CA2766037A1 - Process for upgrading natural gas with a high hydrogen sulfide content - Google Patents
Process for upgrading natural gas with a high hydrogen sulfide content Download PDFInfo
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- CA2766037A1 CA2766037A1 CA2766037A CA2766037A CA2766037A1 CA 2766037 A1 CA2766037 A1 CA 2766037A1 CA 2766037 A CA2766037 A CA 2766037A CA 2766037 A CA2766037 A CA 2766037A CA 2766037 A1 CA2766037 A1 CA 2766037A1
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- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
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Abstract
Process for upgrading superacid natural gas, with a content of hydrogen sulfide higher than or equal to 60% by volume, with the production of hydrogen, which comprises : a. treating the hydrogen sulfide with methane (reforming) according to the endothermic reaction 2 H2S + CH4 = CS2 + 4H2 (1) b. cooling the reaction products, separating the carbon disulfide (CS2) and recovering the hydrogen; c. burning the carbon disulfide; d. feeding at least a part of the hot gases of the combustion of carbon disulfide to the reforming step, as heat source for maintaining the endothermic reaction (1); e. disposing of the cooled combustion gases of carbon sulfide.
Description
PROCESS FOR UPGRADING NATURAL GAS WITH A HIGH HYDROGEN
SULFIDE CONTENT
The present invention relates to a process for the upgrading of natural gas with a high hydrogen sulfide content.
More specifically, the present invention relates to a process for the upgrading of natural gas containing hydrogen sulfide in concentrations higher than or equal to 60% by volume.
Even more specifically, the present invention relates to a process for the upgrading of natural gas containing hydrogen sulfide in concentrations higher than or equal to 60o by volume by the recovery of hydrogen from both the sulfurized compound and hydrocarbon phase present.
As is known, natural gas essentially consists of methane, but, in addition to significant traces of higher C2-C7+ hydrocarbons, it can also contain variable quantities of inert gases or pollutants, for example carbon dioxide or nitrogen, whose presence must be eliminated or reduced to satisfy the specifications of use.
Among the pollutants of natural gas, there is also hydrogen sulfide, which contrary to nitrogen and carbon dioxide, must be completely eliminated, before introducing the gas into the supply system, as it is an extremely harmful product.
Fields/reservoirs of natural gas with a high hydrogen sulfide content can be found all over the world, for example Bearberry fields or Panther River in Canada are natural gas reservoirs containing approximately 90% by volume and 68% by volume of H2S, respectively. In the United States there are fields such as Black Creek and Cox (Missisipi) which contain approximately 78o and 65% of H2S, respectively. "Super-sour" gas fields having large dimensions also exist, such as the Zhaolazhuang-Hebei field in China which comprises 19 wells which produce a natural gas whose concentration of H2S varies from 60 to 90% by volume.
These superacid gas reservoirs, also known as "super-sour" gas reservoirs, either remain unused, as the recovery of natural gas (methane) is too onerous, or, as in the case of the Zholazhuang field, they are used for the production of sulphur by means of the Claus process, sending the gaseous stream, substantially as it leaves the production well, directly to the combustion reactor where the partial oxidation of the hydrogen sulfide to SO2, takes place.
In this way, the methane present is burnt and this is an economic loss which becomes increasingly more significant, the higher the methane content in the natural gas.
As the request for sulfur on a worldwide scale is stationary and does not seem to be increasing, most of the "super-sour" natural gas fields at present have remained unused.
The Applicant has now found a process for upgrading "super-sour" natural gas containing concentrations of H2S higher than or equal to 60o by volume which allows the hydrogen contained in both the methane molecule and in that of the hydrogen sulfide to be recovered.
Hydrogen is a raw material which is extremely requested in refineries, for example, for all hydrotreatment processes such as hydrocracking and hydrodesulfurization, and it would therefore be extremely desirable to be able to obtain it from a source with zero value such as current "super-sour"
natural gas reservoirs.
A method which allows hydrogen to be recovered from natural gas, strongly acid due to hydrogen sulfide, is the reforming reaction with methane according to the reaction:
2H2S + CH4 = CS2 + 4H2 (1) wherein the molar ratios necessary for satisfying the stoichiometry of the reaction are substantially guaranteed by the composition itself of natural gas.
This reaction can be carried out with high conversions only at high temperatures (for example higher than 900 C) and is strongly endothermic (LH298=
232 kJ/mole), consequently energy must be supplied externally by burning a fuel with a considerable increase in production costs.
The Applicant has also found that it is possible to use the CS2, produced by the reforming reaction between methane and H2S, as fuel for sustaining the reaction (1). By exploiting, in fact, the large quantity of reaction heat which is developed in the combustion of CS2, (LH298= -1032 kJ/mole), the previous endothermic reforming reaction of H2S with methane can be sustained without having to burn any high-quality fuel. The SO2 produced by the combustion can be upgraded downstream as intermediate for specific synthesis reactions, for example to produce sulfuric acid, or it can be disposed of by injection into the subsoil.
The possible presence of carbon dioxide in the super-sour gas does not represent a disadvantage. Under the reaction conditions, object of the present invention, the equilibrium is in fact established between the carbon dioxide present and the hydrogen formed according to:
CO2+H2=CO+H20 A further preferred aspect of this reaction is the use of the mixture thus formed of carbon monoxide and hydrogen, after the separation of the water, for the production of methanol according to:
CO + 2 H2 = CH3OH
In the case of the presence of carbon dioxide in the super-sour gas, it is therefore possible to directly produce synthesis gas without having a further reforming unit.
An object of the present invention therefore relates to a process for upgrading superacid natural gas, with a content of hydrogen sulfide higher than or equal to 609,; by volume, with the production of hydrogen, which comprises.
a. feeding the superacid natural gas to a reforming reactor operating at a temperature ranging from 900 to 1500 C and at atmospheric pressure, or slightly lower than atmospheric pressure, for example ranging from 0.08 to 0.1 MPa, to produce a mixture essentially consisting of carbon disulfide (CS2) and hydrogen (H2) ;
b. cooling the reaction products, separating the carbon disulfide from the remaining reaction mixture containing hydrogen and recovering the hydrogen;
c. burning the carbon disulfide with a gas containing oxygen to produce a gaseous mixture, essentially consisting of CO2 and SO2, at a high temperature;
d. feeding at least a part of the hot gases of the combustion of carbon disulfide to the reforming step, as heat source for maintaining the endothermic reaction of step (a); and e. providing the combustion gases of carbon disulfide, also coming from step (d), as intermediates for chemical syntheses downstream or for their disposal by injection into specific geological structures.
At the end of the reforming, the reaction products can be cooled to a temperature which is optimum for the subsequent operations, for example to a temperature lower than 50 C, in order to recover the carbon disulfide, which is liquid at those temperatures, from the gaseous phase essentially consisting of hydrogen, residual H2S and possible reaction by-products and/or hydrocarbons. The gaseous phase can then be treated with conventional methods, for example by means of the selective adsorption technology of the PSA type or treatment with membranes, for the recovery of the hydrogen. The possible H2S in excess can be recovered by the traditional techniques, for example by absorption with amines.
The cooling phase preferably takes place in heat exchangers where the cooling liquid is water, which can be transformed into vapour at a temperature of 100-150 C and a pressure of 0.2-10 MPa. The vapour can then be used to produce electric energy or as a heat source to be destined for the running of other plants.
Alternatively, before being cooled in the heat exchanger, the reaction products can pre-heat the reagents which are to be fed to the reforming reactor.
The carbon disulfide recovered in the liquid state, is burnt in a specific reactor, with air or air enriched in oxygen as comburent.
The combustion gases leaving the reactor at a temperature of 1000-2500 C, are fed, either partially or totally, to a further system of heat exchangers to bring the reagents, possibly pre-heated, to the correct temperature, before being introduced into the reforming reactor.
In this way, from the integrated cycle described in the process, object of the present invention, the production of hydrogen can be obtained from a stream containing hydrogen sulfide without having to use any external high-quality fuel and a stream containing SO2 is also obtained as by-product, which can be advantageously used as raw material for chemical syntheses such as, for example, the production of sulfuric acid. Alternatively, if convenient, the stream containing SO2 can be injected into adequate geological structures.
An alternative embodiment of the process, object of the present invention envisages that only a part of the CS2 produced is burnt as energy source, whereas the remaining part is separated and destined for commercialization.
The balance between the aliquot of burnt CS2 and that separated and destined for sale depends on the quantity of heat which is to be produced to sustain the endothermic reforming reaction of methane with H2S. The sufficient quantity of CS2 to be destined for combustion to sustain the reforming of methane with H2S is equal to at least 556 by weight of the total CS2 produced.
Depending on the demands, the remaining part of CS2 can be separated and sold or burnt to provide heat energy for also sustaining other process equipment, for example for producing high-pressure vapour which can be used in this or other plants.
Another innovative aspect of the process, object of the present invention, consists of the fact that the sulfur present in the H2S molecule is transformed directly into SO2, which can in turn be transformed, by reactions and processes well-known in literature, for example, to sulfuric acid, requested by the chemical industry, rather than into elemental sulfur as in the S conventional Claus process. Elemental sulfur does in fact have considerable environmental storage problems and many nations in which there are natural gas reservoirs impose heavy economic sanctions for the storage of sulfur. By transforming sulfur to sulfuric acid, on the other hand, a liquid product is obtained, which can be easily transported and sold as such.
The process for upgrading superacid natural gas with the production of hydrogen, object of the present invention, can be better understood with reference to the scheme of the enclosed figure which represents an illustrative and non-limiting embodiment.
With reference to the figure, A is a conventional plant using amines for the recovery of hydrogen sulfide in excess with respect to the stoichiometric value of the reforming reaction, B is a heat exchanger system for heat recovery, C is a heat exchanger system which can be used for providing the energy necessary for the reforming, R1 is the methane/H2S reforming reactor and can be, for example, a fixed bed or fluid bed catalytic reactor, E is a condensation and collection system of the CS2 produced in the reactor R1, R2 is the combustion reactor of CS2.
A stream of superacid gas (1) essentially consisting of methane and a fraction of H2S equal, for example, to 60-652,5 by volume, is provided. The stream (1) is preheated in B, brought to the reforming reaction temperature in C and then fed to the reactor R1.
The hot reaction products (2) are recovered from the reactor R1, at a temperature of about 900-15000C.
These hot gases are fed to B, for preheating the reagents, and are then fed to the condenser E where the carbon disulfide CS2, in the liquid state, stream (3), is separated from the gaseous phase essentially consisting of H2, non-reacted H2S/in excess and possibly methane and/or other hydrocarbons and/or reaction by-products, stream (4). A part of the carbon disulfide produced, stream (5), can be deviated from the cycle, object of the present invention, and destined for other purposes.
The carbon disulfide (3) and comburent air (6) are fed to the combustion reactor R2. The combustion gases, stream (7), which comprise CO2 and SO2, leave the reactor at a temperature of about 1000-2500 C and are fed directly to the heat exchanger C where they heat the reagent gases (CH4 e H2S) bringing them to a temperature of about 900-1500 C, or slightly higher.
The stream of heated reagent gases (8) is fed to the reactor R1, in which the catalyst is positioned, consisting for example of one or more sulfides of metals of groups VIB, VIIB and VIIIB of the periodic system. Among these metallic sulfides, chromium, tungsten, molybdenum, iron, cobalt and nickel sulfides are particularly preferred, used alone or in a mixture with each other. The temperature inside Rl is kept uniform at about 900-1500 C.
After bringing the reagents of the reforming reaction to the reaction temperature, the combustion gases of carbon disulfide can be further cooled, in specific equipment not illustrated in the scheme of the enclosed figure, and then used for further chemical processes, for example the synthesis of sulfuric acid, or they can be disposed of by injecting them into the subsoil or into deep seawater.
The products of the reforming reaction which, after cooling in E, are in gas phase, stream (4), are fed to the plant A for recovery of the hydrogen sulfide. At the end, the stream (9) essentially consisting of hydrogen, is discharged from the plant A.
An illustrative and non-limiting example is provided for a better understanding of the present invention and for its practical embodiment.
EXAMPLE
This is a stream of 1000 Nm3/h of a mixture of methane + hydrogen sulfide with a concentration of H2S
equal to 65% in moles, 35o consisting of methane.
The mixture thus obtained with an overall flow-rate of 780 Nm3/h, after being heated (to T=10500C) in a system of two consecutive heat exchangers, is fed to the reforming reactor, consisting in the case of this example of a fixed bed reactor, filled with a catalyst consisting of Cr2S3 supported on silica, operating at T=950 C.
The outgoing fumes, essentially consisting of CS2, hydrogen and non-reacted H2S, are sent to a condenser from which the CS2 is separated as liquid, whereas the gaseous stream comprising hydrogen and H2S, is sent to an amine plant.
The CS2 obtained (149.6 1/h) is fed to the combustion plant together with air, obtaining a stream consisting of CO2 and SO2 (at T=1100 C) . This stream is used for heating the reagents to be fed to the reforming reactor. After transferring its heat to the reagents of the reforming reaction, it can then be subsequently fed to a plant for the production of sulfuric acid or disposed of by injection into the subsoil.
SULFIDE CONTENT
The present invention relates to a process for the upgrading of natural gas with a high hydrogen sulfide content.
More specifically, the present invention relates to a process for the upgrading of natural gas containing hydrogen sulfide in concentrations higher than or equal to 60% by volume.
Even more specifically, the present invention relates to a process for the upgrading of natural gas containing hydrogen sulfide in concentrations higher than or equal to 60o by volume by the recovery of hydrogen from both the sulfurized compound and hydrocarbon phase present.
As is known, natural gas essentially consists of methane, but, in addition to significant traces of higher C2-C7+ hydrocarbons, it can also contain variable quantities of inert gases or pollutants, for example carbon dioxide or nitrogen, whose presence must be eliminated or reduced to satisfy the specifications of use.
Among the pollutants of natural gas, there is also hydrogen sulfide, which contrary to nitrogen and carbon dioxide, must be completely eliminated, before introducing the gas into the supply system, as it is an extremely harmful product.
Fields/reservoirs of natural gas with a high hydrogen sulfide content can be found all over the world, for example Bearberry fields or Panther River in Canada are natural gas reservoirs containing approximately 90% by volume and 68% by volume of H2S, respectively. In the United States there are fields such as Black Creek and Cox (Missisipi) which contain approximately 78o and 65% of H2S, respectively. "Super-sour" gas fields having large dimensions also exist, such as the Zhaolazhuang-Hebei field in China which comprises 19 wells which produce a natural gas whose concentration of H2S varies from 60 to 90% by volume.
These superacid gas reservoirs, also known as "super-sour" gas reservoirs, either remain unused, as the recovery of natural gas (methane) is too onerous, or, as in the case of the Zholazhuang field, they are used for the production of sulphur by means of the Claus process, sending the gaseous stream, substantially as it leaves the production well, directly to the combustion reactor where the partial oxidation of the hydrogen sulfide to SO2, takes place.
In this way, the methane present is burnt and this is an economic loss which becomes increasingly more significant, the higher the methane content in the natural gas.
As the request for sulfur on a worldwide scale is stationary and does not seem to be increasing, most of the "super-sour" natural gas fields at present have remained unused.
The Applicant has now found a process for upgrading "super-sour" natural gas containing concentrations of H2S higher than or equal to 60o by volume which allows the hydrogen contained in both the methane molecule and in that of the hydrogen sulfide to be recovered.
Hydrogen is a raw material which is extremely requested in refineries, for example, for all hydrotreatment processes such as hydrocracking and hydrodesulfurization, and it would therefore be extremely desirable to be able to obtain it from a source with zero value such as current "super-sour"
natural gas reservoirs.
A method which allows hydrogen to be recovered from natural gas, strongly acid due to hydrogen sulfide, is the reforming reaction with methane according to the reaction:
2H2S + CH4 = CS2 + 4H2 (1) wherein the molar ratios necessary for satisfying the stoichiometry of the reaction are substantially guaranteed by the composition itself of natural gas.
This reaction can be carried out with high conversions only at high temperatures (for example higher than 900 C) and is strongly endothermic (LH298=
232 kJ/mole), consequently energy must be supplied externally by burning a fuel with a considerable increase in production costs.
The Applicant has also found that it is possible to use the CS2, produced by the reforming reaction between methane and H2S, as fuel for sustaining the reaction (1). By exploiting, in fact, the large quantity of reaction heat which is developed in the combustion of CS2, (LH298= -1032 kJ/mole), the previous endothermic reforming reaction of H2S with methane can be sustained without having to burn any high-quality fuel. The SO2 produced by the combustion can be upgraded downstream as intermediate for specific synthesis reactions, for example to produce sulfuric acid, or it can be disposed of by injection into the subsoil.
The possible presence of carbon dioxide in the super-sour gas does not represent a disadvantage. Under the reaction conditions, object of the present invention, the equilibrium is in fact established between the carbon dioxide present and the hydrogen formed according to:
CO2+H2=CO+H20 A further preferred aspect of this reaction is the use of the mixture thus formed of carbon monoxide and hydrogen, after the separation of the water, for the production of methanol according to:
CO + 2 H2 = CH3OH
In the case of the presence of carbon dioxide in the super-sour gas, it is therefore possible to directly produce synthesis gas without having a further reforming unit.
An object of the present invention therefore relates to a process for upgrading superacid natural gas, with a content of hydrogen sulfide higher than or equal to 609,; by volume, with the production of hydrogen, which comprises.
a. feeding the superacid natural gas to a reforming reactor operating at a temperature ranging from 900 to 1500 C and at atmospheric pressure, or slightly lower than atmospheric pressure, for example ranging from 0.08 to 0.1 MPa, to produce a mixture essentially consisting of carbon disulfide (CS2) and hydrogen (H2) ;
b. cooling the reaction products, separating the carbon disulfide from the remaining reaction mixture containing hydrogen and recovering the hydrogen;
c. burning the carbon disulfide with a gas containing oxygen to produce a gaseous mixture, essentially consisting of CO2 and SO2, at a high temperature;
d. feeding at least a part of the hot gases of the combustion of carbon disulfide to the reforming step, as heat source for maintaining the endothermic reaction of step (a); and e. providing the combustion gases of carbon disulfide, also coming from step (d), as intermediates for chemical syntheses downstream or for their disposal by injection into specific geological structures.
At the end of the reforming, the reaction products can be cooled to a temperature which is optimum for the subsequent operations, for example to a temperature lower than 50 C, in order to recover the carbon disulfide, which is liquid at those temperatures, from the gaseous phase essentially consisting of hydrogen, residual H2S and possible reaction by-products and/or hydrocarbons. The gaseous phase can then be treated with conventional methods, for example by means of the selective adsorption technology of the PSA type or treatment with membranes, for the recovery of the hydrogen. The possible H2S in excess can be recovered by the traditional techniques, for example by absorption with amines.
The cooling phase preferably takes place in heat exchangers where the cooling liquid is water, which can be transformed into vapour at a temperature of 100-150 C and a pressure of 0.2-10 MPa. The vapour can then be used to produce electric energy or as a heat source to be destined for the running of other plants.
Alternatively, before being cooled in the heat exchanger, the reaction products can pre-heat the reagents which are to be fed to the reforming reactor.
The carbon disulfide recovered in the liquid state, is burnt in a specific reactor, with air or air enriched in oxygen as comburent.
The combustion gases leaving the reactor at a temperature of 1000-2500 C, are fed, either partially or totally, to a further system of heat exchangers to bring the reagents, possibly pre-heated, to the correct temperature, before being introduced into the reforming reactor.
In this way, from the integrated cycle described in the process, object of the present invention, the production of hydrogen can be obtained from a stream containing hydrogen sulfide without having to use any external high-quality fuel and a stream containing SO2 is also obtained as by-product, which can be advantageously used as raw material for chemical syntheses such as, for example, the production of sulfuric acid. Alternatively, if convenient, the stream containing SO2 can be injected into adequate geological structures.
An alternative embodiment of the process, object of the present invention envisages that only a part of the CS2 produced is burnt as energy source, whereas the remaining part is separated and destined for commercialization.
The balance between the aliquot of burnt CS2 and that separated and destined for sale depends on the quantity of heat which is to be produced to sustain the endothermic reforming reaction of methane with H2S. The sufficient quantity of CS2 to be destined for combustion to sustain the reforming of methane with H2S is equal to at least 556 by weight of the total CS2 produced.
Depending on the demands, the remaining part of CS2 can be separated and sold or burnt to provide heat energy for also sustaining other process equipment, for example for producing high-pressure vapour which can be used in this or other plants.
Another innovative aspect of the process, object of the present invention, consists of the fact that the sulfur present in the H2S molecule is transformed directly into SO2, which can in turn be transformed, by reactions and processes well-known in literature, for example, to sulfuric acid, requested by the chemical industry, rather than into elemental sulfur as in the S conventional Claus process. Elemental sulfur does in fact have considerable environmental storage problems and many nations in which there are natural gas reservoirs impose heavy economic sanctions for the storage of sulfur. By transforming sulfur to sulfuric acid, on the other hand, a liquid product is obtained, which can be easily transported and sold as such.
The process for upgrading superacid natural gas with the production of hydrogen, object of the present invention, can be better understood with reference to the scheme of the enclosed figure which represents an illustrative and non-limiting embodiment.
With reference to the figure, A is a conventional plant using amines for the recovery of hydrogen sulfide in excess with respect to the stoichiometric value of the reforming reaction, B is a heat exchanger system for heat recovery, C is a heat exchanger system which can be used for providing the energy necessary for the reforming, R1 is the methane/H2S reforming reactor and can be, for example, a fixed bed or fluid bed catalytic reactor, E is a condensation and collection system of the CS2 produced in the reactor R1, R2 is the combustion reactor of CS2.
A stream of superacid gas (1) essentially consisting of methane and a fraction of H2S equal, for example, to 60-652,5 by volume, is provided. The stream (1) is preheated in B, brought to the reforming reaction temperature in C and then fed to the reactor R1.
The hot reaction products (2) are recovered from the reactor R1, at a temperature of about 900-15000C.
These hot gases are fed to B, for preheating the reagents, and are then fed to the condenser E where the carbon disulfide CS2, in the liquid state, stream (3), is separated from the gaseous phase essentially consisting of H2, non-reacted H2S/in excess and possibly methane and/or other hydrocarbons and/or reaction by-products, stream (4). A part of the carbon disulfide produced, stream (5), can be deviated from the cycle, object of the present invention, and destined for other purposes.
The carbon disulfide (3) and comburent air (6) are fed to the combustion reactor R2. The combustion gases, stream (7), which comprise CO2 and SO2, leave the reactor at a temperature of about 1000-2500 C and are fed directly to the heat exchanger C where they heat the reagent gases (CH4 e H2S) bringing them to a temperature of about 900-1500 C, or slightly higher.
The stream of heated reagent gases (8) is fed to the reactor R1, in which the catalyst is positioned, consisting for example of one or more sulfides of metals of groups VIB, VIIB and VIIIB of the periodic system. Among these metallic sulfides, chromium, tungsten, molybdenum, iron, cobalt and nickel sulfides are particularly preferred, used alone or in a mixture with each other. The temperature inside Rl is kept uniform at about 900-1500 C.
After bringing the reagents of the reforming reaction to the reaction temperature, the combustion gases of carbon disulfide can be further cooled, in specific equipment not illustrated in the scheme of the enclosed figure, and then used for further chemical processes, for example the synthesis of sulfuric acid, or they can be disposed of by injecting them into the subsoil or into deep seawater.
The products of the reforming reaction which, after cooling in E, are in gas phase, stream (4), are fed to the plant A for recovery of the hydrogen sulfide. At the end, the stream (9) essentially consisting of hydrogen, is discharged from the plant A.
An illustrative and non-limiting example is provided for a better understanding of the present invention and for its practical embodiment.
EXAMPLE
This is a stream of 1000 Nm3/h of a mixture of methane + hydrogen sulfide with a concentration of H2S
equal to 65% in moles, 35o consisting of methane.
The mixture thus obtained with an overall flow-rate of 780 Nm3/h, after being heated (to T=10500C) in a system of two consecutive heat exchangers, is fed to the reforming reactor, consisting in the case of this example of a fixed bed reactor, filled with a catalyst consisting of Cr2S3 supported on silica, operating at T=950 C.
The outgoing fumes, essentially consisting of CS2, hydrogen and non-reacted H2S, are sent to a condenser from which the CS2 is separated as liquid, whereas the gaseous stream comprising hydrogen and H2S, is sent to an amine plant.
The CS2 obtained (149.6 1/h) is fed to the combustion plant together with air, obtaining a stream consisting of CO2 and SO2 (at T=1100 C) . This stream is used for heating the reagents to be fed to the reforming reactor. After transferring its heat to the reagents of the reforming reaction, it can then be subsequently fed to a plant for the production of sulfuric acid or disposed of by injection into the subsoil.
Claims (7)
1. A process for upgrading superacid natural gas, with a content of hydrogen sulfide higher than or equal to 60% by volume, with the production of hydrogen, which comprises.
a. feeding the superacid natural gas to a reforming reactor operating at a temperature ranging from 900 to 1500°C and at atmospheric pressure, or slightly lower than atmospheric pressure, to produce a mixture essentially consisting of carbon disulfide (CS2) and hydrogen (H2);
b. cooling the reaction products, separating the carbon disulfide from the remaining reaction mixture containing hydrogen and recovering the hydrogen;
c. burning the carbon disulfide with a gas containing oxygen to produce a gaseous mixture, essentially consisting of CO2 and SO2, at a high temperature;
d. feeding at least a part of the hot gases of the combustion of carbon disulfide to the reforming step, as heat source for maintaining the endothermic reaction of step (a) ; and e. providing the combustion gases of carbon disulfide, also coming from step (d), as intermediates for chemical syntheses downstream or for their disposal by injection into specific geological structures.
a. feeding the superacid natural gas to a reforming reactor operating at a temperature ranging from 900 to 1500°C and at atmospheric pressure, or slightly lower than atmospheric pressure, to produce a mixture essentially consisting of carbon disulfide (CS2) and hydrogen (H2);
b. cooling the reaction products, separating the carbon disulfide from the remaining reaction mixture containing hydrogen and recovering the hydrogen;
c. burning the carbon disulfide with a gas containing oxygen to produce a gaseous mixture, essentially consisting of CO2 and SO2, at a high temperature;
d. feeding at least a part of the hot gases of the combustion of carbon disulfide to the reforming step, as heat source for maintaining the endothermic reaction of step (a) ; and e. providing the combustion gases of carbon disulfide, also coming from step (d), as intermediates for chemical syntheses downstream or for their disposal by injection into specific geological structures.
2. The process according to claim 1, wherein the reforming reaction is carried out in the presence of a catalyst selected from metal sulfides of groups VIB, VIIB and VIIIB of the periodic system.
3. The process according to claim 1 or 2, wherein the reforming reaction products are cooled to a temperature lower than 50°C.
4. The process according to any of the previous claims, wherein the combusted carbon disulfide is equal to at least 55% by weight of the total CS2 produced.
5. The process according to any of the previous claims, wherein the superacid gas, in addition to a H2S
content at least equal to 60%, also has a CO2 content equal to or lower than 10%.
content at least equal to 60%, also has a CO2 content equal to or lower than 10%.
6. The process according to claim 5, wherein the CO2 is converted, under the reaction conditions and in the presence of excess H2, to carbon monoxide.
7. Use of the mixture, consisting of CO and H2, formed according to what is described in claim 6, for the synthesis of methanol.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ITMI2009A001115 | 2009-06-24 | ||
| ITMI2009A001115A IT1394568B1 (en) | 2009-06-24 | 2009-06-24 | PROCEDURE FOR THE ENHANCEMENT OF NATURAL GAS WITH HIGH CONTENT OF HYDROGEN SULPHORATE |
| PCT/IB2010/001344 WO2010150063A1 (en) | 2009-06-24 | 2010-06-02 | Process for upgrading natural gas with a high hydrogen sulfide content |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2766037A1 true CA2766037A1 (en) | 2010-12-29 |
Family
ID=41693527
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA2766037A Abandoned CA2766037A1 (en) | 2009-06-24 | 2010-06-02 | Process for upgrading natural gas with a high hydrogen sulfide content |
Country Status (4)
| Country | Link |
|---|---|
| CA (1) | CA2766037A1 (en) |
| IT (1) | IT1394568B1 (en) |
| RU (1) | RU2522443C2 (en) |
| WO (1) | WO2010150063A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109721028B (en) * | 2017-10-27 | 2020-09-11 | 中国石油化工股份有限公司 | Method for preparing hydrogen by reforming methane and hydrogen sulfide |
| WO2022023365A1 (en) * | 2020-07-28 | 2022-02-03 | Totalenergies Se | Process to conduct an endothermic thio-reforming reaction of hydrocarbons in an installation comprising electrified fluidized bed reactor |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB293172A (en) * | 1927-05-26 | 1928-07-05 | Ig Farbenindustrie Ag | Improvements in the manufacture and production of carbon disulphide |
| US2788262A (en) * | 1953-05-01 | 1957-04-09 | Pan American Petroleum Corp | Process for preparation of carbon disulfide |
| GB1126465A (en) * | 1964-09-14 | 1968-09-05 | Ivor Gray Nixon | Manufacture of hydrogen and carbon disulphide |
| US3388971A (en) * | 1965-06-07 | 1968-06-18 | Seymour C. Schuman | Production of hydrogen |
| US4695443A (en) * | 1985-02-14 | 1987-09-22 | Stauffer Chemical Company | Autothermal process for the production of carbon disulfide and hydrogen sulfide |
| RU2216506C1 (en) * | 2002-02-26 | 2003-11-20 | Институт катализа им. Г.К.Борескова СО РАН | Method for preparing hydrogen and elemental sulfur from hydrogen sulfide |
| DE102004013283A1 (en) * | 2004-03-18 | 2005-10-13 | Guennadi, Berner | Combined production of carbon disulfide and sulfuric acid from sulfur, without use of natural gas fuel, by using heat from oxidation of sulfur to drive the endothermic carbon disulfide production reaction |
| US7426959B2 (en) * | 2005-04-21 | 2008-09-23 | Shell Oil Company | Systems and methods for producing oil and/or gas |
| WO2010102653A1 (en) * | 2009-03-13 | 2010-09-16 | Eni S.P.A. | Process for the abatement of hydrogen sulphide from compositions containing it with simultaneous production of hydrogen |
-
2009
- 2009-06-24 IT ITMI2009A001115A patent/IT1394568B1/en active
-
2010
- 2010-06-02 RU RU2011153109/04A patent/RU2522443C2/en not_active IP Right Cessation
- 2010-06-02 CA CA2766037A patent/CA2766037A1/en not_active Abandoned
- 2010-06-02 WO PCT/IB2010/001344 patent/WO2010150063A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| ITMI20091115A1 (en) | 2010-12-25 |
| WO2010150063A1 (en) | 2010-12-29 |
| IT1394568B1 (en) | 2012-07-05 |
| RU2522443C2 (en) | 2014-07-10 |
| RU2011153109A (en) | 2013-07-27 |
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