INTEGRATED SULFUR RECOVERY AND HYDROGEN PRODUCTION PROCESS

Abstract

H2 production, sulfuric acid and SO2 production process refers to an innovative process VIA the phenomena of the Sulfur-Iodine (S-I) thermochemical cycle. The process consist of the acid gas burner to burn all the acid gases with air, enriched air or oxygen and without using any fuel gas to produce SO2. The acid gases are normally processed in the prior arts of the sulfur recovery units. Iodine is used to produce the hydrogen.

A portion or all of the acid gases are sent to the acid gas burner in accordance with the present invention.

The present innovation not only produces hydrogen but also reduces the SO2 and CO2 emissions.

The produced SO2 is sent to other units to produce other fertilizer products and the produced CO2 is sent to CO2 removal or CO2 Liquefaction process.

The hydrogen is produced is used to supply the needs within the facility like hydrotreaters to reduce external import and to reduce the operating costs.

Claims

1. The present invention of H2 production, SO2 and H2SO4 production steps introduces using the Sulfur-Iodine (S-I) thermochemical cycle and the acid gas burner to process the acid gases that are processed in the prior arts of Claus sulfur recovery and tail gas treating unit, with combinations of necessary modifications to the prior arts wherein, a portion of the acid gases feed is routed to the present invention acid gas burners wherein, first the sulfur compounds, and the ammonia gases are combusted with air or oxygen and without using any fuel gas and then the combusted gases in contact with Iodine produces hydrogen and the remaining of SO2 is converted to the sulfuric acid or is sent to other units to produce other products, the Iodine as the catalyst agent is recovered and re-used in the present invention: step 1) providing acid gas stream(s) from the amine acid gas and sour water stripping gas that is normally processed in prior arts of Claus sulfur recovery unit into properly designed acid gas burner or staged burners, receiving air, enriched air or oxygen and without any fuel gas to combust all the combustible components to SO2, and other inert gases nitrogen, CO2, N2, water and excess oxygen operating at a very high temperature; step 2) when the gases are fully combusted in the acid gas burner(s), the combusted gas containing, SO2, CO2, N2, H2O, O2 and SO3 or H2SO4 is sent to the waste heat boiler to generate HP steam or to H2SO4 vaporizer exchanger to recover the heat and to cool of the combusted gas and vaporize a slim stream of H2SO4; step 3) the combusted gas mixture from step 2 is further cooled off and quenched in the tube side of a exchanger and is sent to a reactor; step 4) in the shell side of the step 3 exchanger, I2, HI and water is added to heat up the mixture and the chemical reaction occurs and H2 and 12 is produced then the mixture is sent to a 3-phase separator to condense H2O which is recycled to step 5, wherein, H2 is separated from I2, and H2 is one of the product from the present innovation; step 5) wherein, the cooled gas mixture, SO2, O2, N2, H2O and SO3 has two choices; (a) a portion of the stream is sent to other units as SO2 product for other applications as valuable fertilizer or other products or SO2 is liquefied; (b) a portion or the full stream is sent to the reactor with I2 and recycled H2O from step 4, to have another reaction at 120 C; wherein, SO2 reacts with I2 accordance to equation of to produce sulfuric acid and HI; Step 6) wherein, the cooled gas from the reactor enters a quench column where N2 and CO2 is separated from the mixture, and is sent to CO2 removal or CO2 liquefaction unit, the bottom of the quench column consists of H2SO4, H2o, IH and HI flows to liquid-liquid contactor to separate H2SO4 from IH and I2 and recycled to step 4; Step 7) wherein, H2SO4 from step 6, bottom of the liquid-liquid contactor is sent to a sulfuric acid concentration to concentrate the H2SO4 as another product on the present invention by using steam reboiler as desired and the water is removed. and wherein, said process produces H2, SO2 and H2SO4 as the products mainly reduce importing of hydrogen and sulfuric acid to a facility and wherein, SO2 emission is eliminated, while CO2 emission is reduced and recovered and sent to other unit.

2. The process of claim 1, wherein, the acid gas streams flow to the high intensity acid gas burner at least containing H2S, COS, N2, HCN, phenol, CS2, CO2, H2O, hydrocarbons, H2SO4 mercaptans, sulfur vapors and high ammonia content and any other sulfur compounds.

3. The process of claim 1, wherein, the acid gases flow to the acid gas burner consists of lean or rich H2S, NH3, mercaptans, sulfur vapors and all other sulfur compounds at all level of concentrations are processed directly in the acid gas burner achieve an stable operation without any requirement of the acid gas enrichment unit.

4. The process of claim 1, wherein, the acid gas burner consists of one to 10 burners to establish staged combustions of the acid gases and cooling between burners to prevent NOx formation.

5. The process of claim 1, wherein, the acid gas burner combustion temperature operates at 900 C to 2000 C to ensure full combustions of all acid gas feed streams with excess oxygen.

6. The process of claim 1, wherein, air stream, enriched air or oxygen enrichment stream is added to the acid gas burner to combust the acid gas feed streams.

7. The process of claim 1, wherein, the acid gas burner is designed with the proper material of construction and is equipped with the advanced refractory lining to protect the metal from exposing to high temperature.

8. The process of claim 1, wherein, the acid gas burner and incineration is equipped with choke ring, checker wall or vector wall to protect the downstream equipment, waste heat boiler or a exchanger from direct radiation from acid gas burners.

9. The process of claim 1, wherein, the acid gas feed streams to the acid gas burners consists one to 10 streams.

10. The process of claim 1, wherein, waste heat boiler or exchanger after the acid gas burners is one to 10 commercial waste heat boilers, condensers or exchangers.

11. The process of claim 1, wherein, Iodine is introduced as a solvent to produce H2, H2SO4 and SO2 VIA the sulfur-Iodine thermochemical cycle, wherein, Iodine is regenerated and reused in the process.

12. The process of claim 1, wherein, the reaction temperature of HI to produce H2 as the product is preferable at 450 C and from 300 C to 500 C.

13. The process of claim 1, wherein, the reaction temperature of SO2 with H2O with I2 present in the reactor is preferable at 120 C from 100 C to 200 C.

14. The process of claim 1, wherein, the acid gas feed streams pressure to the acid gas burner is from 0.5 bar to 10 bar.

15. The process of claim 1, wherein, the produced CO2 is sent to other units for CO2 recovery or CO2 liquefaction unit.

16. The process of claim 1, wherein, the produced SO2 is sent to other unit to produce other products or liquefied SO2.

17. The process of claim 1, wherein, the sources of the acid gas stream are refining, gas plants, sour gas field developments, LNG, IGCC, power plants, mining and smelters, onshore and offshore, and petrochemicals that consisting of H2S streams; wherein, H2S and sulfur compounds come from hydrotreater or coker units, or gas plants or sour gas field developments amine units and H2S and NH3 come from one stage or 2 stage sour water strippers system either phenolic and non-phenolic systems.

18. The process of claim 1, wherein, the internal of the quench column and the liquid-liquid contactor is high performance tray or packing.

19. The process of claim 1, wherein, a slipstream of produced H2SO4 is recycled to the acid gas burner through H2SO4 vaporizer.

20. The process of claim 1, wherein, the produced H2SO4 is concentrated in the concentration column to achieve high purity of market grade H2SO4.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The following figures are part of the present disclosure and are included to further illustrate certain aspects of the present invention. Aspects of the invention may be understood by reference to one or more figures in combination with the detailed written description of specific embodiments presented herein. These figures present the combinations of the modified, upgraded, and revamped of the prior arts plus the present invention. A block flow diagram is shown as FIG. 1 consists of the present innovation scheme.

[0057] While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawings and are described in detail below. The figures and detailed descriptions of these specific embodiments are not intended to limit the breadth or the scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art and enable such person to make and use the inventive concepts.

[0058] FIG. 1 consists of drawings, wherein, represents the overall block flow diagram for the present innovation for the major equipment.

[0059] FIG. 2 consists of drawings, wherein, the amine acid gases, and the sour water stripper acid gases, from the oil and gas facilities are processed in the sulfur recovery, tail gas treating based on the prior arts.

[0060] FIG. 3 consists of drawings, wherein, represents how the present invention can be implemented with the prior arts. Taking full or portion of the acid gases that are currently processed in the sulfur recovery unit prior arts, to the present invention. Wherein, to produce Hydrogen, to reduce the fuel gas consumption, to reduce SO2 and CO2 emissions and to produce the new products. While the hydrogen as a major product in the present invention is produced represents a new H2 source supplying the hydrogen demand to different units such as hydrotreaters, which is resulting to reduce external supply and to reduce the operating costs.

[0061] FIG. 4-A represents the current invention wherein, provides the details of some of the equipment of the FIG. 1. FIG. 4-A shows the main furnace where the acid gases are processed and the combustion products are cooled in the waste heat boiler and the additional cooler before sending to the FIG. 4-B. Basically, FIG. 4-A shows the function of the major equipment of the present invention, it shows the 3-phase separator equipment the separate the mixture that comes from the FIG. 4-B.

[0062] FIG. 4-B represents the current invention wherein, provides the details of the remaining equipment of the FIG. 1. FIG. 4-B shows the reactor, quench column, H2SO4 concentrator and liquid-liquid contactor to process the gases from FIG. 4-A.

[0063] FIG. 4-A and FIG. 4-B together represents the main and actual equipment of the current invention wherein, it is shown in FIG. 1(FIG. 1) as the block flow diagram in a compact and summarized format.

DETAILED DESCRIPTION OF THE INVENTION

[0064] One or more illustrative embodiments incorporating the invention disclosed herein are presented below. Not all features of an actual implementation are described or shown in this application for the sake of clarity.

[0065] It is understood that in the development of an actual embodiment incorporating the present invention, numerous implementation-specific decisions must be made to achieve the developer's goals, such as compliance with system-related, business-related, government related and other constraints, which vary by implementation and from time to time. While a developer's efforts might be complex and time-consuming, such efforts would be, nevertheless, a routine undertaking for those of ordinary skill the art having benefit of this disclosure.

[0066] In general, terms, Applicant has created new processes for the hydrogen production with the integration of the sulfur recovery unit.

[0067] The present invention relates to processes to produce hydrogen, SO2 and other relevant products to also reduce SO2 and CO2 emission, the new invention applies to onshore and offshore applications; refineries, gas plants, IGCC, gasification, coke oven gas, mining and smelters sour gas field developments and flue gas desulfurization, wherein, the acid gases contain H2S and sulfur compounds.

[0068] In accordance with aspects of the present invention, it is an object of the present disclosure to provide a process to produce hydrogen, and SO2 to reduce SO2 and CO2 emission and economically acceptable for, present day industrial operations and higher safety standard.

[0069] Another object is to provide such a process, which can tolerate variances in operating conditions within a given range without major equipment adaptations. A further object is to provide a process, which can be utilized in co-acting phases to provide, at acceptable economics, the capacity required in present-day industrial operations, easy to operate and more reliable and robust operation.

[0070] In the discussion of the Figures, the same or similar numbers will be used throughout to refer to the same or similar components. Not all valves and the like necessary for the performance of the process have been shown in the interest of conciseness. Additionally, it will be recognized that alternative methods of temperature control, heating and cooling of the process streams are known to those of skill in the art, and may be employed in the processes of the present invention, without deviating from the disclosed inventions. Finally, the present invention is a polisher to existing arts therefore, the existing arts and their variations scheme of existing arts are discussed where their FEED stream enters the present invention of acid gas burner incineration.

[0071] The figures illustrate steam reheaters that heats up the gas by using steam, however, any suitable heat exchanger, using different heating media, or fired reheaters using natural gas or acid gas, and hot gas bypass maybe employed in this service.

[0072] The figure illustrates a waste heat boiler that produces steam, however, any suitable heat exchanger, such as a water heater, steam superheater or feed effluent exchanger may be employed in this service.

[0073] The acid gas burner incineration may have multiple burner to prevent NOx formation during the ammonia burning with intercooling system between the acid gas burners and with mixing devices, checker wall or choke ring or vector wall to create the turbulent velocity of gas for a better mixing and to prevent cold spot and condensation. In addition, the checker wall near the tube sheet of the waste heat boiler maybe added to protect the tube sheet from the heat radiation from the burner.

[0074] In accordance to this invention; the prior arts; sulfur recovery units may be modified to improve the operation wherein, the present innovation is integrated.

[0075] Once again, since the prior arts provides feed gas stream to the present invention;

[0076] The prior arts are upgraded, modified, revamped, and optimized by adding related equipment, adding piping, adding recycle from the present invention, changing the catalysts, adding instrumentation, modified existing equipment to be suitable.

[0077] In the prior arts; the last condenser may be modified or replaced as at least one heat exchanger or multiple heat exchangers, dual condensers or combination of water coolers and air coolers to achieve maximum sulfur condensation and sulfur recoveries.

[0078] The new invention comprises that SO2 and CO2 emissions is reduced significantly, while hydrogen is also produced.

[0079] All the heat exchangers defined in this process can be of any type of commercial exchangers such as but not limited to fired heaters, shell and tube, plate and frame, air cooler, water cooler, boiler type, or any suitable exchangers.

[0080] All required control systems in the prior and new arts are defined based on the latest commercial control systems including but not limited to local panel, DCS control room, burner management systems in the sulfur plant, switching valves sequencer control systems, reactors, condensers, incineration and adsorbers and all necessary equipment in this innovation.

[0081] The sequence runs fully automatically without requiring any operator action.

[0082] Turning now to the FIG. 1 consists of the block flow diagram of the present invention wherein, the major chemical reaction is also shown in each box to facilitate the description in FIGS. 4-A and 4-B.

[0083] FIG. 2 consists of the prior arts in the sulfur recovery units, wherein, the amine acid gases from refineries hydrotreaters, coker units or sour gas processing, petrochemicals, power plants and IGCC and LNG and mining and minerals are processed. The sour water stripping gas are known as phenolic, and nonphenolic SWS gases from one stage or 2 stage sour water strippers are also processed in the prior arts of sulfur recovery units according to Claus reaction and sulfur is produced. Two streams shown on FIG. 2, represents the amine acid gases and the sour water stripper acid gases.

[0084] The unrecovered H2S and the sulfur compounds from the prior arts are sent to the prior art incineration and using significant amount of fuel to convert the sulfur compounds to SO2. While the fuel gas needed due to low H2S concentration and burning fuel gas burning produces significant CO2 that is currently emitted to the atmosphere. If SO2 level is in acceptable range of the local regulations then SO2 and CO2 are both emitted. If SO2 level is not in the acceptable range of the local regulations, then SO2 is absorbed by Caustic, SETR process or others, but the CO2 is still emitted.

[0085] In accordance with the present invention, if the acid gases are burned in the acid gas burner first, then since the H2S concentration is high, there is no need to burn the fuel gas, the CO2 emission is reduced and the cost of fuel gas is eliminated. In addition, SO2 emission is reduced and the key advantage is hydrogen is also produced which is another cost saving.

[0086] FIG. 3 consists of the combinations of the prior arts and the present invention. Wherein, a portion or the entire acid gases streams is currently processed in the prior art of the sulfur recovery is sent to the present invention. The acid gases are processed in the present invention and hydrogen is produced and the CO2 and SO2 emission is reduced or eliminated.

[0087] Turning now to the current invention that consists of two pages as FIG. 4-A and FIG. 4-B.

[0088] Iodine is used as a solvent to produce H2, H2SO4 and SO2 VIA the sulfur-Iodine thermochemical cycle, wherein, Iodine is regenerated and reused in the process.

[0089] The amine acid gases, the sour water stripping gas and any other vent streams that contents the sulfur compounds streams 51,52 and 53 flows to the acid gas burner, 30 and the air stream 54 from the air blower 31, flows to the acid gas burner, 30 as shown on FIG. 4-A.

[0090] The acid gas burner consists of the proper material of construction with the refractory inside to protect the metal at high combustion temperature ranging 900 C to 2000 C with 100% stoichiometry and excess oxygen to convert all of the sulfur compounds to SO2. To dissociate NH3, HCN, phenol and the components from the sour water stripping gas to water and nitrogen and the vent stream containing sulfur vapor and H2S to SO2.

[0091] The acid gas burner incineration consists of a suitable refractory and mixing devices such as choke ring, checker wall or vector wall to protect the tube sheet of the waste heat boiler from the heat radiation from the burner.

[0092] The acid gas burner, 30 can use air, enriched air with oxygen or high level of oxygen to the burner.

[0093] The burner is one to ten burner stages and depends on the acid gases to the burner, for cases NH3 is present, the configuration of staged burner or multiple burner is used to prevent NOx formation. High intensity burner operates effectively by using multiple burners and multiple cooling as WHB to achieve less than 20 ppmv of NOx according to the latest air quality regulations.

[0094] Due to high H2S concentration of the acid gases to the burner, using fuel to the acid gas burner is eliminated wherein, the present invention reduces CO2 emission.

[0095] In accordance to present invention, wherein, the acid gas feed streams to the acid gas burners consists one to 10 streams.

[0096] In accordance to present invention, wherein, Iodine is introduced as a solvent to produce H2, H2SO4 and SO2 VIA the sulfur-Iodine thermochemical cycle, wherein, Iodine is regenerated and reused in the process.

[0097] In accordance to present invention, wherein, the reaction temperature of HI to produce H2 as the product is preferable at 450 C and from 300 C to 500 C.

[0098] In accordance to present invention, wherein, the reaction temperature of SO2 with H2O with I2 present in the reactor is preferable at 120 C from 100 C to 200 C.

[0099] In accordance to present invention, wherein, the acid gas feed streams pressure to the acid gas burner is from 0.5 bar to 10 bar.

[0100] In accordance to present invention, wherein, the internal of the quench column, and the liquid-liquid contactor is high performance tray or packing.

[0101] In accordance to present invention, wherein, the produced H2SO4 is concentrated in the concentration column to achieve high purity of market grade H2SO4.

[0102] The combusted products from the acid gas burner 30, flows to the waste heat boiler, WHB 1, 32 to recover the combustion heat by producing HP steam or is used as a sulfuric acid vaporizer to vaporize some H2SO4, stream 67 and to recycle to the acid gas burner.

[0103] In accordance to present invention, wherein, a slip stream of produced H2SO4 is recycled to the acid gas burner through H2SO4 vaporizer.

[0104] The combusted cooled gas, stream 55 contains SO2, H2O, O2, N2 and H2SO4, enters tube side of WHB 2, 33 to cool the gas further and the outlet of WHB 2, 33 stream 56 enters the reactor.

[0105] The shell side of WHB 2, 33 receives H2O, I2 and HI as stream 65, wherein, the chemical reaction of 2HI.fwdarw.H2+I2 at 450 C with 3 phases mixture wherein, enters a 3 phase separator vessel, wherein, H2 is separated as the hydrogen product stream 60. Water is separated as stream 58 as recycle water. I2 is also separated as stream 57 to the reactor.

[0106] The hydrogen production is accordance on the present invention VIA the phenomena of the Sulfur-Iodine (S-I) thermochemical cycle.

[0107] The produced hydrogen can be used to supply the need within the facilities like hydrotreater units, and to eliminate the import of the external supply and to reduce the operating costs.

[0108] A portion of stream 56 can be sent to other units to produce other products like fertilizer products that are used in the agricultural industry or to process SO2 to liquefied SO2.

[0109] Streams 56, 57 and 58 flows to the reactor 35, refers to FIG. 4-B, wherein, the reaction occurs SO2+I2+2H20.fwdarw.H2SO4+2HI at temperature of 120 C.

[0110] All the sulfur compounds are converted to SO2, wherein, the SO2 emission is eliminated.

[0111] The mixture leaving the reactor stream 61 enters the quench column 36, to cool the mixture using air/water cooler not shown.

[0112] CO2 and N2 stream 62 is separated and is sent to CO2 liquefaction system or CO2 removal.

[0113] The liquid stream 64, from the bottom of the quench column 36, consists of H20, H2SO4, I2 and IH enters the liquid-liquid contactor 38, to separate H2SO4 from the I2 and IH. The recovered I2 and IH stream 65 is recycled back to WHB 2 as the thermochemical agent.

[0114] The sulfuric acid stream 66 flows to the sulfuric acid concentration unit 39, to concentrate the H2SO4 by removing water using reboiler as media.

[0115] Stream 70 represents sulfuric acid as another product.

[0116] In summary, the present invention, introduces a process to produce H2, produce SO2, produce H2SO4, while CO2 and SO2 emission is reduced or eliminated. The integration of sulfur recovery prior arts with the present invention produces H2 a valuable product, while SO2 and CO2 emissions are lowered or eliminated. The produced SO2 and CO2 is liquefied to use in other industries.

[0117] All of the compositions, methods, processes and/or apparatus disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions, methods, processes and/or apparatus and in the steps or sequence of steps of the methods described herein without departing from the concept and scope of the invention.

[0118] Additionally, it will be apparent that certain agents which are both chemically and functionally related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes or modifications apparent to those skilled in the art are deemed to be within the scope and concept of the invention. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicant, but rather, in conformity with the patent laws, Applicants intends to protect all such modifications and improvements to the full extent that such falls within the scope or range of equivalents.