(19)
(11)EP 0 221 292 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
23.11.1988 Bulletin 1988/47

(21)Application number: 86112469.1

(22)Date of filing:  09.09.1986
(51)International Patent Classification (IPC)4C10G 47/04, B01J 23/94

(54)

A process for the regeneration of spent catalyst used in the upgrading of heavy hydrocarbon feedstocks

Verfahren zur Regeneration eines verbrauchten Katalysators, der zur Verbesserung schwerer Kohlenwasserstoff-Einsatzprodukte verwendet wurde

Procédé de régénération d'un catalyseur épuisé utilisé pour l'amélioration de charges de départ d'hydrocarbures lourds


(84)Designated Contracting States:
DE FR GB IT

(30)Priority: 09.09.1985 US 773802

(43)Date of publication of application:
13.05.1987 Bulletin 1987/20

(73)Proprietor: Intevep SA
Caracas 1070 A (VE)

(72)Inventors:
  • Rodriquez, Domingo
    Miranda (VE)
  • Schemel, Roberto
    Miranda (VE)

(74)Representative: Ott, Elmar, Dipl.-Ing. 
Kappelstrasse 8
72160 Horb 1
72160 Horb 1 (DE)


(56)References cited: : 
EP-A- 0 016 648
DD-A- 77 772
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] The present invention is directed to a process for regenerating a spent catalyst used in the upgrading of heavy hydrocarbon feedstocks and, more particularly, a process for regenerating a spent naturally-occurring iron base catalyst.

    [0002] In processing heavy hydrocarbon feedstocks for upgrading same into usable distillates, natural catalysts of laterite, limonite and bauxite type have been widely used. Generally in hydrocracking processes for upgrading these heavy hydrocarbon feedstocks catalysts are added in quantities ranging from 5 to 10% by weight with respect to the feedstock. After the hydrocracking process it is necessary to separate the spent catalyst from the processed hydrocracked product. The waste catalyst from the separation stage contains up to 35 wt.% carbon, up to 30 wt.% sulfur and from about 1.0 to 1.5 wt.% vanadium. Heretofore, the waste catalyst generally cannot be used in any other processing stages for upgrading heavy crude and therefore must be considered as a disposable product. In a commercial plant for hydrocracking heavy hydrocarbon feedstocks in which 15.9X 1 06 litres (100,000 barrels) of feedstock are processed a day, approximately 7.26x105 kg (800 tons) per day of waste catalyst is produced. The problems associated with handling the volume of waste catalyst produced are numerous. These problems include the costs for transporting and storing of the waste catalysts. However, a more serious and more important problem results from the fact that the catalysts used in the hydrocracking process, as noted above, are naturally occurring catalysts which have limited known reserves.

    [0003] In light of the foregoing, it would be highly desirable to provide an efficient process for regenerating the spent naturally-occurring catalysts used in the upgrading of heavy hydrocarbon feedstocks in the hydrocracking process of same. In addition, it would be extremely efficient to develop a process for regenerating spent naturally-occurring catalysts wherein the regenerated catalysts could again be employed with the hydrocracking process for upgrading heavy hydrocarbon feedstocks.

    [0004] Accordingly, it is a principal object of the present invention to develop a process forthe regeneration of a spent naturally-occurring catalyst used in upgrading heavy hydrocarbon feedstocks.

    [0005] It is a particular object of the present invention to provide a process as aforesaid wherein the regenerated spent catalysts have physical and structural characteristics similar to the virgin naturally-occurring catalyst.

    [0006] It is a further object of the present invention to provide a process as aforesaid wherein the regenerated catalyst has an activity in treating heavy hydrocarbon feedstocks similar to that obtained with a virgin catalyst.

    [0007] It is a still further object of the present invention to provide a process as aforesaid which is economical and highly efficient.

    [0008] Further objects and advantages will appear hereinbelow.

    [0009] In accordance with the present invention the foregoing objects and advantages are readily obtained.

    [0010] The present invention is directed to a process for the regeneration of a spent naturally-occurring iron base catalyst used in the upgrading of heavy hydrocarbon feedstocks. In accordance with the present invention a spent naturally-occurring iron base catalyst containing carbon, sulfur and vanadium as impurities is roasted at a temperature of not more than 400°C in the presence of a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof so as to eliminate carbon from said catalysts and obtain a roasted product comprising iron oxide and water soluble salts of sulfur and vanadium. The roasted product is then water leached to dissolve the soluble salts of sulfur and vanadium and the iron base regenerated catalyst is thereafter separated from the leaching liquor so as to obtain a regenerated iron base catalyst substantially free of carbon and sulfur. In accordance with the present invention the separated leaching liquor may be, if desired, bubbled with carbon dioxide so as to obtain a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof. The recovered carbonates may then be recycled to the roasting stage so as to produce the water soluble salts of sulfur and vanadium.

    [0011] In accordance with a particular feature of the present invention the naturally-occurring iron base catalyst regenerated in accordance with the process of the present invention is a catalyst selected from the group consisting of laterite, limonite, bauxite and mixtures thereof.

    [0012] Figure 1 is a schematic block diagram illustrating the process of the present invention.

    [0013] The process of the present invention will be described with reference to Figure 1. The regeneration process 10 of the present invention includes three stages: a roasting stage 12, a catalyst washing stage 14 and a carbonate regeneration stage 16. In accordance with the process of the present invention a spent naturally occurring iron base catalyst recovered from the hydrocracked product of a hydrocracking processor is fed via a line 18 to the roasting stage 12. The naturally occurring iron base catalyst is selected from the group consisting of laterite, limonite, bauxite and mixtures thereof. Typically, the spent naturally-occurring catalyst from the hydrocracking process contains up to 35 wt.% carbon, up to 30 wt.% sulfur and from about 1.0 to 1.5 wt.% vanadium. The waste catalyst is mixed in the roasting stage 12 via lines 13 and 15 respectively with a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof and air and roasted at a temperature of not more than 400°C in the presence of the carbonate and air for up to 8 hours so as to eliminate the carbon from the spent catalyst via line 22 and obtain a roasted catalyst product containing iron oxide and water soluble salts of sulfur and vanadium. In accordance with the process of the present invention the carbonate is added to the waste catalyst in a ratio of from about 0.25:1 to 1:1 with respect to the waste catalyst.

    [0014] The product of the roasting stage 12 which comprises iron oxide and water soluble salts of sulfur and vanadium is removed via line 20 and fed to catalyst washing stage 14. Carbon dioxide, a by-product of the roasting operation, is taken off via line 22. The roasted product is water leached in catalyst washing stage 14 by introducing water via line 24 into stage 14 wherein the salts of sulfur and vanadium go into solution leaving a substantially iron oxide green product. The roasted product is water leached with water until the pH of the leaching liquor reaches a pH of about 7. The product from the catalyst washing stage is thereafter removed via line 26 to a separator 28 wherein the green iron oxide solid product is removed via line 30 to dryer 32 where it is dried so as to produce a regenerated iron base catalyst which is removed via line 34 and may if desired be recycled to the hydrocracking processor. The water leaching liquor from separator 28 is removed via line 36 and fed to a carbonate regenerating stage 16 wherein the sodium, potassium, calcium or mixtures thereof is regenerated by bubbling C02 gas in an amount equal to about 40 to 50 wt.% of the carbonate used in the roasting stage 12 through the leaching liquor via line 38 so as to produce a carbonate of sodium, potassium, calcium and mixtures thereof. The resultant product from the regeneration stage 16 is removed via line 40 to a separator 42 wherein the carbonate is removed via line 44 and recycled via line 44 to line 13.

    [0015] The process of the present invention will be made clear from the following example.

    Example



    [0016] A natural iron base limonite catalyst used for the hydroprocessing of a heavy hydrocarbon feedstock, namely Zuata 44X 510°C+ (950°F+), having the following composition was separated from the hydroprocessed product.



    [0017] The spent limonite catalyst was analyzed and had the following composition: iron 45.2 wt.%, carbon 27.0 wt.%, sulfur 26.6 wt.% and vanadium 1.2 wt.%. The spent catalyst weighing 1998.2 grams was roasted in the presence of sodium carbonate in a ratio of 1:1 by weight with respect to the waste catalyst at a temperature of 350°C for about 8 hours so as to form water soluble salts of sulfur and vanadium. The total weight of the sodium carbonate and waste catalyst was 3996.4 grams. After the roasting process the roasted product was washed with fresh water to dissolve the soluble salts. The washing time was controlled by measuring the pH of the washing liquor. The washing stage was completed when the pH of the washing liquor reached 7. The catalyst was thereafter separated from the washing liquor and dried in an oven at a temperature of 140°C. The washing liquor was thereafter treated in a regeneration stage where it was bubbled with C02 gas in an amount of 500 LTS at Standard Pressure and Temperature so as to regenerate sodium carbonate. The sodium carbonate was thereafter removed and recycled back to the roasting stage.

    [0018] The separated dried catalyst was then weighed to determine the catalyst yield. The weight of the regenerated dried catalyst was 999.3 grams which is equivalent to 50.01% of the original waste catalyst thereby indicating that almost the entire amount of carbon, sulfur and vanadium present in the pretreated waste catalyst had been removed. A comparison of the physical properties of the regenerated catalyst and the properties of the original virgin catalysts were compared. The results are set forth below.



    [0019] From the foregoing results it is shown that the vanadium content decreased about 50% while the sulfur and carbon contents of the regenerated catalyst are reduced in excess of 99% with respect to the initial content in the waste catalyst.

    [0020] In order to determine the activity of the regenerated catalyst, catalyst activity was compared to that of a virgin catalyst in treating 510°C+ (950°F+) residuum from Zuata 44X crude oil. The operating conditions were as follows: Feed Weight: 1300 g, Operating Temperature: 450°C, Operating pressure: 13.2 MPa (1900 psig), Catalyst weight percent: 8%, H2 Flowrate, 16 I/min, Stirring speed: 900 rpm, Test time: 3 hrs. The activity test results are shown in the following Table.



    [0021] From the above results it can be seen that the activity of the regenerated catalyst is very similar to that of the naturally-occurring virgin catalyst, with a slightly less liquid yield but with a higher conversion of asphaltenes, Conradson carbon and API gravity in the case of the regenerated catalyst.


    Claims

    1. A process for the regeneration of a spent naturally-occurring iron base catalyst used in the upgrading of heavy hydrocarbon feedstocks comprising:

    providing a spent naturally-occurring iron base catalyst containing carbon, sulfur and vanadium as impurities;

    roasting said catalyst at a temperature of not more than 400°C in the presence of a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof so as to eliminate carbon from said catalyst and obtain a roasted product comprising iron oxide and water soluble salts of sulfur and vanadium;

    water leaching said roasted product to dissolve the soluble salts of sulfur and vanadium; and

    separating said catalyst from said leaching liquor so as to obtain a regenerated catalyst substantially free of carbon and sulfur.


     
    2. A process according to claim 1 including bubbling said separated leaching liquor with C02 so as to obtain a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof and separating and recycling said carbonate to the roasting stage.
     
    3. A process according to claim 1 wherein said catalyst is roasted for up to 8 hours.
     
    4. A process according to claim 1 including water leaching said roasted product until said leaching liquor reaches a pH of about 7.
     
    5. A process according to claim 1 including mixing said carbonate in a ratio of from about 0.25:1 to 1:1 1 with respect to said spent catalyst.
     
    6. A process according to claim 1 wherein said spent catalyst contains up to about 35 wt.% carbon, up to about 30 wt.% sulfur and from about 1.0 to 1.5 wt.% vanadium.
     
    7. A process according to claim 1 wherein said natural iron base catalyst is selected from the group consisting of laterite, limonite, bauxite and mixtures thereof.
     
    8. A hydrocracking process for the upgrading of a heavy crude feedstock comprising:

    hydroprocessing said hydrocarbon feedstock in the presence of a naturally-occurring iron base catalyst wherein said catalyst becomes contaminated with carbon, sulfur and vanadium;

    roasting said contaminated catalyst at a temperature of not more than 400°C in the presence of a carbonate selected from the group consisting of sodium, potassium, calcium and mixtures thereof so as to eliminate carbon from said catalyst and obtain a roasted product comprising iron oxide and water soluble salts of sulfur and vanadium;

    water leaching said roasted product to dissolve the soluble salts of sulfur and vanadium;

    separating said catalyst from said leaching liquor so as to obtain a regenerated catalyst substantially free of carbon and sulfur; and

    recycling said regenerated catalyst to the hydroprocessing stage.


     


    Ansprüche

    1. Ein Verfahren zur Wiederherstellung eines verbrauchten natürlich vorkommenden Katalysators auf Eisenbasis wie er zur Steigerung von schweren Kohlenwasserstoffvorräten verwandt wird, das beinhaltet:

    die Bereitstellung eines verbrauchten, natürlich vorkommenden Katalysators auf Eisenbasis, der Kohlenstoff, Schwefel und Vanadium als Verunreinigungen enthält;

    der Katalysator wird auf eine Temperatur von nicht mehr als 400°C erhitzt und zwar unter Vorhandensein von Karbonat, das aus einer Gruppe bestehend aus Natrium, Kalium, Calzium und einer Mischung daraus ausgesondert worden ist, um so Kohlenwasserstoff aus besagtem Katalysator zu eliminieren und ein erhitztes Produkt zu erhalten, das aus Eisenoxyd und wasserlöslichen Salzen, die aus Schwefel und Vanadium bestehen, besteht;

    das erhitzte Produkt ist wasserdurchlässig, um die wasserlöslichen Salze aus Schwefel und Vanadium aufzulösen;

    des weiteren wird der Katalysator von der wasserdurchlässigen Flüssigkeit getrennt, um so einen wiederhergestellten Katalysator zu erhalten, der sich Substanzen Kohlenwasserstoff und Schwefel nicht mehr enthält.


     
    2. Ein Verfahren nach Anspruch 1, das beinhaltet die wasserlösliche Flüssigkeit mit C02 zu versetzen, um so ein Karbonat zu erhalten, das von einer Gruppe getrennt ist, die aus Natrium, Kalium, Calzium und einer Mischung daraus besteht und die dieses Karbonat davon abtrennt und dem erhitzten Stadium zuführt.
     
    3. Ein Verfahren nach Anspruch 1 bei dem der Katalysator bis zu acht Stunden erhitzt wird.
     
    4. Ein Verfahren nach Anspruch 1 das die Wasserlöslichkeit des besagten Produkts einschließt bis die besagte wasserlösliche Flüssigkeit einen pH-Wert von ca. 7 erreicht.
     
    5. Ein Verfahren nach Anspruch 1, das beinhaltet, daß Karbonat in einem Mischungsverhältnis von 0,25:1 auf 1:1 zu bringen unter Beachtung des besagten verbrauchten Katalysators.
     
    6. Ein Verfahren nach Anspruch 1 nach dem der verbrauchte Katalysator bis zu 35 Vol.-% Kohlenstoff, bis zu 30 Vol.-% Schwefel und Vanadium von 1,0 bis 1,5 Vol.-% enthält.
     
    7. Ein Verfahren nach Anspruch 1 in dem der natürliche Katalysator auf Eisenbasis von einer Gruppe getrennt wird, die aus Laterit, Limonit, Bauxit und einer Mischung daraus besteht.
     
    8. Ein wasserlösliches Verfahren zur Steigerung von schweren Rohmaterialien, das darin besteht,

    daß der besagte Kohlenwasserstoffvorrat hydroprozessiert wird unter Vorhandensein von einem natürlich vorkommenden Katalysator auf Eisenbasis in dem der Katalysator mit Kohlenstoff, Schwefel und Vanadium versetzt wird:

    daß der so konterminierte Katalysator bis auf eine Temperatur von nicht mehr als 400°C erhitzt wird und zwar unter Vorhandensein von Karbonat, das gewonnen ist aus einer Gruppe, die besteht aus Natrium, Kalium, Calzium und einer Mischung daraus, um so den Kohlenstoff aus besagtem Katalysator zu eliminieren und ein erhitztes Produkt zu erhalten, da aus Eisenoxyd und wasserlöslichen Salzen aus Schwefel und Vanadium besteht;

    daß das erhitzte Produkt wasserlöslich ist, um die wasserlöslichen Salze aus Schwefel und Vanadium aufzulösen;

    daß der Katalysator von der besagten wasserlöslichen Flüssigkeit getrennt wird, um so einen wiederhergestellten Katalysator zu erhalten, der die Substanzen Kohlenstoff und Schwefel nicht mehr enthält;

    und schließlich, daß der wiederhergestellte Katalysator in ein hydroprozessiertes Stadium zurückgeführt wird.


     


    Revendications

    1. Procédé pour la régénération d'un catalyseur naturel, à base de fer, épuisé, et que l'on utilise pour l'amélioration de la qualité de charges d'hydrocarbures lourds de départ, ce procédé comprenant:

    l'obtention d'un catalyseur naturel épuisé, à base de fer, contenant comme impuretés du carbone, du soufre et du vanadium;

    le grillage dudit catalyseur a une température non supérieure à 400°C, en présence d'un carbonate choisi parmi l'ensemble constitué par du carbonate de sodium, de potassium, de calcium et leurs mélanges, de façon à éliminer le carbone dudit catalyseur et à obtenir un produit grillé comprenant de l'oxyde de fer et des sels hydrosolubles de soufre et de vanadium;

    la lixiviation à l'eau de ce produit grillé, afin de dissoudre les sels solubles de soufre et de vanadium; et

    la séparation dudit catalyseur d'avec ladite liqueur de lixiviation, de façon à obtenir un catalyseur régénéré, essentiellement dépourvu de carbone et de soufre.


     
    2. Procédé selon la revendication 1, comprenant le barbotage de C02 dans ladite liqueur de lixiviation séparée, afin d'obtenir un carbonate choisi dans l'ensemble constitué par du carbonate de sodium, de potassium, de calcium et leurs mélanges, et la séparation et le recyclage dudit carbonate vers l'étape de grillage.
     
    3. Procédé selon la revendication 1, dans lequel ledit catalyseur est grillé pendant une période pouvant aller jusqu'à 8 h.
     
    4. Procédé selon la revendication 1, comprenant la lixiviation à l'eau dudit produit grillé, jusqu'à ce que ladite liqueur de lixiviation atteigne un pH d'environ 7.
     
    5. Procédé selon la revendication 1, comprenant l'incorporation, par mélangeage, dudit carbonate selon un rapport compris entre environ 0,25:1 et 1:1 par rapport audit catalyseur épuisé.
     
    6. Procédé selon la revendication 1, dans lequel ledit catalyseur épuisé contient jusqu'à environ 35% en poids de carbonate, jusqu'à environ 30% en poids de soufre et d'environ 1,0 à 1,5% en poids de vanadium.
     
    7. Procédé selon la revendication 1, dans lequel ledit catalyseur naturel à base de fer est choisi dans l'ensemble constitué par la latérite, la limonite, la bauxite et leurs mélanges.
     
    8. Procédé d'hydrocraquage pour l'amélioration de la qualité d'une charge de brut lourd de départ, ce procédé comprenant:

    le traitement d'hydrocraquage de ladite charge des hydrocarbures de départ, en présence d'un catalyseur naturel à base de fer, traitement au cours duquel ledit catalyseur devient contaminé par du carbone, du soufre et du vanadium;

    la soumission dudit catalyseur contaminé à un grillage effectué à une température non supérieure à 400°C en présence d'un carbonate, choisi dans l'ensemble constitué par du carbonate de sodium, de potassium, de calcium et leurs mélanges, de façon à éliminer dudit catalyseur le carbone et à obtenir un produit grillé comprenant de l'oxyde de fer et des sels hydrosolubles de soufre et de vanadium;

    la lixiviation à l'eau dudit produit grillé, pour dissoudre les sels solubles de soufre et de vanadium;

    la séparation dudit catalyseur d'avec ladite liqueur de lixiviation, de façon à obtenir un catalyseur régénéré essentiellement dépourvu de carbone et de soufre; et

    le recyclage, vers l'étape de traitement par l'hydrogène (hydrocraquage) dudit catalyseur régénéré.


     




    Drawing