Pore engeneering of ZSM-5 by silylation for the side chain alkylation of tolune
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Pore engeneering of ZSM-5 by silylation for the side chain alkylation of tolune

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Silylation is one of the method by w

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  • 1. A novel stable silylated ZSM-5 zeolite with tunableshape-selectivity for the methylation of toluene to produce p-xylene VIJAYKUMAR MARAKATTI PoornaPrajna Institute of scientific research Bangalore.
  • 2. Outline Of Talk# Introduction to zeolites.# Synthesis of zeolites .# Surface modification.# Catalyst Characterization.# Toluene methylation study.# Conclusions.
  • 3. What are ZEOLITES ?- microporous crystalline aluminosilicates- Strong Brönsted acidity. ZSM-5 zeolite- Acidity arises from framework Al.- high thermal stability.- Heterogeneous shape selective catalyst.
  • 4. Eco-Friendly Catalyst for Alkylation of Toluene CH3 CH3 CH3 ZSM-5 CH3 + CH3OH CH3 CH3 Toluene Methanol p-xylene (27%) o-xylene(23%) m-xylene (50%) B.P 138 °C 139°C 144°C Application* PTA & DMT are raw material for the synthesis of polyester, plasticetc in industry. CH 3 COOH COOCH3 oxida tion e s te rifica tion (O) (CH3 OH) CH 3 COOH COOCH3 PTA DMT
  • 5. CH3 CH3 ZSM-5CH 3 OH
  • 6. O O O O O O O O O O Si O Si O Si O Si - O SiO- Si O Si O Si O Si O O O O O O O O O OO- Si O Si O Si O Si O O- Si O Si O Si O Si O Si O O O O O O O O O CH3 CH3 CH3 PORE CH3 CH3 CH3 CH3 CH3
  • 7. Synthesis of ZeoliteZeolites are synthesized by hydrothermal method. Silica source: Tetra ethyl orthosilicate(TEOS). Template : Tetrapropyl ammonium bromide. (TPABr) Aluminum source : Aluminum sulfate. Solvent : Water Gel autoclave 170 °C for 3 days. Calcined at 550 °C to remove template . By above method zeolites with different SiO2/Al2O3 ratio 84, 187, 272, and 408 are synthesized
  • 8. Lab Procedure for making Extrudates & silylation. Reflux for 6 h Filter & 1M NH4NO3 Dry Alumina/ silica binder Mixed wel Silylation with TEOS Activate 540 CReflux for 6 h Cool dry Activate Distillation REACTION 540 C
  • 9. Characterization of ZEOLITES 1.XRD SAR 84 Intensity (a.u.) SAR 187 SAR 272 SAR 408 5 10 15 20 25 30 35 40 2θ (°)BRUKER D2 Phaser, PPISR.
  • 10. 2. N2 Sorption and AAS Study HZSM5(1) HZSM5(2) HZSM5(3) HZSM5(4)SiO2/Al2O 84 187 272 408 3 Mole Ratio Surface 380 352 356 380 Area m2/gmAAS aanalyst 200,Perkin Elmer,PPISR.N2Sorption Omnisorb-100CX(Coulter analyzer)NCL,PUNE.
  • 11. 3.SEM IMAGES SAR -84 SAR -187Leica Stereoscan-440,(EDAX),NCL ,PUNE.
  • 12. Continuous down flow tubular quartz reactor PreheaterSyringe Pump Quartz reactor(Tol+MeOH) Catalytic bed Automated Micro reactor TEMP CondenserH2 Gas Products
  • 13. Results of reaction 1.Effect of silylation Zeolite + alumina Wt% TEOS Toluene p-Xylene extudates conversion (wt%) * selectvity (wt%) HZSM-5 SAR- 0 9.4 40 187 HZSM-5 SAR- 32 9.3 80.5 187 HZSM-5 SAR- 64 8.7 90.4 187 HZSM-5 SAR- 96 5.1 88.2 187Reaction Conditions: Catalyst wt: 2g, Tol: MeOH mole ratio: 8:1, H2: HC = 2,WHSV = 4 h-1,time = 3h, Pressure = 1 atm
  • 14. 2.Selection of Catalyst recipe Catalyst with Toluene p-xylene selectivity Different Conversion (Wt%) SiO2/Al 2O3 ratio (Wt%) 84 9.5 85 187 8.7 90.4 272 8.5 85.0 408 7.5 87.0Reaction Conditions: Catalyst wt: 2g, Tol: MeOH mole ratio: 8:1, H2: HC = 2, WHSV = 4 h-1,time = 3h, Pressure = 1 atm
  • 15. Effect of SAR SAR 272 showed better conversion and stability but lower PX selectivity Methanol utilization improved by 6% with increase in SARReaction Conditions: Catalyst wt: 10g, Temp = 480 °C, WHSV = 10 h-1Tol: MeOH = 4:1, H2: HC = 0, H2O/HC = 1, time = 3h, Pressure = 1 atm
  • 16. 3.Efect of BinderBinder Zeolite Toluene P-xylene conversion selectivityAlumina SAR-187 8.7 90.4Silica SAR-187 9.5 93 4.Effect of Tol: MeOH mole ratioHZSM-187 With Tol:MeOH Toluene P-xylenesilica binder conversion selectivitySilica 8 9.5 93 6 13.4 92 4 16.6 92.8 5.Effect of WHSVWHSV Toluene P-xylene Reaction Conditions: Catalyst wt: conversion selectivity 2g, Tol: MeOH mole ratio: 4:1, H2:3 18 91.2 HC = 2,WHSV = 4 h-1, time = 3h,4 16.6 92.8 Pressure = 1 atm6 16.1 94.1
  • 17. 6.Effect of TemperatureCatalyst Temperature Toluene P-xylene Conversion selectivitySAR-187 410 15 92Silicabinder With 435 16.6 92.832 Wt % 460 18.7 91.1TEOS7. Life and stabality of catalyst 100 90 p-xylene selectivity 80 70 60 50 40 30 toluene conversion 20 10 0 5 10 15 20 time in hours
  • 18. 8. Effect of hydrogen pressureCatalyst Silylated ZSM-5 extrudates SAR 187Test Conditions 435C, 50psig 435C, H2O &H2 2psig H2O &H2 Pressure effect!Liquid HC 6 hr 6hr ConversionsBenzene 0.16 0.02 improved by 2%Toluene 79.63 79.44Ethyl Benzenep-xylene 0.09 0.03 Selectivities 9.21 10.45m-xylene 1.69 0.76 dropped by 12%o-xylene 0.56 0.16Ethyl toluenes 2.71 0.65 Higher EthylTrimethyl benzenes 0.27 0.03C10 armatics and others 0.31 0.06 toluene!Conversion & Selectivity (mol%)Toluene conversion 13.7 11.7Mixed xylene selectivity 78.5 94.0p-xylene selectivity 80.4 92.0MeOH Utilization 46% 44%
  • 19. 9. Effect of water Water effect! Higher catalyst stability Mix Xylenes improved Increase in PX selectivity Ethyl toluenes decreased Improved MeOH utilization by 10%Reaction Conditions: SAR 187, Catalyst wt: 10g, Temp = 480 °C, WHSV = 10 h-1Tol: MeOH = 4:1, H2: HC = 0, H2O/HC = 1, time = 3h, Pressure = 1 atm
  • 20. Conclusion Silica to alumina ratio of zeolite was optimized to obtain good conversion and high PX selectivity. SAR 187 found to be better with H 2 and water. But without H2 , SAR 187 showed slow deactivation where as SAR 272 showed better stability. Silica binder was found to be better than alumina. Under H2 pressure, conversion improved but PX and MX selectivities decreased by 12%. It is better to operate at low or no H 2 pressure. Presently the reactions with water and no H 2 are underway. SAR 272 showed good stability in the absence of H2 .Advantages of water in the stream The toluene conversion and mix Xylenes improved. Better catalyst stability and higher methanol utilization. Study of catalyst life with time indicated good catalyst stability upto 22h with once increase in temperature by 5°C.
  • 21. Acknowledgement Poornaprajna Institute Of Scientific Research for giving an healthy environment and all facilities to carry out the research activity.Admar mutt education foundation for providing fellowship. Dr. A.B Halgeri Director for his encouragement and support. all the scientists , lab mates and administrative staff of PPISR.