AU634763B2 - Process for eliminating mercury and possibly arsenic in hydrocarbons - Google Patents

Description

OPI DATE 09/10/90 A@JP DATE 15/11/90 APPLN. I D 53319 901 DEMANDE IX (51) Classification iriternatlonale des brevets 5 ClOG 67/06, 25/00, 45/04 1A] PCT NUMBER PCT/FR90/00162

*DEBREVETS(PC'I)

(11) Numiro de publication Internationale: WO 90/10684 (43) Date de publication Internationale: 20 septembre 1990 (20,09.90) (21) Nunifto de In demande Internationale: PCT/FR90/00 162 I (22) Date de dipfit internationvl: 9 mars 1990 (09,03.90) Donn~es relatives i la priorit6: 89/03581 16 mars 1989 (16.03.89) FR (71) D~posant (pour tous les Etats dcbsignbs satif US); INSTITUT FRANQAIS DU PETROLE 4, avenue de Bois-Pr6au, F-92502 Rueil-Malmaison (FR), (72) lInventeurs; et Inventeurs/D~posants (US seulemtent) :COURTY, Philippe [FR/FR]; 91, rue Condorcet, P-78800 Houjlles (FR1), DUFRESNE, Pierre [FR/FR]; 67, rue George-Sand, F.

92500 Ruell-Malmaison BOITIAUX, Jean-Paul [FR/FR]; 4, avenue des Ursulines, F-78300 Poissy (FR).

MARTINO, Germain [FR/FRI; BAtiment Cond6, avenue F.-Lef~bvre, F-78300 Poissy (FR).

(74) Repr~sentantcommun: INSTITUT FRANQAIS DU PE- TROLE; 4, avenue de Bois-Pr~au, F-92502 Rueil-Malmaison (FR), (81) Etats d~sign~s: AT (brevet europ~en), AU, BE (brevet europ~en), CH (brevet europ~en), DE (brevet europ~en), DK (brevet europ~en), ES (brevet europ~en), FR (brevet europ~en), GB (brevet europ~en), IT (brevet europ~en), LU (brevet europ~en), NL (brevet europ~en), NO, SE (brevet europ~en), US, Publi~e Avec rapport de recherchue intemnationale.

Avant l'expiration du d~1ai pr~vu pour la modiication des revendications, sera republi&c si de telics modifications sont rev'ues.

634763 (54) Title: PROCESS FOR ELIMINATING MERCURY AND POSSIBLY ARSENIC IN H-YDROCARBON$ (54)Tltre: PROCEDE POUR L'ELIMINATION DU MERCURE ET EVENTUELLEMENT D'ARSENIC DANS LES HYDROCARI3URES (57) 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 or 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.

(57) AbrkgA Proc~d6 d'6limination du mercure et 6ventoellement d'arsenic dans les charges d'hydrocarbures contenant mercure et soufre, caract~ris6 en ce que V'on fait passer, sous hydrog~ne, ladite charge au contact d'une masse de captation d'arsenic A propri6t6s catalytiques renfermant au moins on m~tal do,~ groupe formA6 par nickel, cobalt, fer, palladium et platine, au moins un mlat du groupe frm6 par chrome, molybd~ne, tungst~ne et uranium et un support de phase active, ladite masse 6tant suivie sur le trajet de la charge de, ou m-lang~e A, one masse de captation du merc~re renfermant un sulfore d'au momns un m~tal du groupe cuivre, fer et argent ou du soufre et on support de phase active, PATENT OF INVENTION INSTITUT FRANCAIS DU PETROLE METHOD OF REMOVING THE MERCURY AD ANY ARSENIC IN HYDROCARBONS Inventors: Philippe COURTY, Pierre DUFRESNE, Jean-Paul BOITIAUX and Gernain MARTINO.

ABSTRACT

Process for eliminating mercury and possibly arsenic from hydrocarbon fillers containing mercury and sulphur, characterised in that said filler is made to pass through in the presence of hydrogen and contact an -arseniccapturing 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 mercurycapturing body containing a sulphide of at least one metal of the copper, iron and silver group or sulphur and an active phase suppor:t.

It is known that liquid condensates which are byproducts of gas production (natural or petroleumn gas) and crude petroleums way contain many metallic compounds in trace form. They are general ly in the form of organo metallic omplexes, in which the metal forms linkages with one or n-re carbon atcmis of the orgarx) metallic radical.

The metallic ompounds are poisonous to the catalysts used in petroleun conversion processes. They particularly po~ison the hydro treatwent and hydrogenation catalysts by being depsited gradually over the active surface. Metallic compounds are found particularly in the heavy cuts from the distillation of petxolexn crude (nickel, vanadium, arsenic, mercury) or in natural gas condensates (mercury, arsenic).- Thermal or catalytic cracking treatment of the above hydrocarbon cuts, e.g. steam cracking for onversion to lighter hydrocarbon cuts, my remove same metals nickel, vanadium, etc.); on the other hand, some other metals mercury, arsenic, etc.) which are liable to form volatile compounds and/or be volatile in the elementary state (mercary) reappear, at least partly, in the lighter cuts and can consequently poison the catalyat-s for the subsequent conversion processes. with mercury there is the .uther risk of causing corrosion through the formation of amalgams, for exam~ple with alumninium based alloys, especially in the parts of processes which operate at a low enough temperature to cause condensation of liquid mercury (cryogenic fractionation, exchangers).

Earlier processes are known for removing irercury or arsenic fran hydrocarbons in gas phase; they operate particularly in the presence of solid materials, which are variously described as adsorption, collecting, trapping, extracticn and mretal transfer materials.

As far as dexercurisation~ materials are concerned, US Patent 3194629 describes materials ccznprising sulphur or iodine deposited oni active carbon.

Applicants' US Patent 4094777 describes other materials comrprising copper, at least partly in sulphide form, and an inorqanic carrier.

They may also contain silver.

Applicants French application 87-07442 describes a specific mrethod of preparing these materials.

French Patent 2534826 describes other materials trade up of elementary sulphur and an inorganic carrier.

As far as dearsenificaticn is concerned: German Patent 2149993 teaches the use of qroup VIII metals (nickel, platinum, palladium).

US Patent 4069140 describes the use of various absorbent materials.

Iron oxide on a carrier is described, the use of lead oxide is described in US Patent 3782076 and that of copper oxide in US Patent 3812653.

Some of the products described in prior art have a good performance in demrercurising or dearsenifying gas hydrogen) or mixtures of gases natural gas), more particularly when the natural gas contains a large amount of hydrocarbons containing three or more than three carbon atoms. However, tests carried cut by Applicants show that the same products are relatively ineffective when the charges contain comnounds other than elementary metals: in the case of arsenic, for example, arsines with hydrocarbon chains containing two or more than two carbon atoms, or in the case of mercury, dimethyl mercury and other mercury cxrpounds with hydrocarbon chains containing two or more than two carbon atoms and rossibly other non-metallic elements (sulphur, nitrogen, etc.).

7 r Lii Other tests successful.ly amprleted by Applicants show that, when sulphur is present in the charge, it wmay interact with the rretallica elemnts active in dearsenification. When these are at least partly zonverted to sul.phides they may then entail a significant loss of activity.

The object of the invention is a method of remroving me~rcury and any arsenic contained in a hydrocarbon charge, and avoiding the defects of earlier processes.

Mnother object of the invention is to remrove the mrercury and any arsenic, even from hydrccarbon charges which also contain significant proportions of sulphur. The term~ "significant proportions" refers to 0.005 to 3% and particularly 0.02 to 2% by weight.

In the method of the invention, a mixture of the charge and of hydlrogen is put into contact with a catalyst (hereinafter referred to arbitrarily as an arsenic collecting m'aterial) with catalytic properties, containing: -at least one metal M from the group formed by iron, cobalt, nickel, palladium an~d platinum at least one metal N from the group formed by chranium, molybdenum, tungsten and uranium and possibly an active phase carrier based cn at least one porous inorganic matrix, said catalyst being followed along the path of the charge by or rixed with a mercury collecting material, containing sulphur and/or at least one metal sulphide of at least one metal P selected frman the group fonrmed by copper, iron and silver, and an active phase carrier.

In another embodiment of the invention, a sulphur canmpound may also be added, e.g. an organic sulphide or hydrogen sulphide; it may either be added to the crude charge (before dearsenification) or to the treated charge in the presence of hydrogen and the dearsenification material with catalytic prqprties, prior to demercurisation in the presence of the second bed.

When the charge also contains arsenic the arsenic is elimninated too.

It is preferable to operate with the charge at least partly in liquid phase.

It has also been discovered, surprisingly, that when there are high concentrations of arsenic or high "liquid" volume speeds per hour which may lead to inadequate collection of arsenic less than on the arsenic collecting material with catalytic properties, the mercury collecting imraterial operates very satisfactorily in collecting the arsenic.

Another surprising discovery is that the catalyst can also hydrodesulphurise, hydrcdenitrify and at least partly hydrogenate any unsaturated compounds in the charge. This nay be advantageous when the charges are intended for steamn cracking. Finally, said material is effective in demetallation, if vanadium and/or nickel are present as well as arsenic and mercury.

The catalytic properties of said arsenic collecting material surprisingly remain unchanged, even if there is absolutely none of said metal in the charge.

Said arsenic collecting material with catalytic properties is thus a complex solid, which has the following action in the presence of hydrogen and umder the conditions described below: 8

I

it activates mercury and arsenic compounds (if there is any arsenic) by catalysis and converts them to compounds which react with the collecting materials according to the invention, it collects arsenic selectively (if there is any arsenic) it activates said mercury compounds by catalysis, even if thxe are absolutely ro arsenic canopounds present.

The arsenic collecting material with catalytic properties (hereinafter referred to as "the catalyst") included in the group of materials according to the invention, is thus made up of at least one metal M selected fran the group formed by iron, nic)kl, cobalt, palladium and platinum and at least one metal N selected from the group formed by chromium, molybdenum, tungsten and uranium. These metals, in the form of oxides and/or oxysulphides and/or sulphides, may be used as they are or preferably deposited on at least one carrier from the following list. Under operating conditions it is essential for the metal M and/or the metal N to be in sulphurised form in at least 50% of the total quantity.

It is known in the art that equilibrium between the reduced and sulphurised forms depends inter alia on operating conditions and, apart fr-, temperature, particularly on partial pressures of hydrogen, hydrogen sulphide and water vapour in the reaction medium, e.g.

Coo H 2 Co H 2 0 (Kp) p.I- 2 9Co 8H 2 S Oo9S 8 8 H2 T 2 p.H 2

S

The respective quantities of metal or metals M and metal or metals N contained in the catalyst are generally 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 about 0.3:1 to about 0.45:1.

The quantity of metals contained in the finished catalyst, expressed as the weight of metal relative to the weight of finished catalyst, is qenerally about 2 to 30% and preferably about 5 to 25% for the metal or metals N. For the metal or metals M it is about 0.01 to more particularly about 0.01 to 5% and preferably about 0.05 to 3% for palladium and/or platinuml and about 0.5 to 15%, preferably about 1 to 10%, for the non-noble nmtals M (Fe, Co, Ni).

Of the metals N it is preferable to use molybdenum and/or tungsten.

Of the metals M it is preferable to use the non-noble metals, iron, cobalt, and/or nickel. It is advantageous to use combinations of the following metals: nickel molybdenum, nickel tungsten, cobalt molybdenum, cobalt tungsten, iron molybdenum and iron tungsten. The preferred combinations are nickel molybdenum and cobalt molybdenum.

It is also possible to use combinations of three metals, e.g. nickel cobalt molybdenum.

The porous inorganic matrix is chosen so as to give the final catalyst optimum pore volume properties. It generally includes at least one material from the group formed by alumina, silica, silica-alumina, magnesia, zirconia, titanium oxide, clays, aluminous cements, aluminates, e.g. magnesium, calcium, strontium, barium, manganese, iron, cobalt, nickel, copper and zinc aluminates, or corbined aluminates, e.g. those containing at least two of the previously-nentioned metals.

It may be preferable to use matrices containing alumina, for example alumina and silica-alumina or titanium oxide. When the matrix contains silica it is preferable for the maximum quantity of silica to be 25% of the total weight of the matrix.

N

The matrix may abo conitain at least one crystalline zeolitic alixiino, silicate, of a synthetic or natural zeolite, as we"Ll as at least one of the above-mentioned compound~s. The quantity of zeo0lite is generally from 0 to 95%, preferably from 1 to 80% of the weight of the matrix.

mixtures of alumina and zeolite, or mixtures of silica-alumina and zeolite, may advantageously be used.

As far as zeolites are concerned, it is normally preferable to use those where the skeleton atcaic ratio of siliccn to alcminiuxn (Si/Al) is over about Zeolites with a faujasite structure, particularly stabilised or ultra-stabilised Y zeolites can advantageously be employed.

The rmst ommnly used n~trix is alumina. Transition aluminas, either pure or mixed, are generally preferred, such as V Ct The matrix will preferably have a large area and an adequate pore ,vlumet that is to say, at least 50 m 2 /g and at least 0.5 an 3 /g rcespectivelyl e.g. 50 to 350 m /g and 0.5 to L2P cm The fraction~ of ma~cro porous volume# mrade up of all pores with an average diameter of at least 0.1 micron, may be froan 10 to 30% of the total pore volume.

The preparation of such a catalyst is sufficiently well-known in the art not to be repeated in describing this invention.

Before it is used the catalyst nmay, if necessary, be treated with a gas containing hydrogen at a temperature of 50 to 500°C. If necessary it may equally be at least partially presulphurised, e.g.

by the French SULFICAT process, or by treatment in the presence of a gas containing hydrogen sulphide and/or any other sulphur compound.

The mercury collecting material included in the ccaposition according to the invention comprises sulphur or a sulphur compound deposited on a porous inorganic carrier or matrix. The carrier or matrix may be selected, for example, from the group formed by alumina, silica-aluminas, silica, zeolites, clays, active carbons, aluminous cements, titanium oxides, zirconium oxide or from the other carriers comprisinq a porous inorqanic matrix which were mentioned for the catalyst.

4 The collecting material may be sulphur deposited on a carrier, for example a ccmiercial product such as CALCC3N HR, and more generally any product comprising sulphur deposited on an active carbon or on a macro porous alumina, as described in French Patent 2534826.

It is preferable to use a ccfipurd containinq sulphur and a metal P, where P is selected from the group formed by copper, iron, silver and preferably copper or a combination of copper and silver. At least 50% of the metal P is used in sulphide form.

The collecting material may be prepared by the method recommended in Applicants' UJS Patent 4094777, or by depositing copper oxide on an alumina then sulphurisation with an organic polysulphide as described in Applicants' French Patent Application 87/07442.

The proportion of elenentary sulphur, either combined cr non-canbined, in the collecting material is advantageously from 1 to 40% and preferably from 1 to 20% by weight.

The proportion of metal P, either conbined or non-cambined in sulphide form, will preferably be fran 0.1 to 20% of the total weight of the collecting material.

The group of materials made up of the catalyst and the mercury collecting material may be employed either in two reactors or one.

When two reactors are used they can be arranged in series. In this case the reactor containing the catalyst advantageously cames before that containing the collecting material.

When only one reactor is used, the catalyst and collecting material can either be arranged in two separate beds or mixed intimately.

Dependent on the quantities of mercury and/or arsenic (calculated in ele entary form) contained in the charge, the volume ratio of the dearsenification material with catalytic properties to the demercurisation material may range from 1:10 to 5:1.

When operating in separate reactors, the one containing the dearsenification material with catalytic properties may be run wi'cdin a temperature range from 180 to 450 0 C, more advantageously from 230 to 420°C and preferably fran 260 to 390 0

C.

The operating pressures will preferably be chosen from 1 to 50 bars absolute, more particularly fram 5 to 40 bars and more advantageously from 10 to 30 bars.

The flow rate of hydrogen, expressed in litres of hydxegen gas (NTP) per litre of liquid charge, should preferably be from 1 to 1000, more particularly fran 10 to 300 and nore advantageously fron 30 to 200.

The hourly volume speed, calculated for the dearsenification naterial with catalytic properties, may be fran 0.1 to 30h 1 more particularly fron 0.5 to 20h-1, and preferably from 1 to 10h (volumes of liquid, per volume of material per hour).

The demercurisation material nay operate within a tenerature range fron 0 to 400 0 C, more advantageously from 20 to 350 0 C, and preferably from 40 to 330 0

C.

The operating pressures and hydrogen flow rate 4.will be those defined for the dearsenification material with catalytic properties.

The hourly volune speed, calculated for the demercurisation material, may be that given for the dearsenification material with catalytic properties, with the provision that the volume ratio of dearsenificaticn material to demercurisation material may range from 1:10 to 5:1 as indicated above, chiefly according to the proportions of arsenic and mercury contained in the charge. The relative proportions of the two materials, and thus the corresponding hourly

N

volume speeds, may obviously be very different then (sane liquid flow rate but different volumes of material).

In one embodimnent of the invention the charge treated in the presence of the catalyst night be cooled before passing over the demercurisation material.

In another arbodiment, where the two collecting materials are placed in one reactor, the reactor may be operated within a temperature range from 180 to 400°DC, nore advantageously from 190 to 3509C and preferably from 200 to 330 0

C.

It may finally be found advantageous to recycle at least part of the hydrogen-rich gas recovered after the separation of the purified liquid product to the top, in a manner known in the art. Apart fran greatly reducing hydrogen consumption, the recycling gives better control of the partial pressure ratio pH 2 S/pH 2 in the reacticn medium. As indicated above, in cases where the charge contains little sulphur less than 20 ppn by weight) it may further be found advantageous to add at least one sulphur cimpound to the charge and/or the hydrogen, in order to increase the pH 2 S/pH 2 ratio.

prd-erc6 (y The charges to which the inventicn more -i ar.Ly- applies contain fran 10 3 to 2 mg of mercury per kilogram of charge, and possibly from 10 2 to 10 mg of arsenic per kilogram of charge.

The following examples illustrate the various aspects of the invention without restricting its scope. It will be obvious to a person skilled in the art fron the examples that the dearsenificaticn material is itself sufficient to treat charges containing cnly arsenic; whereas if charges containing only mercury are to be demercurised effectively, it is necessary to use both the demercurisaticn material and the dearsenificaticn material with catalytic properties. Camparative tests identical with examples 1 to 4 have been carried out without any arsenic in the charge: they produced similar results.

Example 1 (comparison) 250 cm of catalyst HR 306, produced by PROCATALYSE, is placed in a steel reactor 3 an in diameter.

Catalyst HR 306, made up of extrusions 1.2 rm in diameter and 2 to im lcng, contains 2.36% of cobalt and 9.33% of molybdenum by weight: the matrix is made of transition alumina. The specific surface area is 210 square mtres per gram and the pore volume is 0.48/an c/g.

The catalyst is then subjected to presulphurisation treatment. A mixture of hydrogen sulphide and hydrogen in proportions of 3:97 by lumne is injected at 10 1/h. The temperature rises 1 0 C per minute and the final stage 350°C) lasts 2 hours.

With only the delivery of hydrogen maintained, a heavy condensate of liquefied gas (its properties are given in Table I) and hydrogen are passed over the catalyst in an ascending flux under the following conditions: Flow rate of charge 500 cma /h Teaperature 320°C Total pressure 30 bars absolute Flow rate of hydrogen 100 litres/litre of charge, i.e. litres/hour.

The condensate and hydrogen are passed over the catalyst for 500 hours. The results of analyses of the mercury and arsenic in the product after 20, 50, 100, 200 and 500 hours are summarised in Table

III.

The catalyst will be seen to be very ineffective in retaining mercury; yet it is effective in retaining arsenic, Example 2 (ompariscn) The collecting material prepared in this example cmprises a copper sulphide, deposited on an alumina carrier as described in Applicants' US Patent No. 4094777.

The material contains 12% by weight of copper and 6% of sulphur in sulphide form. The matrix is made of transition alumina. The specific surface area is 70 m 2 /g and the pore volume 0.4 cm 3 /g.

100 n 3 of the material is then placed in a reactor identical with that described in Examnple 1. A heavy condensate of liquefied gas, identical with that used in Example 1 (cf. Table is then passed over the material in an ascending flux, under the following coritions: Flow rate of charge 500 an 3/h Total pressure 30 bars absolute Temperature Flow rate of hydrogen 100 litres/litre of charge, i.e. litres/hour.

The condensate is passed over the material for 500 hours. The results of analysing the mercury and arsenic in the product after 20, 50, 100, 200 and 500 hours are summarised in Table III.

A-

The collecting material is found to be ineffective in retaining arsenic. On the other hand, it has a transitory effect in retaining meroury, although this declines very rapidly with the passage of time.- EEmple 3 (comparison) The experiment in Example 2 is repeated, but without the hydrogen flow.

The results in Table III show no improvement in performance.

E (according to the inventio) 250 an 3 of catalyst HR 306 fran Exmple 1 is placed in a first reactor then pretreated, following the method and pretreatment described in that example.

100 an 3 of the collecting tmterial from Exmaple 2 is placed in a second reactor, following the method described in that example.

The same heavy condensate of liquefied gas as in Ex=nple 1 is then passed successively over the catalyst then over the collecting material, in an ascending flux in hydrogen.

The operating ccnditions are as follows: Flow rate of charge Catalyst HR 306 'emperature Total pressure Flow rate of hydrogen litres/hour.

500 an3/h 250 cm 3 320°C 30 bars absolute 100 litres/litre of charge, i.e. Copper sulphide collecting material 100 on 3 Temperature Total pressure 30 bars absolute Flow rate of hydrogen 100 litres/litre of charge, i.e. litres/hour.

The condensate is passed over the catalyst then the collecting material for 1000 hours. The results of analysing the marcury in the product after 50, 100, 200, 500 and 1000 hours are surmarised in Table IV below.

The combination of catalyst HR 306 with a collecting material is unexpectedly found to give a high rate of dearsenification and demercurisation of the condensate.

4'

I..

S Analysis of Catalyst HR 306 shows that over 90% of the arsenic fixed is present in it, whereas the concentration of nrrcury is less than ppm by weight. Analysis of the demercurisation naterial shows it to contain virtually 100% of the mercury fixed and less than 10% of the arsenic.

These metals are essentially present in the first 50 on 3 of the bed.

A very long life can therefore be expected.

xample 5, according to the invention To demonstrate the thioresistance of the catalytic system, 0.5% by weight of sulphur in the form of thiophen is added to the charge treated in Example 1.

The operating conditions are identical, except that the operating tenperature of catalyst HR 306 is brought to 34000°C, and the flow rate of hydrogen is brought to 200 litres/litre of charge, i.e. 100 litres/hour.

The results (sumnarised in Table III) are identical, with analytical precision.

7* Example 6, according to the invention The experimeant described in Example 4 is reproduced. The reactor, containing 100 cm 3 of collcting material made of copper sulphide, is now charged with: 100 cman 3 of said material and an of demercurisation material comprising 13% by weight of sulphur on active carbon of the CALGCW HR type, prepared according to the teaching of US Patent 3194629.

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

The experimental results reproduced in Table III show that the addition of the demercurisation material to the active carbon permits a slight improvement in the demercurisation performance.

The dearsenification performance is however unchanged.

Example 7, according to the invention The first reactor used in Example 3 is now charged with 200 cm 3 of catalyst HM2 841, marketed by PROCATALYSE.

I

f^ The catalyst, in the form of spheres 1.5 to 3 rn in diameter, contains 1.96% of nickel and 8% of molybdenum by weight; the matrix is of transition alumina. The specific surface area is 140 m 2 /g and the pore volume 0.89 cm 3 Catalyst HMC 841 has been presulphurised before being placed in the reactor (ex-situ sulphurisation), by the SULFICAT process marketed by EURECAT; its sulphur content is 4.8% by weight.

The second reactor is charged with 200 an 3 of a demercurisation material containing 8% by weight of sulphur, 14.5% of copper and 0.2% of silver, prepared according to Applicants' US Patent 4094777, then presulphurised by putting it into contact with an organic polysulphide in accordance with Applicants' French Patent 87-07442.

The properties of the new charge treated (heavy condensate of liquefied gas) are given in Table II; the test is carried out for 1000 hours.

The operating conditions recorded are as follows: Flow rate of charge o.6 litre/hour Catalyst HMC 841 200 an 3 Tmperature 390 0

C

Pressure 40 bars FlOw rate of hydrogen 150 litres/litre of charge, i.e. littW/hour.

Collecting material nade of copper and silver sulphides 200 an3 cm, Temperature 100 0

C

Pressure 40 bars The results of analysing the nercury and arsenic in the product after 20, 50, 100, 200, 500 and 1000 hours are sumnarised in Table III. It will be seen that the dearsenification of the cdarge is still above 99%, and the denarcurisation still above 98.8%.

In addition, analysis of the purified liquid effluent after 500 hours experimentatien shows it to contain only 60 ppm (by weight) of sulphirx and 33 Upn of nitrogen. The hydrodesulphurisation rate and the hydro-denitrification rate are thus 95.4 and 24% respectively.

i-breover the effluent only contains 28% of arartics (as cxmpared with 41% in the fresh charge); this denonstrates not only the dearsenification and demercurisation action but also the additional properties of hydro-desulphurising hydrodenitrifying and hydrogenating the arcmatics in the group of materials according to the invention (catalyst dnemrcurisation material).

V

Exarple 8, according to the invention The charge treated is still that described ln Table II.

A single reactor, 4 n in diameter, is now used; it contains, from the inlet to the cutlet: 0.5 litres of catalyst IC 841, pres lphuri.ed ex-situ as in Example 7, 0.2 litre of the material made of copper and silver sulphides used in Example 7.

The operating temperature is 220°C, the operating pressure 50 bars (absolute) and the flow rate is 200 litres per litre of charge, i.e.

100 litres per hour.

The flow rate of charge is 0.6 litre per hour.

Analysis of the hydrogen, recovered at the outlet after separation from the purified charge (high presure separator), shows it to contain hydrogen sulphide, formed by hydrodesulphurisation of the charge in the presence of catalyst W*C 841.

The test is continued for 500 hours, and the results obtained are summarised in Table III.

'CI

j 9 u

AJ

The use of two catalysts in one reactor is seen to Irczuue effective denercurisation and dearsenificaticu of the charge.

TABLE I Properties of the charge in ExaMles 1 to 6 Density S (ppm weight) Ng (ppm weight) As (p weight) 0.754 ga 0.6 Distillation ASTfl D 86 (0)

CID

TABLE II Properties of the charge in Eamples 7 and 8 Density S (PPM %X.

N

fig" As Fe Aranatics eight) we ight) 0.769 1300 1.1 1 41 Pi 5% 50% 95

MP

q/cm 3 42 127 362 497 Distillation ASI11 D 86 0C) *1v 7- 094 Table III I As H As I Hg I As I Hg lexan___ no I I l a e l 0C% 7lppb I CX pI 0%ppb I TpEI C% lppb I IKuation 1 20 h 50 h 100 h 6f te 't

I

1 __9915 1 21480 99 1 5 151510 1 98 1101141517 j 2 19915 197 18 -0 98 28- 177 1 1 1 1 1 1 1 1 ii99 5 197,51 34 99 i 5 I 98 I 11 T9850 7,5197,51 S6 I 98- 150 198,2 1 99I 5 198,51 9 19 I 5 1 98 1 2 i 7 199,517,5 198,91 12 199,31 10 i 99 i 13 199,41 9 i 99 1 1 I 8 199,31 10 198,5 6 I 99 I 3. 199,516 1 99,1 13 199,1 1 SI I I I I I I I I I I I I I I IL I iI_ I C% rate (in percentages by weight) at which rrercury and arsenic are fixed co the group of materials canprising the catalyst and demercurisation material.

ppAb Residual concentratien of arsenic and mercury, expressed in microgram (10-6 grati) per kilogram (or in milligrams per tonne).

TAB III (CONINUED) As1HS Als IH& ASft Hg& lExampl nO II C% Ippb TI lpb C% Ippb C% Tppb IC% Ippb IC-%Ippb 200 h 1 500h 100 OOh 1 99 15 112 15361 5 10 15401 I I I_ _I 2 ~8460I53 II 14IZ75 I3114151 1 1 1 1 3 1-7-1465 1 54 127716 -147013014'Z20 11 1 I 1 4 1 81 98 I 11 1 99 I 5 197,51 15 198,517,5 j 98 I 12 I1 1 5 1 98 9iy-77ll--"9l lT--2 9 I15975114 I1 1 6 198,18919-8,317101 9 1 5 198,817,21 I -1 1 1 1-993[11 91 10 1993 10 199 12 192 12 1_81 13 1 8 1 99 I 15 199.31 8 19891 16 19.31 8 I 1 I 1 1 1 'III .1 I I C%=rate (in percentages by weight) at which muercury and arsenic are fixed mn the group of materials canprising the catalyst and denercurisation material.

ppb =Residual concentration of arsenic ari mercary, exressed in micrograms (10-6 gramn) per kilogran (or in milligramns per tonne).

Claims (14)

1. A method of removing mercury from a hydrocarbon charge containing the elements mercury and sulphur, the amount of sulphur present being from 0.005 to 3% by weight, characterised in that a mixture of hydrogen and said charge is reacted in the presence of an arsenic collecting material with catalytic properties, hereinafter referred to as "the catalyst", and a mercury collecting material, either simultaneously or sequentially such that reaction in the presence of follows reaction in the presence of the catalyst containing at least one metal M selected from the group formed by nickel, cobalt, iron, palladium and platinum, at least one metal N selected from the group formed by chromium, molybdenum, tungsten and uranium, and possibly at least one active phase carrier based on at least one porous inorganic matrix, and the said mercury collecting material containing a sulphide of at least one metal P, selected from the group formed by copper, iron and silver, or sulphur, and an active phase carrier.

2. A method according to Claim 1, wherein the charge contains arsenic as well as mercury and sulphur, characterised in that the arsenic and mercury are removed simultaneously, respectively by interaction with the catalyst and with the mercury collecting material.

3. A method according to Claim 1 or Claim 2, wherein the charge is partly hydroesulphurised, hydrodenitrified and hydrogenated in respect of its unsaturated hydrocarbon fraction, simultaneously with the elimination of the metals mercury and arsenic.

4. A method according to any one of Claims 1 to 3, wherein at least one sulphur compound, selected from the group formed by hydrogen sulphide and sulphurised organic compounds, is added to the charge. A method according to any one of Claims 1 to 4, wherein the catalyst contains 0.01 to 15% by weight of at least one metal M, and 2 to 30% by weight of at least one metal N, and wherein the atomic ratio M/N is 0.3:1 to 0.7:1.

6. The method according to Claim 5, wherein the metals M are cobalt and nickel and the metals N are molybdenum and tungsten, and wherein the catalyst contains to 15% by weight of at least one said metal M and 5 to by weight of at least one said metal N.

7. A method according to Claim 5 or Claim 6, wherein the catalyst contains at least one noble metal, selected from palladium and platinum, among the metals M, and wherein said catalyst contains 0.01 to 5% of metals M.

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

9. A method according to any one of Claims 1 to 8, wherein the mercury collecting material comprises 1 to of sulphur relative to its total weight, and at least one carrier selected from the group formed by alumina, silica- y.md aluminas, silica, titanium oxide, zirconia, zeolites, active carbons, clays and aluminous cements. A method according to Claim 9, wherein the mercury collecting material 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 wherein the metal P is at least partly in sulphide form.

11. A method according to any one of the preceding Claims, wherein: the operating pressure is from 1 to 50 bars absolute the hydrogen flow rate is from 1 to 1000 litres of hydrogen gas (NTP) per litre of liquid charge the hourly volume 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 demercurisation material the operating temperature of the catalyst is 180 to 450°C the operating naterial of che dercurisation material is 0 to 400 0 C the catalyst and demercurisation material are arranged in two separate reactors, the charge being put into contact first with the catalyst then with the collecting material.

12. A method according to Claim 11, wherein the catalyst and demercurisation material are arranged in one reactor, and wherein the operating teamperature is fr,>i IbO to 4009C

13. A method according to Claim 11 or 12, wherein the hydrogen-rich gas is separated from the effluent from the reactor or reactors, then at least partly recycled to the top of the first reactor. oe

14. A method according to anyA of Claims 1 to 13, wherein the catalyst is protreated at from 50 to 500°C, by a gaseous mixture containing at least one campound frcm the group formed by hydroqen, hydrogen sulphide and organic sulphur cacnpounds, prior to the treatment by the hydrocarbon charge. one A method according to anyAof Claims 1 to 14, wherein the dcharge canomprises hydrocarbons which are at least partly liquid at ambient temperature and pressure, and contains 10-3 to 2 milliqrams of mrercury per kilogram of charge and possibly 10-2 to 10 milligrams of arsenic per kilogram of charge. oft

16. A method according to any of Claims 1 to 15, wherein the charges treated are heavy ones or effluents fram thermal and/or catalytic conversion procesaes.

17. A method according to anyAof Claims 1 to 15, wherein the charges treated are gas condensates. K L'ro INTERNATIONAL SEARCH REPORT Interliational Application No PCT /FR9 0 /00162 1. CLASSIFICATION OF SUBJECT MATTER (If several classification symools apply, indicate allit According to Inrernational Patent Classification IIPC) or to both National Classification and IPC ClOG 67/06, ClOG 25/00, CIOG 45/04 11. FIELDS SEARCHED Minimum Documentation Searched I Documentation Searched other than Minimuiii Documentation to the Extent that such Documents are Included in in. Plids Searched I Ill. DOCUMENTS CONSIDERED TO BE RELEVANT'1 Category Citation of Document, 11 with indication, where appropriate, of the relevant vassaaes 13 A US, A, 4069140 (WUNDERLICH) 17 January 1978; see claims 1-12 (cited in the application) A US, A, 4709118 (YAW) 24 November 1987 see claims 1-25 A US, A, 4474896 (CHAO) 2 October 1984 see claims 1-21 A US, A, 3110569 (CARTER) 12 N'ovember 19G3 Relevant to Claim No. 13 1-17 1-17 1-17 S0e4ial categorist OfCited documetst 10 document defining the itenetal tll ol the art which is not considered to be ot particular folsvance IIE' stliet document but oublished on of &list the inteiriatiofl rilinig date 1" document Vihith may khow doubt% On 6110111tv clilat( Of WhiCh It Cited to es1tblish the publication date 01 anOOe Citattion or ottner special reaslon tes specified) I'0" dOcument Weafting to en orat wdisOutt. use, shibition or other means dP ocument published otiot to the internatiottat flingt date but 11lay than the Orit Ot. elai8Me 'IT" later document Published alter the international Abting dateo or priority date and not in Conflict with the sobiictilon but Cited to uildestand the orinciple or theory undstlyirtg the invention document of tarliCular televehee: the Claimed inveniOnl Cannot be comsideteo novel or cannot be Considered to involve an inventive step doCUMent ot bartitular relevance; the Claimed tnventiont cannot be consioered to invoive an inventive oteo whent the document is Combined With one or Mote Other such dOWiJ Monti. such comboination being Obvious to a 0*14601 skilled in tn# alt "'document member Of the same patent temily IV. CER~TIFItCATION bate at the Actual Completion Of the Intetrnational Seatch Tell Of Mailing) Ot this Interntional SwaCh Retior 14 Juhne 1990 (14-06.90) 18 July 1990 (18.07.90) tnterntlonal Searchiing Authortity gonature Of AutlhOritect Ofier European Patent Office Porl" PCTISA2IO tecond ohenac) 144NuIty 1111S) ANNEX TO THE INTERNATIONAL SEARCH REPORT ON INTERNATIONAL PATENT APPLICATION NO- FR 9000162 SA 35555 This annex li6ts the patent family members relating to thec patent documents cited in the above-mentioned international search report. The members aire as contained In thc European (latent Office EDP file on 06/07/90 The European Patent Office is in no way liable for these particulars "hich art merely given for the purpose of information. Patent document I PublicationPaetfmlPuicio cited in search report date jmember(s) date US-A- 4069140 17-01-78 AU-A- 1015876 14-07-77 CA-A- 1051808 03-04-79 US-A- 4709118 24-11-87 None US-A- 4474896 02-10-84 None US-A- 3110569 None f mbte detalis about thk antnex Isee Officil JeuthAl of the Lutooton P'atent Office, 12191 RAPPORT DE RECHERCHE INTERNATIONALE Demands lnlsrnatlonale W PCT /FR 90 /00162 1. CLASUEMINT Of L'INVENTION 41i Plusisura Symbols$ do classification sont opolicablea. Its Indliquer lout) T Solon Is classiicson International@ dos brovets (CII ou A Ia lola salon Is classification nationals at Is CIB 5 CIB i In 9Z '7 /CZ n In t-r in n r' Inf r- A c IrA 11, DOMAINKS SUR L14QUELS LA RKCHKRCHR A PORT9 Documentation mninimal. consulile I Systims do classification Symbol*$ do classification Documentation consuli~es uite 4uo as documentation minimal* dana Ia modUra oii do tell documents font peris dos domeis out losquets Is recherche a PontC 1it, DOCUMENTS CONSIDiRtiSl COMME PERTININTS i cat~gorle *Identification dos docu., trite dile," avic Indication, at nicesairs. N, dos fewendicationa dos passages pertinenla 12 visdos IS A US, A, 4069140 (WUNDERLICH) 1-17 17 Janvier 1978 voir revendications 1-12 (cit6 dans la dernande) A US, At 4709118 (YAI) 1-17 24 novemrbre 1987 voir revendications 1-25 A US, A, 4474896 (CHAO) 1-17 2 octobire 1984 voir revendications 1-23, A US, A, 3110569 (CARTER) 12 novenibre 1963 SCattgoies so~cisas do documents cliit "I aT* document ultdiur oubili Posttlflurementiladteds d461~ a Aa dtocument d~fnissant I'dial vinital do Is technique, non International 01) 6 IS date do Piorit# Ml naspooflenant 048 tonsidaltCcomme particulilrsment pertinent A I'4tat datas techniqus, pertinent, mail clit pour comarendto IS Principe ou IS thiofli constituent IS base do ttnvention aft document antilaur, moaut li AIs data do dAP6t Interna. Xadcmnofluirmntptnnttnotonovn. tiona ausice ctta ate uec no paut Wet considhreo, comm. nouvaill ou commo i L document pouvant l*tt un daut, out unit teondiCatlon de Impliquent Uno actialiC inventive piloft% 0au citC pour detrmner Is data do Publication d'Lun? Y ouetvrlulrmntpriat ivninrs cull ciatin o pot ue riao spiat Itlicputdiq *IdiOU00 no Pout tire considerfo comma Impliquant uno a document so 0t411rant A Una divuldation otate, A, Un Usage.& ativli Inventive lterauo Is document sot aesociC un ou Une asPoaltion ad tOUs auta& mopena plusiouta auta documents do m4m4 nature, calls combi. aeiba document PubliC avant Is date do d~o6l International, mals nation Clant ividente, Pour Un. potsonne du metier, 00o1trieutsment Alas date do ptionto revondiQuos a a document out tali Pattie do Is, m~m* familta do brovata IV, CERTIFICATION oat h tQuelle ts recherche tntemalionaie a M6i efiectivemnt Date d'extpditian du prhaent rapport da t*ch*rche intatnationata achenilo 14 itain 1990 Adntattttiori Cliarg4 do Ia vatherche 5n1rat1ntsSlgAlufid uIncilinnalfd sutarise OFFICE rAUROPEEN4 DES BREVES Wl~- flMIRS fetimuiaire PCYIISA?210 (deusiin feuilla) Ieoww 16441) ANNEXE AU RAPPORT DE RECHERCHE INTERNATION,,LE RELATIF A LA DEMANDE INTERNATIONALE ]NO. FR 9000162 SA 35555 La prisentc annexe Indlque ts: membres de In famille de brevets relatifs aux documents brevets citis dans le rapport de recherche Internationale v'ise ci-dessus. Lesdits menibres sont contcnus au ichier informatique dc I'M=ic europien des brevets i In date du 06/07/90 LeA renscignements fournis sont dionnis i titre indicatif et tlenga~ent pas In responsabiliti de I'Ornce curopien des brevets. US-A- 4069140 17-01-78 AU-A- 1015876 14-07-77 CA-A- 1051808 03-04-79 US-A- 4709118 24-11m87 Aucun US-A- 4474896 02-10-84 Aucun US-A- 3110569 Aucun C Pour tf4.t ftftd~fttmnt coeontrant ettue anneie 1. Voir Journal 011itiel de I'Olic europeen des brevets NId