RU73799U1 - INSTALLING OIL CLEANING (OPTIONS) - Google Patents

Abstract

The utility model relates to installations for commercial purification of sulphurous oils. Hydrogen sulfide-containing oil is piped 1 to a mixing device 9 (Fig. 1). Before the mixer, the calculated amount of the reagent to neutralize the contained hydrogen sulfide and light mercaptans is fed into the oil flow by the metering pump 3 through nozzles 8. The oil treated with the neutralizer through the reactor pipe 10 enters the first buffer tank 11. After filling it, the processed oil is fed into the parallel second buffer tank 12, and the filled tank 11 is put to hold to complete the neutralization reactions and sedimentation of emulsion water containing water-soluble products of neutralization of hydrogen sulfide . In another embodiment (FIG. 2), the oil treated with the neutralizer from the tubular reactor enters the electric dehydrator 17 to separate emulsion water from the oil containing water-soluble products of neutralization of hydrogen sulfide. Up to 5% of fresh water is supplied to the oil stream in front of the electric dehydrator through a pipeline 14 to wash water-soluble products of neutralization of hydrogen sulfide and salts from oil. The installation allows to improve the quality of the produced marketable oil by reducing the content of water, chloride salts, hydrogen sulfide and light mercaptans, as well as to eliminate the negative effect of water-soluble products of neutralization of hydrogen sulfide on the result of the determination of chloride salts in marketable oil according to the standard method GOST 21534.

Description

The utility model relates to the oil and gas industry, in particular to installations for the purification of hydrogen sulfide-containing oils, and can be used for commercial purification of sulfur oils from hydrogen sulfide and light methyl ethyl mercaptans to the level of modern requirements (GOST P 51858-2002).

A known installation of the oxidative purification of sulphurous oil from hydrogen sulfide and light mercaptans, including a supply line of sulphurous oil, a raw (buffer) tank, a unit for the preparation, storage and dosage of an aqueous-alkaline solution of a phthalocyanine oxidation catalyst, containing a capacity of an alkali solution, a capacity of an aqueous-alkaline catalyst solution, equipped with a bubbling device for purging the catalyst solution with an inert gas (nitrogen), metering pumps for supplying alkali and catalyst solutions to the sulfuris stream oil, and an oxidative oil refining unit containing a centrifugal oil pump, an air supply device, a device for mixing air with oil, an oil heater, a column type oxidation reactor, a settling tank for collecting the reaction mixture, the lower part of which is connected by a pipeline through a flow regulator with a feed tank for returning part of the reaction mixture to mix with sulfur oil, and a separator tank for separating the reaction mixture. In this case, an air compressor or a pressure injector is used as an air supply device, and a device for mixing compressed air with oil is made in the form of a torus with holes (RU 2120464, C10G 27/06, 1998, Bull. No. 29).

The disadvantage of this installation is that it requires significant capital costs for construction due to the complexity of the technological design of the process. The operation of the unit leads to contamination of the refined oil with corrosive elemental sulfur resulting from the catalytic oxidation of

hydrogen sulfide by air, as well as to increase the water content in marketable oil due to the formation of reaction water and water introduced with solutions of alkali and oxidation catalyst. In addition, the introduction of air into the hydrogen sulfide-containing oil leads to the formation of a highly corrosive medium containing oxygen and hydrogen sulfide. If the established technological process norms (oil: air ratio) are violated, an explosive mixture of air with light oil hydrocarbons may form. These and other disadvantages impede the widespread use of the known installation for commercial purification of hydrogen sulfide-containing oils.

Closest to the proposed one is a unit for purification of prepared oil from hydrogen sulfide, including a sulfide oil neutralization block, a hydrogen sulfide neutralization unit containing a neutralizing agent preparation and storage unit, a piston metering pump, the pressure piping of which is equipped with a pressure pulsation damper and an injector installed in the sulfur dioxide oil pipeline , a static mixer installed on the pipeline of sulphurous oil after the point of entry of the reagent, the buffer tank and the transportation unit purified commercial oil (RU 45292 U1, B01D 19/00, 2005, bull. No. 13).

The disadvantage of this installation is that it does not provide marketable oil that meets modern requirements (GOST P 51858-2002) according to the standardized quality indicators "Mass fraction of water" and "Concentration of chloride salts", especially when refining heavy carbon oils with a high content of hydrogen sulfide . This is due to the fact that when refining high-sulfur oils using known neutralizing agents, a considerable amount of reaction water is formed as a result of neutralization reactions of hydrogen sulfide. In addition, the known neutralizers contain in their composition as a solvent a significant amount of water (up to 50% or more). Refining oils with a high content of hydrogen sulfide requires high dosages of the neutralizer used (up to 3 kg / t or more in

depending on the content of hydrogen sulfide in the processed oil). The formation of reaction water and its introduction in the composition of the used catalyst leads to an increase in its content in the treated oil above the standards of GOST P 51858 (not more than 0.5% for the first and second groups of oil). In addition, as the field tests showed, the presence of water-soluble products of neutralization of hydrogen sulfide in the oil purified from hydrogen sulfide interferes with the determination of chloride salts according to the standard method GOST 21534-76 (method A by titration of an aqueous extract), giving an overestimated result of the content of chloride salts in marketable oil. The introduction of the neutralizer into the oil through the nozzle leads to its clogging with mechanical impurities and the need for periodic shutdown of the metering pump to clean the nozzle, as a result of which uninterrupted oil cleaning is not ensured. The disadvantage of the installation is that it does not provide the purification of hydrogen sulfide and mercaptan-containing oil simultaneously from light methyl and ethyl mercaptans to the level of modern requirements.

These shortcomings are largely eliminated by the following proposed oil refining unit (options).

The proposed oil refining unit (option 1) includes a sulphurous oil feed pipe, a hydrogen sulfide and light mercaptan neutralization unit, comprising a receiver and storage unit for a neutralizing agent, a pump (s) -doser (s), the pressure pipe of which (s) is connected to the sulphurous pipeline oil, a mixing device for mixing the neutralizing agent with oil, installed on the pipeline of sulfur dioxide, and a buffer tank, which, unlike the known installation (prototype), is equipped with a tubular reactor a conduit effective length of the mixing device to the buffer tank, and at least one additional buffer tank, whose input is connected through valving to the tubular reactor. In addition, to ensure the stability of the feed of the reagent-neutralizer, the pressure pipe of the metering pump can

be equipped with a pressure pulsation dampener, which is a container with air and acts as a shock absorber, a liquid filter (s), a check valve, and also nozzle (s) or a perforated tube with a plugged end installed (s) in the oil pipeline in front of the mixing device. A diaphragm mixer or a mixing (emulsion) valve, or a screw type mixer (screw twisting device), or a centrifugal pump, or a flow rotary mixer, or a rotary pulsating acoustic mixer, or electromagnetic, are mainly used as a mixing device for mixing the neutralizing agent with oil vibro-jet mixer. The neutralizing agent based on the product (s) of the interaction of formaldehyde (formalin or paraformaldehyde) with primary and / or secondary amine and / or ammonia, or based on sodium nitrite or hydrogen peroxide, is predominantly used as a reagent for the simultaneous neutralization of hydrogen sulfide and light mercaptans. .

New is that the installation is equipped with a tubular reactor and at least one additional buffer tank, the inlet of which is connected through shut-off valves to the tubular reactor, a liquid filter installed on the neutralizer feed pipe, a check valve installed on the pressure pipe of the metering pump, as well as the use of the above reagent-neutralizer, providing simultaneous neutralization of the hydrogen sulfide and light mercaptans contained in the oil.

An additional buffer tank, through shut-off valves and a tubular reactor connected to the mixing device in parallel with the first buffer tank, allows the unit to alternately hold the oil treated with the catalyst in static mode in order to effectively sediment reaction and emulsion water containing water-soluble products of neutralization of hydrogen sulfide. With such exposure, refined oil is created

Favorable conditions for sedimentation of produced water, since disturbances that interfere with the process of gravity sedimentation are eliminated. When the oil is held in the first buffer tank, the oil treated with the neutralizer is taken into the second (additional) buffer tank. After holding the oil and settling the bottom water, the refined marketable oil is pumped out for delivery to the main oil pipeline. Then, the next batch of oil treated with the reagent is received in the empty buffer tank. When filling the first buffer tank with treated oil, the second buffer tank is put on hold, i.e. in the mode of sludge water. With the implementation of such a regime of alternate operation of buffer tanks, almost complete separation of produced water from the purified oil with water-soluble products of neutralization of hydrogen sulfide is achieved, as a result of which their negative impact on the determination of chloride salts by the method of GOST 21534 is eliminated. In an advantageous embodiment, the oil treatment plant includes three in parallel connected buffer tanks (tanks), alternately working on a cycle: receiving treated with oil neutralizer - oil exposure and - pumping out of commercial oil. The presence of fine liquid filter (s) makes it possible to exclude clogging of the nozzle or holes of the perforated tube with mechanical impurities and, thereby, ensure the continuity and stability of the neutralizer supply to the oil stream. The presence of a check valve allows you to prevent the reverse movement of the catalyst and to prevent the flow of hydrogen sulfide-containing oil into the feed line of the converter. Thus, during the implementation and operation of the proposed installation, it is possible to obtain refined marketable oil of higher quality according to standardized indicators: mass fraction of water, concentration of chloride salts, mass fraction of hydrogen sulfide and methyl-, ethyl mercaptans. In addition, the negative effect of neutralization products of hydrogen sulfide on the course and the result of the determination of chloride salts in crude oil by the standard method GOST 21534 is excluded.

The drawing (Figure 1) shows a schematic diagram of the proposed installation of oil refining. The installation comprises a sulfur dioxide oil supply pipe 1, a hydrogen sulfide and light mercaptans neutralization unit, including a container (s) for receiving and storing a reagent-neutralizer 2, a pump (s) -doser (s) 3 (working and standby), a pressure pipe 5 of which (s) ) is equipped with a pressure pulsation damper 4, a liquid filter 6, a check valve 7 and nozzle (s) 8 installed in the sulphurous oil pipeline, a mixing device 9, a tubular reactor 10, buffer tanks 11 and 12, the inlets of which are through shut-off valves 13 and soy tube reactor Dinen with the output of the mixing device, as well as shut-off and control valves and instrumentation.

Installation of oil refining works as follows. Prepared sulphurous oil containing more than 100 ppm of hydrogen sulfide and methyl and ethyl mercaptans is fed through a pipe 1 to a mixing device 9. At the same time, the oil flow in front of the mixer from a measuring tank 2 is a metering pump 3 through a pressure pipe 5 equipped with a pressure pulsation damper 4, the liquid filter 6 and the check valve 7, continuously introduced (dosed) through the nozzles 8, the estimated amount of reagent-Converter. A neutralizing agent based on the product (s) of the interaction of formaldehyde (formalin or paraformaldehyde) with primary and / or secondary organic amine (s) and / or ammonia (RU 2121492) is predominantly used as an effective reagent for the simultaneous neutralization of hydrogen sulfide and light mercaptans in oil. , RU 2186957, RU 2191849, RU 2216568, RU 2228946, RU 2302523, etc.) or sodium nitrite (RU 2241018), or hydrogen peroxide (RU 2146693, RU 2182924). The optimal dosage of the converter is determined by the results of its preliminary laboratory tests and is established during pilot tests of the oil refining unit. During operation of the unit, the dosage of the converter is adjusted in

depending on the consumption of refined oil and the residual content of hydrogen sulfide and light mercaptans in the refined oil.

The mixing of the reagent-neutralizer with oil occurs in a mixing device 9, for example, which is a diaphragm mixer. With further movement of the reaction mixture through the tubular reactor 10, neutralization reactions of hydrogen sulfide and light mercaptans occur. The oil treated with the reagent enters the first buffer tank (tank) 11, where the neutralization reactions of hydrogen sulfide and light mercaptans continue if they are not completed in the reactor 10, and water also settles. After filling the first buffer tank 11, the oil treated with the neutralizer is fed into the second buffer tank 12, and the tank 11 is set for aging in static mode for at least 2 hours, as a result of which water is separated from the purified oil containing water-soluble products of neutralization of hydrogen sulfide and thus, their negative influence on the result of determination of chloride salts in marketable oil is excluded. After exposure, purified from hydrogen sulfide and light methyl, ethyl mercaptans to GOST P 51858 standards, marketable oil from tank 11 is sent for delivery to the main oil pipeline, and the separated aqueous phase from the cube of the buffer tank is periodically (as it accumulates) sent to the waste collection and disposal system ( formation) waters. After filling, the second buffer tank 12 is also put on hold, and the oil treated with the reagent is taken into a previously empty tank 11, or into a third buffer tank (not shown in the diagram).

The named technical result - improving the quality of marketable oil obtained at the installation, eliminating the negative impact of the products of the neutralization of hydrogen sulfide on the result of the determination of chloride salts is also achieved during the implementation and operation of the proposed variant of the oil treatment plant described below ..

The proposed installation (option 2) includes a supply line for sulphurous oil, a block of neutralization of hydrogen sulfide and light

mercaptans, containing the receiving and storage unit of the neutralizing agent, pump (s) -dosing (s), the pressure pipe of which (s) is connected to the sulphurous oil pipeline, a mixing device installed on the sulphurous oil pipeline, which, unlike the known installation ( prototype), is equipped with an electric dehydrator and additionally contains a tubular reactor, which is a pipe of the estimated length from the mixing device to the electric dehydrator and providing the minimum necessary contact time and with oil, a fresh wash water (or demulsifier aqueous solution) feed pipe connected to a tubular reactor in front of the electric dehydrator. In addition, the fresh water supply pipe can be equipped with a check valve and nozzle or perforated tube with a plugged end, placed in a tubular reactor in front of the electric dehydrator. The tubular reactor may be equipped with a static mixer installed after the point of entry of fresh water. To ensure the stability of the neutralizer supply, the pressure pipe of the metering pump can be equipped with a pressure pulsation dampener, a fine filter (s), a non-return valve, and a nozzle (s) or perforated tube with a plugged end installed in the sulphurous oil pipeline before mixing device.

New is that the installation is equipped with a tubular reactor, an electric dehydrator connected to the reactor, a fresh wash water supply pipe connected to the tubular reactor in front of the electric dehydrator, a static mixer installed on the tubular reactor after the fresh water inlet point, a liquid filter and a check valve installed on the pressure pipe of the metering pump, as well as the nozzle or perforated tube installed in the tubular reactor in front of the electric dehydrator.

The drawing (Figure 2) shows a schematic diagram of the proposed installation of oil refining (option 2). The installation contains a lead

sulphurous oil pipeline 1, a block of neutralization of hydrogen sulfide and light mercaptans, including a container (s) for receiving and storing a catalyst 2, a pump (s) -doser (s) 3 (operating and standby), the pressure pipe 5 of which (s) is equipped with a pressure pulsation damper 4, a liquid filter (s) 6, a check valve 7 and a nozzle (s) 8 installed in the sulphurous oil pipeline, a mixing device 9, a tubular reactor 10 connected to the outlet of the mixing device, a fresh water supply pipe 14 provided with a return valve 7 and force Coy 15 placed in a tube reactor, a static mixer 16 mounted on the tubular reactor after the point of input of fresh water, and electrical dehydrators 17 connected to the tubular reactor, and shut-off control valves and instrumentation means.

Installation of oil refining works as follows. Prepared oil containing more than 100 ppm of hydrogen sulfide and light methyl and ethyl mercaptans is fed into mixing device 9 through pipeline 1. At the same time, oil flow ahead of mixer 9 from measuring tank 2 is pumped by metering pump 3 via pressure pipe 5 equipped with a pressure pulsation dampener 4 , with a liquid filter 6 and a check valve 7, the calculated amount of the neutralizing agent is continuously introduced (dosed) through the nozzles 8. As an effective reagent that provides the simultaneous neutralization of hydrogen sulfide and light mercaptans, neutralizers are mainly used based on the product (s) of the interaction of formaldehyde with amines and / or ammonia, sodium nitrite or hydrogen peroxide. The reagent is mixed with the oil to be purified in a mixing device 9, for example, which is a diaphragm mixer. With further movement of the reaction mixture through a tubular reactor 10, which is a pipeline of the calculated length and providing the minimum necessary contact time of the reagent with the oil being purified (at least 3-15 minutes depending on the oil temperature, the content of hydrogen sulfide and light mercaptans), neutralization of hydrogen sulfide and

light mercaptans. The oil treated with the neutralizer from the tubular reactor 10 under its pressure enters the electrodehydrator 17, where the neutralization reactions of hydrogen sulfide and light mercaptans continue if they do not end in the reactor 10. Before the electrodehydrator 17, fresh water is supplied to the oil stream through nozzles 15 through pipeline 14 in an amount up to 5% for effective washing of water-soluble products of neutralization of hydrogen sulfide and chloride salts from oil. The mixing of fresh water with oil takes place in a static mixer 16, for example, which is an emulsion valve. The water separated in the electric dehydrator, containing the products of neutralization of hydrogen sulfide and salt, enters the system of collection and disposal of waste (formation) water. Refined from hydrogen sulfide and light methyl-, ethyl mercaptans to GOST P 51858 standards, commercial oil from the electric dehydrator is fed to the main oil pipeline for delivery.

The last version of the oil refining unit can be used for refining heavy sulphurous oils prone to the formation of persistent oil emulsions.

Thus, as can be seen from the foregoing, the proposed installation (options) compared with the prototype has the following advantages:

- provides a reduction in the content of water and chloride salts in refined crude oil to the level of modern requirements;

- eliminates the negative impact of water-soluble products of neutralization of hydrogen sulfide on the result of the determination of chloride salts in refined crude oil according to the standard method GOST 21534;

- an uninterrupted and stable supply of the used reagent-neutralizer to the stream of purified oil is ensured and, therefore, the oil is cleaned simultaneously from hydrogen sulfide and light methyl, ethyl mercaptans to the level of modern requirements (GOST P 51858).

Claims (8)

1. Installation of oil refining, including the supply pipeline of sulfur dioxide, a block of neutralization of hydrogen sulfide and light mercaptans, containing the receiving and storage unit of the neutralizing agent, pump (s) -doser (s), the pressure pipe of which (s) is connected to the pipeline of sulfur dioxide, a mixing device installed on the pipeline of sulphurous oil, and a buffer tank, characterized in that it is equipped with a tubular reactor made in the form of a pipe of the estimated length from the mixing device to the buffer tank, and, in at least one additional buffer tank, the inlet of which is connected through a stop valve to a tubular reactor. 2. Installation according to claim 1, characterized in that the pressure pipe of the pump (s) -dosing (s) is equipped with a pressure pulsation dampener, a liquid filter (s), a check valve and nozzle (s) or a perforated tube with a plugged end installed ( s) in the sulphurous oil pipeline in front of the mixing device. 3. Installation according to claim 1, characterized in that as a chemical reagent that provides the simultaneous neutralization of hydrogen sulfide and light mercaptans, a neutralizer based on the product (s) of the interaction of formaldehyde (formalin or paraformaldehyde) with primary and / or secondary amine (s) is mainly used ), and / or ammonia, or sodium nitrite, or hydrogen peroxide. 4. An oil refining unit, including a sulfur dioxide oil feed line, a hydrogen sulfide and light mercaptan neutralization unit, comprising a neutralizing agent receiving and storage unit, a pump (s) -doser (s), the pressure pipe of which (s) is connected to the sulfur oil pipeline, a mixing device mounted on a sulphurous oil pipeline, characterized in that it is equipped with an electric dehydrator and further comprises a tubular reactor made in the form of a pipeline of calculated length from the mixing device to an electric dehydrator, a fresh rinse water supply pipe connected to a tubular reactor in front of the electric dehydrator. 5. Installation according to claim 4, characterized in that the pressure pipe of the pump (s) -doser (s) is equipped with a pressure pulsation dampener, a liquid filter (s), a check valve and nozzle (s) or a perforated tube with a plugged end installed ( s) in the sulphurous oil pipeline in front of the mixing device. 6. Installation according to claim 4, characterized in that the tubular reactor is equipped with a static mixer installed after the point of entry of fresh water. 7. Installation according to claim 4, characterized in that the fresh water supply pipe is equipped with a check valve and a nozzle or perforated tube with a plugged end, placed in a tubular reactor in front of the electric dehydrator. 8. Installation according to claim 4, characterized in that as a chemical reagent that provides the simultaneous neutralization of hydrogen sulfide and light mercaptans, a neutralizer based on the product (s) of the interaction of formaldehyde (formalin or paraformaldehyde) with primary and / or secondary amine (s) is mainly used ), and / or ammonia, or sodium nitrite, or hydrogen peroxide.