HK1158130A - Hydrogen sulfide conversion to hydrogen - Google Patents

Description

Conversion of hydrogen sulfide to hydrogen

Technical Field

The present invention relates to the recovery of hydrogen from gases, and in particular to the removal and consumption of hydrogen sulfide and other impurities from natural and industrial gases.

Background

Many natural and process gases contain hydrogen sulfide, carbon dioxide, and other impurities or contaminants. It is desirable to remove these impurities or contaminants from the natural gas prior to commercial use of the natural gas. Hydrogen sulfide occurs naturally in natural gas and is referred to as "sour gas" when the concentration of hydrogen sulfide is high. Hydrogen sulfide is also produced when refining petroleum and in other processes. Natural gas may contain hydrogen sulfide contents of up to 90%. Hydrogen sulfide is a toxic inflammable substance that cannot be legally released into the air.

Hydrogen can be found in nature in elemental form, usually in trace amounts, because hydrogen is reactive. Hydrogen is an ideal fuel because it is a clean burning fuel, i.e., its combustion produces only water. However, hydrogen is often very expensive to produce and very difficult to store and transport. For example, a steel cylinder weighing about 50 pounds (23kg) typically contains only about 2.5 ounces (71g) of hydrogen gas at pressures up to 3,000psi (20,684 kPa). These steel cylinders can be very dangerous due to the ultra high pressure and the extreme flammability of hydrogen.

Methods for removing hydrogen sulfide and carbon dioxide from gases are known. For example, hydrogen sulfide and carbon dioxide may be separated from the gas by solvent extraction, adsorption, absorption, or other means.

Processes for recovering sulfur from hydrogen sulfide are also known. For example, in a conventional sulfur recovery process known as the Claus process, up to about 1/3% of the hydrogen sulfide in the gas can be oxidized with air or oxygen to sulfur dioxide, reacting with the balance of the hydrogen sulfide and producing elemental sulfur and water. Part of the process is carried out at a temperature above 850 ℃ and part is carried out in the presence of a catalyst such as activated alumina or titania. The chemical reaction of the Claus process is:

2H₂S+3O₂→2SO₂+2H₂O

4H₂S+2SO₂→3S₂+4H₂O

many times, the sulfur produced is of low quality and is generally considered to be a toxic waste due to contamination caused primarily by the commonly employed amine extractant entering the Claus reactor with hydrogen sulfide.

Another approach is disclosed in us publication No. 2005/0191237. This publication discloses a method and apparatus for obtaining a hydrogen product and a sulfur product from a feed gas by separating the feed gas to obtain a purified hydrogen sulfide component having at least about 90% by volume hydrogen sulfide, dissociating the hydrogen sulfide in the hydrogen sulfide component to convert it to a purified hydrogen sulfide component of elemental hydrogen and sulfur, separating the dissociated purified hydrogen sulfide component to obtain a hydrogen-rich component of elemental hydrogen, and obtaining the hydrogen product of elemental hydrogen. The dissociation is carried out at a temperature between 1500 ℃ and 2000 ℃.

U.S. publication No. 2002/0023538 also discloses a method of removing hydrogen sulfide and other impurities. The two-step process comprises removing at least a portion of the impurities from the gas using a first adsorbent disposed in a fluidized bed operating at a temperature of about 20-60 ℃ and removing another portion of the impurities from the gas using a second adsorbent disposed in another fluidized bed operating at a temperature of about 100-300 ℃. Also disclosed is a conversion element, i.e. a non-thermal plasma corona reactor, for converting said impurities to elemental sulphur and hydrogen at a temperature below 400 ℃.

Disclosure of Invention

In one aspect, the invention provides a process for substantially eliminating impurities from a gas comprising providing a gas having hydrogen sulfide and hydrocarbons in a reactor, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, and separating the sulfur from the gas. This process can be represented by the following chemical reaction:

xCH₄(g)+8H₂S(g)→xCH₄(g)+8H₂(g)+S₈(s)；

where x is any number, indicates that the ratio of hydrocarbon gas to hydrogen sulfide is variable and unimportant because it remains constant. The heating zone is generated by a heating element comprising a catalyst and/or a resistance wire.

Another aspect of the invention provides a method for substantially removing impurities from a gas comprising providing a gas having hydrogen sulfide, hydrocarbons and carbon dioxide, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, reacting the hydrogen with the carbon dioxide to form water and carbon and/or carbon-sulfur compounds (carsuls), oxidizing the hydrogen with the oxygen of the carbon dioxide, and separating the sulfur, water and carbon and/or carbon-sulfur compounds from the gas. This process can be represented by the following chemical reaction:

xCH₄(g)+8H₂S(g)+4CO₂(g)→xCH₄(g)+8H₂O(l)+S₈(s) +4 c(s); and/or

xCH₄(g)+8H₂S(g)+4CO₂(g)→xCH₄(g)+8H₂O (l) + carbon-sulfur compounds;

where x is any number, indicates that the ratio of hydrocarbon gas to hydrogen sulfide is variable and unimportant because it remains constant. The heating zone is generated by a heating element comprising a catalyst and/or a resistance wire.

Another aspect of the invention provides a method for recovering hydrogen from hydrogen sulfide comprising passing hydrogen sulfide through a heating zone requiring a first measure of energy (measure), producing hydrogen and sulfur, oxidizing the hydrogen with air or oxygen, and releasing a second measure of energy, the second measure of energy being 10-12 times greater than the first measure of energy. This process can be represented by the following chemical reaction:

8H₂S(g)→8H₂(g)+S₈(s); and

8H₂(g)+4O₂(g)→8H₂o (g) + energy.

The heating zone is generated by a heating element comprising a catalyst and/or a resistance wire.

Another aspect of the invention provides a method for providing hydrogen as a fuel comprising storing a gas having hydrogen sulfide in the form of a liquefied gas in a vessel, providing a reactor associated with the vessel having a heating element comprising at least one of a catalyst and a resistance wire, releasing the gas from the vessel into the reactor, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, and separating the sulfur from the gas.

Another aspect of the invention provides a gas substantially free of impurities removed by a process comprising providing a gas having hydrogen sulfide and hydrocarbons in a reactor, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, and separating the sulfur from the gas. The heating zone is generated by a heating element comprising a catalyst and/or a resistance wire.

Yet another aspect of the invention provides a system for substantially eliminating impurities from a gas, comprising a reactor for receiving a gas having hydrogen sulfide and hydrocarbons, and a heating element located within the reactor that contacts the gas to produce a product substantially free of hydrogen sulfide. The heating element comprises a catalyst and/or a resistance wire.

Drawings

FIG. 1 is a perspective view of an exemplary reactor employed in the present invention.

FIG. 2 is a flow chart of the method of the present invention.

FIG. 3 is a perspective view of an exemplary reaction chamber for use with the present invention.

FIG. 4 is a cross-sectional view "A" of the exemplary reaction chamber of FIG. 2.

FIG. 5 is a perspective view of an exemplary reaction system of the present invention.

Detailed Description

The present invention provides a method for substantially eliminating impurities from a gas. These impurities include hydrogen sulfide, carbon dioxide, and other undesirable impurities, and the gas may be natural gas, also referred to as "sour gas" when the hydrogen sulfide content is high, and industrial gases produced by petroleum refining or other industrial processes, or combinations thereof. Methane is the major component in natural gas and may be a component of other gases including hydrogen sulfide. Although methane is shown as a reactant in the process, any other gas may be included in the gasHydrocarbons, e.g. unsubstituted and substituted hydrocarbons, including the number of carbon atoms C₁-C₂₀Preferably C₁-C₆Branched or unbranched alkanes and alkenes, cycloalkanes, cycloalkenes, aromatics or mixtures thereof. Examples include, but are not limited to, ethane, propane, butane, pentane, ethylene, and propylene. The hydrocarbon depends on the particular gas. In addition, natural and industrial gases may contain many other different impurities and other chemicals not specifically listed herein, such as nitrogen and helium.

"substantially" means at least 50% removal, but removal may be as high as 100%. Preferably, at least 70% of the impurities are removed in the process of the invention, more preferably at least 85%, and most preferably at least 95%.

A process for substantially eliminating impurities from a gas includes providing a gas having hydrogen sulfide and other impurities in a reactor, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, and separating the sulfur from the gas. This process can be represented by the following chemical reaction:

xCH₄(g)+8H₂S(g)→xCH₄(g)+8H₂(g)+S₈(s)；

where x is any number, indicates that the ratio of hydrocarbon gas to hydrogen sulfide is variable and unimportant because it remains constant.

The gas may be fed to the reactor in a continuous manner. The reactor may be sealed and purged with an inert gas, such as argon or nitrogen, before being charged with reactants. In particular, if there are multiple gases to enter the reactor, the gases may also be fed through a mixer before entering the reactor. Preferably, the reactor is a continuous tubular or cylindrical reactor, and may be a plurality of reactors in series.

On a micro-laboratory scale, a thermocouple wrapped in a glass tube with a resistance wire can be used. On a medium-sized laboratory scale, the column reaction can be carried outThis was done with a multi-neck glass flask, where the neck was equipped with a heated reaction column of various temperatures, arranged to hold the packing in place and suitable for the addition of reactants, monitoring of temperature and the discharge of products. The reactor can be made of high-temperature-resistant borosilicate or quartz glass, for exampleGlass, United Glass Technologies or other companies. The temperature may be detected by a thermometer or thermocouple via glass contact or by other means, such as a contactless laser guided infrared reading. The product liquid and solid can be cooled and collected in a flask with a Vigreux column or other device. The cooled gas may be conveyed through a liquid/solid collector to a gas sampling device and a flow monitor.

On a large scale, the reactor may be a packed column type reactor or any other of the various types of reactors commonly used to contact reactants. The reactor may be glass lined and/or made of a metal or other material resistant to hydrogen sulfide and may also contain a hydrogen porous ceramic or other type of membrane material if it is desired to separate hydrogen from the gas stream. On an industrial scale, the column may incorporate a hydrogen sulfide resistant metal heating/cooling coil within the reactor zone, as it is desirable to preheat the catalyst to operating temperature. Once the gas is fed into the reactor and the reaction is started, the same coil can be used to remove the excess heat generated in the exothermic reaction. In one embodiment, the reactor is a ceramic column of catalyst-coated hydrogen permeable structure located within a cylinder of hydrogen sulfide that continuously separates the released hydrogen gas. The devices are not limited to those described in this application. Any equipment may be used as long as it can carry out the respective steps of the method.

Heating elements are provided within the reactor to create a heated zone. The heating element may be any element or device capable of supplying heat, but is preferably a catalyst coated steam tube or a heating resistance wire. Examples of resistance wires are nickel-chromium resistance wires, commonly known as nichrome wires. A catalyst may be used to accelerate the rate of chemical reactions in the heated zone of the reactor. Preferred catalysts include copper compounds such as copper carbonates, hydroxides, oxides or sulfides, vanadium compounds such as vanadium oxides or sulfides, and tungsten compounds such as tungsten oxides or sulfides, and mixtures thereof, but any other catalyst that accelerates the reaction may be used. Exemplary catalysts include, but are not limited to, minerals such as malachite and chalcopyrite, and chemicals such as vanadium pentoxide, vanadium sulfide, nickel chromium wire, chromium oxide, tungsten sulfide, tungsten oxide, molybdenum sulfide, and titanium dioxide. Other catalysts include those specifically disclosed in U.S. patent 6,099,819. The catalyst may be in any form, including powder, granules, and other shapes suitable for a given reactor.

The catalyst may be a coating on a support such as a ring or bead, or may be particles that are not fine enough to impede the flow of gas through the heated catalyst bed. For example, the catalyst may consist of vanadium chips with an oxidized surface. Preferably, the catalyst is placed in a column having a specific composition so as to be structurally stable and resistant to the impact of the gas passing through the reactor, and is placed above or in contact with a collector for receiving or discharging sulfur and purified gas. Multiple stages and additional filtering processes may be employed to ensure elimination of entrained particles, as desired.

Preferably, the pressure in the reactor is from atmospheric to 3,000psi (20,684 kPa). Higher pressures may also be employed, where appropriate, to accelerate the reaction; operation can also be achieved below atmospheric pressure. Heating the reactor to form a heated zone having a temperature of 50 ℃ to 700 ℃. If a catalyst is used as the heating element, separation of sulfur from the gas stream is visible shortly after passage through the heating zone. The decomposition reaction of hydrogen sulfide in a gas can be carried out at a temperature ranging from about 50 c, starting at a temperature above the melting point of sulfur (about 115 c at atmospheric pressure), up to about 700 c, using a catalyst other than a resistive wire. When sulfur is above its melting point, it may escape from the catalyst without covering it.

Higher temperatures are generally required if a resistance wire is used as a catalyst to contact the gas. Preferably, the temperature of the heating zone is from 400 ℃ to 700 ℃. Higher temperatures may also be used.

In the process of the present invention, hydrogen sulfide is converted to hydrogen and sulfur, preferably elemental hydrogen and elemental sulfur. The sulfur is preferably separated from the gas rapidly so that the liberated hydrogen does not react with the sulfur.

In one embodiment of the invention, a trap is used to remove the sulfur. The collector may be a receiver, conveyor, drum, or other design. The collector may also be equipped with a doctor blade or other device designed to remove solidified sulfur. Multiple stages may be employed to eliminate the hydrogen sulfide. If the reactor column is composed of a material that is permeable to hydrogen and impermeable to the gas, hydrogen sulfide or sulfur, such as a controlled porosity ceramic, and the column is located within another column that is impermeable to hydrogen and of appropriate design, the hydrogen can be removed from the gas and used alone. If no hydrogen is separated from the gas after the hydrogen sulfide decomposition reaction, the gas is hydrogen enhanced and has a higher energy storage and produces less carbon dioxide on combustion than gas not treated by the process of the present invention.

The hydrogen produced by the process of the invention may be separated from the reaction products by conventional membrane techniques or other means, or may be immediately used to convert the carbon dioxide (either naturally or deliberately added) contained in the gas into water as the main product. When the method of the present invention is used to decompose hydrogen sulfide in a gas containing carbon dioxide, the hydrogen produced during the decomposition of hydrogen sulfide reacts with the carbon dioxide in the gas and produces water with sulfur and carbon and/or water with carbon-sulfur compounds known as carbon-sulfur compounds.

Also, another aspect of the present invention provides a method for substantially removing impurities from a gas comprising providing a gas having hydrogen sulfide, hydrocarbons and carbon dioxide, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, reacting the hydrogen with the carbon dioxide to form water and carbon and/or carbon-sulfur compounds, oxidizing the hydrogen with the oxygen of the carbon dioxide, and separating the sulfur, water and carbon and/or carbon-sulfur compounds from the gas. This process can be represented by the following chemical reaction:

xCH₄(g)+8H₂S(g)+4CO₂(g)→xCH₄(g)+8H₂O(l)+S₈(s) +4 c(s); and/or

xCH₄(g)+8H₂S(g)+4CO₂(g)→xCH₄(g)+8H₂O (l) + carbon-sulfur compounds;

where x is any number, indicates that the ratio of hydrocarbon gas to hydrogen sulfide is variable and unimportant because it remains constant.

Carbon dioxide may already be a component of the gas or added to a gas with a high hydrogen sulfide content; the hydrogen sulphide may already be a constituent of the gas or be added to a gas with a high carbon dioxide content. The hydrogen produced by the decomposition of hydrogen sulfide reacts with the oxygen of the carbon dioxide, eliminating the carbon dioxide from the gas. The preferred temperature in this reaction is above 59 ℃ to react the liberated hydrogen with carbon dioxide.

The process of liberating hydrogen and elemental sulfur from hydrogen sulfide involves combustion with oxygen, or oxidation, the hydrogen to release energy and is shown by the following equation:

H₂S(g)→H₂(g) + S(s); and

2H₂(g)+O₂(g)→2H₂o (g) + energy; or

8H₂S(g)→8H₂(g)+S₈(s); and

2H₂(g)+0₂(g)→2H₂o (g) + energy.

As shown in table 1 below, the energy released during this hydrogen oxidation process is about 12 times the energy required in the first reaction in which hydrogen is released from its chemical bond with sulfur.

TABLE 1

The invention also provides a method for providing hydrogen as a fuel comprising storing a gas having hydrogen sulfide in the form of a liquefied gas in a vessel, providing a reactor having a heating element connected to the vessel, releasing the gas from the vessel into the reactor, passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, converting the hydrogen sulfide to sulfur and hydrogen, and separating the sulfur from the gas. At ambient temperature, hydrogen sulfide is a liquid at a relatively low pressure of about 250psi (1,724 kPa). It can be stored and transported and subsequently converted to hydrogen and by-product sulfur, which can be recycled. In addition, combustion of hydrogen produces only water vapor, as opposed to contaminants produced by other fuels.

The use of hydrogen as a fuel is particularly suitable for the utility and transportation industries, since hydrogen is a clean fuel and can be stored in conventional containers, such as cylinders, in the form of low pressure liquefied gas. Hydrogen itself is very active and flammable. The storage and transportation of hydrogen typically requires very high pressure thick steel cylinders of up to 3,000psi (20,684 kPa). Hydrogen sulfide, on the other hand, is far less reactive or flammable and can be transported in very low pressure thin (and thus very light weight) cylinders below 300psi (2,068 kPa). The hydrogen sulfide cylinder holds 12 times the amount of available hydrogen as a hydrogen cylinder of equivalent size.

In this embodiment, the reactor may be included as part of the vessel, or may be connected to the vessel by a hose or other means to provide hydrogen sulfide gas. When hydrogen is required, a hydrogen sulfide stream 80 is passed into a chamber 51 (which is resistant to and impermeable to hydrogen sulfide, sulfur and hydrogen) and contacts a catalyst coated heating zone 52, which is also a hydrogen sulfide and sulfur impermeable hydrogen permeable membrane. High-purity hydrogen 81 passes through the hydrogen permeable membrane and flows out of the reactor cartridge via a delivery pipe. In this embodiment, heating zone 52 is heated by means of a nickel chrome wire 61. For further removal of hydrogen sulfide, final filtration may also be performed through another hydrogen permeable membrane. In addition, a hydrogen sulfide absorbent bed may also be used for trace hydrogen sulfide removal. Sulfur can be collected below the bottom of the reactor.

The invention also provides a gas substantially free of impurities wherein the impurities are removed by the above method, and a system for substantially eliminating impurities in a gas. As shown in fig. 2, the system comprises a gas source 1 of at least hydrogen sulphide and hydrocarbons feeding a reactor 3. The reactor 3 has a heating element with a catalyst and/or a resistance wire. A mixer 2, such as a static mixer, may be provided to mix the gas from the gas source 1. Reactor 3 produces a substantially hydrogen sulfide-free product comprising a substantially sulfur-free gas 4 and sulfur 5. Water may also be generated.

While the method of the present invention may be carried out in any apparatus or system capable of or suitable for carrying out each step of the method described herein, the method is preferably carried out using preferred embodiments of the system described herein. Thus, the terminology used and defined for one method and system is equally applicable to another method and system.

The following examples are provided to illustrate the process, system and resulting gas of the present invention. These examples are intended to aid those skilled in the art in understanding the present invention. However, the present invention is not limited in any way.

Examples

Example 1: process for removing hydrogen sulfide from natural gas

Wrapping at an Outer Diameter (OD) of 3mmThe thermocouple 110 (for detecting the reaction temperature) in the glass tube 120 is obtained from an adapter 145 fitted with suitable threadsBoth ends of the glass "T" 140 are inserted with a length of 20cm and a length of about 5mm in Inner Diameter (ID) by 7mm ODThe center of the glass tube 130, thereby forming a microreactor chamber 150, as shown in fig. 3 and 4. A portion of the outside of the 7mm glass tube 130 was wrapped with a 75% nickel and 25% chromium nichrome wire 160 helix, the distance between each wire of the helix was about 2mm, and the temperature of the reaction chamber heating element was controlled by a laboratory rheostat.

Test gas is fed into the reaction tube 130 via the third end 165 of the "T" 140. The test involving the catalyst was performed by placing a catalyst (not shown) in the space between the thermocouple glass tube 120 and the inside of the reaction glass tube 130. As shown in fig. 3, the microreactor is formed by slightly inclining the reaction tube 130 downward at an angle of about 10 degrees from the horizontal and preventing the downward movement of the catalyst by means of the porous glass fiber plug 125. By associating a segment 1/4' IDA tube (flex tube) 170 is connected to the lower end of the glass reactor tube 130 and the other end of the flex tube 170 is connected to a glass bubbler or flow tube (not shown) to monitor the flow of gas out of the reactor tube 130. The test gas was a mixture of natural gas and hydrogen sulfide and vanadium pentoxide was used as the catalyst in the apparatus, and hydrogen sulfide detectable by the human nose was not vented from the reactor at temperatures of about 115 ℃ to 700 ℃ and atmospheric pressure, and thus was in a very low ppb concentration range (4.7 ppb is generally considered to be detectable by the human nose).

In the absence of catalyst, no reaction was observed. The same reaction was observed when the chemical catalyst was replaced with a nickel chromium resistance wire placed inside the glass tube rather than outside the glass tube, but at temperatures above about 400 ℃.

Example 2: process for removing hydrogen sulfide and carbon dioxide from natural gas

Wrapping at OD 3mmThermocouple 110 (for detecting reaction temperature) in glass tube 120 from adapter 145 fitted with appropriate threadsBoth ends of the glass "T" 140 are inserted with a length of 20cm and 7mm OD of about 5mm inside diameterThe center of the glass tube 130, thereby forming a microreactor chamber 150. A portion of the outside of the 7mm glass tube 130 was wrapped with a 75% nickel and 25% chromium nichrome wire 160 helix, the distance between each wire of the helix was about 2mm, and the temperature of the reaction chamber heating element was controlled by a laboratory rheostat.

Test gas is fed into the reaction tube 130 via the third end 165 of the "T" 140. The test involving the catalyst was performed by placing a catalyst (not shown) in the space between the thermocouple glass tube 120 and the inside of the reaction glass tube 130. The microreactor is formed by slightly tilting the reaction tube 130 downward at an angle of about 10 degrees from horizontal and preventing downward movement of the catalyst by means of a porous glass fiber plug 125. By associating a segment 1/4' IDA tube (flex tube) 170 is connected to the lower end of the glass reactor tube and the other end of the flex tube 170 is connected to a glass bubbler or flow tube (not shown) to monitor the flow of gas out of the reactor tube 130. The test gas was a mixture of natural gas, hydrogen sulfide and carbon dioxide, with the proportion of hydrogen sulfide being 2 moles per 1 mole of carbon dioxideHydrogen sulfide, and using malachite as a catalyst in the apparatus, hydrogen sulfide detectable by the human nose is not vented from the reactor at temperatures of about 115 ℃ to 300 ℃ and atmospheric pressure, and is thus in the very low ppb concentration range (4.7 ppb is generally considered to be detectable by the human nose).

In the absence of catalyst, no reaction was observed. The same reaction was observed when the chemical catalyst was replaced with a nickel chromium resistance wire placed inside the glass tube rather than outside the glass tube, but at temperatures above about 400 ℃.

Example 3; process for recovering hydrogen from hydrogen sulfide

Wrapping at OD 3mmThermocouple 110 (for detecting reaction temperature) in glass tube 120 from adapter 145 fitted with appropriate threadsBoth ends of the glass "T" 140 are inserted with a length of 120cm and a length of 7mm OD of about 5mm inside diameterThe center of the glass tube 130, thereby forming a microreactor chamber 150. A portion of the outside of the 7mm glass tube 130 was wrapped with a 75% nickel and 25% chromium nichrome wire 160 helix, the distance between each wire of the helix was about 2mm, and the temperature of the reaction chamber heating element was controlled by a laboratory rheostat.

Test gas is fed into the reaction tube via the third end 165 of the "T" 140. The test involving the catalyst was performed by placing the catalyst (not shown) in the space between the thermocouple glass tube 120 and the inside of the reaction glass tube 130. The microreactor is formed by slightly tilting the reaction tube 130 downward at an angle of about 10 degrees from horizontal and preventing downward movement of the catalyst by means of a porous glass fiber plug 125. By passingOne segment 1/4' IDA tube (flex tube) 170 is connected to the lower end of the glass reactor tube 130 and the other end of the flex tube 170 is connected to a glass bubbler or flow tube (not shown) to monitor the flow of gas out of the reactor tube 130. Hydrogen without hydrogen sulfide odor was produced with hydrogen sulfide as the test gas and vanadium pentoxide as the catalyst in the apparatus.

In the absence of catalyst, no reaction was observed. The same reaction was observed when the chemical catalyst was replaced with a nickel chromium resistance wire placed inside the glass tube rather than outside the glass tube, but at temperatures above about 400 ℃.

Example 4: method for removing hydrogen sulfide from gas in larger laboratory scale

A catalyst-filled column 230 having a 25mm OD borosilicate column constructed by United Glass Technologies, inc. as shown in fig. 5 was used. The thermocouple 210, wrapped in a glass tube 220, is inserted into the column 230 and the "T" 240 of an adapter 245 fitted with suitable threads, thus forming a reactor chamber 250. A portion of the outside of post 230 is helically wrapped with nickel chromium resistance wire 260.

Test gas is fed into column 230 via third end 265 of the "T" 240. Any downward movement of the catalyst is prevented by means of a porous glass fibre plug 225. The gas stream exiting the column 230 is received by a receiver 270, the receiver 270 beingBorosilicate glass 3-neck 500cc capacity flask. A product sample is extracted using a drip tube 275. A pair of jacket condensers 280 is used to condense water and sulfur with extremely cold water circulating in the outer jacket. Rotameter 290, which is a flow meter, is held in place by two adapters 246 to visually monitor the gas flow exiting the reactor. The second "T" 241 is connected to a gas analyzer and another reactor in series.

As noted, in the continuous flow reactor, hydrogen sulfide and carbon dioxide (in a ratio of 2 moles of H)₂S to 1 mol CO₂) 50% of the gas mixture and methane the other 50% of the gas mixture, and reached a completion of about 99.89% after a brief contact with malachite as catalyst at 154 ℃. The liquid and solid products (water, sulfur and carbon) were collected in a 3-neck round-bottom flask placed below the column, and the purified methane flowed out of the flask in a continuous flow through a sub-zero condenser to a gas chromatograph (sampling approximately every 40 minutes). The reaction was found to be thermodynamically favourable above room temperature and to be extremely rapid with a drastic volume contraction, the temperature rising due to the exothermic heat of reaction.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. It is therefore intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims (24)

1. A method for substantially eliminating impurities from a gas, comprising:

providing a gas having hydrogen sulfide and hydrocarbons in a reactor;

passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, said heating zone being generated by a heating element comprising at least one of a catalyst and a resistance wire;

converting hydrogen sulfide to sulfur and hydrogen;

sulphur is separated from the gas.

2. The method of claim 1, wherein the hydrocarbon comprises methane.

3. The method of claim 1, wherein the gas comprises at least one of natural gas, industrial gas, and refinery gas.

4. The method as recited in claim 1, wherein the temperature comprises about 400-700 ℃.

5. The method of claim 1, wherein the temperature comprises about at least 115 ℃.

6. The process of claim 1, wherein the reactor comprises a pressure from about atmospheric pressure to 20,684 kPa.

7. The method of claim 1, further comprising feeding the gas into a hydrogen permeable reactor.

8. The method of claim 1, wherein the hydrogen permeable reactor comprises a ceramic.

9. The method of claim 1, further comprising:

providing carbon dioxide in a ratio of about 2 moles of hydrogen sulfide to 1 mole of carbon dioxide;

converting the carbon dioxide to water and at least one of carbon and carbon-sulfur compounds;

reducing the carbon dioxide with hydrogen; and

separating the water and at least one of the carbon and carbon-sulfur compounds from the gas.

10. The method of claim 1, further comprising:

oxidizing the hydrogen; and

in an exothermic process, energy is released which is 10-12 times the absorbed energy required in an endothermic process for converting hydrogen sulfide to sulfur and hydrogen.

11. The gas produced by the method of claim 1.

12. A method for substantially eliminating impurities from a gas, comprising:

providing a gas having hydrogen sulfide, hydrocarbons and carbon dioxide in a reactor;

passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, said heating zone being generated by a heating element comprising at least one of a catalyst and a resistance wire;

converting hydrogen sulfide to sulfur and hydrogen;

reacting the hydrogen with carbon dioxide to form water, and at least one of carbon and carbon-sulfur compounds; and

oxidizing said hydrogen with the aid of oxygen of said carbon dioxide; and is

Separating at least one of sulfur, water, and carbon-sulfur compounds from the gas.

13. The method of claim 12, wherein the hydrocarbon comprises methane.

14. The method of claim 12, wherein the gas comprises at least one of natural gas, industrial gas, and refinery gas.

15. The method as recited in claim 12, wherein the temperature comprises about 400-700 ℃.

16. The method of claim 12, wherein the temperature comprises about at least 59 ℃.

17. The process of claim 12, wherein the reactor comprises a pressure from about atmospheric pressure to 20,684 kPa.

18. The method of claim 12, further comprising releasing energy in an exothermic process that is 10-12 times the absorbed energy required in an endothermic process for converting hydrogen sulfide to sulfur and hydrogen.

19. The method of claim 12, wherein the gas comprises a ratio of about 2 moles of hydrogen sulfide to 1 mole of carbon dioxide.

20. A method for providing hydrogen as a fuel, comprising:

storing the gas with hydrogen sulphide in the form of a liquefied gas in a vessel;

providing a reactor connected to the vessel, the reactor having a heating element comprising at least one of a catalyst and a resistance wire;

releasing the gas from the vessel into the reactor;

passing said gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, which is generated by said heating element;

converting hydrogen sulfide to sulfur and hydrogen; and

separating sulfur from the gas.

21. The method of claim 20, further comprising filtering the hydrogen through at least one of a hydrogen-only permeable membrane and a hydrogen sulfide absorbent bed.

22. The method of claim 20, wherein the reactor comprises a hydrogen permeable reactor.

23. A gas substantially free of impurities, said impurities being removed by a process comprising the steps of:

providing a gas having hydrogen sulfide and hydrocarbons in a reactor;

passing the gas through a heating zone having a temperature of about 50 ℃ to 700 ℃, said heating zone being generated by a heating element comprising at least one of a catalyst and a resistance wire;

converting hydrogen sulfide to sulfur and hydrogen; and

sulphur is separated from the gas.

24. A system for substantially eliminating impurities from a gas, comprising:

a reactor for receiving a gas having hydrogen sulfide and hydrocarbons; and

a heating element having at least one of a catalyst and a resistance wire located within the reactor that contacts the gas to produce a product substantially free of hydrogen sulfide.