In the name of Allah the mostGracious and MercifulKnowledge of Ammonia CatalystsBy: Nasir HussainPak Arab Fertilizers Mult...
Training outline Introduction to catalysis Principal characteristics of a catalyst Ammonia plant catalysts Poisoning o...
Introduction Catalysis is the change in rate of a chemical reaction due to the  participation of a substance called a cat...
Introduction cont.….Catalyst is a substance that increases the rate of thereaction at which a chemical system approaches e...
Introduction cont.…. Activation Energy can be defined as the minimum energy required to start a  chemical reaction. The a...
Activation EnergyCatalyst lowers the activation energy for both forward and reversereactions.
Activation EnergyThis means , the catalyst changes the reaction path by lowering its activationenergy and consequently the...
Principal Characteristics                The efficiency of the catalyst depends upon three components Good mechanical str...
Activity It is the extent to which the catalyst influence the rate of change of a  reaction as measured by the disappeara...
Selectivity The selectivity of a catalyst is the ability to promote a particular reaction  whilst minimizing the producti...
Life of a catalyst The life of a catalyst is the period during which it produces the required  product at the required de...
Hydrogenation Hydrogenation is the conversion of organic Sulphur compound into  inorganic Sulphur compound. For example...
Hydrotreator 107-D Catalyst                    CoMo Catalyst Type               ICI 41-6T Form             Cylinders S...
2.0 H2S Removal H2S is removed by ZnO bed according to  following reaction       ZnO + H2S = ZnS + H2O There are Two ves...
Desulphrisers 101/102-D                                           101-D   Catalyst Type             Mixture of Catalysts ...
Primary Reformer 101-B Catalyst Type         R-67-7H/R-67-R7H (Topsøe) Volume                15.5 m3 Loaded on         ...
Primary reformer catalyst Performance of reforming catalysts is periodically evaluated by considering  following paramete...
101-B catalyst
Primary Reformer 101-B (cont.)
Secondary Reforming Air is introduced in secondary reformer.   The combustion of a part of H2 & CH4 takes place at top p...
Secondary Reformer 103-D   Catalyst Type              ICI 54-4   NiO               10.5 %   Catalyst Volume            ...
   The purpose of HTS converter is to oxidize CO to CO2.HTSC  Reaction         CO + H2O = CO2 + H2           - 41.1 KJ ...
HTSC 110-D   Catalyst Type                  C-12-4 (SUD CHEMIE)   Catalyst Volume                53 m3   Loaded on     ...
LTSC 104-D   Catalyst Type               LK-821-2 & LSK-2   Catalyst Volume             60 m3   Loaded on              ...
LTSC by product CO2+H20                  CH3OH+H20 Methanol increase with• High temperature• High inlet CO levels• Low S...
29
Methanator The Methanation reactions are: CO2 + 4 H2 = CH4 + 2 H2O        -165 KJ/Kg mole CO + 3 H2 = CH4 + 1 H2O -206 ...
Methanator 106-D   Catalyst Type                ICI 11-3   Catalyst Volume              24 m3   Loaded on              ...
Ammonia Converters 105-D A/B   Catalyst Type            KM1R & KM1 (Haldor Topsøe)   Catalyst Volume          2 Beds 9.3...
Promotors  Ammonia synthesis catalyst is based on metallic iron promoted with   alkali (potash) and various metal oxides ...
Promoters Chromium promoted Iron catalyst is of HTSC.
Poisons for Ammonia CatalystsCatalysts         PoisonsLTSC              S power full poison( trapped by the               ...
Poisons for Ammonia Catalysts106-D                S, Catacarb solution blocks pores of Ni                     catalyst by ...
Heating rate of 107-D p-29 op. m
Thanks
Catalysis12
Catalysis12
Catalysis12
Catalysis12
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Catalysis12

  1. 1. In the name of Allah the mostGracious and MercifulKnowledge of Ammonia CatalystsBy: Nasir HussainPak Arab Fertilizers Multan13-12-12
  2. 2. Training outline Introduction to catalysis Principal characteristics of a catalyst Ammonia plant catalysts Poisoning of catalysts Replacement/Reduction of catalysts Catalysts catastrophes
  3. 3. Introduction Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations. Catalysts that speed the reaction are called positive catalysts. Substances that slow a catalysts effect in a chemical reaction are called inhibitors. Substances that increase the activity of catalysts are called promoters, and substances that deactivate catalysts are called catalytic poisons.
  4. 4. Introduction cont.….Catalyst is a substance that increases the rate of thereaction at which a chemical system approaches equilibrium ,without being substantially consumed in the process.Catalyst affects only the rate of the reaction, i.e. Kinetics. Itchanges neither the thermodynamics of the reaction nor theequilibrium composition.
  5. 5. Introduction cont.…. Activation Energy can be defined as the minimum energy required to start a chemical reaction. The activation energy of a reaction is usually denoted by Ea, and given in units of kilojoules per mole. The Activation Energy (Ea.) determines how fast a reaction occurs, the higher Activation barrier, the slower the reaction rate. The lower the Activation barrier, the faster the reaction
  6. 6. Activation EnergyCatalyst lowers the activation energy for both forward and reversereactions.
  7. 7. Activation EnergyThis means , the catalyst changes the reaction path by lowering its activationenergy and consequently the catalyst increases the rate of reaction
  8. 8. Principal Characteristics The efficiency of the catalyst depends upon three components Good mechanical strength Activity Selectivity Life low pressure drop · high tolerance for contaminants
  9. 9. Activity It is the extent to which the catalyst influence the rate of change of a reaction as measured by the disappearance of the reactants i.e. conversion It is often expressed as a rate per unit volume. The activity per unit volume is of practical importance because process economics can depend critically upon the cost of packed reactor space. The bulk density of a catalyst must always be as small as possible , consistent with other requirements.
  10. 10. Selectivity The selectivity of a catalyst is the ability to promote a particular reaction whilst minimizing the production of unwanted compounds. Very often a catalyst can be made more specific for a particular reaction whilst the activity can be diminished by poisoning with some other metal.
  11. 11. Life of a catalyst The life of a catalyst is the period during which it produces the required product at the required degree of activity and selectivity. The life of a catalyst is usually ended because of loss of mechanical strength or because of unacceptable changes in activity and selectivity.
  12. 12. Hydrogenation Hydrogenation is the conversion of organic Sulphur compound into inorganic Sulphur compound. For example RSH + H2 = RH + H2S Exothermic R2S + 2H2 = 2RH + H2S
  13. 13. Hydrotreator 107-D Catalyst CoMo Catalyst Type ICI 41-6T Form Cylinders Size Dia 3.2 mm Length 10mm CoO 3.3 % MoO 14 % Alumina Balance Bulk Density 700 kg/m3 or 0.9 kg/lit Volume 2 Beds each of 6.35 m3 Loaded Jan 2008
  14. 14. 2.0 H2S Removal H2S is removed by ZnO bed according to following reaction ZnO + H2S = ZnS + H2O There are Two vessels for H2S removal 101-D & 102-D
  15. 15. Desulphrisers 101/102-D 101-D Catalyst Type Mixture of Catalysts (ZnO) Volume 22.5 m3 (NCT 305 +10.5 Mixture) Loaded on 2010 Bulk density 1.1 kg/lit Shape Pellets Service Life 2 years 102-D Catalyst Type Mixture of Catalysts (ZnO) Volume 22.5 m3 (NCT 305 +10.5 Mixture) Loaded on 2010/2008 Bulk density 1.1 kg/lit Shape Pellets
  16. 16. Primary Reformer 101-B Catalyst Type R-67-7H/R-67-R7H (Topsøe) Volume 15.5 m3 Loaded on 2004 Shape Pellets Catalyst Size 11*16 & 13*20 mm Carrier of catalyst Magnesium Aluminate NiO 16 ~ 18 wt. % Carrier Balance
  17. 17. Primary reformer catalyst Performance of reforming catalysts is periodically evaluated by considering following parameters and operating conditions are duly adjusted : Approach to equilibrium Methane slip Pressure drop Tube skin temperature 19
  18. 18. 101-B catalyst
  19. 19. Primary Reformer 101-B (cont.)
  20. 20. Secondary Reforming Air is introduced in secondary reformer. The combustion of a part of H2 & CH4 takes place at top portion. Heat of combustion is utilized for further reforming. CH4 + H2O = CO +2 H2 CH4 + O2 = CO + 3H2 2H2 + O2 = 2 H2O - 242 kJ / mole The gases leaves the secondary reformer at 996 OC.
  21. 21. Secondary Reformer 103-D Catalyst Type ICI 54-4 NiO 10.5 % Catalyst Volume 33.5 m3 Loaded on 1993
  22. 22.  The purpose of HTS converter is to oxidize CO to CO2.HTSC  Reaction  CO + H2O = CO2 + H2 - 41.1 KJ / mole  The CO slippage from HTS should be less than 3.0 %.  The principle operating variables are steam to gas ratio & temperature.  Increasing steam results in an increase to CO conversion.  Under  severe condition magnetite can be reduced to FeO or even metallic iron. Such change of phases and over  reduction causes crystallite changes in the catalyst that lead to physical degradation, weakening and  fracture of pellets, and increase in pressure drop. Metallic iron promotes side reaction such as Fisher  Tropsh reaction. Such reactions can affect adversely the performance of down stream catalysts.
  23. 23. HTSC 110-D Catalyst Type C-12-4 (SUD CHEMIE) Catalyst Volume 53 m3 Loaded on 2006 Service Life 4 years Size Dia 9 * 5 ~ 7 mm Shape Tablet Fe2O3 88 % Cr2O3 09 % CuO 2.6 % Catalyst is supplied in the form of Fe2O3 Hematite Catalyst is reduced to active Fe3O4 Magnetite
  24. 24. LTSC 104-D Catalyst Type LK-821-2 & LSK-2 Catalyst Volume 60 m3 Loaded on 2012 Service Life 4 years Size 4.5*3.4 mm & 4.5*4.5 mm Shape Tablets CuO ZnO Al2O3
  25. 25. LTSC by product CO2+H20 CH3OH+H20 Methanol increase with• High temperature• High inlet CO levels• Low S:C ratio 27
  26. 26. 29
  27. 27. Methanator The Methanation reactions are: CO2 + 4 H2 = CH4 + 2 H2O -165 KJ/Kg mole CO + 3 H2 = CH4 + 1 H2O -206 KJ /kg mole 74 oC rise in temp for 1 % CO 60 oC Rise in temp for 1 % CO2
  28. 28. Methanator 106-D Catalyst Type ICI 11-3 Catalyst Volume 24 m3 Loaded on 1993 Service Life 18 years Size 5.4*3.6 mm Shape Cylindrical PelletsBulk Density 1.23 kg/lit NiO 35 % wt. MgO 4 % wt. Support Balance
  29. 29. Ammonia Converters 105-D A/B Catalyst Type KM1R & KM1 (Haldor Topsøe) Catalyst Volume 2 Beds 9.3 m3 & 23.4 m3 Loaded on 2011 Size 1.3*3.0 mm Shape Irregular Fe FeO Fe oxides
  30. 30. Promotors  Ammonia synthesis catalyst is based on metallic iron promoted with alkali (potash) and various metal oxides such as those of aluminum, calcium or magnesium. The main component of the catalyst is magnetite (Fe3O4). Various promoters in catalyst plays main role in catalyst activity.  Such promoters are classified as structural or electronic depending on their accepted mode of action. Production and preservation of porous structure during reduction of ammonia synthesis catalyst is main role of  structural promoters such as alumina, magnesia and chromium. Alkali metal such as calcium, potassium ,rubidium etc. are essential components of catalyst to attain high activity, are called electronic promoter. 34
  31. 31. Promoters Chromium promoted Iron catalyst is of HTSC.
  32. 32. Poisons for Ammonia CatalystsCatalysts PoisonsLTSC S power full poison( trapped by the catalyst as CU2S and ZNS) Cl, reacts with Cu and Zn to from chlorides. CuCl provides the mechanism for loss of activity by sintering. Water, excess water can damage the catalysts du to thermal shock101B S, can affect the catalyst by chemisorption on its surface. C105-D Main poisons to synthesis catalyst are oxygenated compounds such as water, CO, CO2.(reversible) chloride and sulphur affect the catalyst irreversibly.
  33. 33. Poisons for Ammonia Catalysts106-D S, Catacarb solution blocks pores of Ni catalyst by evaporating K2CO3 Arsenic107-D Carbon, this cab be avoided by operating at low temperatures. 37
  34. 34. Heating rate of 107-D p-29 op. m
  35. 35. Thanks

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