SE444580B - PROCEDURE FOR EXTRACTION OF VANADIN FROM A DEACTIVATED CATALYST BY ACID EXTRACTION - Google Patents

Description

v »wwwwf .. 7 8 0 3 3 2 1 - 4 2 Swedish patent application, it is also preferred to treat the daide-activated catalyst first with steam to remove sulfur and then with an oxygen-containing gas to remove carbon, before the catalyst is subjected the acid extraction. It should be mentioned in this context that, if the purpose is not only to extract vanadium and possibly nickel from the catalyst but also to regenerate the catalyst, the treatment of the deactivated catalyst with an oxygen-containing gas in the manner set forth in the examples in the said Swedish patent application, where a small amount of the deactivated catalyst is treated with air for 3 hours at SSO ° C, is not suitable for larger amounts of deactivated catalyst, due to the large amount of heat which would then be released. When larger amounts of deactivated catalyst must be treated in order to extract vanadium and possibly nickel from the catalyst as well as to regenerate the catalyst, the three-step process described below has until recently been considered to be the most attractive embodiment of the process according to Swedish patent application 75.ll450-4. The deactivated catalyst is first treated for 1-5 hours at 250-240 ° C and atmospheric pressure with a mixture of steam and nitrogen and then for 1-5 days at 350-600 ° C and atmospheric pressure with a mixture of air and nitrogen. and finally it is subjected to acid extraction in the presence of a reducing agent for 0.5-3 hours at 50-150 ° C. The treatment times required in the various steps depend, among other things, on the amounts of sulfur, carbon and metals present in the deactivated catalyst and on the selected conditions, ie. treatment temperature, gas flow rate and composition of treatment gas and extraction liquid, hitherto the long treatment time required in the second stage Vgvid_nämndaNtrestegs procedure has been considered to constitute a serious inconvenience ¿'for use of the procedure according to the Swedish patent application in 15-114S0f4 «1t = - ¿: Recent studies of the process according to the Swedish patent application, _ »gf7§, ll4SQf4É have led to the discovery that in terms of vanadium removal and activity of the regenerated catalyst, a result] comparable to what is achieved can be obtained. by performing the three-step procedure according to the above-described three-step process N33 På mYCket ßYr§ »s> <fi r = f? <# I <2nsvau försgåS in 'ns fi behan @ 1i fl g av den idea * - fivérë fl snaiitkafalvsßtwfn få # §äít“ v1 fl n ë fl tidfempsfsturiï ¿¿ß ß 25 ° föftfa-a ......, vv, _., ~ ~~. _. ., V, .. ,, ~, .ï ,,, .. smín fivçw _. .r ,,. w., v ,,,., w..yf-f- _ WW '_ 78Û3321 ~ 4 3 of a comparable result in terms of vanadium removal and activity of the regenerated catalyst, the new process has three additional advantages over the above-mentioned three-step process in that the number of treatment steps preceding the acid extraction has been reduced by one, in that the number of gases required for treatment of the deactivated catalyst before the acid extraction has been reduced to one and in that a reducing agent is no longer required in the acid extraction.

The present invention thus relates to an improved process for the extraction of vanadium from a deactivated catalyst according to Swedish patent application 75.11450-4, in which process vanadium is extracted from a catalyst which has been deactivated by using Ba fi anáiiag of aa vaaaäla fi äiëig fi aa v via elevated temperature and elevated pressure, by which Bëhâñäííhš kâtâíyšåtöfñš vanadium content has increased by at least 10 parts by weight, and in which process the vanadium extraction, the vanadium content of the catalyst being reduced by at least 40% of the amount by which it has increased the catalyst deactivation. in parts by weight of vanadium / 100 parts by weight of catalyst support), is carried out by extracting the deactivated catalyst with an aqueous solution of a mineral acid (hereinafter referred to as "acid extraction"), after which the vanadium is separated from the vanadium-containing solution thus obtained. according to the invention consists in that the acid extraction is preceded of a treatment of the deactivated catalyst with steam at a temperature above 250 ° C and at a pressure above 1.5 bar.

In the process according to the invention, the treatment with steam should be carried out at a temperature above 250 ° C, but preferably below 550 ° C and in particular between 325 and 45000. The steam treatment should be carried out at a pressure above 1.5 bar, but preferably below 10 bar and in particular between 2 and 7 bar. The acid extraction to which the deactivated catalyst is subjected in the process according to the invention is preferably carried out at elevated temperature, in particular at a temperature above 50 ° C. The acid extraction is preferably carried out with an aqueous solution of sulfuric acid. via catalytic nyarabenanaiing of coivate oils at elevated temperature_and elevated pressure, carbon is deposited on the catalyst during the initial stage of the process until a certain carbon content has been reached, after which the carbon content of the catalyst remains virtually constant during the further course of the process, the new process * Vf-vw «» -ffw-we- ~ - ~ - »w-.a-mmwwma-.M“ f 7803321-4 4 according to the invention with the results of the three-step process described above, it is found that carbon removal such as in the three-step procedure does not take place now. It can also be seen that catalysts which have been regenerated according to the present invention, despite the presence of carbon thereon, have an activity comparable to the activity of carbon-free catalysts which have been regenerated according to the three-step process. Optionally, carbon can be removed from the catalysts also in the process of the present invention by treating the catalysts after the acid extraction at elevated temperature with an oxygen-containing gas. Compared with the second step in the three-step process, in which carbon is also removed from the catalyst, the possible treatment with an oxygen-containing gas according to the invention means a much simpler step, since the amount of heat generated in this treatment is much smaller. M A In the catalytic hydrotreatment at elevated temperature and elevated pressure of hydrocarbon oils containing nickel in addition to vanadium, nickel is also deposited on the catalyst. A comparison of the results of the process of the present invention with the results of the three-step process described above shows that nickel is removed to a lesser extent in the process of the invention than the three-stage process.

It has also been found that catalysts which have been regenerated according to the present invention, despite the presence of nickel thereon, have an activity comparable to the activity of practically nickel-free catalysts which have been regenerated according to the three-step process. Optionally, additional nickel can be removed from the catalysts in the process of the invention. This can advantageously be done by treating the regenerated catalyst only at elevated temperature with an oxygen-containing gas, after which the catalyst is again subjected to an oxygen extraction. Hydrocarbon oils, which contain nickel in addition to vanadium and which in the hydrotreatment at elevated temperature and elevated pressure give both vanadium and nickel deposits on the catalyst, generally contain a much larger amount of vanadium than nickel. The amount of nickel deposited on the catalyst is therefore usually only a fraction of the amount of vanadium deposited. Alternatively, when a catalyst is used to hydrotreat a vanadium- and nickel-containing hydrocarbon oil at elevated temperature and elevated pressure and regenerated according to the invention, the nickel content can in the long run accumulate to an undesirably high level. »._- e..é. Fl,,» 'fi WWWw-f l, -, ~ .-- i- .WW .___, __ 780,332'1-4 5 This can be prevented during regeneration by subjecting a sidestream The catalyst side stream, from which the nickel has been removed, is then fed to the main stream of the regenerated nickel-containing catalyst, in which the regenerated catalyst is then treated with an oxygen-containing gas at elevated temperature and an acid extraction. nickel accumulation on the catalyst is prevented by subjecting a sidestream of the regenerated catalyst to a further treatment, can also be carried out in the following manner: The regenerated catalyst is subjected to a treatment at elevated temperature with an oxygen-containing gas to remove carbon. A side stream is separated from the catalyst thus treated, which is subjected to an acid extraction. The catalyst side stream from which nickel has been removed is then fed to the main stream of the nickel-containing catalyst from which carbon has been removed.

The process of the present invention is particularly important in cases where the purpose is not only to extract vanadium and optionally present from the deactivated catalyst but also to regenerate the catalyst (which in the fresh state may contain one or more metals with hydrogenation activity), so that it can again be used for catalytic purposes. The present invention therefore relates not only to a process for extracting vanadium and optionally nickel from a deactivated catalyst but also to a process in which this extraction is carried out in such a way as to obtain a regenerated catalyst which can again be used for catalytic purposes. , either as such or after a supplementary amount of metals with hydrogenation activity has been added to the catalyst. The process according to the invention is particularly important for the extraction of vanadium and possibly nickel from a catalyst, which consists mainly of silica, in combination with the regeneration of the catalyst, which has been used in a process for hydromethalization of a hydrocarbon oil. The invention is further illustrated by the following exemplary embodiments, in which the temperature indications refer to degrees Celsius.

Example 17 A catalyst comprising 0.5 parts by weight of nickel and 2.0 parts by weight of one part vanadium per 100 parts by weight of silica support was prepared by z; ~~ W ~ w-vi, y;. ~ F- = ~ w «wn ~ ,,,. 7803321-4 impregnation of a silica support with an aqueous solution of nickel nitrate and vanadyloxalate, after which the composition was dried and calcined. The catalyst (catalyst A) was used in sulphidic form for the hydroavmetalization of hydrocarbon oil (oil A) with a total vanadium and nickel content of 62 parts by weight, a C5 asphaltene content of 6.4% by weight and a sulfur content of 3.9% by weight and which oil had been obtained as a residue in distillation at atmospheric pressure of a crude oil from the Middle East. The hydrometallization was carried out by passing the oil and hydrogen in a downward direction through a cylindrical, vertically modified stationary catalyst bed at a temperature of 4200, a total pressure of 150 bar, a volume velocity of 5 kg.l_l.h_l and a gas flow rate (measured at reactor outlet) of 25ONl H2.kg_l.

The activity of the catalyst, expressed as "% vanadium removed" (= average vanadium removal during the life of the catalyst from 1 ton of oil / kg of catalyst to 4 tons of oil / kg of catalyst), was 51.

After the catalyst was deactivated in this process, it was extracted with toluene to remove residual oil residues, and after evaporation of the toluene from the catalyst, it was analyzed. The deactivated catalyst (Catalyst B) contained 9.7 parts by weight of carbon, 20.6 parts by weight of sulfur, 4.1 parts by weight of nickel and 24.3 parts by weight of vanadium per 100 parts by weight of silica. Example 2 5 kg of decatalyst was charged with a 4: 1 mixture of steam and nitrogen for 3 hours at 350 °, at atmospheric pressure and with a gas flow rate of 2N1 gas mixture. (g catalyst) * l.h_l. The catalyst is heated to a 1: 9 mixture of air and nitrogen at 4000 for 50 hours, at atmospheric pressure with a gas flow rate of 1 Nl gas mixture (g catalyst) _l.h_l. Finally, the catalyst was extracted for 2 hours at 900 with stirring with 40 liters of 2 N sulfuric acid, which had been saturated with sulfur dioxide. After washing the extracted catalyst with water, it was dried at 120 ° and calcined at 550 ° for 3 hours. Upon analysis of the catalyst thus obtained (Catalyst C), 96% of the vanadium and 95% of the nickel were found to have been removed from the catalyst by this treatment.

Example 3 - 5 kg of catalyst B were treated with steam for 5 hours at a temperature of 350 °, a pressure of 3 bar and a volume velocity of 7803321-4 l -1 2.6 kg of steam. (Kg of catalyst) - .h. The catalyst was then extracted for 2 hours at 900 with stirring with 40 liters of 2 N sulfuric acid.

After washing the extracted catalyst with water, it was dried at 1200. Upon analysis of the catalyst thus obtained (Catalyst D), 95% of the vanadium and 45% of the nickel were found to have been removed from the catalyst by this treatment.

Example 4 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the steam treatment was carried out at a temperature of 4250. Upon analysis of the catalyst thus obtained (catalyst E), 90% of the vanadium and 60% were found. of the nickel have been removed from the catalyst by this treatment.

Example 5 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the steam treatment was carried out at a pressure of 6 bar.

In the analysis of the catalyst thus obtained (catalyst F), 93% of the vanadium and 57% of the nickel were found to have been removed from the catalyst by this treatment.

Example 6 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the acid extraction was carried out for 1 hour with 20 liters of 4 N sulfuric acid. In the analysis of the catalyst thus obtained (catalyst G), 96% of the vanadium and 60% of the nickel were found to have been removed from the catalyst by this treatment.

Example 7. 5 kg of Catalyst B were treated in a manner similar to that of Example 3, but now the acid extraction was carried out for 1 hour with 20 liters of 6_N sulfuric acid. In the analysis of the catalyst thus obtained (catalyst H), 96% of the vanadium and 75% of the nickel were found to have been removed from the catalyst by this treatment. A Example 8 V 5 kg of catalyst D; which, like Catalysts B, E, F, G and H containing 9.7 parts by weight of calcium per 10 parts by weight of silicon auxia, was treated with a 1: 5 mixture of air and nitrogen at 400 ° for 10 hours, at atmospheric pressure and at a gas flow rate. of 1 Nl gas mixture. (g catalyst) f; .h-1. Analysis of the catalyst thus obtained (Catalyst I) showed that it contained only 0.1% by weight of carbon dioxide per 10 parts by weight of chiseloxyl. Example 9 5 kg of catalyst I was extracted for 2 hours at 900 with 5 liters of 2 N sulfuric acid. After the extracted catalyst was washed with water, it was dried at 120 ° and calcined for 3 hours at 5509. Analysis of the catalyst thus obtained (catalyst J) showed that in relation to the deactivated catalyst B 99% of the vanadium and 99% of the nickel had been removed from the catalyst.

Example 10 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the steam treatment was carried out at a temperature of 2000 and at a pressure of 4 bar. In the analysis of the catalyst thus obtained (catalyst K), 46% of the vanadium and 35% of the nickel were found to have been removed from the catalyst by this treatment.

(Example 11 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the steam treatment was carried out at a pressure of 0.5 bar.

Upon analysis of the catalyst thus obtained (Catalyst L), it was found that 71% of the vanadium and 43 of the nickel had been removed from the catalyst by this treatment.

Example 12 - 5 kg of catalyst B were treated in a manner similar to that of Example 3, but now the steam treatment was carried out at a pressure of 1.0 bar.

In the analysis of the catalyst thus obtained (catalyst M), 80% of the vanadium and 43% of the nickel were found to have been removed from the catalyst by this treatment.

Example 13 A catalyst containing 0.5 parts by weight of nickel and 2.0 parts by weight of vanadium per 100 parts by weight of silica support was prepared by impregnating Catalyst C with an aqueous solution of nickel nitrate and vanadyl oxalate, after which the composition was dried. The catalyst C 'thus obtained was used in sulphidic form for the hydroavmetalization of oil A under the same conditions as the hydroavmetalization of this oil with catalyst A according to Example 1. The activity of catalyst Cj expressed as "% vanadium removed" was 48.

Example 14 Catalysts containing 1.0 + 2.8 parts by weight of nickel and 2.0 parts by weight of vanadium per 100 parts by weight of silica support were prepared by impregnating Catalysts D, E, F, G, H and I with an aqueous .._ ~. ~ __-, ------ ~ ---- ~ - ~ - - »._ _. - is .. .... m -.-._.._-.........- e ....., ..., .. ,, i _.... ~ ....., _ ___ ___,. . 7 _ - ~ r- .- .. ~ ............; \ _ ~ ._-_ t _.....-............ ..-.- W .... ~ M ,. ~ »-e ,,.«, .- ~.-1f ,,, w -.- l_ WW ......._ r ._. M_ __... ____ [_ _ 7803321-4 9 solution of vanadyl oxalate, after which the compositions were dried. The dried catalysts D ', E', F ', G', H 'and I' thus obtained were used for hydroavmetalization of oil A in the same manner as described in Example 13. The activities of catalysts D ', E', F ", fy G", H 'and I ", expressed as"% vanadium removed ", were 47, 48, 49, 48, 49 and 51, respectively.

Example 15 In the same manner as described in Example 13, a catalyst J 'was prepared from Catalyst J and used for the hydrodemetallization of oil A. The activity of Catalyst J', expressed as "% vanadium removed", was 51.

Of Embodiments 1-15 above, Examples 3-9, 14 and 15 are examples of embodiments of the present invention. Other examples have been incorporated for comparison purposes.

Thus, Example 1 relates to hydro demetallization, in which a fresh catalyst A is deactivated to a deactivated catalyst B.

Example 2 relates to the three-step process described above, in which a regenerated catalyst C is prepared from the deactivated catalyst B and in which it takes a total of 53 hours to carry out the first two steps. Examples 3-7 relate to the improved process of the invention, in which regenerated catalysts D-H are prepared from the deactivated catalyst B. A mutual comparison between Examples 2-7 shows that the process of the present invention leads to the same excellent vanadium removal as the three-step process. However, the steam treatment at a pressure above 1.5 bar, which has replaced the first V and the second stage of the three-stage process, takes only five hours.

Example 8 relates to treatment with an oxygen-containing gas at elevated temperature of the carbon- and nickel-containing, regenerated catalyst H, giving a catalyst I, where the carbon has been removed. Example 9 relates to acid extraction of the nickel-containing, regenerated catalyst I, which gives a catalyst J from which the nickel has been removed. Examples_10-12 relate to the treatment of the deactivated catalyst with steam followed by acid extraction, where "regenerated catalysts" K-M are prepared starting from the deactivated catalyst B.

During the steam treatment, in Example 10 the temperature was too low and in Examples 11 and 12 the pressure was too low. This resulted in 1 fi »

Claims (11)

x %% fi Wßïßwwr ~ fl ayy W »7803321-4 l0 an unsatisfactory vanadium removal for the catalysts K-M (and consequently in a low activityl). Examples 13-15 show that catalysts which have been regenerated according to the present invention (catalysts D'-J ') show the same high activity as a catalyst which has been regenerated according to the three-step process (catalyst C'). Patent claims 1. An improved process for extracting vanadium from a deactivated catalyst, in which process vanadium is extracted from a catalyst which has been deactivated by using a vanadium-containing hydrocarbon oil with hydrogen at elevated temperature and elevated pressure, during which treatment of the catalyst vanadium content has increased by at least 10 parts by weight, and in which process the vanadium extraction, the vanadium content of the catalyst being reduced by at least 40% of the amount by which it has increased during deactivation (the vanadium content of the catalyst is expressed in parts by weight of vanadium / 100 parts by weight of catalyst support) , is carried out by extracting the deactivated catalyst with an aqueous solution of a mineral acid (hereinafter referred to as "acid extraction"), after which the vanadium is separated from the vanadium-containing solution thus obtained, characterized in that acid ex. get the traction preceded by a treatment of the deactivated catalyst with steam at a temperature island above 25 ° C and at a pressure above 1.5 bar. lÉ_ 2. A process according to claim 1, characterized in that the treatment of the deactivated catalyst with steam is carried out at a temperature below 550 ° C and preferably between 325 and 425 ° C. Ni _ 3. A process according to claim 1 or 2, characterized in that the treatment of the deactivated catalyst with steam is carried out at a pressure below 10 bar and preferably between 2 and 7 bar. 4. A process according to any one of claims 1-3, characterized in that the acid extraction is carried out at elevated temperature and preferably at a temperature above SOOC. Process according to one of Claims 1 to 4, characterized in that the acid extraction is carried out with an aqueous solution of sulfuric acid. fšå Process according to one of Claims 1 to 5, characterized in that the carbon is removed from the catalyst by treating it after the oxygen extraction with an oxygen-containing gas at elevated temperature. 'A- pff 7803321-4 ll 7. A process according to claim 6, characterized in that the nickel is removed from the catalyst by subjecting it again to an oxygen extraction after the treatment with an oxygen-containing gas. 8. A process according to claim 6, characterized in that to remove nickel a side stream of the catalyst which has been treated at elevated temperature with an oxygen-containing gas is again subjected to an acid extraction, and that the catalyst side stream from which the nickel has removed, the main stream is fed to the nickel-containing catalyst from which carbon has been removed. 9. A process according to claim 1-5, characterized in that a side stream of the regenerated catalyst is in turn subjected to a treatment with an oxygen-containing gas at elevated temperature and an acid extraction, and that the catalyst side stream , from which nickel and carbon have been removed, is added to the nickel and carbonaceous catalyst. . 10. l0. Process according to any one of claims 1 to 9, characterized in that it is carried out in such a way that a regenerated catalyst is obtained, which can again be used for catalytic purposes, either as such or after a supplementary amount of metals with hydrogenation activity has been added to it. 11. ll. Process according to Claim 10, characterized in that it is applied to a catalyst which consists essentially of silica and which has been used in a process for the hydrometallization of a hydrocarbon oil.4