poorna prajna institute of scientific research

1. Silylation and M n O modifications of solid acids for Toluene Methylation to p-Xylene Presentation By :- Vijaykumar.S.M December 31-12- 2010 Poornaprajna Institute of scientific research , Bangalore.

2. Silylation Process Silylation is a process in which zeolite (eg:HZSM-5) is treated with silicon compound selected from the group of alkoxysilane and polysiloxanes . TEOS TMOS POLYSILOXANE

3. In Silylation the Silicon compound react with the external Surface Silanol group of zeolite and Reducing the Pore size so that only para xylene can pass through the pore. H OEt pore Zeolite Surface Silyalation Process O H O H O H O H O O H O H O H O H O H Si(OEt) 4 Si OEt OEt EtO O O O O O Si O Si O O Si O O HO-Si O O Si O O O O O O O Si O Si O O Si O O Si O O Si-OH O O Si OH Si OH O Si OH O Si OH O Si-OH OH O Si OH Si OH O Si OH O HO-Si OH O Si OH O

4. CH 3 OH CH 3 CH 3 CH 3

5. Effect of silylation Effect of Silylation CH 3 OH CH 3 CH 3 CH 3

7. Lab Procedure for making Extrudates 1M NH 4 NO 3 Reflux for 6 h Filter & Dry alumina binder Mixed well Activation at 813K 18% aq. AcOH

8. Lab Procedure for Silylation Activated Extrudates TEOS, MeOH, Toluene Reflux 6 Hour Distill out solvents 1 Hour Cool add Water After 30 min Dry At 393 K calcination 1 silylated extrudates

9. Patent No Catalyst Reaction Condition Toluene Conversion P-Xylene selectivity 4613717 Research ASSo light oil,Tokayo,japan(1985) AZ-1,AZ-2,Az-3 (1,8 diamino 4 aminomethyloctane)HZSM-5(Al,Cr,B) S.A -Silicic acid ester (vapour) Calcine in presence of oxygen. Tol/MeoH=2,WHSV=4/Hr,T=450, P=1atm Fixed Bed reactor 20% (mole) 95% (Wt%) 7387978B2 Chevron phillip chemical companyLP, TX(US) HZSM-5,Silica Binder(1/16 extrudates.calcined S.A- 10Wt% Poly(Methyl phenyl)Siloxane.(cyclohex) Steaming ,0.1HCl Treatement,wash with water ,calcined. Tol/MeOH=4,WHSV=20ml/Hour,H2 =260ml/min, T= 600 c, P=5-6 atm, Time 7.5 Hour 11.5% (total xylene yield) 100% HZSM-5 ,S.A-10% TEOS ,Silica Binder, Extrudates ,S.A-Poly(Methyl phenyl)Siloxane.(cyclohexane),calcine . Tol/MeOH=4,WHSV=20ml/Hour,H2 =260ml/min, T= 600 ,P=5-6 atm, Time 7 Hour 21.5 (total xylene yield) 84.6%

10. Patent No Catalyst Reaction Condition Toluene Conversion P-Xylene selectivity 4127616 Mobil Oil company 1978 H-Zsm-5,S.A-Phenyl Methyl silicone,(n-Hexane)Pelletes (14-30mesh),calcine. 7.5 Wt% Silica . H2/HC=2 ,WHSV=10/Hr T=400-550,P=1atm T=400 T=450 T=500 T=550 36 44 60 84 95 94 91 Wt% 88 4283306 E I Du Pont de Nemours company,,wiliington(1981) HZSM-5, 5%TEOS(Pyridine ) Tol/MeOH=3,WHSV=3.9 /Hr,H2/HC=0.8 P=1atm. T=450 T=500 T=550 T=600 Mole% 13.4 16.6 18.8 20.1 Wt% 94 93 93 92 7321072B2 Johnson Matthey,PLC,London 2010 (Low contact time) 10 wt% Mg/ HZSM-5 (SAR = 80) HZSM-5 + 10% aq MgNO3 impregnated, dried, calcined 500 C . T = 440 , Tol/meOH = 8, Flow rate= 999 ml h -1 H 2 = 66.6 ml min -1 , water : feed = 1, WHSV of toluene = 33.35 h -1 , time = 7h 12.6% Wt% 98.8% Wt%

11. Patent No Catalyst Reaction Condition Toluene Conv p-Xylene selecty 10Wt% B/HZSm-5 WHSV=11.12/Hr,Contact time=0.33sec, Tol/MeOH=1.3,T=450c WHSV=33.35 T/M=8 T/M=4 T/M=1.3 C.T=0.1s C.T=0.115 C T=0.11s 32% mol% 12.5% 24.1% 22.6% 94.6 mol% 99% 98.3% 94.8% 6864200 B2 IPCl BARODA 2005 Silanated Ga-AlZSM-5 (35 wt% on alumina binder) Preparation: GaAlZSM-5 H form + alumica binder was silanated twice with TEOS by repeated soak and dry method, calcined at 535 °C. Fixed bed continuous flow reactor. Temp = 450 °C, Toluene : methanol = 2:1 WHSV toluene = 3.5 h -1 25.8% 85.1% wt% 7494951B2 China petroleum corporation Beijing (2006) ZSM-5 , S.A *-Dimethylsilicone oil *Benzyl silicone oil &Dimethyl silicon oil *Diamine silicone oil &Dimethyl silicone oil (Solvent n-Hexane) WHSV=4/Hr,T=440c,P=5atm ,H2/HC=2 Wt% 30.8% 30.7% 30.1% Wt% 90.7% 90.4% 90.5%

12. Patent No Catalyst Reaction Condition Toluene Conversion P-Xylene selectivity Tech overview report on Toluene methylation IPCL, Baroda 2002 Silanated HZSM-5 (SAR 240) 65% HZSM-5 with alumina binder, extrudate, added TEOS in toluene+ methanol mixture, solvents distilled out, water added, dried and calcined 540°C Fixed bed continuous flow reactor. Catalyst wt = 1g, Temp = 425 °C, Toluene : methanol = 4:1 WHSV toluene = 5.3 h -1 H 2 : feed = 2 15.7 wt% 87.1% wt% Catalyst pilot plant Catalyst wt = 100g, Temp = 430 °C, Toluene : methanol = 8:1 WHSV toluene = 3.4 h -1 H 2 : feed = 2, After 3 cycles 29.7% wt% 85.9% wt% US7074739 B2 Dekka et al Exxon Mobil Chemical patents 2006 17 wt% La x O y / ZrO 2 physical mixture with steamed HZSM-5 (SAR = 450). Fixed bed continuous flow reactor. Temp = 585 C, Toluene : methanol = 2:1 WHSV = 8 h -1 H 2 : feed = 2, water : feed = 2, pressure = 2.8atm 32 % (after 25 h) 28 (after140hr) 89 wt% 83wt%

13. Reaction condition's :T=523K,WHSV=2.5 /Hr, Tol:MeOH=1:1.5 time on stream=6hr, P=1atm, Reactor :continuous Down flow reactor. Catalyst :Dodeca-Molybdo Phosphoric acid(PMA)loaded on clay with Surface area :176 m 2 /gram Toluene Alkylation with Methanol to P-Xylene over Heteropoly Acids Supported by Clay Journal of natural gas chemistry 16(2007)42-45

14. Effect of Pt on stability of nano-scale ZSM-5catalyst for toluene alkylation with methanol into p-xylene Reactor :Continous Flow Fixed Bed reactor Reaction condition's : 460 c ,WHSV=2 /Hr, Tol/MeOH =2 , H2/HC=8,water/HC=8 .P=1 atm. Catalyst a : 3%SiO2+5% P2O5+3% MgO+3%SiO2+ 0.3 % Pt/nanoscale –ZSM-5 Catalyst b: 3%SiO2+5% P2O5+3% MgO+3%SiO2+ 1.0 % Pt/nanoscale –ZSM-5 Catalysis Today(2010)

15. Toluene Alkylation to selective Formation Of P-Xylene Over Co-Crystalline ZSM-12/ZSM-5 Catalyst : ZSM-12(A),ZSM-5/ZSM-12(B),ZSM-5(C), Reaction Condition :T=573K ,Tol/MeOH=1:2,LHSV=2.5/Hr, P=1atm.catalyst Wt=4gm. Reactor : Fixed Bed continuous Flow reactor Journal of Natural Gas chemistry 16(2007)37-41

16. The Roles and Structure Of Zeolite for catalyzing Toluene Alkylation With Methanol to xylene Microporous and Mesoporous marterial88(2006)16-21 Zeolites with higher number of mid strength acid sites show high catalytic activity Eg: ZSM-5(SAR-136),SAPO-11, MCM-22 . The Acidic site required For Catalyzing toluene alkylation with methanol are lower in strength than those for Catalytic toluene disproporation

17. Summary * By using different Silylating agent or Mixture of silylating agents can give good yield on toluene methylation. Tetra Ethyl orthosilicate ,Poly siloxane ,Diamine silicone oil Benzyl silicone oil ,dimethyl silicone oil,Tetratertiarybutoxysilane etc. * By Lowering the contact time to 0.1 Second a good selectivity has been observed *Use of suitable binder like alumina and Silica Will selectively enhance the p -Xylene selectivity. * With Impregnation of different metal oxides like LaOx, MgO, ZrO2 on zeolites can give good selectivity.