminary screening of catalysts

9. Laboratory reactors Continuous Flow reactor
Consists of a liquid feed pump (F), inlet gas control (GI), Pre-heater (P), reactor ®, gas-liquid separator (C) with provisions for gas outlet (GO) and liquid sampling (L)
1-5 g of samples can be used
Useful for fast screening of catalysts
Can be operated at atmospheric or higher pressures
Preliminary data on effect of temperature, contact time, feed-gas molar ratios can be studied
Model compounds as reactants F P GI R GO C L
To study vapor phase reactions

10. Continuous Flow reactor
Reactor system can be
configured for on-line /
off-line analysis using
6 port sampling valves
Fluid flow, pressure & temperature controls are critical

11. Ideal reactors - CSTR No temperature or concentration gradients
Isothermal
Plug flow
Continuous Stirred Tank Reactor CSTR
Useful for generation of true kinetic data

12. Laboratory reactors Differential flow reactors
Conversion across the bed is very small (8-10 %)
Inlet & outlet stream composition would be almost identical
There is no rate variation across the bed
One can get the actual kinetic rate data
Isothermal conditions and external & internal mass transfer criteria (particle size, reactor aspect ratios, flow rates) to be maintained

13. Laboratory reactors Integral flow reactors
Can be operated with large conversions
Isothermicity is the most essential condition
Dilution with inerts is resorted to in exo / endo thermic reactions
Activity, selectivity, stability & reaction kinetics data can be generated with suitable equations
Data can be extended to large scale operation/ process development after appropriate corrections
Can be validated with actual commercial reactor data

14. Pilot plant data- Criteria
Use of actual feedstock
Susceptibility to feed/ process impurities
Actual process conditions to be employed
Reactor design similar to commercial one
Statistical design of experiments to optimize process parameters- Use of different models
Data accuracy, reliability & reproducibility to be ensured
Critical for catalyst/process development

15. Methods for life test Constant Temperature Policy
Temperature, pressure & flow
conditions are kept constant.
Variations in conversion w.r.t time
are traced
Constant Conversion Policy
At set pressure & flow conditions,
temperature required to maintain
fixed conversion is traced
% C
Time T
Data from both approaches can be fitted into
standard mathematical expressions
Time
Needs judicious choice of experimental conditions

16. Accelerated Life Test
Under typical process conditions some catalysts display steady activity over long period
Evaluation of actual life may take long time
Process parameters are chosen in such a way that catalyst gets deactivated fast.
Under these conditions life of the
new catalyst is compared with that
of standard catalyst
Time required for life test is drastically
reduced
Methods comparative
Validated with actual commercial
Performance data T
Time
Highly useful approach for catalysts development

17. Types of reactors Fixed bed /Packed bed Fluid bed
Axial Flow - Most common, simple design
Radial flow - Lower pressure drop, higher feed flow, better selectivity
Isothermal – Multi tubular –Exothermic reactions
Adiabatic- Exothermic reactions
Fluid bed
Effective solid- fluid contact
Efficient heat removal
Reactor designs specific to the process

18. Types of industrial reactors
Hydrogenation / Dehydrogenation    
Catalyst
Catalyst                
Ethylene
oxidation 
Adiabatic
Axial flow
Adiabatic
Radial flow
Multi tubular
Axial flow

19. Fluid bed reactor Butane to MA Oxychlorination of Ethylene to EDC
Ammoxidation of
Propylene to ACN

20. Slurry phase reactors
Catalytic hydrogenation

21. Trickle bed reactor
Hydrotrating-
HDS,HDN,
HDM

22. Bubble column reactors
Oligomerization
of olefins

23. Deactivation patterns- Specific to catalyst-reaction

24. Wide variation of deactivation time scale

25. Catalyst life & Reactor types
Deactivation pattern decides the reactor configuration

26. Catalytic dehydrogenation of Paraffins- Reactor configurations

27. Catalytic dehydrogenation of Paraffins- Reactor configurations

28. Testing of Catalysts- Essentials
Purpose –Screening, optimization, stability, process development, kinetics
Choice of appropriate reactor systems at Lab/Pilot scale
Ensure proper process control systems, P,T,F
Ensure Isothermicity & freedom from transport limitations
Planning suitable experimental methodology/approach
Evolve standard analytical methods
Ensure accuracy, reliability, reproducibility of data
Develop mathematical correlations- Pilot scale- Commercial scale
Continuous review & up gradation of the protocols

29. Q & A
Thank you !