WO2020022871A1

WO2020022871A1 - Method for processing oil-containing waste

Info

Publication number: WO2020022871A1
Application number: PCT/KZ2019/000007
Authority: WO
Inventors: Рустем Рифович САФИН; Аслан Абдрахманович ОРЫНГАЛИЕВ
Original assignee: Тоо "Reef Центробежные Технологии"
Priority date: 2018-07-25
Filing date: 2019-05-16
Publication date: 2020-01-30
Also published as: EA202092127A1; EA038683B1

Abstract

The invention relates to a method of processing oil-containing waste. Separate processing of a liquid feedstock and a solid feedstock is carried out so as to produce streams of oil, water and a solid phase. In the first step, the liquid feedstock is heated and fed to a centrifugal separator for separation into oil, water and an aqueous suspension. The solid feedstock is flushed with hot water and the suspension obtained is fed to a horizontal scroll conveyor centrifuge. Then said suspensions are fed to a horizontal scroll conveyor centrifuge for separation into solid particles and liquid. Said liquid and water are fed from the centrifugal separator to a settling tank. Oil from the tank is returned to the start of the process, while the water, with has a reduced oil content, is cleaned in a separator and removed from the unit.

Description

5 Method for the processing of oily waste

The invention relates to the oil industry, and in particular to methods for processing oily waste and can be used for almost any oily waste ~ from K) solid (contaminated soils, drilling waste, etc.) to liquid, including stable oil emulsions.

The processing of oily waste is traditionally carried out by methods of their destruction or neutralization or separation methods. Most methods for irretrievable loss of oil and today 15 more than half of the oil is destroyed. The most effective method is separation on tricanters (three-phase horizontal screw centrifuges), but the separation products often require further preparation and the method itself has several limitations. In particular, it is not possible to process stable emulsions or raw materials with a high content of 0 ultrafine particles.

Waterlogged fuel oil is usually tried to defend with heating in tanks, but it is rarely possible to bring them to regulatory requirements. Used oils and other heavy petroleum products are often burned as fuel.

5 The closest in essence to the present invention is a method of processing an aqueous suspension of oil refinery waste, comprising separate processing of liquid and solid raw materials to obtain streams of oil, water and solid phase, from which oil products can be extracted and practically no hydrocarbon residue cake, including stages :

a) heating said suspension to a temperature of at least about 82 ° C. to produce hot slurry; b) holding said slurry at said temperature for a period of time sufficient to digest said hot slurry, wherein said digestion involves melting any entrained solid oil products, reducing the apparent viscosity of the slurry, and reducing the density of the oil fractions of said slurry; c) passing said hot digested slurry through a first centrifuge to separate a first centrate containing liquid hydrocarbon fractions from a first cake containing associated oil residues;

d) dispersing said first lozenge in water to form a second suspension;

e) treating said second suspension by adding a certain amount of hydrogen peroxide to it in order to lyse and release bound oil residues from the inert solids contained in said first cake; and

f) passing the specified second suspension through a second centrifuge to separate the second centrate, containing oil fractions, from the second cake, where the specified second cake contains these inert solids and practically does not contain hydrocarbon residues / EA001892 B 1, 22 L 0.2001, /.

The disadvantage of this analogue is the low yield of refined petroleum products and a low degree of automation of processes.

The objective of the invention is to develop a method for the processing of oily waste with improved technical characteristics.

The technical result is the versatility and high mobility of processing technology, an increase in the yield of refined petroleum products, a high degree of automation of processes.

This is achieved by the fact that the method of processing oily waste, providing for the separate processing of liquid and solid raw materials with obtaining flows of oil, water and solid phase, according to the invention, includes the following stages:

i) the liquid raw material is heated and fed to a centrifugal separator with the subsequent withdrawal of the separated flows of oil, water and aqueous suspension, ii) the solid raw material is washed with hot water to remove large particles and / or objects and the prepared suspension is fed to a horizontal screw centrifuge,

iit) said suspensions from stages i) and I) are fed into a horizontal screw centrifuge with a further withdrawal of the separated solid particles dump and the liquid stream,

iv) said water and liquid flows from stages i) and III) are supplied to an intermediate tank with a further withdrawal, after gravitational sludge, of the oil flows returned to the process head and water with a reduced oil content,

v) said water with a reduced oil content, if necessary, is purified on a separator with a further withdrawal of purified water.

In step i), the centrifugal separator is a nozzle centrifugal separator, by means of a main feed pump, if necessary, heating said liquid feed is passed through at least one heat exchanger or heating device in which it is heated to an operating temperature (usually 60-98 ° C), and filters protecting the separator from large mechanical particles. Mentioned heat exchangers are a set of no more sin heat exchangers such as "raw materials / water", "raw materials / oil", "raw materials / agent". Depending on the properties, the oil stream after the separator is removed with heat exchange with an incoming raw material stream in the raw / oil heat exchanger or without it, removing the water stream! in the said intermediate tank, as well as the stream of aqueous suspension accumulate in at least one suspension tank with further output to a horizontal screw centrifuge.

At stage ii), large objects and particles up to 5 mm in size are removed from solid raw materials by mechanical sorting methods (grates, vibrating screens, screens, etc.), they are washed with hot water using stirrers or other mixing methods and then put on a horizontal screw centrifuge . If there is a significant content of large particles and / or the need to achieve low humidity of the solid dump, the stage of preliminary deposition of solid particles on the filter centrifuge is added, the suspension of fine particles separated is removed to a horizontal screw centrifuge, and the solid dump is removed from the installation.

At stage ίίί) in a horizontal screw centrifuge, the suspension from stages i), d) and V) is separated into a liquid and a dump of solid particles. Said dump of solid particles is directed to a sludge tank located under a horizontal screw centrifuge, with a further withdrawal from the unit, and a liquid stream is supplied to said intermediate tank. The precipitation of the solid phase from suspensions of various sources can be joint or separate (using several centrifuges), and the centrifuges themselves can be performed in two-phase (main) and three-phase versions. In a three-phase version, two fluid flows are discharged from the centrifuge: oil for purification at the centrifugal nozzle separator (stage ί)) and water into the intermediate tank.

In step iv), said intermediate tank is a storage tank with an oil trap located above or near the storage tank, or without it. The oil flow from the oil trap is led out to the main feed pump directly or through an additional oil tank. Water with reduced oil content from 5 oil traps, a nozzle centrifugal separator of a three-phase screw centrifuge are accumulated in the said storage tank.

At stage v), through the pump, water is pumped from the storage tank through a filter (protection from large particles), if necessary, it is heated in a heat exchanger or other heating device and fed to a self-discharging separator for separation into water, oil and a suspension of fine solids. The purified water from the separator is sent to the washing of solid raw materials (stage I)), and the excess is removed from the installation with heat exchange with or without a flow of incoming liquid raw materials. The oil flow from the separator is discharged directly to the main feed pump or 5 through an additional oil tank. The said suspension of fine particles, depending on the properties, is sent to step in) for precipitation or is withdrawn from the installation.

The processing of liquid and solid raw materials can be carried out jointly or separately. Depending on the processed raw materials and (1 product requirements, the technology can be used in full configuration or partially. For example, if there is no need to process solid raw materials, the technology can work without step n) or at low requirements for the quality of treated water, the process can be carried out without additional purification self-discharging separator 5 - stage v).

The claimed method for the processing of oily waste is carried out on the basis of a single technological complex for the processing of oily waste, based on the principle of physical separation of produced fluids into components in the centrifugal force field and is implemented using centrifugal equipment.

Figure 1 presents a visual diagram of the implementation of the method of processing oily waste. PI ~ Main feed pump; TO ~ heat exchangers; ODA-20 - nozzle centrifugal separator; CF-3000 - Decanter; WSE-20 - Self-loading centrifugal separator; PSE - Primary suspension capacity; ALL - Secondary suspension capacity; NOT - Intermediate capacity.

The invention works as follows. The description is given on the example of a small industrial plant based on components manufactured by GEA Westfalia Separator. Production of plants of a different capacity and using equipment from other manufacturers is also possible.

Recycling liquid waste.

Liquid raw materials are supplied to the installation from raw materials tanks installed next to the installation. The maximum liquid level in the raw material tanks should be below the overflow mark in the oil trap by at least 20 cm.

The stage of separation of liquid raw materials (emulsions).

The raw material enters the installation at the reception of the main raw material pump R-1, which operates with a capacity control of 1 to 5 m / h. The pump pumps the feed through three consecutive pipe-in-pipe heat exchangers, where the feed is heated by the outgoing flows of water (TO feed / water) and oil (TO feed / oil), and then the coolant: (TO feed / agent) is brought to the specified operating temperature - usually from 60 to 98 ° C.

The heated raw material is pumped through a double strainer or wire filter (DF 1 mm.), Where particles> 1 mm in size stop, the filter sections work alternately and, as clogged, the filter elements are cleaned manually.

In case of changing the settings of the nozzle separator, additional filter elements for stopping particles are additionally provided 0.5 mm in size. Prepared raw material through a metering device enters the nozzle centrifugal separator (ODA-20).

In the ODA-2G separator, the emulsion is divided into oil and water streams, as well as an aqueous suspension of mechanical parts c (from 1 micron and above). Refined oil is measured by a meter and under its own pressure of 2-3 atm. It is removed from the installation after heat exchange with incoming raw materials. The water flow is sent to an intermediate tank with flow metering on the meter, from which water is pumped to a centrifugal separator to ensure nozzle flushing - the flow rate is maintained at 0.5-1 m / h.

The suspension of solid particles from the separator flows into the primary suspension tank installed under the separator. When working without a decanter unit, the suspension flows from the primary tank by gravity to an external drainage tank.

The stage of deposition of the solid phase.

The suspension flows from the primary tank by gravity to the secondary suspension tank located in the decanter unit. The total capacity of the containers is at least 2 m ³ . In the operating mode, the containers should be filled no more than by 60%, since in case of emergency blackouts the nozzle separator will be washed with water for another 15 minutes and thus the container will be filled with water.

From the secondary suspension tank, the suspension is pumped to a horizontal screw centrifuge, where, under the action of centrifugal forces, they are separated into a solid phase dump and water. The dump of mechanical impurities from the decanter falls into the slurry receiver installed directly below it, and then the screw conveyor is removed from the installation into an 8 m ³ container installed next to the installation.

The liquid purified on the decanter from the solid phase (main part) under its own pressure is sent to the intermediate tank with measurement on the flow meter. Stage water treatment.

The water released during the processing (from the nozzle separator and decanter) enters an intermediate tank consisting of two elements: an oil trap and a storage tank. The liquid enters the oil trap, where due to gravity sludge, oil is partially separated for 10-30 minutes and sent to the main feed pump PE. Water with a reduced oil content flows into a storage tank with a volume of 3-4 m located directly under the oil trap.

Water from the storage tank is drawn in by a pump and pumped through a double strainer (DF 0.5 mm.), Where particles> 0.5 mm in size stop.

The principle of operation of the filter is similar to the filter of the nozzle separator. Then, in a plate heat exchanger (water / agent maintenance), the liquid is heated by the heat carrier to the operating temperature (from 70 to 98 ° C) and through the flow meter enters the self-unloading centrifugal separator type WSE-20.

In the WSE-20 separator, water is purified from oil and fine solids.

The purified iodine water with its own pressure (up to 2 atm.) Is measured in the meter and after heat exchange with incoming raw materials in the heat exchanger (TO raw materials / water) is removed from the installation. During processing of solid raw materials, the separated water feeds into the supply water tank installed in the decanter unit. Depending on the required mode, water is supplied for recharge before or after heat exchange.

The oil separated in the separator, together with the oil separated in the oil trap, is sent through the flow meter to the reception of the main raw material pump P1 and then to the after-treatment in the nozzle separator as part of the main process. A suspension of fine particles from the separator falls into a suspension tank installed directly below the separator. Depending on the properties, the suspension is sent for precipitation into the decanter unit together with the suspension of the nozzle separator or is withdrawn from the installation into an 8 m ³ container installed next to the installation.

Stage of solid waste processing.

The processing of solid waste is carried out by washing the raw materials with hot water with washing additives. The raw materials for processing are transported by road and unloaded into the receiving hopper, and the washing water is supplied by means of a pump from a water tank installed in the decanter unit.

A 100 mm grate is installed on the hopper to stop large items. Clumped and frozen lumps are manually broken on the grate, and large objects (sticks, stones, metal, etc.) are washed on the grate with hot water and removed. From the receiving hopper, raw materials are conveyed by a screw conveyor into the receiving chamber of the washing tank, where 5 mm on the surface of the vibrating slotted filter. (vibrating screen) is washed away by flowing jets of hot water. Washed items larger than 5 mm are removed from the process automatically or manually.

The mixture of raw materials and water that has passed through the grate is in a washing tank, where it is mixed with turbine mixers for 30-40 minutes and thereby the raw materials are washed from oil and soluble salts. From the washing tank, the mixture is taken by a screw pump and fed to the decanter unit for separation.

In the decanter, the solid phase is deposited and removed from the installation. The liquid through the meter is sent to the intermediate tank and then cleaned as part of the overall technological cycle. The refined oil and water are removed from the installation under pressure up to 2 atm. The heat source at the installation is a boiler operating on liquid fuel - primarily, oil produced at the installation. To ensure the operation of the installation, there are systems for supplying operating water, nitrogen generation and distribution, ventilation, heating and air conditioning, a fire alarm and an uninterruptible power supply. The installation is controlled from a single remote control.

The oil obtained by the claimed method corresponds to the 1st quality group according to GOST R 51858-2002. "Oil. General technical conditions ”(water not more than 0.5%, solids up to 0.05% and chloride salts up to 100 mg / l), Water is purified from solids and oil and is intended for injection into reservoirs to maintain reservoir pressure. In water, less than 30 ppm of mechanical impurities and oil products, which corresponds to an average and good level of water purification according to OST 39-225-88 “Water for flooding oil reservoirs. Quality Requirements. ”

Claims

Claim

1. A method of processing oily waste comprising separate processing of liquid and solid raw materials to obtain flows of oil, water and solid phase, characterized in that it includes the following stages;

ΪP) said suspensions from steps Ϊ) and ii), as well as from step v) are fed into a horizontal screw centrifuge with a further withdrawal of separated solid particles and a liquid stream,

2. The method according to claim 1, characterized in that at the stage ί) the centrifuge is a nozzle centrifugal separator.

3. The method according to PD, characterized in that in stage 1) by means of the main feed pump, said liquid feed is passed through at least one heat exchanger through the main feed pump.

4. A method according to claim 1, characterized in that in step 1), said liquid feedstock beneath _f evayug to 60-98 ° C.

5. The method according to p. 1, characterized in that in stage 1) the said heat exchangers are sequentially placed three heat exchangers of the type "pipe in pipe" with a coolant type "raw / water", "raw / oil", "raw / agent" .

6. The method according to claim 1, characterized in that in stage i) said oil stream is withdrawn in the form of a heat carrier through a heat exchanger.

7. The method according to claim 1, characterized in that in step i) said water stream is discharged into said intermediate container.

8. The method of claim 1, wherein in step i) said stream of aqueous suspension is accumulated in at least one suspension vessel with a further outlet to a horizontal screw centrifuge.

9. The method according to claim 1, characterized in that in step p) large objects and particles up to 5 mm in size are removed from solid raw materials by mechanical sorting methods, washed with hot water using agitators and then displayed on a horizontal screw centrifuge.

10. The method according to p.! characterized in that in step iii) in a horizontal screw centrifuge, the suspension from steps i), ii) and v) is separated into a liquid and a dump of solid particles.

1 1. The PL method, characterized in that, in stage Hi), the aforementioned dump of solid particles is sent to a sludge tank located under a horizontal screw centrifuge, with further withdrawal from the installation.

12. The method according to claim 1, characterized in that in step iii) said liquid stream is supplied to said intermediate container.

13. The PL method, characterized in that in step iv) said intermediate tank is a storage tank with an oil trap located above or near the storage tank, or without it.

14. The method according to claim 1, characterized in that in stage iv) said oil stream from the oil trap is led out to the main feed pump directly or through an additional oil tank.

15. The method according to claim 1, characterized in that in step ίn) water with a reduced oil content from the oil trap, the nozzle centrifugal separator of a three-phase screw centrifuge is accumulated in the said storage tank.

16. The method according to claim 1, characterized in that in step n), through the pump, water is pumped from the storage tank through a filter, if necessary, heated and fed to a self-unloading separator for separation into water, oil and a suspension of fine solids.