B y : yadollah tavan S upervisorS : Dr. A. Shariati Dr. M.R. Khosravi Nikou October 2011

2. Petroleum University of Technology Gas Engineering Department Laboratory preparation of modified ZSM- 5 nano catalyst with aluminophosphate (AlPO) for methanol to Dimethyl Ether reaction By: yadollah tavan SupervisorS: • Dr. A. Shariati • Dr. M.R. Khosravi Nikou October 2011

3. Contents

4. Importance of DME Dimethyl ether (DME) is found to be an alternative diesel fuel because of: • low NO emission • near-zero smoke amounts • less engine noise and • replace chlorofluorocarbons (CFCs) • used as an aerosol propellant • At present DME is commercially produced by the dehydration of methanol

5. MTD process and its Catalysts • The general reaction path of the methanol conversion: • First methanol dehydration to dimethylether (DME). • Then converted to light olefins.

6. MTD process and its Catalysts The reaction takes place on: • different solid–acid catalysts such as • γ-alumina • H-ZSM-5 • temperature range of 250–400 °С • pressures up to 18 bar

7. MTP process and its Catalysts HZSM-5: • Interesting feature: • Drawback • Hydrocarbons formation at 270 C

8. Catalyst Modification Generally adopted methods for acidity modification of ZSM-5 are: • Exchange of protons with Na ions • Modification with P containing compounds and Promoters • Using Binder materials • Other modifications

9. Synthesize • Chemicals • Aluminium nitrate nano-hydrate [ANN; Al (NO3)3.9H2 O, extrapure, Merck] • Ortho-phosphoric acid [H3PO4, 85wt%, analysisgrade, Merck] • HZSM-5(SiO2 /Al2O3=67.6, ZEOCHEM, Switzerland)

10. Synthesize Catalyst Preparation Steps

11. Characterization

12. Experimental • Vertical fixed bed micro-reactor • 316 stainless steel tubing • I.D = 0.75 inch • length=19 cm • Nearby atmospheric pressure. • Methanol (Grade AA, 99.9% purity, Fanavaran petrochemical) was supplied by the HPLC pump, vaporized through the heater and fed to the reactor. • The reaction temperature from 155 to 460°C. • All the experiments were performed with 3gr of catalysts. • Weight Hourly Space Velocity (WHSV) of 15 to 90 grams of methanol per grams of catalyst per hour (g g-1h-1) by changing methanol rate • Product analysis was performed using gas chromatography (Young Lin, ACME 6100).

13. Results

14. Results Scherrer Equation: • HZSM-5: • B=0.0218 (1.25°*π/180) • maximum peak was occurred in 23.235° • the crystal size derived by Scherrer equation is 10.79 nm • Synthesized Catalysts: • crystal sizes were 13-15nm for synthesized catalysts and are well nano sized.

15. Results • The HZSM-5 exhibits higher surface area. • By addition of phosphorus to the binder, the surface area decreased • Attributed to the formation of AlPO

16. Results • The nature of N2 adsorption-desorption isotherms • Type IV curve using IUPAC classification for hysteresis loops • The predominance of mesopores for HZSM-5 • Mesopores: pore diameter=2-50nm due to capillary condensation taking place in mesopores. • Hysteresis loops may exhibit a wide variety of shapes. • In present work pore shape might be ink-bottle form.

17. Results • Pore diameter was varied from 18 to 963nm for HZSM-5. • the prominent distribution was observed at range of 25-47nm mainly includes mesopore size. • Well-developed mesopore structure of the catalyst would help mass and heat transfer easy in reaction.

18. Results

19. Results • The ammonia TPD plots of the calcined samples • low temperature peak around 190°C • high temperature peak around 390°C. • The former from the weakly acidic that cover the external surface of the catalysts. • The latter peak arises from the Bronsted acid sites • The intensityof high temperature peak decreases with the increase of phosphorous • Effective interaction of phosphorous with the binder and zeolite framework.

20. Results • The effect of Temperature on HZSM-5:

21. Results • The effect of WHSV: • The influence of WHSV within wide range of 15-90 gr/ (hr.gr-cat) was investigated

22. Results . Design of Experiments (DOE): • L9 orthogonal array • Optimum Temperature was 252 C

23. Results

24. Conclusion In the present research: • Synthesized catalysts showed better conversion than HZSM-5. • It was found that P/Al molar ratio of 0.8 has better conversion than other. • For optimum catalyst, reactor temperature was raised to 315°C and no comparable by-product was detected in GC spectra.

25. Acknowledgments: • I would like to thank Dr. Ahmad Shariati and Dr. Mohammad Reza Khosravi Nikou, for their supervision throughout my research project. • I would like to thank ZEOCHEM,AG company for supplying zeolites. • I would like to thank Abadan Refinery Company and Iranian nanotechnology initiative council for their financial support of my thesis. • Finally, I would like to thank lab mates.

26. Thanks for Your Attention