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
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/202—Heteroatoms content, i.e. S, N, O, P
• • 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
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/20—Characteristics of the feedstock or the products
  • C10G2300/201—Impurities
  • C10G2300/207—Acid gases, e.g. H2S, COS, SO2, HCN
• • 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
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/40—Characteristics of the process deviating from typical ways of processing
  • C10G2300/42—Hydrogen of special source or of special composition
• • 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
  • C10G2400/02—Gasoline

Definitions

• the present invention relates to a process for producing low sulfur hydrocarbons.
• This invention applies primarily to hydrocarbon mixtures which contain an olefin fraction generally greater than 5% by weight and most often greater than 10% by weight, and at least 50 ppm by weight of sulfur.
• the method makes it possible to use hydrogen containing very low CO contents, but relatively high CO 2 contents without the performance of the catalysts used during the hydrodesulfurization step being significantly affected. This makes it possible to diversify the possible sources of hydrogen and / or to simplify the treatment of hydrogen, without the need for a very thorough elimination of CO2.
• the hydrodesulphurization processes are based on the treatment of hydrocarbon cuts on a catalyst containing non-noble sulphide metals and supported on a mineral support, in the presence of hydrogen.
• the metals used generally contain at least one Group VIII metal (for example cobalt) and optionally a Group VI B metal (for example molybdenum) of the periodic table of elements.
• the catalytic formulations most often encountered are based on Co and Mo or Ni and Mo deposited on alumina.
• the catalyst and the operating conditions are optimized to limit the degree of hydrogenation of olefins, while maximizing the conversion rate of organic sulfur compounds into H 2 S.
• such processes have in particular been described in European patents EP 1 031 622 and EP 1 250 401.
• Hydrodesulfurization processes can use hydrogen from multiple sources.
• the main source of hydrogen in the refinery is catalytic reforming.
• the catalytic reforming unit produces hydrogen in aromatic naphthenes dehydrogenation and dehydrocyclization reactions. This hydrogen has a rate of purity generally between 60% and 90% but is substantially free of CO and CO 2 .
• hydrogen can also be produced by steam reforming light hydrocarbons or by partial oxidation of various hydrocarbons, especially heavy residues.
• the steam reforming process consists of converting a light hydrocarbon feedstock into synthesis gas (H 2 , CO 2 , CO 2 , CH 4 , H 2 O mixture) by reaction with steam on a nickel-based catalyst.
• Partial oxidation hydrogen production consists in treating a hydrocarbon fraction by oxidation with oxygen at high temperature to produce a synthesis gas consisting of CO, CO 2 , H 2 and H 2 O.
• a synthesis gas consisting of CO, CO 2 , H 2 and H 2 O.
• the production hydrogen is accompanied by a production of carbon oxides which are generally substantially eliminated either by methanation or by adsorption.
• the residual contents of carbon oxides (CO and CO2) may in some cases be greater than 50 ppmv, or 100 ppmv or more.
• Other sources of hydrogen are also sometimes used, such as hydrogen from catalytic cracking gases, which contains significant amounts of CO and CO2.
• CO and CO2 may be contributed by the hydrocarbon feed itself, in the form of dissolved gas, if the feed has been in contact with traces of these gases upstream.
• Refinery hydrogen, and hydrogen at the reaction zone of a hydrotreatment may therefore contain varying amounts of CO and CO2.
• the most used technique, when using or producing hydrogen containing CO and CO2 is to perform a treatment of total elimination of these impurities, typically by "PSA, or pressure swing adsorption", which means “Adsoption by pressure variation”. This technique is however expensive, and consumes some of the available hydrogen.
• One of the aims of the invention is to allow the proper functioning of hydrotreatments, especially hydrotreatments for the selective desulfurization of olefinic cuts (typically gasolines), while using more diversified hydrogen sources, and typically treatments. less advanced purification.
• Another object of the invention is to reduce hydrogen consumption by reducing the hydrogen purge rate at the hydrotreatment level (purge of a part of the recycle gas around the hydrodesulphurization reactor).
• a stage of pretreatment of the hydrogen of CO 2 oxidation in CO 2 without extraction of the CO 2 thus formed made it possible to overcome the harmful effect of carbon oxides, and this, even for CO 2 contents greater than 200 ppmv.
• the economics of an expensive step of almost total CO2 removal is a very significant benefit, as well as the possibility of using less pure hydrogen sources.
• a desulfurization process of hydrocarbon cuts compatible with a very low CO content, but a significant COx content.
• This process preferably comprises a step of selective oxidation of the CO contained in the hydrogen to CO 2 and a hydrodesulfurization step, the two steps being carried out successively, typically without intermediate extraction of the CO 2 formed.
• the main processes for substantially eliminating CO are the methods of oxidation of CO 2 to CO 2, which are preferred according to the invention, and the methods of methanation of CO (in methane).
• the principal processes for oxidizing CO 2 to CO 2 are the steam conversion reaction which makes it possible to convert CO to CO 2 by reaction with water vapor carried out for example on a nickel-based catalyst, or the reaction selective oxidation of CO to CO 2 by oxygen.
• This second option (the most preferred according to the invention) is developed in more detail in the present application. Methods for the selective oxidation of CO to CO 2 by oxygen are described in the literature.
• the COx content is less than 10,000 ppmv, and most often 5000 ppmv.
• the COx content is between 120 and 1000 ppmv, and very generally between 120 and 500 ppmv.
• the method according to the invention does not exclude an operation in which for a portion of the time the COx content is less than 120 ppmv, or 50 ppmv or even less. This can occur for example when the sources of "clean" hydrogen, substantially free of CO and CO2, are available in sufficient quantity to supply the different consuming units (which depends on the nature of the crude oil treated).
• the invention provides a process for the hydrodesulphurization of an HC hydrocarbon fraction comprising at least 5% by weight of olefins, in which said hydrocarbon fraction is mixed, an additional hydrogen HYD stream, and generally a current REC recycling hydrogen, to form an overall feed that is fed to the inlet of at least one reactor comprising a desulfurization catalyst, under operating conditions for converting the organic sulfur compounds of the HC cut into H 2 S, in which the hydrogen source (s) forming the HYD current is chosen, and optionally at least one hydrogen purification treatment carried out on HYD, REC (or a fraction of REC), or their mixture, of so that said overall charge comprises at most 50 ppmv of CO, and comprises at least 120 ppmv of COx for at least a significant fraction of the time.
• the aforementioned purity conditions [at most 50 ppmv of CO (or 20, or 10 ppmv) and at least 120 ppmv of COx for at least a significant fraction of the time] are according to the invention also obtained on the current Hydrogen HYD make up.
• the best qualities of extra hydrogen are those in which the CO content is very low (less than 10 ppmv, and preferably less than 5 ppmv), and in which the CO 2 / CO ratio is high (eg greater than 5, or 10, for example between 5 and 60).
• a recycle hydrogen recycle stream is used around the hydrodesulphurization unit, a purge stream WGAS is also used to avoid an accumulation of impurities.
• the hydrogen loop tends to concentrate CO and CO2.
• the invention which leads to accepting significant amounts of CO2, then makes it possible to increase the recycling rate REC / HYD, which can exceed 4, or even be between 6 and 30. This leads to reducing the hydrogen purge WGAS needed.
• the purge rate can be advantageously controlled so that the CO content in the overall feed is less than 50 ppmv, and preferably less than 20 ppmv, but, but the COx content in the overall feed is greater than 120 ppmv.
• the process typically comprises at least one T1 hydrogen purification treatment carried out on HYD, REC, or their mixture, this T1 treatment producing a limited CO2 removal leading to at least 200 ppmv of CO2 being obtained in the overall charge.
• the process comprises at least one T2 treatment of hydrogen purification carried out on HYD, REC, or their mixture, this T2 treatment performing a catalytic oxidation of CO by O2 and / or H2O to obtain at most 50 ppmv of CO (and preferably at most 20 ppmv) in the overall charge.
• the oxidation can be carried out by the process of converting CO to water vapor, known as "shift conversion", which can be carried out in one or two stages.
• the process comprises a hydrogen purification treatment carried out on HYD, and optionally on REC (or a part of REC) or their mixture, this treatment comprising a T2 treatment producing a catalytic oxidation of CO by O 2 (preferential oxidation of CO with respect to the hydrogen present), followed directly and without secondary removal of CO2 by the desulfurization of the HC section in the presence of the stream of hydrogen thus purified. It is also possible to combine a conversion with steam, typically low temperature, and a final preferential oxidation.
• the process may comprise at least one T3 hydrogen purification treatment carried out on HYD, REC, or their mixture, this T3 treatment producing a catalytic methanation of CO by H 2 in order to obtain at most 50 vppm of CO in the overall charge.
• the process often comprises a hydrogen purification treatment carried out on HYD, and optionally on REC or their mixture, this treatment comprising T3 carrying out methanation of CO by H 2, directly followed and without secondary removal of CO2 by the desulfurization of the HC section in the presence of the stream of hydrogen thus purified.
• the process comprises a hydrogen purification treatment carried out on HYD, and optionally on REC (or a part of REC) or their mixture, this treatment comprising a T2 treatment producing a catalytic oxidation of CO by O 2, followed directly and without secondary removal of CO2 by the desulfurization of the HC section in the presence of the stream of hydrogen thus purified.
• This hydrogen can then be treated by a preferential oxidation treatment T2 with oxygen (or by conversion to steam then preferential oxidation), and mix it preferably with another source of very pure hydrogen (catalytic reforming hydrogen, substantially free of CO and CO2), with a suitable flow rate to obtain a final make-up hydrogen having a CO content of less than or equal to 10, or even 5 ppmv, and a CO 2 content of between 120 and 1000 ppmv.
• a preferential oxidation treatment T2 with oxygen or by conversion to steam then preferential oxidation
• Another source of very pure hydrogen catalytic reforming hydrogen, substantially free of CO and CO2
• a suitable flow rate to obtain a final make-up hydrogen having a CO content of less than or equal to 10, or even 5 ppmv, and a CO 2 content of between 120 and 1000 ppmv.
• the amount of H 2 S contained in the hydrogen should generally not exceed 10 ppmv (ppm volume), and preferably 1 ppmv before the preferred oxidation step.
• the copper blade test well known the person skilled in the art must prove negative. It is therefore necessary to purify hydrogen sulfide hydrogen by any method well known to those skilled in the art. There may be mentioned, for example, the methods of absorption, extraction or washing with amines or chemical conversion treatments of H 2 S, without this list being able to limit in any way the treatments that can be used according to the invention. .
• the preferred oxidation step of CO 2 CO 2 according to the present invention can be carried out for example on a selective catalyst in the presence of hydrogen.
• the metals which can carry out this reaction can be chosen from the group of noble metals, Pt, Pd, Ru, Rh, Ir, Au or else Cu, Cr, V, Mn or Ce.
• the metals can be used alone or in combination with other metals or even in the form of alloys. They can be used in massive metallic form (filaments, foam, sponge etc.) or supported on porous refractory oxides such as alumina, ceria, anatase or rutile, zirconia, silica, oxide ferric iron ( ⁇ -Fe 2 O 3 ) or zinc oxide.
• the preferred oxidation reaction of CO according to this invention can be carried out for example on a finely divided gold catalyst on ferric hydroxide.
• Such a catalyst can be prepared by a method described in the publication by Haruta et al, J. Catal., 1993, 144, p.175 but it can also be prepared according to any other protocol described in the literature.
• the catalyst is prepared, for example, by coprecipitation of a solution containing HAuCl 4 .3H 2 O and Fe (NO 3 ) 3 .9H 2 O and a solution containing sodium carbonate. These two solutions are gradually added and then vigorously stirred in a precipitation reactor containing distilled water. The reaction mixture is maintained at 80 ° C throughout the addition of the two solutions, throughout the operation the pH is maintained between 8 and 8.5.
• the precipitate is washed with hot water until the washing water no longer contains chloride (control by reaction with silver nitrate) and then dried at 40 ° C. in a vacuum oven for 12 hours. .
• the powder obtained is then calcined in dry air at 400 ° C. for 2 hours with an air flow rate of 0.5 l / g catalyst / h. After grinding, a powder having an average particle size of about 20 ⁇ m and a surface area of about 60 m 2 / g is obtained.
• the catalyst contains an amount of 3% by weight of Au.
• the shaping of the catalyst can be done by all the methods well known to those skilled in the art, for example, and without this being able to limit the scope of the invention, the deposit on monolith using a wash-coat (coating deposited in liquid phase), granulation, extrusion etc ...
• the hydrodesulfurization step is carried out on a catalyst which comprises at least one group VIII element and preferably a group VIII element and a group VI B element.
• the group VIII element is selected from the group consisting of nickel, cobalt, iron.
• the group VI B element if present, is preferably molybdenum or tungsten.
• the metals are deposited on an amorphous solid support selected from the group consisting of silica, silicon carbide or alumina, shaped in the form of beads or extrudates.
• the hydrodesulfurization step may advantageously be carried out in two stages, a first hydrodesulphurization step making it possible to transform more than 50% of the sulfur present in the feedstock into H 2 S, and a finishing step consisting of, at the choice of a step of hydrogenolysis of saturated sulfur compounds on a catalyst containing a Group VIII metal, or a hydrodesulfurization step on a catalyst having a lower activity than the catalyst of the first step.
• This type of sequence makes it possible to improve the selectivity of the hydrodesulfurization step.
• the catalyst or catalysts used during this step are in sulphurized form.
• the sulphurisation procedure can be carried out in situ or ex situ.
• the catalyst is sulphurized before being charged to the reactor, while in the second case, the catalyst is loaded into the reactor in the form of metal oxides, the sulphurization is carried out in the reactor by injection of H 2 S or compounds capable of decomposing into H 2 S such as DMDS and hydrogen.
• Any sulphurization method conventionally used by those skilled in the art to sulphide at least 50% and preferably 70% of the metal oxides deposited on the support can be implemented.
• the reactor pressure is generally between 0.5 MPa and 5 MPa
• the flow rate of hydrogen is such that the ratio of hydrogen flow rates in normal liters per hour on the hydrocarbon flow rate in liters per hour is between 50 and 800 and preferably between 60 and 600.
• the temperature is between 200 ° C and 400 ° C and preferably between 230 ° C and 350 ° C depending on the sulfur content of the hydrocarbon fraction to be desulphurized.
• a pilot unit consisting of a reactor with a capacity of 200 ml is charged with 100 ml of HR806S catalyst marketed by AXENS.
• This catalyst is based on cobalt and molybdenum deposited on alumina, it is delivered in presulfided form and therefore does not require a subsequent sulphurization step before contact with the load.
• the treated feedstock is a gasoline A from a catalytic cracking unit. This species has been depentanized in order to treat only the C 6 + fraction in hydrodesulfurization.
• This feed contains 425 ppm of sulfur including 6 ppm of sulfur in the form of mercaptans and a bromine number measured according to the ASTM method D1159-98 of 49 g / 100 g.
• the cutting points of this essence A were determined by simulated distillation: the essence A has points 5% weight and 95% weight respectively of 61 ° C and 229 ° C.
• Example 2 In order to measure the influence of CO and CO 2 on the performance of the catalyst, a hydrogen bottle containing 100 ppmv of CO and 350 ppmv of CO 2 is used . This hydrogen is mixed with gasoline A at flow rates identical to those of Example 1. The mixture thus formed has CO contents of 65 ppmv and CO 2 of 228 ppmv. The operating conditions are identical to Example 1. Table 2 presents the results of the tests. Table 2 Temperature ° C 260 280 300 Sulfur recipe ppm 103 25 13 HBr g / 100g 38.4 32.3 23.6 selectivity 5.8 6.8 4.8
• Example 3 is carried out according to the invention, that is to say that the hydrogen containing CO and CO 2 used in Example 2 is pretreated to oxidize the CO 2 CO 2 .
• the oxidation is carried out by mixing the hydrogen with oxygen and treating the mixture on an oxidation catalyst.
• the hydrogen is mixed with a stream of pure oxygen, whose flow rate is adjusted so that the molar ratio between oxygen and CO is 1.1.
• the reactor is operated at a temperature close to ambient temperature (50 ° C.) at a pressure of 2.1 MPa.
• the catalyst is prepared, for example, by coprecipitation of a solution containing HAuCl 4 .3H 2 O and Fe (NO 3 ) 3 .9H 2 O and a solution containing sodium carbonate. These two solutions are gradually added and then vigorously stirred in a precipitation reactor containing distilled water. The reaction mixture is maintained at 80 ° C throughout the addition of the two solutions, throughout the operation the pH is maintained between 8 and 8.5. After filtration the precipitate is washed with hot water until the washing water contains more chloride (control by reaction with silver nitrate) and then dried at 40 ° C in a vacuum oven for 12 h. The powder obtained is then calcined in dry air at 400 ° C.
• the catalyst contains an amount of 3% by weight of Au. X-ray diffraction analysis makes it possible, from the Au (111) line, to obtain a gold particle size of 60 ⁇ .
• the catalyst (100 mg, diluted 1:20 with ⁇ -Al 2 O 3 ) is then placed in a stainless steel reactor of 10 mm internal diameter and then inserted into a heated tubular furnace via a double jacket at 50 ° C.
• the implementation of the oxidation step to pretreat the hydrogen makes it possible to significantly improve the activity in hydrodesulfurization of the catalyst and to recover performance in activity and selectivity similar to those of the tests carried out with hydrogen free of CO and CO 2 presented in Example 1.

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• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Catalysts (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

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Citations (8)

• 2004
  • 2004-09-28 FR FR0410260A patent/FR2875809B1/fr not_active Expired - Lifetime
• 2005
  • 2005-08-05 DE DE602005004474T patent/DE602005004474T2/de not_active Expired - Lifetime
  • 2005-08-05 EP EP05291688A patent/EP1647590B1/de not_active Expired - Lifetime
  • 2005-08-05 AT AT05291688T patent/ATE384777T1/de not_active IP Right Cessation
  • 2005-09-28 JP JP2005281992A patent/JP4938278B2/ja not_active Expired - Lifetime

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