NO883985L

NO883985L - FISCHER-TROPSCH CATALYST WITH HIGH SELECTIVITY.

Info

Publication number: NO883985L
Application number: NO88883985A
Authority: NO
Inventors: James George Miller; Jule Anthony Rabo
Original assignee: Union Carbide Corp
Priority date: 1988-09-07
Filing date: 1988-09-07
Publication date: 1990-03-08
Also published as: NO883985D0

Description

Regjeringen i USA har i henhold til kontrakt nr. DE-AC22-84PC70028 rettigheten til foreliggende oppfinnelse. The government of the United States has, according to contract no. DE-AC22-84PC70028, the right to the present invention.

Foreliggende oppfinnelse angår kobolt Fischer-Tropsch-katalysatorer i kombinasjon med en forbedret molekylsikt-bærer. The present invention relates to cobalt Fischer-Tropsch catalysts in combination with an improved molecular sieve support.

Jern Fischer-Tropsch (F-T)-katalysatorer har generelt vært foretrukket kommersielt i forhold til kobolt-baserte katalysatorer og er i dag de eneste kommersielt benyttede F—T-katalysatorer. Iron Fischer-Tropsch (F-T) catalysts have generally been preferred commercially over cobalt-based catalysts and are today the only commercially used F-T catalysts.

Ved omdanning av syngass (CO + Hg-blanding) i Fischer-Tropsch-reaksjonen har kobolt-katalysatorene fordelene ved høyere aktivitet og bedre selektivitet mot motorbrennstoffer, de lider av inherent dannelse av overskytende metan (et uønsket produkt) så vel som den paraffiniske art av produktet. Det ville være en vesentlig katalysatorfordel hvis en stabil kobolt F-T-katalysator blir oppdaget som kunne redusere metanproduksjonen, øke C5<+->utbyttet og forbedre olefinkomponenten spesielt i Cg-området. When converting syngas (CO + Hg mixture) in the Fischer-Tropsch reaction, the cobalt catalysts have the advantages of higher activity and better selectivity towards motor fuels, they suffer from the inherent formation of excess methane (an unwanted product) as well as the paraffinic species of the product. It would be a significant catalyst advantage if a stable cobalt F-T catalyst is discovered that could reduce methane production, increase the C5<+->yield and improve the olefin component especially in the Cg region.

Det foreligger en rimelig mengde kjent teknikk som dreier seg om Fischer-Tropsch-metaller kombinert med molekylsikt-komponenter. Den nyeste kjente teknikk som ansees pertinent i forbindelse med foreliggende oppfinnelse er US-PS 4 652 538 There is a fair amount of prior art that involves Fischer-Tropsch metals combined with molecular sieve components. The latest known technique that is considered relevant in connection with the present invention is US-PS 4,652,538

i navnet J.A. Rabo et al. samt den deri anførte kjente teknikk. in the name of J.A. Rabo et al. as well as the known technique stated therein.

En utmerket oppsummering av tidligere publikasjoner på kobolt Fischer-Tropsch-katalysatorer er angitt av R.B. Anderson i "The Fischer-Tropsch Synthesis", Academic Press, Orlando FL, 1984. I denne oppsummering angis det promotere og katalysatorer som tidligere er studert inkludert er videre syns-punkter med henblikk på bruk av Mn- og Zr-promotere. Nedenfor gis en oppsummering av de informasjoner som finnes fra denne artikkel i forbindelse med bruken av Mn- og Zr-promotere. Fischer og Koch viste at Mn tilsatt til en kobolt kieselgur-katalysator var effektiv som skiftmiddel for produktfordeling mot tyngre produkt, noe som også er observert for katalysatorene ifølge foreliggende oppfinnelse. Arbeider av Eidus og Bulanova viste en tilsvarende virkning på tilsetning av ZrCtø til samme type katalysator, dette ble ikke observert ved foreliggende søkeres tilsetning av Zr02til det Mn-promoterte Co/TC-123-katalysatorsystem. Så vidt søkeren vet er intet arbeid angitt med henblikk på bruk av kombinerte Mn- og Zr-promoterte katalysatorer. An excellent summary of previous publications on cobalt Fischer-Tropsch catalysts is provided by R.B. Anderson in "The Fischer-Tropsch Synthesis", Academic Press, Orlando FL, 1984. In this summary, promoters and catalysts that have previously been studied are indicated, including further points of view regarding the use of Mn and Zr promoters. Below is a summary of the information contained in this article in connection with the use of Mn and Zr promoters. Fischer and Koch showed that Mn added to a cobalt kieselguhr catalyst was effective as a shift agent for product distribution towards heavier product, which is also observed for the catalysts according to the present invention. Work by Eidus and Bulanova showed a similar effect on the addition of ZrCtø to the same type of catalyst, this was not observed with the present applicant's addition of ZrO2 to the Mn-promoted Co/TC-123 catalyst system. As far as the applicant is aware, no work has been indicated with a view to the use of combined Mn- and Zr-promoted catalysts.

Dent, A.L. og Lin, M., "Adv. Chem. Ser." 178, 47 (1979) angir at tilsetningen av Mn til en kobolt-aluminiumoksyd-katalysator øker olefininnholdet i produktet, noe som er konsistent med søkerens erfaring. Dent, A.L. and Lin, M., "Adv. Chem. Ser." 178, 47 (1979) states that the addition of Mn to a cobalt-alumina catalyst increases the olefin content of the product, which is consistent with applicant's experience.

Den eneste kjente teknikk søkeren er klar over i forbindelse med Zr for å forbedre stabiliteten for en kobolt F-T-katalysator er angitt i Eidus og Bulanova U.S.S.R. 150, 102, sept. 26, 1962, Appl. Nov. 27, 1954. I dette arbeidet ble Zr benyttet i stedet for thorium for å redusere sensitiviteten for katalysatoren i forbindelse med overheting. The only prior art Applicant is aware of in conjunction with Zr to improve the stability of a cobalt F-T catalyst is disclosed in Eidus and Bulanova U.S.S.R. 150, 102, Sept. 26, 1962, Appl. Nov. 27, 1954. In this work, Zr was used instead of thorium to reduce the sensitivity of the catalyst in connection with overheating.

Foreliggende oppfinnelse er rettet mot en kobolt Fischer-Tropsch-katalysator-molekylsiktkombinasjon som benytter en nyutviklet molekylsikt som viser forbedret ytelse som katalysatorbaerer i forhold til tidligere kjente molekylsikt-bærere. The present invention is directed to a cobalt Fischer-Tropsch catalyst-molecular sieve combination which uses a newly developed molecular sieve which shows improved performance as a catalyst carrier compared to previously known molecular sieve carriers.

Det er funnet at den resulterende katalysator viser overlegen produktselektivitet og høy stabilitet, noe som påvises av lavere metanproduksjon, høyere C5<+->utbytter, øket olefinproduksjon og lengre katalysatorlevetid. The resulting catalyst has been found to exhibit superior product selectivity and high stability as evidenced by lower methane production, higher C5<+> yields, increased olefin production and longer catalyst life.

Man har således funnet en ny zeolittisk molekylsikt basert bærer som generelt reduserer den uønskede metanfremstilling av en kobolt Fischer-Tropsch-katalysator kombinert med denne. Denne reduksjon i metanproduksjon oppnås ved å skifte produksjonsspektre mot tyngre og mer ønskelige produkter. En betydelig økning i produkt fremstilt utover motorbrennstoff-området er imidlertid observert, dette ansees imidlertid ikke som en mangel fordi disse tyngre produkter lett kan hydro-behandles tilbake til motorbrennstoffkokepunktområdet. Molekylsiktsbæreren bevirker redusering av hydrogenerings-evnen for kobolt-katalysatoren, noe som fremmer hydrokarbon-kjedeveksten i forhold til kjedeavslutning. Konsistent med denne teori blir olefininnholdet av F-T-produktet øket, noe som øket verdien av produktet, spesielt i Cg-området. A new zeolitic molecular sieve based support has thus been found which generally reduces the unwanted methane production of a cobalt Fischer-Tropsch catalyst combined with this. This reduction in methane production is achieved by shifting production spectrums towards heavier and more desirable products. A significant increase in product produced beyond the motor fuel range has been observed, however, this is not considered a deficiency because these heavier products can easily be hydrotreated back to the motor fuel boiling point range. The molecular sieve carrier causes a reduction in the hydrogenation ability of the cobalt catalyst, which promotes hydrocarbon chain growth in relation to chain termination. Consistent with this theory, the olefin content of the F-T product is increased, which increased the value of the product, especially in the Cg region.

Molekylsiktbæreren ifølge oppfinnelsen, her kalt TC-123, består av en dampbehandlet, syreekstrahert form av den molekylsikt som er kjent som LZ-210, beskrevet i US-PS The molecular sieve carrier according to the invention, here called TC-123, consists of a steam-treated, acid-extracted form of the molecular sieve known as LZ-210, described in US-PS

4 503 023. Den best kjente måte å gjennomføre oppfinnelsen på er å begynne med en LZ-210 med et SiC>2:A^C^-forhold på 8,0 eller derover. Den foretrukne prosedyre for fremstilling av LZ-210-materialet ifølge oppfinnelsen er beskrevet av Staniulis i den paralleltløpende søknad US-SN 4,503,023. The best known way to practice the invention is to start with an LZ-210 having a SiC>2:A^C^ ratio of 8.0 or greater. The preferred procedure for producing the LZ-210 material according to the invention is described by Staniulis in the parallel application US-SN

Denne prosedyre involverer å underkaste en Y-zeolitt til en LZ-210 sekundær synteseprosedyre uten efterfølgende ammonium-utbyttingstrinn. Dette materialet kan så ammoniumutbyttes og dampbehandles ved 750" C i 1 time i 100$ damp fulgt av syreekstrahering i 3M HCl-oppløsning i 3 timer under tilbakeløpsbetingelser. Det resulterende materiale har følgende egenskaper: SiC^A^C^ = 200, overflateareal (1 pt. BETO = 800 m<2>/g og et røntgen A null = 24,260. This procedure involves subjecting a Y-zeolite to an LZ-210 secondary synthesis procedure without a subsequent ammonium recovery step. This material can then be ammonium exchanged and steam treated at 750" C for 1 hour in 100$ steam followed by acid extraction in 3M HCl solution for 3 hours under reflux conditions. The resulting material has the following properties: SiC^A^C^ = 200, surface area ( 1 pt BETO = 800 m<2>/g and an x-ray A zero = 24.260.

Bæreren blir så porefylt med en oppløsning som etylenglykol, vann eller alkohol inneholdende Co(N03)2og en Mn(N03)4~promoter for derved å gi en teoretisk prosentandel Co = 8,2$ og Mn = 1,6#. Metoden for silisiumdioksydbinding og forming er ikke ansett å være vesentlig innenfor oppfinnelsens ramme. The carrier is then pore-filled with a solution such as ethylene glycol, water or alcohol containing Co(N03)2 and a Mn(N03)4 promoter to thereby give a theoretical percentage of Co = 8.2$ and Mn = 1.6#. The method of silicon dioxide binding and forming is not considered to be essential within the scope of the invention.

Karakterisering av katalysatorene viser det forbedrede koboltoksyd innkapslet i den sekundære porestruktur av TC- 123-molekylsikten oppnådd ved damp- og syreekstraherings-behandlingene. De sekundære porer ved tilpasning og opprett-holdelse av koboltpartiklene for optimal størrelse med henblikk på maksimal aktivitet og selektivitet under samtidig mulighet for syngass og produkter å diffundere gjennom den primære zeolitt-porestruktur. Characterization of the catalysts shows the improved cobalt oxide encapsulated in the secondary pore structure of the TC-123 molecular sieve obtained by the steam and acid extraction treatments. The secondary pores by adapting and maintaining the cobalt particles for optimal size with a view to maximum activity and selectivity while simultaneously allowing syngas and products to diffuse through the primary zeolite pore structure.

Bruken av det nye katalysatorsystem omfattende kobolt og en dampbehandlet syreekstrahert LZ-210-bærer som Fischer-Tropsch-katalysator er også beskrevet. The use of the new catalyst system comprising cobalt and a steam-treated acid-extracted LZ-210 support as a Fischer-Tropsch catalyst is also described.

Katalysatorsystemet ifølge oppfinnelsen kan mest effektivt benyttes i forbindelse med en egnet Fischer-Tropsch-katalysator-promoter som for eksempel et mangan- eller zirkonoksyd eller kombinasjoner derav. The catalyst system according to the invention can be most effectively used in connection with a suitable Fischer-Tropsch catalyst promoter such as, for example, a manganese or zirconium oxide or combinations thereof.

EKSEMPLEREXAMPLES

Mens oppfinnelsen er beskrevet ovenfor, skal detaljene være bedre tilgjengelige ved hjelp av de følgende eksempler som skal illustrere at, for en Mn-behandlet kobolt F-T-katalysator bruken av en dampbehandlet syre ekstrahert LZ-210-molekylsiktbærer forbedrede resultater kan oppnås sammenlignet med resultater oppnådd med samme katalysator og i forhold til en kjent syreekstrahert UHP-Y-molekylsikt (US-PS 4 401 556 Bezman et al., og US-PS 4 652 538 Rabo et al.). While the invention has been described above, the details shall be better accessible by means of the following examples which shall illustrate that, for a Mn treated cobalt F-T catalyst the use of a steam treated acid extracted LZ-210 molecular sieve support improved results can be obtained compared to results obtained with the same catalyst and relative to a known acid-extracted UHP-Y molecular sieve (US-PS 4,401,556 Bezman et al., and US-PS 4,652,538 Rabo et al.).

De følgende eksempler sammenligner en manganbehandlet syreekstrahert UHP-Y-båret F-T-katalysator med den samme katalysator ved bruk av en dampbehandlet, syreekstrahert LZ-210-molekylsiktbærer. The following examples compare a manganese-treated acid-extracted UHP-Y supported F-T catalyst with the same catalyst using a steam-treated acid-extracted LZ-210 molecular sieve support.

Katalysatorene ble begge fremstilt ved samme prosedyre og prøvet under identiske betingelser. The catalysts were both prepared by the same procedure and tested under identical conditions.

Eksempel IExample I

Katalysatoren ble fremstilt ved porefylling av 100,0 g vannfri TC-123 med en varm etylenglykoloppløsning av 7,21 g The catalyst was prepared by pore-filling 100.0 g of anhydrous TC-123 with a hot ethylene glycol solution of 7.21 g

Mn(N03)2'H20, 55,8 g Co(N03)2'6H20 og 48,0 g etylenglykol. Katalysatoren ble tørket og kalsinert 1 luft ved følgende prosedyre: lOOb i 10 timer, stigning til 200°C i løpet av en Vi time, dynking i 200" C i time, stigning til 450° C i 1 1/4 time, dynking i 450°C i 4 timer. Det resulterende pulver ble silisiumdioksydbundet og ekstrudert til en 1/8" ekstrudater, tørket ved 110°C over natt fulgt av kalsinering ved 250°C i 2 timer. De beregnede prosentuale komponenter i katalysatoren basert på de benyttede råmaterialer var: Co = 8,2, Mn = 1,6, S102-bindemiddel = 15* og TC-123 = 72,1. Mn(N03)2'H20, 55.8 g Co(N03)2'6H20 and 48.0 g ethylene glycol. The catalyst was dried and calcined 1 air by the following procedure: lOOb for 10 hours, rise to 200°C during one Vi hour, soak at 200°C for hour, rise to 450°C for 1 1/4 hours, soak in 450°C for 4 hours. The resulting powder was silica bonded and extruded into a 1/8" extruder, dried at 110°C overnight followed by calcination at 250°C for 2 hours. The calculated percentage components of the catalyst based on the raw materials used were: Co = 8.2, Mn = 1.6, S102 binder = 15* and TC-123 = 72.1.

En 80 cm<J>prøve ble fylt i en Berty-reaktor der den ble behandlet med H2ved 300 psig og 350" C i 18 timer og eksponert til 1:1 H2: CO-syngass ved 220°C. Katalysatoren ble prøvet ved 240"C og 260°C under forskjellige trykk og H2bo-forhold. Resultatene er vist 1 tabell 1. An 80 cm<J> sample was loaded into a Berty reactor where it was treated with H2 at 300 psig and 350°C for 18 hours and exposed to 1:1 H2:CO syngas at 220°C. The catalyst was tested at 240 "C and 260°C under different pressures and H2bo conditions. The results are shown in Table 1.

Eksempel IIExample II

En andre katalysator ble fremstilt ved bruk av den samme metode som beskrevet i eksempel I, men man benyttet syreekstrahert UHP-Y-molekylsikt i stedet for TC-123-molekyl-sikten i eksempel I. Katalysatorprøven ble prøvet på samme måte og resultatene er vist i tabell 1. A second catalyst was prepared using the same method as described in Example I, but acid-extracted UHP-Y molecular sieve was used instead of the TC-123 molecular sieve in Example I. The catalyst sample was tested in the same way and the results are shown in table 1.

Den TC-123-bårede katalysator viste en vesentlig reduksjon i metan- og C2-C4~produksjonen sammenlignet med den UHP-Y-bårede katalysator mens den viste en sammenligningsbar eller høyere syngassomdanning. Den reduserte C^-C4-fraksjonen ble realisert i den mer verdifulle C5<+->fraksjon. Olefininnholdet i produktet ble også funnet å være høyere enn UHP-Y-tilfellet var, antydet ved olefin:paraffin-forholdet i C4~fraksjonen. The TC-123 supported catalyst showed a significant reduction in methane and C2-C4~ production compared to the UHP-Y supported catalyst while showing comparable or higher syngas conversion. The reduced C^-C4 fraction was realized in the more valuable C5<+->fraction. The olefin content of the product was also found to be higher than the UHP-Y case, as indicated by the olefin:paraffin ratio in the C4~ fraction.

Betingelser: 240°C, H2:C0 1:1, 300 psig, 300 GHSV. Conditions: 240°C, H2:CO 1:1, 300 psig, 300 GHSV.

Mens oppfinnelsen er beskrevet med henblikk på forskjellige spesifikke eksempler og utførelsesformer skal det være klart at oppfinnelsen ikke er begrenset dertil og at den kan gjennomføres på forskjellige måter innenfor rammen av de ledsagende krav. While the invention has been described with reference to various specific examples and embodiments, it should be clear that the invention is not limited thereto and that it can be implemented in various ways within the scope of the accompanying claims.

Claims

1. Cobalt Fischer-Tropsch catalyst, characterized in that it consists of a steam-treated, acid-extracted LZ-210 molecular sieve.

2. Catalyst according to claim 1, characterized in that the extracted LZ-210 has an S102 rA^OQ ratio of 8.0 or more.

3. Catalyst according to claim 1, characterized in that the LZ-210 used is steam treated at 750°C for 1 hour in 100* steam followed by acid extraction.

4. Catalyst according to claim 1, characterized in that it is present in combination with an effective amount of a suitable promoter.

5. Catalyst according to claim 4, characterized in that the promoter is Mn oxide.

6. Use of a cobalt/steam-treated, acid-extracted LZ-210 molecular sieve-supported catalyst according to claim 1 for catalyzing a Fischer-Tropsch reaction.

7. Use of a cobalt/steam treated, acid extracted LZ-210 molecular sieve supported catalyst according to claim 6 wherein the LZ-210 molecular sieve support has a SiC>2 :A^ C^ ratio of 8.0 or greater.

8. Use of a cobalt:steam treated, acid extracted LZ-210 molecular sieve supported catalyst according to claim 6 wherein the LZ-210 molecular sieve support is steam treated at 750°C for 1 hour in 100* steam followed by acid extraction.

9. Use of a cobalt:vapor treated, acid extracted LZ-210 molecular sieve supported catalyst according to claim 6 in combination with an effective amount of a suitable promoter to catalyze a Fischer-Tropsch reaction.

10. Use of a cobalt/steam-treated, acid-extracted LZ-210 molecular sieve-supported catalyst according to claim 9, characterized in that the promoter is the Mn oxide, to catalyze a Fischer-Tropsch reaction.

11. A method of conducting a Fischer-Tropsch reaction on a syngas feed stream comprising contacting the feed stream with a catalyst comprising cobalt and a steam-treated, acid-extracted LZ-210 molecular sieve support under suitable Fischer-Tropsch reaction conditions.

12. Method for carrying out a Fischer-Tropsch reaction according to claim 11, characterized in that the LZ-210 molecular sieve carrier has a SiC^rA^C^ ratio of 8.0 or more.

13. Method for carrying out a Fischer-Tropsch reaction according to claim 11, characterized in that the LZ-210 molecular sieve carrier is steam treated at 750°C for 1 hour in 100* steam followed by extraction.

14. Method for carrying out a Fischer-Tropsch reaction on a syngas feed stream according to claim 11, characterized in that the catalyst also comprises an effective amount of a suitable promoter.

15. Method for carrying out a Fischer-Tropsch reaction according to claim 14, characterized in that the catalyst also comprises a Mn oxide promoter.

16. Process for carrying out a Fischer-Tropsch reaction on a syngas feed stream, characterized in that it comprises contacting this feed stream with a catalyst comprising a cobalt and steam-treated, acid-extracted LZ-210 molecular sieve in combination with the Mn oxide at suitable Fischer-Tropsch reaction conditions.