Catalysts Catalytic Processes in Petrochemical Industry

1. Catalysts & Catalytic Processes in Petrochemical Industry

2. Contents Petrochemicals from: Ethylene Propylene Butadiene Pyrolysis gasoline Linear alkyl benzene Processes for production of Xylenes Processes for production of other aromatics Hydrodesulphurization

3. Thermal cracking

4. Ethylene stream�

5. Propylene stream

6. Butene-butadiene stream

7. Pyrolysis gasoline - Hydrogenation

8. Pyrolysis gasoline � Hydrogenation�

10. Dehydrogenation: the reaction An equilibrium controlled endothermic reaction Side reactions: secondary dehydrogenation, aromatization, cracking and coking Requires extremely severe reaction conditions: Higher temperature (> 450C) Lower operating pressure High space velocity Lower paraffin conversion (12-14%) Controlled dosing of moisture

11. Dehydrogenation of Paraffins Good dispersion of Platinum Stability against sintering Low level residual chloride Presence of moisture in the feed Diffusion controlled reaction : highly porous support Proper understanding of metal - metal & metal - support interactions

12. Catalyst design features Maximum platinum metal dispersion ?desired activity/conversion Selection and optimization of promoter levels ? Maximizing selectivity Preparation methods ? promoter-platinum interactions ? maximizing selectivity Attenuation of acidity ? additional promoters ? minimize acid catalyzed side reactions Optimum surface area and stability of pore structure ? catalyst life Modulation of porosity of alumina support ? facile diffusion ? better selectivity ? retard deactivation by coking

13. Linear Alkyl Benzene (LAB)

14. Aromatics in Petrochemicals Aromatics compounds can be obtained by catalytic reforming of naphtha or by alkylation route starting from Benzene Benzene can be alkylated with methanol to get toluene Benzene alkylation with ethylene/ethanol gives ethylbenzene Toluene alkylation with methanol gives isomeric xylenes Benzene alkylation with propylene / isopropanol gives cumene etc.. Aromatics compounds can be obtained by catalytic reforming of naphtha or by alkylation route starting from Benzene Benzene can be alkylated with methanol to get toluene Benzene alkylation with ethylene/ethanol gives ethylbenzene Toluene alkylation with methanol gives isomeric xylenes Benzene alkylation with propylene / isopropanol gives cumene etc..

15. Catalytic routes for aromatics production There are various catalytic processing routes for aromatics production. Depending upon the product slate requirement and the feedstock characteristics appropriate processes can be integrated in an aromatics complexThere are various catalytic processing routes for aromatics production. Depending upon the product slate requirement and the feedstock characteristics appropriate processes can be integrated in an aromatics complex

16. Catalytic reforming of Naphtha Feed-stock � Product specific Different fractions of Naphtha based on product requirement 60-80�C Naphtha cut- Benzene-Toulene production 110-140�C Naphtha cut- Xylenes production 70-140/Wide Naphtha cut � Gasoline production Conversion of Naphthenes & Paraffins to Aromatics Naphtha Parafiins ( n- & Iso), Naphthenes,Aromatics- PIANO Analyser Naphtha fractions- 100-150 individual components Model reactions- Cyclohexane, MCH, n-Octane Catalysts Bi-functional- Metal, & Acidic functions Pt (0.6%)- Alumina- Monometallic Pt (0.3%-Re(0.3%),Pt-Sn-Alumina- Bimetallic- (IPCL/RIL-IIP) Pt-Re-M-Alumina-Multimetallic Bi / Multi metallic catalysts display better activity & stability Oxychlorination, pre-sulfiding, chloride/moisture dosing Cycle life -18-24 months, 5-6 cycles- 8-10 years- SR process

17. Catalytic Naphtha Reforming

18. Reformer Reactor systems-SR & CCR modes This slide gives a comparison of the reactor systems for Semi Regenerative and CCR mode of reforming processes. Modern day trend is to opt for CCR technology.This slide gives a comparison of the reactor systems for Semi Regenerative and CCR mode of reforming processes. Modern day trend is to opt for CCR technology.

19. Xylene Isomerisation

20. Reformer reactor effluent after splitting of light ends, orthoxylene with C9 Aromatics by distillation, is sent to paraxylene recovery by sorptive separation. The raffinate containing meta xylene(~60%) and ethylbenzene(~30%) is then subjected to isomerization process to obtain para and orthoxylene. Thus the xylene yield is maximized with respect to naphtha input. The ethylbenzene is hydrodealkylated to benzene and ethylene preventing build up of it in the reactor loop.Reformer reactor effluent after splitting of light ends, orthoxylene with C9 Aromatics by distillation, is sent to paraxylene recovery by sorptive separation. The raffinate containing meta xylene(~60%) and ethylbenzene(~30%) is then subjected to isomerization process to obtain para and orthoxylene. Thus the xylene yield is maximized with respect to naphtha input. The ethylbenzene is hydrodealkylated to benzene and ethylene preventing build up of it in the reactor loop.

21. Xylene Isomerization Process A comparison of the feed and product stream of the isomer reactor clearly gives an idea of what exactly happens in the process. While meta xylene isomerizes to equilibrium mixture of xylenes, ethylbenzene undergoes cracking to form benzene. The C9 aromatics are formed by side reactions involving xylenes and EB.A comparison of the feed and product stream of the isomer reactor clearly gives an idea of what exactly happens in the process. While meta xylene isomerizes to equilibrium mixture of xylenes, ethylbenzene undergoes cracking to form benzene. The C9 aromatics are formed by side reactions involving xylenes and EB.

22. Xylene isomerization technology is based on two types of catalysts. The Platinum based catalyst system and the Zeolite based catalyst system. IPCL, in collaboration with NCL, Pune, has developed and commercialized a zeolite based catalyst for xylene isomerization process.Xylene isomerization technology is based on two types of catalysts. The Platinum based catalyst system and the Zeolite based catalyst system. IPCL, in collaboration with NCL, Pune, has developed and commercialized a zeolite based catalyst for xylene isomerization process.

23. Aromatics complex The schematic diagram above gives a generalized view of an aromatics complex producing Benzene, Toluene, Ethylbenzene, Xylenes and C9 Aromatics. Various process steps such as Hydrodesulphurization of naphtha, reforming, distillative separation of BT stream and Ortho xylene and C9 Aromatics, sorptive separation of paraxylene and isomerization of meta xylene are presented.The schematic diagram above gives a generalized view of an aromatics complex producing Benzene, Toluene, Ethylbenzene, Xylenes and C9 Aromatics. Various process steps such as Hydrodesulphurization of naphtha, reforming, distillative separation of BT stream and Ortho xylene and C9 Aromatics, sorptive separation of paraxylene and isomerization of meta xylene are presented.

24. Enormous amount of toluene is formed during reforming operation. This can be economically converted to xylenes by Transalkylation and Disproportionation routes. Toluene disproportionation can yield either an equilibrium mixture of Xylenes (as in TDP) or selectively upto >97% Para Xylene (as in STDP). In the latter case a modified catalyst is used to effect shape selective features in the zeolite catalyst used.Enormous amount of toluene is formed during reforming operation. This can be economically converted to xylenes by Transalkylation and Disproportionation routes. Toluene disproportionation can yield either an equilibrium mixture of Xylenes (as in TDP) or selectively upto >97% Para Xylene (as in STDP). In the latter case a modified catalyst is used to effect shape selective features in the zeolite catalyst used.

25. In the TADP process an appropriate mixture of C7 (toluene) and C9 (trimethylbenzenes) aromatics are reacted to obtain xylenes. The Tatoray process of UOP is flexible enough to swing from TDP to TADP as shown by the feed composition range in the slide above.In the TADP process an appropriate mixture of C7 (toluene) and C9 (trimethylbenzenes) aromatics are reacted to obtain xylenes. The Tatoray process of UOP is flexible enough to swing from TDP to TADP as shown by the feed composition range in the slide above.

26. This slide gives a comparative picture of the TDP, STDP and TADP processesThis slide gives a comparative picture of the TDP, STDP and TADP processes

27. Paraxylene is used to manufacture Purified Terephthallic Acid(PTA) or Dimethyl Terephthallate (DMT) by catalytic oxidation. In the latter case esterification with methanol is a subsequent step. Both PTA and DMT are fibre intermediates. Ortho xylene is used as a chemical to manufacture Phthallic acid/ phthallic anhydride. There are a few solvent grade streams obtained in the aromatics process.Paraxylene is used to manufacture Purified Terephthallic Acid(PTA) or Dimethyl Terephthallate (DMT) by catalytic oxidation. In the latter case esterification with methanol is a subsequent step. Both PTA and DMT are fibre intermediates. Ortho xylene is used as a chemical to manufacture Phthallic acid/ phthallic anhydride. There are a few solvent grade streams obtained in the aromatics process.

28. Another route of aromatics production is by the catalytic aromatization of light paraffins usually in the range C3 to C5. This process has attracted attention in the 80s.Another route of aromatics production is by the catalytic aromatization of light paraffins usually in the range C3 to C5. This process has attracted attention in the 80s.

29. A few process licensors in the area of Paraffin aromatization are enlisted above.A few process licensors in the area of Paraffin aromatization are enlisted above.

30. The UOP-BP�s CYCLAR� Process uses a Ga2O3/ZSM-5 catalyst system of BP and CCR technology of the UOP and is commercially practiced by M/s SABIC in Saudi Arabia. The process uses propane(C3 Paraffin) as feed.The UOP-BP�s CYCLAR� Process uses a Ga2O3/ZSM-5 catalyst system of BP and CCR technology of the UOP and is commercially practiced by M/s SABIC in Saudi Arabia. The process uses propane(C3 Paraffin) as feed.

31. Ethylbenzene Synthesis Another important aromatics is Ethylbenzene which goes into preparation of Styrene. EB formed during reforming cannot be easily recovered due to requirement of costly recovery process rendering it uneconomical. Hence catalytic alkylation of Benzene using ethylene or ethanol is followed. The new generation Zeolite catalysts have advantage over the conventional catalysts such as Sulphuric acid and alumina.Another important aromatics is Ethylbenzene which goes into preparation of Styrene. EB formed during reforming cannot be easily recovered due to requirement of costly recovery process rendering it uneconomical. Hence catalytic alkylation of Benzene using ethylene or ethanol is followed. The new generation Zeolite catalysts have advantage over the conventional catalysts such as Sulphuric acid and alumina.

32. Styrene is produced from EB by catalytic dehydrogenation. The widely practiced route used potassium promoted iron oxide catalyst.Styrene is produced from EB by catalytic dehydrogenation. The widely practiced route used potassium promoted iron oxide catalyst.

33. Another interesting route is the Propylene Oxide-Styrene Monomer coproduction process. Predominantly used in the production of PO, the byproduct formed, (alpha phenyl ethyl alcohol) is dehydrated to give Styrene. This route significantly affect the market trends in the styrene prices especially when the demand for PO is high.Another interesting route is the Propylene Oxide-Styrene Monomer coproduction process. Predominantly used in the production of PO, the byproduct formed, (alpha phenyl ethyl alcohol) is dehydrated to give Styrene. This route significantly affect the market trends in the styrene prices especially when the demand for PO is high.

34. A catalyst and process for this reaction has been developed by IPCL R&D and licensed to an entrepreneur. A catalyst and process for this reaction has been developed by IPCL R&D and licensed to an entrepreneur.

36. Cumene Synthesis Cumene is another aromatics compound which finds application in specialty products. Cumene is synthesized by catalytic propylation of Benzene. The novel zeolite catalysts give better process efficiency in the commercial processing.Cumene is another aromatics compound which finds application in specialty products. Cumene is synthesized by catalytic propylation of Benzene. The novel zeolite catalysts give better process efficiency in the commercial processing.

37. Hydroprocessing