Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
  • C10G45/02—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
  • C10G45/04—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used
  • C10G45/06—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing nickel or cobalt metal, or compounds thereof
  • C10G45/08—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing characterised by the catalyst used containing nickel or cobalt metal, or compounds thereof in combination with chromium, molybdenum, or tungsten metals, or compounds thereof
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/18—Solvents

Definitions

• This invention concerns a process for hydrogenating aromatic compounds, particularly such aromatic compounds as benzene, alkylbenzenes, polycyclic aromatic hydrocarbons and their alkyl derivatives, alone or diluted in various petroleum cuts, in the presence of a composite catalyst system which has in particular the advantage of permitting the treatment of materials having high sulfur compound contents and of providing a product which is not only dearomatized but also desul furized.
• An important application of this invention consists of hydrogenating aromatic compounds present in certain petroleum cuts such as white spirit, commonly used in various industries such as those of paint, rubber, solvents for use in agriculture etc.
• Another application which is not less important, is the hydrogenation of the aromatic hydrocarbons present in the kerosene cuts, used as fuel, in view of improving their smoke point; this empirical index is in fact proportional to the ratio of hydrogen to carbon in the considered hydrocarbon or cut.
• This ratio H/C is directly responsible for the combustion heat which is higher as the ratio I-I/C is greater, i.e. when the aromatic hydrocarbons have been more completely hydrogenated.
• the processes performed in a single stage using catalysts comprising metals of the iron group (iron, cobalt, nickel) of the periodic classification of elements, associated with metals of group VI A.
• the catalysts are active in the sulfurized state.
• the catalysts used in this category of processes perform simultaneously the hydrodesulfurization of the feed charge and a certain hydrogenation of the aromatic compounds.
• the final contents of aromatic hydrocarbons are generally high 3 to 5% by volume as a minimum) and do not permit the production of sufficiently dearomatized sol-' vents.
• a certain amount of hydrocracking is always observed and requires subsequent fractionations which increase the cost of the process.
• the second category of processes performed in two stages makes use of catalysts comprising metals of group VIII acting in the metal state after reduction.
• the catalysts generally, used are either based on nickel, or on noble metals such, for example, as platinum.
• the catalysts are particularly sensitive to the presence of sulfur compounds and/or hydrogen sulfide. It is accordingly necessary to desulfurize the charges and to remove H 8 before the hydrogenation step so that a charge whose sulfur content is generally smaller than 50 ppm (parts per million of parts) is contacted by the hydrogenation catalyst.
• the process consists of treating, in the presence of hydrogen, at a temperature of from 200to 450C, preferably from 250 to 350C, under a. pressure of from 10 to 200 Kglcm preferably from i 20 to Kg/cm at least one aromatic hydrocarbon in a reaction system comprising in successiveorder: first of all a hydrodesulfurization catalyst adapted to retain the hydrogen sulfide formed during the hydrodesulfurization reaction and then a hydrogenation catalyst, without intermediary fractionation.
• the treated material may consist for example of benzene, alkylbenzenes,
• the treated feedstocks generally have boiling points within the range of from 50 to 350C and may be obtained by straight run distillation of petroluem or by any other operation of refining and/or transformation of petroleum cuts. They may contain for example from 1 to substantially of aromatic hydrocarbons.
• the catalyst used according to this invention for simultancously removing the sulfur compounds from the feedstock and retain the hydrogen sulfide formed during the dehydrodesulfurization reaction comprises essentially:
• At least one element active for hydrodesulfurization as known in the art, for example molybdenum and/or tungsten, with or without nickel and/or cobalt, and preferably cobalt-molybdenum, nickel molybdenum, cobalt-tungsten, nickel-tungsten etc. particularly in the form of oxides or.sulfides;
• bauxite is dissolved in a soda lye: the obtained sodium aluminatesolution is separated from an insoluble residue, called red mud. The red mud is then washed with waterfojr extracting soda and sodium aluminate therer m!
• iron source there can be used an iron salt, for ex ample a nitrate, acetate, carbonate, sulfate or chloride, although this is less preferable.
• the proportion of active elements, molybdenum, tungsten, cobalt and/or nickel oxides and/or sulfides in the catalyst is generally from 2 to 40%, expressed by weight of vthejcorresponding metal.
• a preferred catalyst contains from 5 to 35% by weight of molybdenum and- /or tungsten and from 1 to by weight of nickel and- /or.-cobalt calculated as metal.
• the catalyst has a specificsurface generally from 50 to 400 m /g, preferably from 100 to 300 m /g.
• the material containing iron oxide also contains alumina; it is the case of the red muds; however, these red muds generally do not permit, by themselves, to obtain a catalyst having the required specific surface, unless a certain proportion of conventional alumina such as, for example, an alumina gel, is added thereto.
• the so-composed catalyst is particularly interesting since it performs the hydrodesulfurization reaction over a relatively long period without formation of hydrogen sulfide in the gaseous and/or liquid effluents. in contrast to the use of conventional hydrodesulfurization catalysts, such as Co Mo, Ni M0 or Ni W supported on alumina, for example.
• This catalyst is also very-interesting in that it is easily regenerated by a mere treatment with steam, so that its use results in an economical and really continuous process.
• the compounds of metals which are precursors of species active for hydrodesulfurization may be introduced into the catalyst either by mixing with the mixture alumina iron oxide or red muds or by impregnating of the mixture alumina-l-iron oxide or red muds preliminarily brought to the desired shape, for example by extrusion.
• the catalyst carrier there will advantageously be used ratios of A1 0, to red muds, from 9 to 0.1 l by weight and preferably from 2.3 to 0.43 these values being not limitative.
• Another technique consists of mixing, as homogeneously as possible, the particles, extrudates for example, of a conventional hydrodesulfurization catalyst with particles, e.g. extrudates, of iron oxide and/or red muds.
• metals of group VIII of the periodic classification of elements such as Ni, Co, Pt, Rh, Ru, Pd etc. incorporated to (or deposited on) any carrier such for example as alumina, silica, alumina-silica etc.
• metals may be used alone or in association in the form of mixtures and/or alloys with one another or with an element from groups VI A or VII A such for example as: W, Mo, Re,
• the content of metal from group VIII is generally from 0.1 to 1.5% by weight of the catalyst.
• molybdenum, tungsten, nickel, cobalt or noble metal compounds which can be used for manufacturing the abovementioned catalysts need not to be listed here, since they are well-known in the art.
• the two catalysts in the process of the invention may be used in different manners.
• the two catalysts may be catalysts are placed in two successive reactors which are traversed in successive order by the totality of the reactants.
• the absorbing hydrodesulfurizing catalyst is placed in two reactors branched in parallel and used alternatively, one being in regenera-' tion, while the other is in operation, the hydrogenation catalyst being placed in a third reactor following the hydrodesulfurization reactor in operation.
• An important feature of the process described in the present invention is that, irrespective of the retained flow sheet and of the use of a single reactor or successive reactors, there is still obtained an integrated system which does not require any intermediate treatment of the effluents (such as for example cooling, separation, gas expansion Moreover, the operating conditions are such that practically no hydrocracking occurs and therefore, it is unnecessary to provide for a fractionation system of the liquid product.
• the regeneration of the absorbing hydrodesulfurizing catalyst may be easily carried out by passing steam through the catalyst bed, for example at a temperature from to 600C and preferably from 350 to 450C, these values being not limitative.
• This treatment may be applied only to the absorbing-hydrodesulfurizing catalyst or to both catalysts used according to the invention.
• the steam may be either pure or diluted with inert gas; for example gas produced by the combustion of hydrocarbons may be convenient.
• a steam content of at least 10% in the regeneration gas is preferred.
• This regeneration is appropriate as soon as there is observed the presence of a noticeable proportion of free H S in the effluent issuing from the first catalyst zone. During the regeneration, H S is liberated from the catalyst. The regeneration may be discontinued as soon as H S is no longer liberated in a noticeable amount.
• the regeneration period is generally from minutes to 48 hours according to the selected steam flow rate.
• This regeneration is advantageously followed by a scavenging with hydrogen so as to expel the residual hydrogen sulfide.
• the p.p.h. will be advantageously from 0.2 to 10 and preferably from 0.5 to 5; the optimal p.p.h. depends on the sulfur content of the feedstock and of the ratio alumina/iron oxide of the catalyst; for example, for feedstock containing from 300 to 600 ppm of sulfur, treated over a catalyst having a ratio alumina/red muds of l, the p.p.h. values may be chosen in the range of from 0.5 to 2.
• the selected p.p.h. over the hydrogenation catalyst depends on the desired aromatic hydrocarbons content of the hydrogenated product; it will generally be in the range of from 1 to and preferably from 5 to 15.
• the first catalyst is a hydrodesulfurization catalyst containing cobalt oxide and molybdenum oxide in a proportion of 4.7% by weight of C00 and 13.6% by weight of M00;, admixed with an alumina gel.
• the incorporation of the metal oxides is carried out in a conventional manner, for example by mixing, in the presence of a small amount of water, the alumina gel with the desired proportion of cobalt nitrate and ammonium paramolybdate; the resulting paste is extruded and then calcined in air at about 550C so as to obtain the corresponding oxides of cobalt and molybdenum.
• Another equivalent method for incorporating the metal oxides consists of impregnating the alumina, preliminarily brought to the desired shape, by means of aqueous solutions of catalyst metals and then calcining as above in air at about 550C.
• the second catalyst is a hydrogenation catalyst containing 0.3% by weight of platinum deposited on an alumina carrier.
• the deposit of platinum is carried out in a conventional manner by impregnating the carrier with an aqueous solution of hexachloroplatinic acid and then drying and calcining at about 550C.
• the third catalyst is an absorbing hydrodesulfurization catalyst containing 4.7% by weight of cobalt oxide and 13.6% by weight of molybdenum oxide introduced by mixing cobalt nitrate and ammonium molybdate with an alumina-red mudmixture having a ratio alumina/red mud equal to 0.67, i.e. containing 40% by weight of alumina and 60% by weight of red muds; the
• Shape extrudates of a 1.5 mm diameter Filling density: 0.61 g/cc Total pore volume: 0.7 cc/g Specific'surface: 214 m /h (B.E.T. method) Absorbing hydrodesulfurizing catalyst (A.HDS.CATA.)
• the feedstock subjected to hydrogenation consists of a petroleum cut from straight run distillation, of the white spirit type, having the following characteristics:
• Aromatic content 17.5% by volume
• the desired final product is a solvent which does not contain more than 3% by volume of aromatic compounds.
• H /feed stock 1.5 moles/mole 2.
• H /feed stock 1.5 moles/mole 2.
• H /feed stock 1.5 moles/mole 2.
• the same white-spirit is hydrogenated in a reactor containing two successive beds of catalyst: the first bed is formed from the hydrodesulfurization catalyst (HDS. CATA.) and the second bed from the platinum hydrogenation catalyst (H. CATA.
• the device although operating with a p.p.h. value of 8 over a platinum hydrogenation catalyst gives better results than the device of test 2 with a p.p.h. value of 4 (8/2) over the hydrogenation catalyst.
• EXAMPLE 3 In this example the feedstock subjected to the treatment is kerosene and it is intended to improve its smoke point; for this purpose there iscarried out a par- I tial hydrogenation of the aromatic hydrocarbons contained therein.
• the device used for carrying out this test is the following:' 1
• the hydrodesulfurization catalyst also acting as H 5 absorbent is placed into two parallel reactors, one of which is in a regeneration phase while the other is in operation; the hydrogenation reactor is placed at the outlet of the operating hydrodesulfurization 'reactor' without using any intermediary fractionation device.
• H.CATA are identical to those described in example l. v
• the conditions of pressure, temperature and ratio of the hydrogen to the feedstock are the same for both operating reactors:
• the first reactor containing the absorbing hydrodesulfurizing catalyst is then put in regeneration under a stream of steam as indicated in Example 2, while the second reactor containing the absorbing hydrodesulfurizing catalyst is put in operation until the smoke point limit is reached.
• EXAMPLE 4 alumina and red muds with a ratio of the aluminaa to the red muds equal to 0.67 by weight.
• the hydrogenation catalyst is the same as in the third test of example i.
• the operating conditions are in any respect identical to those of test No. 3 of example I.
• the obtained results are given in the following table:
• EXAMPLE 5 There is carried out again a test identical to test No. 3 of example i, but using an absorbinghydrodesulfurizing catalyst based on nickel-tungsten.
• the catalyst prepared as described in example l from nickel nitrate and ammonium tungstate, contains 4.7% by weight of nickel oxide and 2i .8% by weight of tungsten oxide on a carrier of alumina and red muds with a ratio of the alumina to the red muds of 0.67 by weight.
• H-C 8 l A process for hydrogenating a feedstock of aro- The results obtained are given in table Ill below: matic compounds containing sulfur impurities in which TABLE III Operating 50 l()() 151i 200 320 240 2m 2x0 sou time in hours Smoke point 30 30 29 m5 :7 In 24.5 235 23 in mm ii by volume of (1.5 (L5 1.7 2.2 4.l .3 8.2 10.3 ll residual aromatics yields 71 h. ⁇ '. 100 100.5
• a mixture of hydrogen with at least one aromatic compound containing sulfur impurity is contacted, at a temperature of from 200 to 450C, under a pressure of from 10 to 200 kg/cm"; in successive order with:
• At least one desulfurizing element selected from the oxides and/or sulfides of molybdenum, tungsten, nickel and cobalt;
• red mud contains, by weight, from 30 to 60% of iron, ex pressed as Fe O from 1 to 10% of titanium, expressed as TiO from 5 to 20% of silicon, expressed as SiO from 5 to to l5% of sodium, expressed as Na co and from 5 to 30% of aluminum, expressed as A1 0 6.
• the catalyst contains from 5 to 35% by weight of molybdenum and/or tungsten oxide/or sulfide and from i to 10% by weight of nickel and/or cobalt oxide or sulfide, expressed as metal.

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• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Catalysts (AREA)

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Cited By (22)

Citations (7)

• 1972
  • 1972-09-01 FR FR7231209A patent/FR2197967B1/fr not_active Expired
• 1973
  • 1973-07-27 BE BE1005262A patent/BE802861A/xx not_active IP Right Cessation
  • 1973-08-09 DE DE19732340337 patent/DE2340337A1/de active Pending
  • 1973-08-23 JP JP48094805A patent/JPS4966704A/ja active Pending
  • 1973-08-24 GB GB4023273A patent/GB1418328A/en not_active Expired
  • 1973-08-31 IT IT28458/73A patent/IT998521B/it active
  • 1973-08-31 US US393607A patent/US3899543A/en not_active Expired - Lifetime
  • 1973-08-31 NL NL7312090A patent/NL7312090A/xx not_active Application Discontinuation

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