WO1990010684A1

WO1990010684A1 - Process for eliminating mercury and possibly arsenic in hydrocarbons

Info

Publication number: WO1990010684A1
Application number: PCT/FR1990/000162
Authority: WO
Inventors: Philippe Courty; Pierre Dufresne; Jean-Paul Boitiaux; Germain Martino
Original assignee: Institut Français Du Petrole
Priority date: 1989-03-16
Filing date: 1990-03-09
Publication date: 1990-09-20
Also published as: NO913622D0; NO180121C; CN1045596A; DE69002941T2; DZ1402A1; DE69002941D1; CA2012344C; MY106411A; NO913622L; FR2644472B1; CA2012344A1; JPH02248493A; FR2644472A1; AU5331990A; AU634763B2; EP0463044B1; JP2620811B2; NO180121B; EP0463044A1; ZA893265B

Abstract

Process for eliminating mercury and possibly arsenic from hydrocarbon fillers containing mercury and sulphur, characterized in that said filler is made to pass through in the presence of hydrogen and contact an arsenic-capturing body ('catalyst') having catalytic properties, said 'catalyst' containing at least one metal of the group consisting of nickel, cobalt, iron, palladium and platinum, at least one metal of the group consisting of chromium, molybdenum, tungsten and uranium and an active phase support, whereby said 'catalyst' is followed on the same filler path by, or is combined with, a mercury-capturing body containing a sulphide of at least one metal of the copper, iron and silver group or sulphur and an active phase support.

Description

PROCESS FOR THE REMOVAL OF MERCURY AND POSSIBLY ARSENIC

IN HYDROCARBONS

It is known that the liquid condensates by-products of gas production (natural gas, associated gas) and crude oils can contain many trace metal compounds, generally present in the form of organometallic complexes, in which the metal forms bonds with one or more carbon atoms of the organometallic radical.

These metal compounds are poisonous catalysts used in petroleum transformation processes. In particular, they poison the hydrotreatment and hydrogenation catalysts by gradually depositing on the active surface. Metallic compounds are found in particular in heavy cuts from the distillation of petroleum crude oil (nickel, vanadium, arsenic, mercury) or in natural gas condensates (mercury, arsenic).

The thermal or catalytic cracking treatments of the above hydrocarbon cuts, for example their steam cracking for conversion into lighter hydrocarbon cuts, can allow the elimination of certain metals (for example nickel, vanadium ...) ; on the other hand, certain other metals (for example mercury, arsenic ...) capable of forming volatile compounds and / or being volatile in the element state (mercury) are found at least in part in the cuts more light and can therefore poison the catalysts of subsequent transformation processes. Mercury also presents the risk of causing corrosion by the formation of amalgams, for example with aluminum-based alloys, in particular in the process sections operating at a temperature low enough to cause the condensation of liquid mercury (cryogenic fractionations , exchangers).

Prior methods are known for removing mercury or arsenic from gas phase hydrocarbons; one operates in particular in the presence of solid masses, which can be called indifferently: adsorption, capture, trapping, extraction and metal transfer masses.

As regards the masses for demercurization: US Pat. No. 3,194,629 describes masses made up of sulfur or of iodine deposited on activated carbon.

US patent 4094777 of the applicant describes other masses comprising copper at least partly in the form of sulphide and an inorganic support. These masses may also contain money.

French application 87-07442 of the applicant describes a specific method of preparation of said masses.

Patent FR 2534826 describes other masses consisting of elemental sulfur and an inorganic support.

Regarding the de-arsenification:

Patent DE 2149993 teaches the use of Group VIII metals (nickel, platinum, palladium).

US Patent 4,069,140 describes the use of various absorbent masses. The supported iron oxide is described, the use of lead oxide is described in US Pat. No. 3,782,076 and that of copper oxide in US Patent 3,812,653.

However, if some of the products described in the prior art exhibit good performance for demercurization or also for the de-arsenification of gas (for example hydrogen) or gaseous mixtures (for example natural gas) and more particularly when the gas natural contains a significant amount of hydrocarbons containing three or more than three carbon atoms, the tests carried out by the applicant show that the same products prove to be ineffective as soon as the fillers contain compounds other than elemental metals, for example for arsenic, arsines comprising hydrocarbon chains containing two or more of two carbon atoms or, for mercury, dimethylmercury and the other mercury compounds comprising hydrocarbon chains containing two or more of two carbon atoms and, possibly other non-metallic elements (sulfur, nitrogen, etc.).

In addition, other tests carried out by the applicant show that when sulfur is present in the charge, it can interact with the active metallic elements for the de-arsenification which, then transformed into sulfides at least in part, can then have significant loss of activity.

The object of the invention is a process for removing mercury and possibly arsenic contained in a hydrocarbon feedstock and which remedies the defects of the previous processes.

Another object of the invention is to be able to remove the mercury and possibly the arsenic even in hydrocarbon feedstocks further containing significant proportions of sulfur. By significant proportions is meant from 0.005 to 3% by weight and in particular from 0.02 to 2% by weight.

According to the process of the invention, a mixture of the charge and of hydrogen is passed through in contact with a catalyst which will subsequently be called arbitrarily arsenic capture mass, with catalytic properties, containing:

- at least one metal M from the group formed by iron, cobalt, nickel, palladium and platinum - at least one metal N from the group formed by chromium, molybdenum, tungsten and uranium

- And optionally an active phase support, based on at least one porous mineral matrix, the said catalyst being followed on the path of the charge of, .or mixed with, a mass for capturing mercury, containing sulfur and / or at least one metal sulfide of at least one metal P chosen from the group formed by copper, iron and silver, and an active phase support.

According to another embodiment of the invention, it is also possible to add a sulfur compound; for example an organic sulphide, or alternatively hydrogen sulphide, either in the raw charge (before de-arsenification), or in the charge treated in the presence of hydrogen and of the de-arsenification mass with catalytic properties, before demercurization in the presence of the second bed.

When the charge also contains arsenic, it is also eliminated. The operation is preferably carried out with the charge at least partly in the liquid phase.

It has also been surprisingly discovered that in the presence of high arsenic concentrations or in the presence of high "liquid" hourly volumetric velocities which can cause imperfect arsenic uptake (for example less than 90%) on the arsenic capture mass with catalytic properties, the mercury capture mass also functions very satisfactorily for the capture of arsenic.

Finally, it has been discovered that, surprisingly, the catalyst also allows hydrodesulfurization, hydrodenitrification and, at least in part, hydrogenation of the unsaturated compounds which may be in the feed, which can prove to be advantageous when said feeds are intended for steam cracking. Finally, said mass allows effective demetallation if, in addition to arsenic and mercury, vanadium and / or nickel are present.

Surprisingly, the catalytic properties of said arsenic capture mass remain unchanged, even in the event of the strict absence of said metal in the charge.

Said arsenic capture mass with catalytic properties is therefore a complex solid, which, in the presence of hydrogen and under the operating conditions described below:

- activates by catalysis the mercury and arsenic compounds (if arsenic is present) and transforms them into reactive compounds vis-à-vis the capture masses object of the invention,

- selectively captures arsenic (if arsenic is present)

- activates by catalysis the said mercury compounds even in the strict absence of arsenic compounds.

The mass of arsenic capture with catalytic properties subsequently designated as "the catalyst" used in the composition of the assembly which is the subject of the present invention therefore consists of at least one metal M chosen from the group formed pa iron, nickel, cobalt, palladium, platinum and at least one metal N chosen from the group formed by chromium, molybdenum, tungsten and uranium, these metals, in the form of oxides and / o of oxysulphides and / or sulphides, which can be used as such o preferably be deposited on at least one support from the list which follows. Under conditions of use, it is imperative that the metal M and / or the metal N are in sulphurized form for at least 50% of their totality. It is known to those skilled in the art that the state of equilibrium between the reduced and sulphurized forms depends inter alia on the operating conditions and in particular, in addition to the temperature, partial pressures of hydrogen, of hydrogen sulphide, and of vapor of water in the reaction medium, eg:

9Co + 8H_S ^** = - Co _n S_ + 8 H dyo __ (K 'p) _ --______

P. H.Ξ

The respective amounts of metal or metals M and of metal or metals N contained in the catalyst are usually such that the atomic ratio of metal or metals M to metal or metals N, M / N is approximately 0.3: 1 to 0, 7: 1 and preferably from about 0.3: 1 to about 0.45: 1.

The quantity by weight of metals contained in the finished catalyst expressed by weight of metal relative to the weight of the finished catalyst is usually, for the metal or metals N, from approximately 2 to 30% and preferably from approximately 5 to 25%, and for the metal or metals M of approximately 0.01 to 15%, more particularly of approximately 0.01 to 5% and preferably of approximately 0.05 to 3% for palladium and / or platinum; and about 0.5 to 15% and preferably about 1 to 10% in the case of non-noble metals M (Fe, Cà, Ni).

Among the metals N, molybdenum and / or tungsten are preferably used, and among the metals M, the non-noble metals iron, cobalt and / or nickel are preferred. Advantageously, the following combinations of metals are used: nickel-molybdenum, nickel-tungsten, cobalt-molybdenum, cobalt-tungsten, iron-molybdenum and iron-tungsten. The most preferred combinations are nickel-molydene and cobalt-molybdenum. It is also possible to use combinations of three metals, for example nickel-cobalt-molybdenum.

The porous mineral matrix is chosen so that the final catalyst has the optimal pore volume characteristics. This matrix usually comprises at least one of the elements of the group formed by alumina, silica, silica-alumina, magnesia, zirconia, titanium oxide, clays, aluminous cements, aluminates, for example magnesium, calcium, strontium, barium, manganese, iron, cobalt, nickel, copper and zinc aluminates, mixed aluminates, for example those comprising at least two of the metals mentioned above.

It is preferable to use matrices containing alumina, for example alumina and silica-alumina or alternatively titanium oxide. When the matrix contains silica it is preferable that the quantity of silica is at most equal to 25% by weight relative to the total weight of the matrix.

The matrix can also contain, in addition to at least one of the compounds mentioned above, at least one crystalline or natural zeolitic alumino-silicate (zeolite). The amount of zeolite usually represents from 0 to 95% by weight and preferably from 1

80% by weight relative to the weight of the matrix.

It is also advantageous to use mixtures of alumina and zeolite, or alternatively mixtures of silica-alumina and zeolite.

Among the zeolites, it is usually preferred to use zeolites whose atomic ratio of framework, silicon to aluminum (Si / Ai) is greater than about 5: 1. Advantageously, zeolites with faujasite structures are used, and in particular stabilized or ultra-stabilized Y zeolites. The most commonly used matrix is alumina, and usually pure or mixed transition alumina, such as Y, Y_, _, Q, is preferred.

Said matrix will preferably have a large surface area and a sufficient pore volume, that is to say respectively at least 50 m2 / g and at least 0.5 cm3 / g, for example 50 to 350 m2 / g and 0 , 5 to 1.2 cm3 / g. The fraction of macroporous volume, consisting of all of the pores with an average diameter at least equal to 0.1 Am, may represent from 10% to 30% of the total pore volume.

The preparation of such a catalyst is sufficiently known to those skilled in the art not to be repeated in the context of the present invention.

Before use, the catalyst can, if necessary, be treated with a gas containing hydrogen at a temperature of 50 to 500 ° C. It can also, if necessary, be presulphurized at least in part, for example according to the French SULFICAT (R) process, or else by treatment in the presence of a gas containing hydrogen sulphide and / or any other sulphurized compound.

The mass of mercury capture used in the composition of the assembly which is the subject of the present invention consists of sulfur or a sulfur compound deposited on a porous mineral support or matrix chosen, for example, from the group formed by l alumina, silica-aluminas, silica, zeolites, clays, active carbon, aluminous cements, titanium oxides, zirconium oxide or among the other supports, consisting of a porous mineral matrix, cited for the catalyst.

It is possible to use, as capture mass, sulfur deposited on a support and for example a commercial product such as CALGON HGR, and more generally any product constituted by sulfur. deposited on an activated carbon or on a macroporous alumina as described in French patent 2534826.

A compound containing sulfur and a metal P is preferably used, where P is chosen from the group formed by copper, iron, silver and, preferably, by copper or the copper-silver association. At least 50% of the metal P is used in the form of sulphide.

This capture mass can be prepared according to the method recommended in US patent 4094777 of the applicant or by depositing copper oxide on an alumina then sulfurization by means of an organic polysulphide as described in the French patent application 87 / 07442 of the plaintiff.

The proportion of elemental sulfur, combined or not, in the capture mass is advantageously between 1 and 40% and preferably between 1 and 20% by weight.

The proportion of metal P combined or not in the form of sulphide will preferably be between 0.1 and 20% of the total weight of the capture mass.

The assembly consisting of the catalyst and the mercury capture mass can be used either in two reactors or in one.

When two reactors are used, they can be arranged in series, the reactor containing the catalyst being advantageously placed before that containing the capture mass.

When only one reactor is used, the catalyst and the capture mass can be arranged either in two separate beds or mixed thoroughly. Depending on the quantities of mercury and / or arsenic (calculated in elementary form) contained in the charge, the volume ratio of the mass of desarsenification with catalytic properties to the mass of demercurization may vary between 1:10 and 5: 1.

When operating in a separate reactor, it is possible to operate the one containing the mass of desarsenification with catalytic properties in a temperature range which can range from 180 to 450 ° C., more advantageously from 230 to 420 ° C. and in a preferred manner, from 260 to 390 ° C.

The operating pressures will preferably be chosen from

1 to 50 bars absolute, more particularly from 5 to 40 bars and more advantageously from 10 to 30 bars.

The hydrogen flow rate, expressed in liters of gaseous hydrogen (TPN) per liter of liquid charge will preferably be chosen between 1 and 1000, more particularly between 10 and 300 and more advantageously from 30 to 200.

The hourly volumetric speed, calculated with respect to the mass of desarsenification with catalytic properties, may be

0.1 to 30 hours more particularly from 0.5 to 20h ~ and in a way

—1 preferred, from 1 to 10 hours (volumes of liquid, per volume of mass and per hour).

The demercurization mass will be operated in a temperature range which can range from 0 to 400 ° C., more advantageously from 20 to 350 ° C. and, preferably, from 40 to 330 ° C.

The operating pressures and the flow rate of hydrogen D will be those defined with respect to the mass of desarsenification with catalytic properties. The hourly volumetric speed, calculated with respect to the mass of demercurization, may be that indicated for the mass of desarsenification with catalytic properties, it being understood as indicated above, that the volume ratio of the mass of desarsenification to the mass of demercurization may vary from 1:10 to 5: 1, depending in particular on the proportions of arsenic and mercury contained in the charge. It will ^'therefore obvious that the relative proportions of the two masses and therefore the volumetric hourly speeds over they may then be very different (even liquid flow but different mass volumes).

In one embodiment of the invention, the charge treated in the presence of the catalyst can optionally be cooled before passing over the demercurization mass.

In another mode, the two capture masses then being placed in a single reactor, this can be operated in a temperature range which can range from 180 to 400 ° C, more advantageously 190 to 350 ° C and in a way preferred 200 to 330 ° C.

Finally, as is known to those skilled in the art, it may prove advantageous to recycle at the top, at least in part, the hydrogen-rich ga recovered after separation of the purified liquid product. In addition to a significant reduction in hydrogen consumption, the said recycling allows better control of the partial pressure ratio pH S / pH „in the reaction medium. As indicated above, in the case where the feed contains little sulfur (for example less than 20 ppm by weight) it may also prove advantageous to add to the feed and / or in the hydrogen at least one sulfur compound. in order to increase the said pH_S / pH_ ratio.

The charges to which more particularly applies

_3 the invention contains 10 to 2 milligrams of mercury pa

_ kilogram of load and possibly 10 to 10 milligrams arsenic per kilogram of charge.

The following examples illustrate the various aspects of the invention without limiting its scope. It will go without saying for those skilled in the art, given the examples, that if the mass of de-arsenification alone is. sufficient to process charges containing only arsenic; on the other hand, it is necessary to use the mass of demercurization and the mass of desarsenification with catalytic properties, in order to effectively demercurize charges containing only mercury. Comparative tests identical to the series of examples 1 to 4 were carried out in the absence of arsenic in the charge; they have led to similar results.

Example 1 (comparison)

250 cm3 of HR 306 catalyst, produced by PROCATALYSE, are loaded into a steel reactor 3 cm in diameter.

Said HR 306 catalyst, consisting of diameter extrudates

1.2 mm and 2 to 10 mm in length, contains 2.36% cobalt and 9.33% molybdenum by weight; the matrix consists of transition alumina. The specific surface is 210 square meters per gram and the pore volume is 0.48 / cm3 / g.

The catalyst is then subjected to a presulfurization treatment. A hydrogen sulfide-hydrogen mixture in the volume proportions 3:97 is injected at a rate of 10 l / h. The temperature rise rate is 1 ° C / min and the final level (350 ° C) is 2 hours.

Since the hydrogen flow rate is only maintained, a heavy condensate of liquefied gas, the characteristics of which are indicated in Table I, and hydrogen under the following conditions are finally passed over the catalyst, in upward flow. Charging flow: 500 cm3 / h

Temperature: 320 ° C

Total pressure: 30 bar absolute

Hydrogen flow 100 liters / liter of charge, i.e. 50 liters / hour.

The condensate and the hydrogen are allowed to pass for 500 hours. The results of analyzes of mercury and arsenic in the product after 20, 50, 100, 200 and 500 hours are summarized in Table III.

We see that this catalyst has a very low efficiency in retaining mercury; on the other hand, it has good effectiveness in retaining arsenic.

Example 2 (comparison)

In this example, a capture mass is prepared consisting of a copper sulphide, deposited on an alumina support as described in US Patent No. 4094777 of the Applicant.

The mass contains 12% by weight of copper and 6% by weight of sulfur in the form of sulphide. The matrix consists of transition alumina. The specific surface is 70 m2 / g and the pore volume of 0.4 cm3 / g.

100 cm3 of this mass are then loaded into a reactor identical to that described in Example 1. Next, a heavy liquefied gas condensate identical to that used in Example 1 is passed over the mass. Table I) under the following conditions:

Charging flow: 500 cm3 / h Total pressure: 30 bar absolute Temperature: 40 ° C

Hydrogen flow: 100 liters per liter of charge, i.e.

50 liters per hour

The condensate is allowed to pass for 500 hours. The results of analyzes of mercury and arsenic in the product after 20, 50, 100, 200 and 500 hours are summarized in Table III.

It can be seen that the capture mass is not effective in retaining arsenic. On the other hand, it has a transient effectiveness in retaining mercury, but it drops very quickly over time.

Example 3 (comparison)

The experiment of Example 2 is repeated, but suppressing the flow of hydrogen.

The results indicated in Table III show that the performance has not improved.

Example 4 (according to the invention)

In a first reactor, 250 cm3 of HR 306 catalyst of Example 1 are then charged and pretreated, according to the technique and the pretreatment described in said example.

In a second reactor, 100 cm3 of the capture mass of Example 2 is charged according to the technique described in said example.

The same heavy condensate of liquefied gas is then passed in ascending flow under hydrogen as in Example 1, successively over the catalyst then over the capture mass. The operating conditions are as follows:

Charging flow: 500 cm3 / h HR 306 catalyst: 250 cm3 Temperature: 320 ° C Total pressure -: 30 bar absolute

Hydrogen flow: 100 liters per liter of charge, or 50 liters per hour.

Copper sulphide capture mass: 100 cm3

Temperature: 40 ° C

Total pressure: 30 bar absolute

Hydrogen flow: 100 liters per liter of charge, i.e.

50 liters per hour.

The condensate is allowed to pass for 1000 hours. The results of analyzes of mercury in the product after 50, 100, 200, 500 and 1000 hours are summarized in Table IV below.

It is found, unexpectedly, that the combination of the HR 306 catalyst and a capture mass makes it possible to obtain a high rate of de-arsenification and demercurization of the condensate.

Analysis of the HR 306 catalyst shows that more than 90% of the fixed arsenic is present in said catalyst; the mercury concentration, on the other hand, is less than 20 ppm by weight. Analysis of the demercurization mass shows that it contains practically 100% of the mercury and less than 10% of the fixed arsenic.

These metals are mainly present in the first 50 cm3 of the bed. We can therefore expect a very long service life. Example 5, according to the invention.

In order to demonstrate the thioresistance of the catalytic system, 0.5% by weight of sulfur in the form of thiophene is added to the charge treated in Example 1.

The operating conditions remain identical, with the exception of the operating temperature of the HR 306 catalyst, brought to 340 ° C. and to the hydrogen flow rate, brought to 200 liters / liter of charge, ie 100 liters / hour.

The performances, summarized in Table III, are identical to the precision of the analyzes.

Example 6, according to the invention

The experiment described in Example 4 is reproduced. The reactor containing 100 cm3 of copper sulphide capture mass is now loaded with:

100 cm3 of said mass and

50 cm3 of demercurization mass composed of 13% by weight of sulfur on activated carbon, of the CALGON HGR type, prepared according to the teaching of patent USP3194629.

The other operating conditions remain strictly identical and the test is limited to 500 hours.

The experimental results reproduced in Table III show that the addition of the demercurization mass to activated carbon allows a slight improvement in demercurization performance. On the other hand, the de-arsenification performance remains unchanged.

REPLACEMENT SHEET Example 7, according to the invention.

The first reactor used in Example 3 is now loaded with 200 cm3 of the HMC 841 catalyst, sold by PROCATALYSE.

This catalyst consisting of beads of diameters 1.5 to 3 mm contains 1.96% nickel and 8% molybdenum by weight; the matrix consists of transition alumina. The specific surface is 140 m2 / g and the pore volume of 0.89 cm3 / g. The HMC 841 catalyst was presulphurized before loading (ex-situ sulphurization) according to the SULFICAT (R) process sold by the company EURECAT; its sulfur content is 4.8% by weight.

The second reactor is charged with 200 cm3 of a demercurization mass containing 8% of sulfur, 14.5% of copper and 0.2% by weight of silver, prepared according to the teaching of US Pat. No. 4,094,777, then presulfurized by contacting with an organic polysulfide according to the teaching of French patent 87-07442 of the applicant.

The characteristics of the new charge treated (heavy liquefied gas condensate) are shown in Table II; the duration of the test is 1000 hours.

The operating conditions used are as follows:

Charging flow: 0.6 liters / hour HMC 841 catalyst: 200 cm3 Temperature: 390 ° C Pressure: 40 bars

Hydrogen flow: 150 liters per liter of charge, i.e.

90 liters / hour. Copper and silver sulphide capture mass: 200 cm3

Temperature: 100 ° C Pressure: 40 bars.

- The results of analysis of mercury and arsenic in the product after 20, 50, 100, 200, 500 and 1000 hours are summarized in Table III. It can be seen that the desarsenification of the charge always remains greater than 99% and that the demercurization always remains greater than 98.8%.

In addition, the analysis of the purified liquid effluent, after 500 hours of testing, shows that it contains only 60 ppm (weight) of sulfur and 33 ppm (weight) of nitrogen. The hydrodesulfurization rate and the hydrodenitrogenation rate are therefore 95.4 and 24% respectively. In addition, the effluent contains only 28% of aromatics (for

-_ compared to 41% in the fresh charge) which demonstrates, in addition to the activity in desarsenification and in demercurization, the additional properties in hydrodesulfurization in hydrodenitrogenation and in hydrogenation of the aromatics of the whole (catalyst + demercurization mass) according to l 'invention.

Example 8, according to the invention

The charge treated is always that described in Table II.

We now use a single reactor, 4 cm in diameter, containing the inlet to the outlet:

0.5 liter of catalyst HMC 841, presulfurized off site as in Example 7,

0.2 liters of the copper and silver sulphide mass used in Example 7. The operating temperature is equal to 220 ° C., the operating pressure equal to 50 bars (absolute) and the flow rate is 200 liters per liter of charge, or 120 liters per hour.

The charge rate is 0.6 liters per hour. Analysis of the hydrogen, recovered at the outlet after separation (high pressure separator) of the purified feed, shows that it contains hydrogen sulfide, formed by hydrodesulfurization of said feed in the presence of the HMC 841 catalyst.

The test lasts 500 hours and the performances obtained are summarized in Table III.

It can be seen that the use of the two catalysts in a single reactor leads to good efficiency for the demercurization and for the de-arsenification of the feed.

20

TABLE I

Load characteristics of examples 1 to 6

| Density 0.754 g / cm3 J

| S (ppm weight) 150

| Hg (ppm weight) 0.6

| As (ppm weight) 0.5

Pi 22 |

| Distillation 5% 35 |

| ASTM D 86 50% 129 |

1 (° c) 95 330 |

PF 475 |

TABLE II

Load characteristics of Examples 7 and 8

| Density 0.769 g / cm3 |

| S (ppm weight) 1300

| N "" 45

I Hg 1.1

| Ace "" 1.5

| Fe "" 1

| Aromatics (% by weight) 41

Pi 30 |

| Distillation 5% 42 |

| ASTM D 86 50% 127 |

1 (° c) 95 362 |

PF 497 | 21

Table III

C% = rate of fixation, in mass percent, of mercury and arsenic on the assembly constituted by the catalyst and by the mass of demercurization. ppb = Residual concentration of arsenic and mercury, expressed in micrograms (10 gram) per kilogram (or in milligrams per ton). 901

22

Table III (CONTINUED)

C% = rate of fixation, in mass percent, of mercury and arsenic on the assembly constituted by the catalyst and by the mass of demercurization. ppb = Residual concentration of arsenic and mercury, expressed in micrograms (10 ~ gram) per kilogram (or in milligrams per ton).

Claims

1. A method of removing mercury from a hydrocarbon charge containing the elements mercury and sulfur, characterized in that a mixture of hydrogen and said charge is reacted in the presence of an arsenic capture mass , with catalytic properties, called "the catalyst" containing at least one metal M chosen from the group formed by nickel cobalt iron palladium and platinum, at least one metal N chosen from the group formed by chromium molybdenum tungsten and uranium and optionally at least one active phase support based on at least one porous mineral matrix, said arsenic capture mass with catalytic properties being followed on the path of the charge of, or mixed with, a mercury capture mass containing a sulphide at least one metal P chosen from the group formed by copper, iron and silver, or sulfur, and an active phase support.

2. Method according to claim 1 wherein, in addition to the mercury and the sulfur, the charge contains arsenic, characterized in that the arsenic and the mercury are simultaneously eliminated, respectively by interaction with the mass of desarsenification with property catalytic called "the catalyst" and with the mass of demercurization.

3. Method according to claims 1 and 2, according to which simultaneously with the removal of the mercury and arsenic metals, the filler is also partly hydrodesulfurized, hydrodenitrogenated and hydrogenated for its fraction of unsaturated hydrocarbons.

4. Method according to claims 1 to 3 wherein optionally adding to the feed at least one sulfur compound selected from the group formed by hydrogen sulfide and organic sulfur compounds.

REPLACEMENT SHEET 24

5. Method according to claims 1 to 4 wherein the catalyst contains from 0.01 to 15% by weight of at least one metal M, from 2 to 30% by weight of at least one metal N and where the atomic ratio M / N is 0.3: .l to 0.7: 1.

6. Method according to claim 5, in which the metals M are cobalt and nickel and the metals N are molybdenum and tungsten and in which the catalyst contains 0.5 to 15% by weight of at least one metal M, from 5 to 25% by weight of at least one metal N.

7. Method according to claims 5 and 6, wherein the catalyst contains, among the metals M, at least one noble metal, chosen from palladium and platinum, and wherein said catalyst contains from 0.01 to 5% of metals M .

8. Method according to one of claims 5 to 7 wherein, in addition to the metals M and N, the catalyst contains an active phase support consisting of a porous mineral matrix comprising at least one of the elements of the group formed by alumina , silica, silica-alumina, magnesia, zirconia, titanium oxide, clays, aluminous cements, aluminates, synthetic or natural zeolitic aluminosilicates.

.

9. Method according to one of claims 1 to 8 wherein the capture mass consists of 1 to 40% of sulfur relative to its total mass and of at least one support chosen from the group formed by alumina , silica-aluminas, silica, titanium oxide, zirconia, zeolites, active carbon, clays and aluminous cements.

10. The method of claim 9 wherein the capture mass also contains 0.1 to 20% by weight of at least one metal P selected from the group formed by copper, iron and silver, and where the metal P is at least partly in the form of sulfide.

REPLACEMENT SHEET

11. Method according to one of the preceding claims, in which:

- the operating pressure is chosen between 1 and 50 bar absolute

the hydrogen flow rate is chosen between 1 and 1000 liters of gaseous hydrogen (TPN) per liter of liquid charge - the hourly volumetric speed, expressed in volumes of liquid charge is from 0.1 to 30 volumes per volume of catalyst and from 0.1 to 30 volumes per volume of demercurization mass,

- the operating temperature of the catalyst is 180 to 450 ° C.

- the operating temperature of the demercurization mass is from 0 to 400 ° C

- The catalyst and the demercurization mass are placed in two separate reactors, the charge being first brought into contact with the catalyst and then with the capture mass.

12. The method of claim 11 wherein

- The catalyst and the demercurization mass are placed in a single reactor, and in which the operating temperature is from 180 to 400 ° C.

13. Method according to one of claims 11 to 12 wherein the hydrogen-rich gas is separated from the effluent from the reactor or reactors and is then recycled, at least in part, at the head of the first reactor.

14. Method according to one of claims 1 to 13 wherein the catalyst is pretreated between 50 and 500 ° C by a gas mixture containing at least one compound selected from the group formed by hydrogen hydrogen sulfide and the compounds organic sulfur, prior to treatment with the hydrocarbon charge

15. Method according to one of claims 1 to 14 wherein feed, consisting of at least partially liquid hydrocarbons

_3 tempéérraattuurree eett pprreessssiioonn aammbbiiaanntteess ,, ccoonnttiieenntt 1100 to 2 milligrams

REPLACEMENT SHEET of mercury per kilogram of charge and possibly lθ ^"2-10 milligrams of arsenic per kilogram of feedstock.

16. Method according to one of claims 1 to 15 wherein the treated charges are heavy charges or effluents from thermal and / or catalytic conversion processes.

17. Method according to one of claims 1 to 15 wherein the treated charges are gas condensates.

REPLACEMENT SHEET