RU2642861C1 - Unit for producing elemental sulphur from hydrogen sulphide - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: unit for producing elemental sulfur from hydrogen sulphide includes two sealed tanks installed on the foundations and equiped with an anode and a cathode mounted inside the electrodes, which are connected to positive and negative poles of direct current source. The unit also comprises inlet branch pipes provided with shut-off elements in lower parts of gas supply containers, meters of gas pressure in tanks, level of distilled water and the gas outlet line, the branch pipe with the shut-off element for withdrawal of the released gas to the collection point of the consumer. The gas outlet line communicates the upper part of the first tank with the lower part of the second tank. The unit is additionally provided with a third tank with anode and cathode mounted inside the electrodes. The volume of the third tank is smaller than the volume of the second one, and the second tank has a volume less or equal to the volume of the first. Each tank is equipped with a water temperature meter. Lower parts of each tank are provided with gas-water contact amplifiers which are made in form of perforated tube divided into several sections in ascending order of diameters of holes in sections starting from side of gas inlet. Said tube is made of an anti-corrosion material, such as polyethylene, polypropylene, or stainless steel. The gas-water contact amplifiers are connected to the gas supply line, equipped with a shut-off element with a bypass gas line connected to it for supplying dissociated gas to the gas-water contact amplifiers of the second and third tank, and equipped with the shut-off elements. The unit is provided with an additional gas line communicating with compressed inert gas source and upper parts of each tank by means of branches equipped with shut-off elements.

EFFECT: invention makes it possible to increase efficiency and reliability of the unit.

4 cl, 4 dwg

Description

The invention relates to the field of the oil and gas industry, in particular to installations for producing elemental sulfur from hydrogen sulfide or carbon disulfide, or in the purification of petroleum, natural gases from sulfur-containing compounds such as hydrogen sulfide or carbon disulfide by their decomposition to produce elemental sulfur, and can also be used in other industries industries: chemical, petrochemical, gas processing and metallurgical.

A known method of producing sulfur (see US patent No. 4592905, publication date 03.06 1986) by contacting and reacting gaseous hydrogen sulfide with anthraquinone dissolved in a polar organic solvent to produce sulfur and the corresponding anthrahydroquinone. In this case, sulfur is precipitated from the solution and is recovered as a product. The remaining anthrahydroquinone solution is fed to a dehydrogenation reactor, where it is thermally or catalytically regenerated to obtain the initial form of anthraquinone in solution and hydrogen gas. The anthraquinone solution is recycled back to the hydrogen reactor, and hydrogen is recovered as a product.

The disadvantage of this method is that it requires sophisticated equipment, the use of a polar organic solvent, in which gaseous hydrogen sulfide with anthraquinone is dissolved, which also requires the adoption of measures to protect the health of staff and environmental safety.

There is also a method of producing elemental sulfur and molecular hydrogen (see the description of the application No. 94040929 from 11/08/1994, IPC СВВ 17/04, published in BI from 09/20/1996 under the name "Method for producing elemental sulfur and molecular hydrogen from a hydrogen sulfide-containing initial mixture of gases and a device for its implementation "), which provides for dissociation by electromagnetic action in the reaction zone, followed by separation of the dissociation products into sulfur and hydrogen and their removal from the reaction zone. In this case, the electromagnetic effect is carried out continuously by feeding directed microwave radiation to the reaction zone at a temperature of 135 ° C, and the direction of movement of the initial mixture in the reaction zone coincides with the vector diagram of the microwave emitter, and the basic separation of the dissociation products is carried out at the exit from the reaction zone by changing the direction of movement of the initial mixture of dissociation products.

The specified method for implementation requires heating the initial mixture to 135 ° C, which increases energy consumption, it is technologically complex and requires sophisticated equipment for its implementation.

There is also known a method of producing elemental sulfur from hydrogen sulfide or carbon disulfide and installation for its implementation (see the description of patent No. 2287617 dated April 8, 2005, published November 20, 2006, Bull. No. 32) by dissociation with subsequent separation sulfur. In this case, dissociation is carried out by dissolving them in distilled water in sealed containers and then elemental sulfur is deposited by electrolysis on the anode, and hydrogen is isolated on the cathode, followed by its transportation together with purified oil gas from sulfur to the consumer.

The specified installation for producing elemental sulfur from hydrogen sulfide-containing petroleum gas by electrolysis includes two sealed containers installed on the bases with electrodes mounted inside - anode and cathode, connected to the positive and negative poles of a DC source, respectively, inlet pipes in the lower parts of the tanks, equipped with shut-off elements, a pressure meter, a level meter of distilled water in tanks and a gas outlet line communicating the upper parts of the first mkosti with the lower part of the second vessel with water and a branch pipe with a locking element for discharging the separated gas - hydrogen - with oil in electrolysis to a collection point consumer.

The known installation in technical essence is closer to the proposed one and can be adopted as a prototype.

Its disadvantage is low efficiency. This is explained by the fact that the dissociated gas entering the tank through the inlet pipe does not have time to dissolve immediately in distilled water, most of it can float to the surface of the water, since the pressure of the incoming gas must be greater than the static pressure of the water in the tank, by definition, that leads to a decrease in the efficiency of its work. In addition, when a large layer of elemental sulfur is deposited on the anode as a result of electrolysis of hydrogen sulfide, the anode gradually begins to lose its ability to accept sulfur and when it reaches a certain thickness on its surface, it ceases to fulfill its function, and it is not provided to quickly remove it from the tank and replace it with a new electrode therefore, the installation also needs to eliminate this drawback. The installation also does not provide for monitoring the temperature of water in containers. It is known that in the process of electrolysis in them the water is heated, which leads to a slowdown in the decomposition of hydrogen sulfide.

The technical task of the present invention is to increase the efficiency and reliability of the installation.

The stated technical problem is solved by the proposed installation, including two sealed containers installed on the bases with electrodes mounted inside - anode and cathode, connected to the positive and negative poles of the DC source, respectively, equipped with shut-off elements, inlet pipes in the lower parts of the gas supply tanks, pressure gauges gas in containers, the level of distilled water and a gas outlet line communicating the upper part of the first tank with the lower part of the second tank STI, fitting with the locking member for discharging the separated gas to a collection point

What is new is that the installation is additionally equipped with a third tank with inside-mounted electrodes — the anode and cathode — and with a volume smaller than the volume of the second, and the second tank is made with a volume less than or equal to the volume of the first, each tank equipped with a water temperature meter, and the lower parts of each tank are amplifiers for contacting gas with water, made in the form of a perforated pipe, divided into several sections in order of increasing hole diameters in the sections, starting from the gas inlet side, and t uba is made of an anticorrosive material, such as polyethylene, polypropylene, or stainless steel, in communication with a gas supply line equipped with a shut-off element, with a bypass gas line connected to it for supplying dissociated gas to gas and water contact amplifiers of the second and third capacities and equipped with shut-off elements elements, the installation is also equipped with an additional gas line in communication with a source of compressed inert gas and with the upper parts of each tank using taps equipped with shut-off ele cops.

Another difference of the installation is that a thermometer or a temperature sensor can be used as a temperature meter if automation of the control system is necessary.

Another difference of the installation is that nitrogen is chosen as an inert gas for the source of compressed gas.

Another difference of the installation is also that as a shut-off element of the gas supply and gas exhaust lines, a non-return valve can be used, which works to open the gas supply and exhaust side, or a valve.

Patent studies in retrospect for 20 years were carried out in the patent library of the TatNIPIneft Institute in order to determine the technical level and preliminary examination for novelty. The results of patent studies showed that objects of similar purpose with such a combination of essential features as the claimed one were not found. Analysis of the known technical solutions found in the art showed that the claimed technical solution has features that are not in the analogues, and their use in the claimed the combination of essential features allows to obtain a new technical result. Therefore, we can assume that the claimed technical solution meets the conditions of patentability "novelty" and "inventive step", and its practical applicability is confirmed by the description of the implementation of the installation

The presented drawings explain the essence of the proposed installation, where in FIG. 1 shows the proposed installation with three containers, inside which are mounted amplifiers for contacting gas with distilled water, electrodes connected to a direct current source are also visible, bends are mounted to the upper parts of the containers and connected to a line connected to a source of compressed inert gas, which is shown in the form of a cylinder, the piping of the gas supply and gas discharge line with locking elements is visible, as well as a level gauge, measuring instruments.

In FIG. 2 is a view of A of FIG. 1, which shows the neck of the capacitance for introducing the electrode — the anode — closed by means of flanges — a sleeve with a sealant is visible through which an electric wire is passed from the positive pole of the direct current source to the anode.

In FIG. 3 - amplifier for contacting gas with distilled water, made in the form of a perforated pipe, divided into sections B, C, and D, where holes are seen made in increasing diameter in sections starting from section B from the gas inlet side with the smallest openings .

In FIG. 4 - a grounded capacitance with several electrodes lowered into it - anodes connected to the positive pole of a direct current source, and also the cathode is visible, an amplifier for contacting gas with water is visible.

Installation for producing elemental sulfur from hydrogen sulfide (see Fig. 1) includes installed on the bases 1, 2 and 3 in the amount of at least three grounded containers 4, 5 and 6 with electrodes 7 and 8 mounted inside them, serving as an anode (+) and cathode (-), respectively, connected to the positive and negative poles of the DC source. The containers in shape can be made in the form of a cylinder, as shown in FIG. 1 and 4, or rectangular, square in cross section and equipped with gas pressure gauges 9, level gauges 10, hydrogen sulfide analyzers 11, temperature gauges 12. Tank 6 is selected with a smaller volume than tank 5, and tank 5 is made with a volume less than or equal to a container 4 to which a dissociable gas (hereinafter gas) is supplied via a gas supply line 13 provided with a filter 14 and a shut-off element 15, which can be made in the form of a valve or check valve, which works to open from the gas inlet side. The use of a check valve is preferred. Each tank is grounded and equipped with gas inlets 16, 17 and 18 with locking elements 19, 20 and 21 (hereinafter taps), respectively, to which amplifiers 22 are mounted using flanges (flange connection not shown) (see Fig. 1 and 3 ) contacting the gas with distilled water 23 (hereinafter referred to as water), connected to a gas supply line 13, to which in turn is connected a gas bypass 24 with taps 25 and 26, which is in communication with the capacities 5 and 6 through amplifiers 27 and 28 of gas contact with water (hereinafter referred to as amplifier). One possible embodiment of the amplifier is shown in FIG. 3. It is made in the form of a perforated pipe and, to increase the efficiency of gas dissolution in water, is conditionally divided into several sections B, C and D (see Fig. 3) in increasing order of the diameters of holes 29 in its sections, starting from section B from the entrance side gas, and is made of an anticorrosive material such as polyethylene, polypropylene or stainless steel.

The installation is additionally equipped with a gas line 30 in communication with a source of compressed inert gas 31, which is shown in the form of a cylinder, and with the upper part of each tank 4, 5 and 6 using taps 32, 33 and 34, equipped with taps 35, 36 and 37. In this case, nitrogen can be used as an inert gas. Tanks 4 and 5 are equipped with gas exhaust lines 38 and 39 with shut-off elements 40 and 41, respectively, which can be made in the form of a check valve, working to open the gas inlet from the gas inlet side, or a valve to discharge the released hydrogen in a mixture with a certain amount of surfaced hydrogen sulfide, in case this happens, from the upper parts of containers 4 and 5 to the lower parts of containers 5 and 6, respectively. The third tank 6 is equipped with a pipe 42 with a valve 43 for discharging the separated hydrogen to the consumer. If necessary, tanks 4 and 5 can be equipped with similar nozzles with a tap. Tanks can be equipped with several anodes 44, 45 and 46 (see Fig. 4) to accelerate the separation of sulfur from H ₂ S or when the volume of incoming gas is large. The lower parts of the tanks are equipped with technological pipes 47, 48 and 49 with cranes. During the electrolysis operation, the capacities are heated, which is recorded by a thermometer 12 or a temperature sensor, and the process of H ₂ S dissociation slows down, and the installation efficiency decreases. Therefore, to maintain the optimum temperature of the water in the tanks, they must be equipped with a cooling jacket (cooling jacket not shown)

Installation works as follows.

Before turning on the installation, the presence of distilled water 23 in the tanks 4, 5 and 6 by the level gauge 10, the tightness of the piping, locking elements, grounding of the tanks, the presence and serviceability of measuring instruments, as well as the reliability of the sealing rod 50 (see Fig. 2 and 1) are checked , electrodes with a head 51 for capturing the lifting mechanism and flange connections by hook 52, the volume of distilled water in the containers is taken into account so that the static back pressure P ₂ exerted by it is less than the pressure P ₁ entering the tank 4 H ₂ S or sulfur hydrogen-containing petroleum gas supplied through the gas supply line 13. It is also known from information sources (see also the description of patent No. 2287617, p. 5) that distilled water is the only initial chemical compound that does not change its chemical and physical properties during the isolation of elementary sulfur from H ₂ S and its containing gases and can be used for a long time. After the preparatory work is completed, a constant electric current is supplied to the electrodes 7 and 8 of the capacitance 4 (see FIG. 1), as well as to the electrodes of the capacities 5 and 6, the taps 19, 20 and 21 of the inlet pipes 16, 17 and 18 are opened, and then the valve 15 of the gas supply line 13 with the closed taps 25 and 26 of the bypass gas line 24, thereby disociable H ₂ S or H ₂ C containing petroleum gas is supplied to the tank 4. In doing so, the following occurs. Gas H ₂ S, passed through the filter 14 into contact with the water container 4 partially hydrated and dissolved and then enters the amplifier 22, the gas contacting with the water, where the maximum of its dissolution and subsequent dissociation of sulfur to form hydrogen ions and

H ₂ S↔H ⁺ + HS↔H ⁺ + S ²

In the amplifier H ₂ S, several sections B, C and D pass, first falling into section B with a small diameter of holes 29 (see Fig. 3), then it enters into section B with a larger diameter than in the first, and so on in increasing order the diameters of the holes in other areas, which prevents the gas from floating up and being in space above the liquid. It is known that of all the gases that make up the oil and associated gases, only hydrogen sulfide and carbon disulfide are soluble in water, turning distilled water into an electrolyte, in which negatively charged sulfur ions under the influence of a direct current electric field move directionally to the positive electrode 7 (anode) , forming elemental sulfur insoluble in water on it, and hydrogen insoluble in water is released on the negatively charged electrode 8 - the cathode:

(2H ⁺ + 2e) + (S ² -2e) → H2 ↑ + S ↓

and it floats to the surface of the water.

While periodically checking the composition of the released hydrogen gas in the presence of H ₂ S, as indicated by gas analyzer 11 hydrogen sulfide or by taking samples for rapid analysis through the pipe 53 with a tap 54 for removal of H ₂ to the user In case of a composition of the evolved hydrogen H ₂ S above the MPC, provided in the regulatory documents, then along the gas outlet line 38, having previously opened the valve 40 and the contact amplifier 27, they are sent to a container 5 for finer separation of S ₂ , where a similar process is carried out as in the container 4 . If H ₂ S in the tank 5 is not found or within the MPC, then through the pipe 53 for exhaust gas N ₂ , opening the valve 54, is directed to the consumer.

Over time, due to the deposition of a large amount of viscous insoluble elemental sulfur on the anode 7, its action weakens, as a result of which the presence of H ₂ S in the released hydrogen is inevitable and even it can cease to fulfill its function. In this case, the valve 19 at the inlet of the H ₂ S gas into the container 4 is closed, the taps 20 and 24 are opened, and with the valve 26 H ₂ S closed, they are sent to the container 5 along the bypass line 24. Next, the anode 7 with adherent viscous sulfur is replaced - S ₂ on new. For this purpose, existing above the water level in the tank gas - H ₂ - is displaced into the container 5 through the gas supply line 38 with an open cock 40 (instead of the crane is desirable to install a check valve) by means of pressurized inert gas from the cylinder 31, opening the tap 35 the vent pipe 32. Then, the sleeve 55 (see Fig. 2) is unscrewed from the flange connection and the head 51 of the anode electrode 7 is hooked by the hook 52 (see Fig. 1 and 2) of the lifting mechanism and removed from the tank 4 and sent to clean it from adhering sulfur. time in the tank 4 lower the spare electrode and fix its sleeve 55 to the flange connection. After H ₂ S closure assembly again fed into the container 4. To this valve 19 is opened and the valve 25 of the gas bypass line 24 is closed and then the cycle repeats.

The technical and economic advantage of the proposal is as follows.

The proposed installation, in comparison with analogs, has increased efficiency and reliability in operation, does not require large energy costs and the use of sophisticated component equipment, is simpler and safer to maintain by the operator. The installation ensures the separation of elemental sulfur not only from hydrogen sulfide, but also from hydrogen sulfide and carbon disulfide containing oil and natural gases, which will protect oilfield processing equipment from corrosion, will lead to environmental improvement in the oil fields, and will positively affect the health of the population living in oil and gas production areas , since hydrogen sulfide and carbon disulfide are potent toxic substances of nerve agent. In addition, in the process of electrolysis, the separated hydrogen or hydrogen mixed with purified oil gas from sulfur can be used as fuel and as a valuable raw material for the oil and gas refining and chemical industries. Using the proposed installation will provide tangible economic benefits.

Claims (4)

1. Installation for producing elemental sulfur from hydrogen sulfide, including two sealed containers installed on the bases with electrodes mounted inside - anode and cathode, connected to the positive and negative poles of a DC source, respectively, inlet pipes equipped with locking elements in the lower parts of the gas supply tanks, gas pressure gauges in the tanks, the level of distilled water and a gas outlet line communicating the upper part of the first tank with the lower part of the second tank, pa tubes with a locking element for evacuating the released gas to the consumer’s collection point, characterized in that the installation is additionally equipped with a third capacity with electrodes mounted inside - anode and cathode, and with a volume less than the volume of the second, and the second capacity is made with a volume of less than or equal to the volume of the first, and each tank is equipped with a water temperature meter, and the lower parts of each tank are amplifiers for contacting gas with water, made in the form of a perforated pipe, divided into several sections the increasing diameter of the holes in the sections, starting from the gas inlet side, and the pipe is made of anticorrosive material, such as polyethylene, polypropylene, or stainless steel, in communication with a gas supply line equipped with a shut-off element, with a gas bypass connected to it to supply a dissociated gas to the amplifiers for contacting the gas with water of the second and third capacities and equipped with locking elements, the installation is also equipped with an additional gas line in communication with the source of compressed inert th gas and with the top of each container by means of taps provided with locking element. 2. Installation according to claim 1, characterized in that a thermometer or a temperature sensor can be used as a temperature meter in case of automation of the control system. 3. Installation according to claim 1, characterized in that nitrogen is selected as an inert gas for the source of compressed gas. 4. Installation according to claim 1, characterized in that as a shut-off element of the gas supply and exhaust lines, a non-return valve can be used to open the gas inlet and outlet, or a valve.

Images