IT201800010229A1 - PROCESS OF PARTIAL CATALYTIC OXIDATION WITH LOW CONTACT TIME FOR THE PRODUCTION OF SULFUR AND SYNTHESIS GAS STARTING FROM ACID GASES - Google Patents

Description

PROCESS OF PARTIAL CATALYTIC OXIDATION WITH LOW CONTACT TIME FOR THE PRODUCTION OF SULFUR AND SYNTHESIS GAS FROM ACID GAS

Description

The present invention relates to a low contact time catalytic partial oxidation (SCT-CPO) process for the production of elemental sulfur and synthesis gas in a single step starting from acid gases, in particular starting from a hydrocarbon stream which contains hydrogen sulphide, possibly other sulfur compounds and / or carbon dioxide, also present in significant quantities up to 60% by volume, indicated in the text as acid hydrocarbon gases or acid gases.

The main purpose of the process that is the subject of this patent application is to enhance the acid hydrocarbon gases produced in oil fields, which due to the high content of acidic components should be treated using complex and costly technologies before they can be exploited industrially and commercially.

In the present patent application, acid hydrocarbon gases mean hydrocarbons which contain sulfur compounds, such as for example hydrogen sulphide, and / or carbon dioxide up to 60% by volume. In particular, the process object of the present patent application can treat acid natural gas, associated acid gases, acid offgas deriving from the processes of exploitation of oil reserves and from refining processes.

The technological solutions described and claimed herein lend themselves to expanding the possibilities of exploiting available and accessible hydrocarbon resources, but also to contribute to the development of a business of marketing a technology that may have different fields of application, since the synthesis gas produced is a intermediate of numerous industrial chains, such as synthesis of methanol and its derivatives, olefins, DME, gasolines and gas oils, synthesis of ammonia and urea, production of hydrogen for refining processes. In the present patent application, all the operating conditions indicated in the text must be understood as preferred conditions even if not expressly stated.

For the purposes of this discussion, the term "understand" or "include" also includes the term "consist in" or "essentially consisting of".

For the purposes of this discussion, the definitions of the intervals always include the extremes unless otherwise specified.

The removal of H2S and in general of other sulfur compounds (such as carbon sulphide and mercaptans) and the removal of CO2 from Acid Gases or from any other hydrocarbon stream is necessary:

i) in the processes of exploitation of Oil & Gas resources;

ii) in refining processes, as emissions from refineries cannot contain high levels of sulfur compounds;

iii) in all processes of chemical conversion via synthesis gas of hydrocarbon streams.

As regards point (i), and specifically for the use of Acid Natural Gas resources, there are several alternative technological solutions that are selected with the aim of removing those components that would cause problems of freezing, corrosion, erosion, clogging. and / or safety and environmental problems.

Typical values of the specifications on the impurities that may be contained in the natural gas pumped into the pipelines are: maximum CO2 about 2 - 3% (v / v) and H2S <4 ppm. These values also drop considerably if you intend to liquefy natural gas to obtain Liquefied Natural Gas (LNG), for example in this case the CO2 content must be below 50 ppm and the H2S content below 4 ppm.

The removal of contaminants from gaseous hydrocarbon streams is typically achieved with physical absorption methods, which also include Pressure Swing Adsorption (PSA), chemical absorption or membrane processes.

Physical absorption methods exploit the different solubility characteristics of various gases in liquids. An ideal liquid is, in this case, one that does not chemically react with the components of the gaseous mixture.

Solvents of this type are most effective when:

a) the partial pressure of the acid gas is higher than 5 atm, b) when a complete removal of the acid component is desired,

c) when seeking selective removal of a component, in particular of H2S,

d) when the concentration of heavy hydrocarbon compounds in the gas to be purified is low ("R. Wagner and B. Judd, Fundamentals – Gas Sweetening" in LRGCC 2006 Conference Proceedings: Laurance Reid Gas Conditioning Conference 56; Norman, OK, [February 26 - March 01, 2006] ").

Pressure Swing Adsorption (PSA) processes are based on the selective adsorption of certain components of the gaseous mixture, using a solid support placed in a column packed at a relatively high pressure. This operation produces a gaseous stream at a relatively high pressure which is deprived of most of the molecules which remain more strongly absorbed on the solid support. The adsorbed components are then desorbed by reducing the pressure of the gas phase. After desorption, the solid is again ready for another adsorption-desorption cycle (Ind. Eng. Chem. Res., 2002, 41 (6), pp. 1389–1392; Chem. Eng. Journal, Elsevier, 2009, 155 (3), pp. 553-566).

Chemical solvents are based on acid-base equilibria in a solution in which H2S and CO2 form soluble salts, while non-acid gases pass unaltered in the absorption columns. The reversibility of the absorption is then obtained by increasing the temperature and / or reducing the pressure and / or diluting the gas phase (with steam or another inert gas). Almost all chemical solvents of this type belong to one of the following two groups: aqueous solutions of potassium carbonate or aqueous solutions of alkanolamines.

The latter are the most widely used (A.J. Kidnay, W.R. Parrish, D.G. Mccartney, “Fundamentals of natural gas processing”. CRC Press).

By combining some physical absorption solutions it is also possible to obtain hybrid processes and solvents. The methods of removing natural gas contaminants using membranes still have a rather limited but growing use (Ind. Eng. Chem. Res., 2008, 47 (7), pp. 2109–2121). The membranes were initially used in Natural Gas purification systems in the 1980s with the aim of removing CO2. The first system that was used for this purpose contained anisotropic cellulose acetate membranes, still widely used even though the use of alternative membranes based on polyamides and fluorinated polymers is spreading.

The membranes are formed as hollow fibers or flat sheets packaged as spiral-wound modules. Furthermore, various solutions of composite membranes are being developed, in which an anisotropic system is created in which a structure with high permeability and high mechanical resistance is used, and on which a thin layer of permeo-selective material is deposited (with a thickness typically 0.2-1 μm). Composite membranes are formed as hollow-fiber and flat sheet membranes.

The sulfur recovery plants transform the sulfur compounds removed from the Acid Gas. This removal operation is mainly carried out by amine washing which, in the absence of CO2 in the acid gas, generates a desulphurized hydrocarbon stream and an aqueous amine solution containing H2S. The H2S contained in the amine solution is released by thermal effect (regenerating the amine), heating the solution with steam. The H2S thus obtained is sent to a sulfur recovery section consisting of a Claus unit which in its modified and more advanced version uses a combination of heat and catalytic treatments and can remove most of the Sulfur (up to 98% v / v). In the increasingly frequent case in which a removal greater than 99% v / v is required, an additional tail gas treatment section is required, which allows an almost complete removal of sulfur.

The Claus process produces elemental sulfur (Sx, with x between 2 and 8 depending on the reaction temperature) from gas streams containing mainly H2S. These streams are obtained not only from natural gas purification treatments, but also from the softening processes of refinery gases.

The Claus process produces elemental sulfur through the partial oxidation of H2S, based on the overall reaction:

H2S 1⁄2 O2 = 1/8 S8 + H2O �H ° = - 209 kJ / mol [1] The final flue gas, which has no commercial value, is incinerated in a thermal or catalytic burner to convert all sulfur compounds into sulfur dioxide (SO2). The elemental sulfur produced by the Claus process is of excellent quality and is used as a raw material in the chemical industry.

In reality, current technologies carry out the reaction [1] in several stages.

In the first stage (or thermal zone), one third of the H2S is oxidized to SO2 with air or enriched air, at high temperature (about 925-1200 ° C), according to the reaction [2]: H2S 3/2 O2 = SO2 + H2O �H ° = - 560 kJ / mole [2] Still in the thermal stage, the unburned H2S in the acid gas reacts with SO2 (the stoichiometric ratio H2O / SO2 is 2/1 v / v), forming elemental sulfur vapors according to reaction [3], which is endothermic and occurs at temperatures in which the formation of gaseous S2 species is favored. This stage is limited by thermodynamics and is responsible for producing 60-70% of the total Sulfur. This stage also has the function of destroying any other impurities, but if CO2 is present it cannot limit the formation of COS and CS2:

2 H2S SO2 = 3/2 S2 + 2 H2O �H ° = 47 kJ / mole [3] Subsequently the process of conversion of H2S to elemental sulfur continues in a series of catalytic reactors (from 1 to 3) by means of the reaction [4 ] which occurs at much lower temperatures (190-360 ° C), in which the formation of clusters of eight Sulfur atoms is favored: 2H2S SO2 = 3/8 S8 + 2 H2O �H ° = - 108 kJ / mole [ 4] With three catalytic beds in which the reaction is carried out [4] it is possible to reach a sulfur removal efficiency between 95-98%. The use of catalytic reactors and temperature control also allows the elimination of COS and CS2.

The process scheme provides that a waste heat boiler cools the gases, bringing them from the high temperature of the furnace in the thermal zone to the much lower temperature of the catalytic reactors, generating high pressure steam. The process also provides that the cooling sections located downstream of each reaction stage are combined with systems of condensation and separation of elemental sulfur, or solidification of sulfur, and low pressure steam generation.

The synthesis gas (a mixture whose main components are H2 and CO and minority components are CO2 and CH4) is produced to obtain H2 which will be used in the refining processes, for the synthesis of NH3 and Urea , methanol and its derivatives, gasolines and gas oils through the Gas to Liquids (GTL) processes, electricity through the integrated gasification combined cycle (IGCC) processes.

Synthesis gas is currently produced with three main technologies: Steam Reforming, partial non-catalytic oxidation and Auto-Thermal Reforming - ATR (Catal. Today 2005, Volume 106, Issues 1–4, pp. 30- 33).

In addition to these three technologies that have reached a remarkable level of maturity, the low contact time catalytic partial oxidation technology (SCT-CPO) is a solution that is moving from the pilot to the industrial phase (Ind. Eng. Chem. Res. , 2013, 52 (48), pp.

17023-17037).

The importance of synthesis gas processes is known and the conditions are in place for their further expansion in the coming years. If carbon-containing molecules are neglected and for simplicity only the H2 content is considered, it is estimated that the world production of this molecule corresponds to about 80 MT per year and that this H2 is used for 46% in the synthesis of NH3 ( approximately 37 MT per year), 38% in refinery operations (approximately 30 MT per year), 9% in methanol synthesis (approximately 7 MT per year) and the remaining 7% for other uses (approximately 6 MT per year).

It is also estimated that the capital invested (ISBL) in the synthesis gas production plants alone corresponds to 175−180 B € and that in the next few years this value will grow by approximately 6-7 B € per year (Ind. Eng. Chem. . Res., 2013, 52 (48), pp. 17023-17037).

There are also several other paths based on the use of synthesis gas that could be added to the current ones, for example those that allow the use of natural gas, coal and bio-masses to be integrated. This integration would add flexibility to production systems to support variations in the accessibility of primary energy sources and improve the problem of emissions (see for example i) (Nexant. Coal to Chemicals - Visiting and Revisiting the future; ChemSystem Prospectus; Nexant: White Plains, NY, 2012, ii; Chem. Rev., 2007, 107 (10), pp. 3952–3991, iii; Ind. Eng. Chem. Res. 2010, Volume 49, July 19, PP.

7371-7388).

Finally, it is emphasized that the production of electricity with combined cycles (IGCC) is also undergoing strong expansion, which strongly reduces CO2 emissions when coal or compounds such as high-grade oil processing residues are used as primary energy sources. carbon content.

As already mentioned, among the many solvents that can be used for the removal of sulfur compounds from natural gas streams and refinery gases, the most common are alkanolamines. It is estimated that 75-80% of the world production of sulfur is obtained through combined processes of removal of sulfur compounds with solvents based on alkanolamines and their subsequent decomposition by the Claus process. In this way, which uses consolidated technologies, there are considerable operational complexities, high energy consumption is determined and high capital costs are required.

The onerousness of the separation and conversion processes of sulfur compounds becomes particularly heavy in concentrated gas streams and is further aggravated by the presence of CO2. The presence of significant quantities of CO2, in fact, requires to increase the circulation speed of the amine and the volumes of the softening section, also reducing the efficiency of the Claus process, which reaches high conversion values of sulfur compounds if the charge has a low CO2 content. For this reason, a technology for the selective absorption of acid molecules or for the enrichment of acid gas (AGE, Acid Gas Enrichment) has been developed, which uses two treatment units with amines, one of which, selective for hydrogen sulphide, has the the task of supplying a charge with a high concentration of H2S to the Claus unit: the procedure therefore becomes even more onerous.

The Applicant has found a low contact time catalytic partial oxidation process (SCT-CPO) for the production of elemental sulfur and synthesis gas in a single step starting from acid gases, which eliminates the need to use separation processes. acid components and transformation processes of sulfur compounds.

Therefore, the subject of this patent application is a low contact time catalytic partial oxidation process (SCT-CPO) for the production of elemental sulfur and synthesis gas in a single step starting from acid gaseous hydrocarbons (acid gases), in particular starting from a current

hydrocarbon rich in hydrogen sulphide, optionally

other sulfur compounds and / or carbon dioxide, too

present in significant quantities up to 60% by volume.

Said procedure comprises the following stages:

● if necessary, preheat this current

acid hydrocarbon, optionally mixed with

superheated water vapor, at temperatures included

between 50 ° C and 400 ° C; so

● feed to a so-called mixing section

acid hydrocarbon current, possibly pre-

heated, and / or possibly mixed with steam

superheated water; and separately feed a

said mixing section an oxidizing stream

choice between air, enriched air, oxygen,

possibly mixed with water vapor

overheated; forming a mixture of reactants;

● feed to a partial oxidation reactor

low contact time catalytic said mixture

reagent and conduct the oxidation reaction

partial catalytic with low contact time in

presence of a catalytic bed possibly a

multiple layers converting said reagent mixture

and producing an effluent that contains synthesis gas

and sulfur and possibly sulfur products;

● cooling said effluent in an exchange system

thermal coupled to said oxidation reactor

partial catalytic with low contact time and place

downstream of said partial oxidation reactor

low contact time catalytic, at temperatures

between 10 ° C and 500 ° C and with a residence time

less than or equal to 1s in the trading system

thermal;

● condense, possibly precipitate, or solidify elemental sulfur from synthesis gas.

It constitutes a further object of this application for

patent a reaction system to conduct oxidation

partial catalytic with low contact time which

comprehends:

● a reagent mixing section;

● A reaction section containing at least one reactor

of low time catalytic partial oxidation

contact (SCT-CPO), coupled to said section of

mixing;

● a heat exchange system located downstream of said

SCT-CPO reactor and coupled to said SCT-reactor

CPO; and

● a possible sulfur condensation system;

in which said mixing area includes an area of

distribution to feed the reagents and a chamber of

mixing in which the reagents are mixed;

wherein said catalytic partial oxidation reactor

it comprises a sectional truncated conical catalytic zone

increasing, connected to the mixing zone, in which si

they consume the oxidant, water vapor and gases

acid hydrocarbons and the reaction effluent is formed;

wherein said heat exchange system is characterized

by comprising two cooling devices,

one primary and one secondary, where:

● the primary device is paired

fluid dynamically to the catalytic zone and is either a

device that includes one or more ducts of

tubular transfer, possibly jacketed, the

whose ends are open to allow the

passage of the reaction effluent; or said

primary device is a system that injects water

directly in the reaction effluent;

● the secondary device is able to generate water vapor by exploiting the heat of the reaction effluent, is connected fluid-dynamically to the primary device and is placed downstream of said primary device.

Advantageously, the process and the reaction system described and claimed can also effectively treat sulfur hydrocarbon streams, for example with a sulfur content ranging from 1 ppm to 25% by volume, which also contain significant quantities of CO2, quantities ranging from 0.01% by volume up to 60% by volume. It has in fact been shown that the presence of this molecule does not affect the conversion of sulfur compounds into elemental sulfur.

The proposed solution avoids the separation of CO2 and sulfur compounds, in particular H2S, from the hydrocarbon sources used to produce synthesis gas.

Thanks to the described and claimed process and reaction system, it is possible to produce elemental sulfur and synthesis gas in a single reagent system, the latter with a high degree of purity which makes it directly usable in downstream treatments.

The proposed solution will allow to manage any gaseous hydrocarbon source containing H2S and other sulfur compounds, expanding the conditions in which it is possible and advantageous to avoid flaring phenomena. The proposed solutions will make it possible to develop alternative and considerably more advantageous ways than the existing ones to exploit different types of Acid Natural Gas, Gas Associated with the processes of exploitation of oil reserves and streams produced downstream of refining operations. The improvements will concern both the economic aspects, such as the reduction of CAPEX and OPEX, and the technological aspects, such as operational and constructive simplicity of the sulfur conversion processes, and energy, such as the reduction of consumption and emissions.

The proposed solutions will also make it possible to strengthen the possibilities of developing a business for the commercialization of low contact time catalytic partial oxidation processes.

Further objects and advantages of the present invention will become clearer from the following description and from the attached figures, provided purely by way of non-limiting example, which represent preferred embodiments of the present invention. Figure 1 illustrates a simplified block diagram that integrates synthesis gas and sulfur production with SCT-CPO technology (section A) and the state of the art Acid Natural Gas treatment processes (section B). In Figure 1: C is the section for removing condensates and water (2) from the acid gas (3), D is the section of partial catalytic oxidation in which an oxidizing current (oxygen, air or enriched air) is fed which produces sulfur (5) and synthesis gas (6). Synthesis gas can be used to make methanol (7), urea or ammonia (8), diesel fuel (9) and hydrogen (10). Methanol can subsequently be converted to gasoline and olefins. Unit E removes carbon dioxide (11) and sulfuric acid (12) from acid gases which are then treated in an NGL unit (F) to separate natural gas (14) from ethane, propane, butane and C5 + compounds (13) . The hydrogen sulphide (12) is then converted in a Claus process (G) into sulfur (15) by separating tail gases which are treated to become offgas (H, 17).

Figure 2 illustrates a block diagram of the experimental apparatus used for the tests that describe the operation of the described and claimed procedure. In Figure 2: D1 is the Input Section to which H2S (100%), H2O, CO2, CH4, N2 and O2 are separately fed, represented with the currents nominated with 100: downstream of this section, three currents nominated with 200 are obtained, respectively consisting of H2O, O2 possibly added with CO2, a mixture of CH4, H2S, N2 which are preheated in D2, the Preheating Section. Downstream of D2, two streams are obtained, one containing CH4, H2O, H2S and N2 (300) and the other containing O2 possibly added with CO2 (400). D3 is the Mixing Section which forms a single mixture of reactants (500), D4 is the Reaction Section which produces synthesis gas, sulfur, nitrogen, water, minor percentages of unreacted hydrocarbons and by-products (600), D5 is the Cooling section that separates water and solid sulfur (700) from the rest of the effluent (801), which enters the abatement section (D6) of any gaseous sulfur compounds present, D7 is the Blow-down section in which the gas part of the effluent purified from any gaseous sulfur compounds (802), D8 is the storage section of solid Sulfur and condensed water, D9 is the Analysis Section in which the sulfur components that may be present are analyzed respectively (901 ) and synthesis gas (902).

Figure 3 illustrates the geometry of the D4 reaction zone used in the bench-scale system, consisting of D401, D402, D403 and D404. D401 is the upper heat shield with height h = 192mm, D402 is the catalytic zone with height 23 mm composed of catalyst 424-89, D403 is the catalytic zone with height h = 36.5 mm composed of catalyst 424-95 and finally D404 is the lower thermal screen with height h = 10mm. Catalysts 424-89 and 424-95 consist of spherical supports of α-Al2O3 with a diameter of 1.8 and 3 mm respectively, on which Rhodium in a concentration of 1.5% by weight has been deposited. The reactor has a truncated cone shape in the catalytic zone and is tubular in the zones of the thermal shields.

Figure 4 illustrates the mixing area D3 and the reaction area D4, the latter coupled with the cooling area D5, used to conduct the experimental tests with the process according to the present invention. In Figure 4 it is possible to see how the Cooling area D5 is structured, consisting of a primary cooling device D501 (which is a jacketed single-tube exchanger cooled by an external circulation chiller) and a secondary cooling device D502 (which is a jacketed tank partially filled with water and cooled by an external circulation chiller).

Detailed description

The process and the reaction system object of the present patent application are now described in detail also with reference to Figures 1-4.

The low contact time catalytic partial oxidation process (SCT-CPO) for the production of sulfur and synthesis gas starting from acid gases takes place in a single step. The feedstocks fed are known as acid gases, in particular they are hydrocarbon streams rich in hydrogen sulphide, possibly other sulfur compounds and / or carbon dioxide, also present in significant quantities up to 60% by volume.

Said process can preferably take place in at least one SCT-CPO low contact time catalytic partial oxidation reactor, preferably in at least one known and proprietary low contact time catalytic partial oxidation reactor so that the sulfur produced in the catalytic zone can be separated from the synthesis gas, the low contact time catalytic partial oxidation reactor must be coupled to a heat exchange system specially designed for this type of application as described in the present patent application.

The proprietary low contact time catalytic partial oxidation reactor may comprise:

● a catalytic bed optionally with multiple layers, preferably at least one layer, of a truncated cone shape with an increasing section, which contains in each layer a catalyst consisting of a support on which the active part of the catalyst is deposited;

● layers of material that function as a heat shield arranged upstream and, optionally, downstream of the catalytic bed according to a cylindrical geometry;

● refractory materials that contain the reaction section, in turn placed in a metal container.

● A grid or structure made of pre-formed refractory materials supports the heat shields and the catalytic bed.

The feeding to the mixing area can be carried out by sending separate streams (also referred to in the text as reagents) through separate inputs: an acidic hydrocarbon stream, possibly also containing CO2, and possibly mixed with superheated water vapor; an oxidizing current selected from air, enriched air or oxygen, possibly mixed with superheated water vapor.

The acidic hydrocarbon stream can preferably be preheated (D2) at temperatures between 100 ° C and

400 ° C, before being fed to the SCT-CPO reactor (D4).

Optionally the acidic hydrocarbon stream can be

mixed with water vapor.

The oxidizing stream, possibly mixed with steam

aqueous, can be preheated (D2) preferably a

temperatures between 100 ° C and 250 ° C.

Said acid hydrocarbon stream, possibly pre-

heated, and / or possibly mixed with water vapor

overheated, it is fed to a mixing zone. TO

said mixing zone, separately, is fed

also an oxidizing current selected from air, air

enriched, oxygen, possibly mixed with steam

superheated water.

The mixing zone (D3) preferably includes:

● an input section containing inputs for

separately feed acid hydrocarbon gases,

possibly added with water vapor, and the

oxidizing current, possibly with the addition of

water vapor;

● a distribution area of the gaseous reagents,

preferably containing at least one tubular element

preferably vertical, ed

● a mixing chamber in which i

gas phase reagents possibly added with

water vapor and possibly the oxidizing current

added with water vapor, forming a mixture

homogeneous.

The reaction mixture subsequently flows into the zone

of Reaction of SCT-CPO (D4), which can contain the screens

upper thermals (D401), and optionally lower

(D404), and the catalytic zone (D402, D403).

The reagents are brought together within the zone

mixing specially designed to avoid the triggering of oxidation reactions in the homogeneous phase; then the reactant mixture crosses an upper thermal screen placed upstream of the catalytic zone and enters the catalytic zone in which the reactions take place.

The upper heat shield and reaction zone are designed in such a way as to avoid the propagation of reactions in the gas phase, favored when operating at high pressure or in the typical applications of synthesis gas, and to confine the reactions in the catalytic zone, more precisely. in a high temperature solid-gas interphase zone, in which the formation of stable sulfur compounds other than elemental sulfur and the deactivation phenomena of the catalysts are inhibited. Preferably, the mixing zone can be a mixing device coupled to the reaction section, and in particular coupled to the low contact time catalytic partial oxidation reactor. Said mixing device can include:

- A distribution area that includes a bundle of parallel tubes in which a first fluid flows, said tubes inserted in a support plate;

- A mixing chamber separated from the distribution area by means of said support plate, in which the tubes of the bundle extend;

- A supply area through which a first fluid flows into the tubes of the bundle, and a second fluid flows into the distribution area externally to the tubes of the bundle, said first and second fluid being fed through separate inputs.

The tubes of the bundle can have slots or openings for the passage of the first fluid into the mixing chamber which can allow an axial, radial or transversal distribution of the fluids or combinations thereof. The tubes of the bundle can have different lengths or the same length.

The low contact time catalytic partial oxidation reaction is carried out in a catalytic bed possibly with multiple layers (D402, D403), preferably at least one layer, in which each layer contains a catalyst producing an effluent that contains synthesis gas and elemental sulfur .

The catalytic zone can be delimited by a heat shield upstream (D401) and optionally one downstream (D404) of the catalytic bed. The catalytic zone is truncated cone with an increasing section. The heat shields can be layers of alpha-alumina pellets. The catalyst, present in each layer of the catalytic bed, can comprise an active part consisting of a metal selected from the group of noble metals; and a support selected from ceramic oxides with high thermomechanical resistance and chemical stability in oxidizing and reducing conditions higher than or equal to 1500 ° C.

The noble metals can be preferably selected from Rh, Ru, Pd, Pt, Ar, Os, Ir, Au and their mixtures.

Among the metal mixtures, the Rh-Ir mixture is preferred. Preferred is Rh among the noble metals.

The preferred supports can be selected from Aluminum oxides with alpha phases; Zirconium oxides also stabilized with Yttrium; cerium oxides; mixed oxides of Magnesium and Aluminum and / or mixed oxides of Magnesium or Manganese, more preferably selected from MgAl2O4 and MgMn0.25Al1.75O4, hexaluminates, more preferably selected from LaAl11O19 and LaMnAl11O19, compounds having a perovskitic structure, more preferably selected from LaCrO3 or LaCoO3 , LaFeO3, LaAlO3, CaTiO3, CaZrO3. Alpha-alumina is preferred among the ceramic oxides.

The amount of noble metals present as an active component can preferably vary in the range 0.2% 10% by weight, more preferably in the range 0.2% -5%

by weight. The reactions can preferably be

carried out at pressures between 1 atm and 40 atm. THE

feeding relationships can be summarized as

follows (C indicates the number of moles of hydrocarbon carbon

and S the number of moles of sulfur contained in the mixture

reagent):

● O2 / (C S) ratio preferably between 0.2 v / v

and 0.8 v / v, more preferably between 0.4 v / v e

0.7 v / v, even more preferably between 0.5 and 0.65 v / v. ● Water vapor / C ratio preferably between

0.0 v / v and 3.0 v / v more preferably between 0.1

v / v and 1.0 v / v and even more preferably between 0.2 e

0.8 v / v.

The reaction effluent can be found at temperature

between 800 ° C and 1100 ° C.

Immediately downstream of the catalytic zone, it is positioned

a heat exchange system coupled to said reactor

SCT-CPO. Said heat exchange system comprises two

cooling devices, a primary device and

a secondary one (Figure 4).

The primary device may preferably include a

or more tubular transfer pipes, optionally

jacketed, the ends of which are open so as to

allow the passage of the reaction effluent. The

transfer pipes can preferably be

vertical or horizontal.

The primary device is coupled to the SCT reactor-

CPO to which it is structurally and fluid-dynamically connected.

A preferred way of making said connection is o

coupling is to employ a flange where they are

inserted multiple tubular transfer pipes,

possibly jacketed (in this text called

refrigerated flange), preferably at least one duct.

In this case the chilled flange functions as the primary cooler.

Possibly the coupling can also be achieved by means of a transfer line, vertical or horizontal, which includes one or more cylindrical ducts, possibly jacketed and cooled with water and / or coolant. When present, the transfer line is the primary device: the hot synthesis gas flows into the transfer line ducts to subsequently enter the secondary cooler.

The primary device can alternatively be a system that injects water directly into the reaction effluent (direct water-quenching), for example a device that includes injectors for liquids and flanges. A direct quenching system consists in the direct injection of water into the synthesis gas, for example in the transfer line where the synthesis gas flows and subsequently flows into the secondary cooling device.

The secondary device is located downstream of the primary device, is capable of generating steam and is fluid-dynamically connected to the primary device. Preferably said secondary device is a boiler, such as for example a steam boiler or a waste heat boiler, more preferably a tube bundle or helical exchanger.

It is essential that the reaction effluent is cooled to temperatures between 10 ° C and 800 ° C, more preferably between 10 ° C and 500 ° C, even more preferably between 12 ° C and 400 ° C, more preferably comprised between 15 ° C and 350 ° C.

It is essential that the cooling takes place with a residence time calculated on the entire heat exchange system (i.e. considering both the primary and secondary devices) less than or equal to 1s, preferably less than or equal to 1/10 of a second and again more preferably less than or equal to 1/100 of a second. In this way the condensation of water and elemental sulfur is obtained, which are separated from the synthesis gas.

In addition to cooling effectively in a short time, it is crucial not to remove heat from the reaction zone, which invariably would not work properly, producing carbon deposits.

Downstream of the secondary cooling device, a vertical or horizontal condensation and possibly precipitation or sulfur solidification system can be present. In this way it is also possible to separate the water through condensation, and possibly precipitation, or solidification of the sulfur.

The cooling devices have been designed to ensure the immediacy and efficiency of cooling, fundamental requirements for the success of the technology (i.e. recovery of sulfur greater than 95%), taking into consideration the constraints imposed by high temperatures / pressures and the chemical composition of the effluent.

The process and the system described and claimed in the present patent application can be integrated in all industrial solutions in which it is advantageous to recover the sulfur contained in the acid gas streams and at the same time produce synthesis gas suitable for the main processes via synthesis gas.

In particular, Figure 1 shows a simplified block diagram which shows how the system object of the present patent application can be used in the treatment of raw gas coming from an acid natural gas reservoir containing high quantities of H2S and CO2, for a grand total of up to 60% by volume.

Figure 1 shows a block diagram in which, in parallel to the "conventional" gas treatment system (section B), a treatment scheme for acid gases is integrated which uses a low contact time catalytic partial oxidation reactor for the direct production of synthesis gas and sulfur (section A). In this scheme it is possible to balance the gas flow in the two sections A and B according to the needs of the context and therefore to balance the production of Natural Gas and its by-products with the production of the chemical species obtainable via synthesis gas.

It should be noted that the increase in the production capacity of section A allows to reduce greenhouse gas emissions for the same volume of raw gas consumed in sections A and B and to increase the added value of overall production.

The figure also indicates the possible industrial applications of the synthesis gas produced, such as the synthesis of methanol, the synthesis of ammonia and urea, the production of gas oils by Fischer-Tropsch processes and the exploitation of hydrogen in the refinery which can then be reused in various hydrotreating processes, increasing refining yields towards fine products and at the same time reducing energy consumption and emissions.

In the refineries, both in the atmospheric distillation processes and in the treatments of the various process streams, off-gas streams containing sulfur compounds are produced.

Also in the refining processes these compounds are removed (mainly with amine washes) and then treated in the Claus units to produce elemental sulfur and a low sulfur content fuel gas stream (section B of Figure 1).

Some application examples of the present invention are now described which have a purely descriptive and non-limiting purpose and which represent preferred embodiments according to the present invention. EXAMPLES

The catalytic tests for the treatment of acid gases with the reaction system object of the present patent application were carried out in a bench-scale plant as illustrated in Figures 3 and 4 equipped with a fixed bed low contact time catalytic partial oxidation reactor. . This plant is characterized by a production capacity of up to 6 Nm <3> / h of synthesis gas and consists of the following seven sections:

- Power section

- Mixing section

- Reaction section

- Cooling section

- Section for abatement of Gaseous Sulfur Residues - Storage of Liquid Products

- Analyses

Figure 2 shows a block diagram of the system. The acid gas streams, consisting of methane, hydrogen sulphide, nitrogen, oxygen optionally added to carbon dioxide and possibly water vapor are separately preheated (D2) and mixed (D3) before being fed to a catalytic partial oxidation reactor. low contact time (D4). A homogeneous mixture of the reagents is produced in the mixer. Once this mixture is formed it is fed to the SCT-CPO reactor. Here the reactions that lead to the prevalent production of synthesis gas and elemental sulfur take place.

The effluent leaving the reactor at a temperature of about 800-1100 ° C, depending on the operating conditions, enters the cooling section (D5), consisting of two heat exchange devices that reduce the temperature to about 20 ° C, condensing the process water together with elemental sulfur. The synthesis gas without sulfur is sent to the abatement section of gaseous sulfur residues (D6, a soda trap), then in a third exchanger, to the filters, to the pressure regulation valve and finally to the blow-down section ( D7) while the condensed water and sulfur are sent to the storage section (D8).

The online gas sampling points are positioned before the soda trap (to ascertain the presence of any sulfur compounds, current 901) and downstream of the third exchanger (to analyze the composition of the synthesis gas produced, current 902). Both sampling currents flow into the Analysis section D9. There is also a sampling point for the liquid stream, downstream of the second exchanger.

The sensors on the system, located in a cell suitable for operations under pressure, ensure that you can operate safely. In fact, there are sensors to detect the possible presence of flammables in the cell, H2S and lack of aspiration. In the event of an alarm, the flammable gas supplies are intercepted outside the cell and the electricity supply is interrupted. An environmental sensor in the control room, on the other hand, detects any leaks of H2S to / from the GC.

The plant sections are described in detail.

Power section

The gases, fed by cylinders and / or cylinder packs, are conveyed to a power panel adjacent to the system, equipped with Mass-Flow Meter and Controllers for regulating flows.

The H2S cylinder is locked in a cabinet, equipped with a special washing system with N2 for cylinder change and equipped with a leak sensor, with visual and acoustic signaling on site and reported to the control room.

CH4, H2S, H2, H2O are conveyed in the same line and preheated in two preheating furnaces, while O2, CO2 and N2 are conveyed in a second line and preheated in a single furnace.

There is a double system washing system (N2 mains and N2 HP) in case of Emergency Shut-Down.

The "cold" parts were made in SS 316, while the "hot" parts are in Inconel 625.

The Mixing section

The mixer is positioned at the head of the reactor and in it the homogeneous and safe mixing of the acid charge with water vapor, and of the oxidizing stream possibly added with CO2 is carried out. The mixing device is a 10x6 mm cylindrical chamber equipped with a tube-in-tube system, made of Inconel 625; the dimensions have been calculated in order to obtain residence times of less than 5 ms.

The Reaction section

The furnace consists of an external steel tank, containing a layer of refractory cement with embedded three resistances that are used exclusively to preheat the catalytic bed and to trigger the reaction. The reactor, which is inserted in the furnace, is made up of a ceramic tube (Sillimantin, MonoCriram or other suitable material) suitably shaped and containing the catalytic bed and the upper thermal shields (Figure 3), positioned in correspondence with the central resistance. The gas-impermeability is achieved in the upper part by using ceramic glue. A cordierite honeycomb grid supports the catalyst and the lower and upper thermal screens, made with alpha-alumina pellets. The thermal screens perform the dual function of avoiding the back-propagation of the reaction heat from the catalytic bed towards the “fresh” flow of the reagent mixture and of limiting heat dispersion. The catalyst is positioned as a “sandwich” between the thermal screens, in this case made up of alpha-alumina pellets (from NORPRO-Saint Gobain) with dimensions ranging from 1.2 to 3 mm.

The catalysts 424/89 and 424/95 occupy the truncated cone part of the reactor; to realize the examples described below, a catalyst was used consisting of alpha-alumina pellets (from NORPRO-Saint Gobain) on which 1.5% by weight of Rhodium was deposited as an active ingredient with the wettability impregnation method incipient. The dimensions of the catalytic pellets have been selected in order to reduce the vacuum degree and optimize the aspect ratio over the entire length of the catalytic bed. The aspect ratio, i.e. the ratio between the particle size (diameter, dp) and the reactor diameter, in fixed bed reactors must assume values ≥ 5. The vacuum degree, i.e. the ratio between the packed bed density) and the particle density, is optimal when it assumes values not exceeding 40%. Carriers (i.e. supports on which the noble metal (s) were then deposited) of such dimensions as to optimize the values assumed by these two parameters were therefore procured. For each type of carrier, the particle diameter (dp) was verified with the gauge on at least 30 particles.

The Cooling section

In the cooling section (Figure 4) the effluent temperature is reduced from 800 ° C - 1100 ° C to about 10 ° C - 20 ° C. The condensation of process water and elemental sulfur is thus obtained, which then separate from the gaseous stream and reach the liquid storage section.

In the configuration used to conduct the tests described in the examples, the cooling section is made up of two devices, named primary (D501, Figure 4) and secondary (D502, Figure 4).

The primary cooler (D501) is a jacketed transfer line (positioned immediately downstream of the catalytic bed (D402, D403); the jacketed line enters a jacketed tank positioned downstream and containing a water bath, referred to as a secondary cooling (D502) A mixture of H2O / glycol circulates in the two jackets, kept refrigerated by two external circulation chillers, Lauda WKL 7000 and Lauda WKL 2200 not shown in Figure 4.

The reaction effluent flows in the jacketed transfer line, cooling down: in this way the process vapor and the sulfur formed in the catalytic bed condense, respectively, to the liquid and solid state. The three-phase mixture consisting of synthesis gas, sulfur and water are released in D502 through a series of holes in the lower end of D500A, partially immersed in the water bath that constitutes D502.

The temperature is monitored in three distinct positions of the primary cooler, respectively at 36.3 mm, 311.3 mm and 724.3 mm from the catalytic bed. The three thermocouples are inserted in an Inconel 625 pocket consisting of a 6x4 mm tube (lower end) welded to a 1/8 ”tube (upper end). The latter is inserted in a ceramic sheath (Alsint 99.7) to protect against metal dusting phenomena.

The catalytic tests have shown that the ability to cool the effluent quickly is essential to prevent the sulfur produced in the reaction section from recombining with hydrogen by reforming H2S, a widely known phenomenon. In fact, it commonly occurs in the wasteheat boilers of Claus plants, in conditions much more unfavorable to recombination (operating pressure little more than atmospheric and low partial pressure of hydrogen).

In the configuration used to conduct the tests described in the examples, the primary cooling device, made of SS 316, is a single-tube exchanger with an external diameter of 40 mm and an internal diameter, through which the effluent, equal to 10 mm, passes. . This diameter widens from 10 to 20 mm at its entrance into the secondary cooling device (jacketed vessel). In this way, a “jacket” is created in which the refrigerant fluid, a water-glycol mixture, circulates. The upper end of the device, 1 mm from the catalyst support grid, consists of a solid cylinder with a height of 5 mm in which a conical inlet has been created for conveying the effluent. In the lower end of the device 18 holes with a diameter of 3 mm have been made, for the release of the effluent. The thermocouple well is housed inside the device, which reduces the passage section of the effluent to a 10x6 mm crown. The abatement section of gaseous sulfur residues The dry, sulfur-free gaseous stream reaches the abatement section of gaseous sulfur residues, introduced to avoid the emission into the atmosphere of any unreacted H2S and other sulfur compounds that may have formed (COS, CS2, SO2). It consists of a flanged tank with a capacity of about 10 liters containing concentrated sodium hydroxide at 20% by volume. The exhaustion of the solution is checked manually, with the system stopped, with litmus paper. The effluent passes into a float fitted with holes, is released into the caustic solution where it gurgles and rises towards the outlet through a demister, passes through a filter, the pressure regulating valve and is finally sent to Blow-Down.

The Liquid Products Storage section

The two-phase H2O-S mixture is discharged from the bottom of the secondary cooling device by means of a regulating valve and sent to the storage section, i.e. two closed drums inserted in parallel.

The analysis section.

Two online GCs positioned in the control room monitor the composition of the effluent withdrawn at two different sampling points, upstream and downstream of the gaseous sulfur residue abatement section. One of the two GCs, equipped with an FID and TCD detector, analyzes the composition of the synthesis gas while the other, equipped with an FPD detector, is dedicated to the analysis of sulfur compounds (any unreacted H2S and its gaseous conversion products - COS , CS2 and SO2-). The sampling line upstream of the Gaseous Sulfur Residues Abatement Section was built in Sulfinert.

There is also a liquid sampling point upstream from the liquid product storage section. The sampler, made of steel, is equipped with a double valve to be taken from the system and emptied under the hood.

Comparative Example 1

In the experimental system of Figures 2, 3 and 4 the following gas streams were fed:

- hydrocarbon stream consisting of Methane, Nitrogen (2.7% vol.), H2 (4.4% vol.) and H2S (5% vol.)

- water vapor

- pure oxygen

The flow rates of the three currents are such as to achieve O2 / (C + S) and Water vapor / C ratios equal to 0.60 v / v and 0.50 v / v respectively. The space velocity was found to be about 44,000 Nl / l cat / h.

The O2 / (C + S) ratio is calculated as the molar or volumetric ratio of oxygen, hydrocarbon carbon and sulfur present in the reaction mixture.

The water vapor / (C + S) ratio is calculated as the molar or volumetric ratio of the vapor and hydrocarbon carbon present in the reaction mixture.

The space velocity is defined as the ratio between the supplied flow rate, expressed in normal conditions Nl / h, and the volume of catalyst, expressed in liters.

The inlet temperature of the reagent mixture was 268 ° C. The test was carried out at 6 bar.

The plant was started up with a consolidated procedure that involves the use of only methane, water vapor and oxygen, while H2S was added only after reaching stationary conditions. In this test the primary cooler was not operated and the outlet temperature (measured by the thermocouple positioned at 36.3 mm from the catalytic bed) was 912 ° C. With this configuration, it was observed that a large part of the powered H2S was not converted. On the basis of gas chromatographic analyzes, a conversion of H2S equal to 29.2% vol was determined. In the "dry" effluent, in addition to the unreacted H2S, 347 ppm of COS were found.

The other main results are reported in Table 1. It is observed that the oxygen consumption, an efficiency index of the process, indicated as O2 consumed and calculated as the ratio between moles of O2 consumed and moles of H2 and CO produced, is quite high.

Table 1

Conversion component

CH4 86.0%

O2 100.0%

H2S 29.2%

Selectivity component

H2 87.7%

<CO> 78.0%

<CO> 2 21.4%

C2H4 0.6%

C2H6 0.4%

O2 consumption v. 0.293

H2 / CO v / v ratio 2.324

Example 2

The test described in example 1 was replicated, with the exception of the fact that the primary cooling system was inserted. In this case, the outlet temperature (measured by the thermocouple positioned at 36.3 mm from the catalytic bed) decreased from 912 ° C to 498 ° C and the H2S conversion was complete. The only compound found in the "dry" effluent was COS, in a very low concentration (10 ppm).

The other main results are shown in Table 2. It is noted that there are no traces of higher hydrocarbons and that the efficiency of the process is higher, as the consumption of oxygen (O2 cons.) Decreases to 0.245 v / v.

Table 2

Conversion component

CH4 89.4%

<O> 2 100.0%

<H> 2 <S> 100.0%

Selectivity component

H2 94.8%

CO 85.4%

CO2 14.6%

C2H4 0.0%

C3H6 0.0%

C2H6 0.0%

O2 consumption v. 0.245

H2 / CO v / v ratio 2.287

Example 3

In the experimental system described in the introductory part of the examples, the following gas streams were fed:

- Hydrocarbon charge with the composition shown in Table 3

- Water vapor

- Pure oxygen

Table 3

Natural gas

CH4 92.0 vol.%

H2S 460 ppmv

N2 2.5 vol.%

CO2 8,813 ppmv

H2 4.6 vol. %

The flows of hydrocarbon, oxygen and water vapor were such as to achieve O2 / (C + S) and water vapor / C ratios respectively equal to 0.58 v / v and 0.51 v / v, while the space velocity was equal to approximately 44.4 Nl / l CAT / h.

The inlet temperature of the reagent mixture was 260 ° C. The plant was started up using only methane, steam and oxygen, while H2S was added only after reaching stationary conditions. The test was carried out at 6 bar and the secondary cooling system was inserted, so the outlet temperature (measured by the thermocouple positioned at 36.3 mm from the catalytic bed) was 483 ° C. The test had a total duration 957 hours, in which no decay of the catalytic activity was observed. The H2S conversion has always been complete and no sulfur compound was detected in the gas stream (therefore the selectivity to elemental sulfur was 100%).

The other main results are shown in Table 4.

At the end of the test, the catalyst was discharged and subjected to physico-chemical analyzes using SEM-EDS, TEM and XRD. No carbon deposits or sulfur compounds adhering to the solid surface or otherwise retained in the catalyst were found. Therefore the catalyst is suitable for the treatment of acid charges by SCT-CPO technology.

Table 4

Conversion component

CH4 85.8%

O2 100.0%

H2S 100.0%

Selectivity component

H2 94.7%

<CO> 78.4%

<CO> 2 21.3%

C2H4 0.1%

C3H6 0.0%

C2H6 0.1%

O2 consumption v. 0.252

H2 / CO v / v ratio 2.42

Example 4

In the experimental system described in the introductory part of the examples, the following gas streams were fed:

- Hydrocarbon charge with the composition shown in Table 3

- Water vapor

- Pure oxygen

in order to achieve O2 / (C + S) and Water vapor / C ratios equal to 0.58 v / v and 0.50 v / v respectively. The flows of the currents were such as to obtain spatial velocity values equal to about 92 Nl / l CAT / h. The inlet temperature of the reagent mixture was 272 ° C. The test was carried out at 6 bar.

The plant was started up using only methane, steam and oxygen, while H2S was added only after reaching stationary conditions. Having inserted the primary cooler, the outlet temperature (measured by the thermocouple positioned at 36.3 mm from the catalytic bed) was 499 ° C.

The H2S conversion was equal to 100% vol. In the "dry" effluent, no trace of any sulfur compound was detected (selectivity to elemental sulfur equal to 100%).

The other main results are reported in Table 5.

Table 5

Conversion component

CH4 87.2%

O2 100.0%

H2S 100.0%

Selectivity component

<H> 2 93.2%

<CO> 83.9%

<CO> 2 15.5%

<C> 2 <H> 4 0.3%

C3H6 0.0%

C2H6 0.3%

O2 consumption v. 0.244

H2 / CO v / v ratio 2.22

Example 5

In the experimental system described in the introductory part of the examples, the following gas streams were fed:

● Hydrocarbon charge with the composition shown in Table 3

● Water vapor

● Pure oxygen

in order to achieve O2 / (C + S) and water vapor / C ratios equal to 0.50 v / v and 0.50 v / v respectively. The flows of the currents were such as to obtain spatial velocity values equal to approximately 41 Nl / l CAT / h. The inlet temperature of the reagent mixture was 264 ° C. The test was carried out at 6 bar.

The plant was started up using only methane, steam and oxygen, while H2S was added only after reaching stationary conditions. Having inserted the primary cooler, the outlet temperature (measured by the thermocouple positioned at 36.3 mm from the catalytic bed) was 456 ° C.

The H2S conversion was equal to 100% vol. In the "dry" effluent, no trace of any sulfur compound was detected (selectivity to elemental sulfur equal to 100%).

The other main results are reported in Table 6.

Table 6

Conversion component

CH4 71.3%

O2 100.0%

H2S 100.0%

Selectivity component

H2 91.7%

CO 79.2%

<CO> 2 20.4%

<C> 2 <H> 4 0.1%

C3H6 0.0%

C2H6 0.2%

O2 consumption v. 0.266

H2 / CO v / v ratio 2.32

Example 6

In the experimental system described in the part

introductory examples, the

following gas streams:

● Hydrocarbon charge with composition shown in

Table 3

● Water vapor

● Pure oxygen

in order to achieve O2 / (C + S) and water vapor / C ratios

respectively equal to 0.58 v / v and 0.50 v / v. The flows of

currents were such as to obtain velocity values

spatial equal to approximately 68.24 Nl / l CAT / h. The temperature of

inlet of the reagent mixture was 271 ° C. The test

was made at 15 bar.

The plant was started up using only methane and steam

and oxygen, while H2S was added only after

achievement of stationary conditions. Having

inserted the primary cooler, the

outlet temperature (measured by the thermocouple

positioned at 36.3 mm from the catalytic bed) was

495 ° C.

The H2S conversion was equal to 100% vol.

In the "dry" effluent, no trace of

no sulfur compounds (selectivity to elemental sulfur

equal to 100%): it is observed how the rise of the

pressure does not alter the reactivity characteristics of the

system.

The other main results are shown in the Table

7.

Table 7

Component Conversion CH4 87.2%

<O> 2 100.0%

<H> 2 <S> 100.0% Component Selectivity H2 94.4%

CO 79.7%

CO2 19.9%

C2H4 0.1%

C3H6 0.0%

C2H6 0.3% O2 consumption v. 0.248 H2 / CO ratio v / v 2.37

Claims (12)

CLAIMS 1. A process for partial catalytic oxidation a low contact time for sulfur production elementary and synthesis gas in a single step a starting from acid gaseous hydrocarbons, said process comprising the following stages: ● if necessary, preheat this current acid hydrocarbon, optionally mixed with superheated water vapor, at temperatures included between 50 ° C and 400 ° C; so ● feed to a so-called mixing section acid hydrocarbon current, possibly pre- heated, and / or possibly mixed with steam superheated water; and separately feed a said mixing section a stream oxidant chosen from air, enriched air, oxygen, possibly mixed with water vapor overheated; forming a mixture of reactants; ● feed to a partial oxidation reactor low contact time catalytic said mixture reagent and conduct the oxidation reaction partial catalytic with low contact time in presence of a catalytic bed possibly a multiple layers converting said mixture reacting and producing an effluent that contains gas of synthesis and sulfur and possibly products sulphured; ● cooling said effluent in a system of heat exchange coupled to said reactor low time catalytic partial oxidation contact is located downstream of said reactor low time catalytic partial oxidation contact, at temperatures between 10 ° C and 500 ° C and with a residence time less than or equal to 1s in the heat exchange system; ● condense, possibly precipitate, or solidify elemental sulfur thus separating it from synthesis gas. 2. The process according to claim 1 wherein the acid gaseous hydrocarbons contain hydrogen sulphide, optionally other sulfur compounds and / or carbon dioxide in quantities up to 60% by volume. 3. The process according to claim 1 or 2 wherein the catalytic bed optionally with multiple layers contains in each layer a catalyst comprising an active part consisting of a metal selected from the group of noble metals, and a support selected from the ceramic oxides with high thermo-mechanical resistance and chemical stability in oxidizing and reducing conditions higher than or equal to 1500 ° C. 4. The process according to claim 3 wherein the noble metals are selected from Rh, Ru, Pd, Pt, Ar, Os, Ir, Au and their mixtures. 5. The process according to claim 3 wherein the supports are selected from aluminum oxides with alpha phases; Zirconium oxides also stabilized with Yttrium; cerium oxides; mixed oxides of Magnesium and Aluminum and / or mixed oxides of Magnesium or Manganese, hexaluminates, compounds with a perovskite structure. The process according to any one of claims 3 to 5 wherein the quantity of noble metals present as active component varies from 0.2% to 10% by weight. 7. The process according to any one of claims 1 to 6 wherein the reaction is carried out at pressures ranging from 1 atm to 40 atm. 8. The process according to any one of claims 1 to 7 wherein the ratio O2 / (C S), where C are the hydrocarbon carbon atoms and S the sulfur atoms, is between 0.2 v / v and 0.8 v / v. 9. The procedure according to any one of the claims 1 to 8 wherein the vapor ratio aqueous / C is between 0.0v / v and 3.0v / v. 10. A reaction system to conduct oxidation partial catalytic with low contact time which comprehends: ● a reagent mixing section; ● A reaction section containing at least one reactor of low time catalytic partial oxidation contact (SCT-CPO), coupled to said section of mixing; ● a heat exchange system located downstream of said SCT-CPO reactor and coupled to said SCT-reactor CPO; and ● a condensation system, and possibly precipitation, or solidification of sulfur; in which said mixing area includes an area of distribution to feed the reagents and a chamber of mixing in which the reagents are mixed; wherein said catalytic partial oxidation reactor it comprises a sectional truncated conical catalytic zone increasing, connected to the mixing zone, in which si they consume the oxidant, water vapor and hydrocarbons gaseous acids and the reaction effluent is formed; wherein said heat exchange system is characterized by comprising two cooling devices, one primary and one secondary, where: ● the primary device is paired fluid dynamically to the reaction reactor SCT-CPO and it is either a device that includes one or more conduits tubular transfer, possibly jacketed, whose ends are open so as to allow the passage of the reaction effluent; or said primary device is a system that injects water directly in the reaction effluent; ● the secondary device is capable of generating water vapor by exploiting the heat of the effluent of reaction, is fluid-dynamically connected to the primary device and is placed downstream of said primary device. 11. The reaction system according to claim 10 in which the mixing zone includes: ● an input section containing inputs for separately feed acid hydrocarbon gases, possibly added with water vapor, and the oxidizing current, possibly with the addition of water vapor; ● a distribution area of the gaseous reagents, preferably containing at least one element tubular, preferably vertical, ed ● a mixing chamber in which i gas phase reagents possibly added with water vapor and possibly the oxidizing current added with water vapor, forming a mixture homogeneous. 12. The reaction system according to claim 10 in which the reaction section includes: ● a possibly multiple catalytic bed truncated cone-shaped layers with increasing section, which contains a catalyst in each layer consisting of a support on which the active part of the catalyst; ● Layers of material that act as a screen thermal arranged upstream and, optionally, downstream of the catalytic bed according to a geometry cylindrical; ● refractory materials that contain the reaction section, in turn placed in a metal container. ● A grid or structure made of pre-formed refractory materials supports the heat shields and the catalytic bed.