RU2513196C1 - Method of oil sludge processing - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: oil sludge is delivered from a sludge collector by a pump under pressure up to 1.0 MPa and flow rate up to 10 m³/h to a pipe furnace; oil sludge is heated up to temperature of 110-120°C and delivered to a coaslescer filled with coalescent material in the form of granite macadam with bulk density of 1.36-1.40 t/m³ and size of particles from 5 up to 50 mm; oil sludge is processed in the coaslescer by steam coming from the flow centre and perimeter and by water at the outlet, then the processed product is delivered to a horizontal settler and in the settler it is separated into oil phase and water phase.

EFFECT: improving separation degree for highly stable oil sludge.

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Description

The invention relates to the oil industry and may find application in the processing of oil sludge for oil and water.

A known method of treating sewage sludge, including preliminary dewatering of oil-sludge-containing sludge by capillary suction with fibrous material to a moisture content of 60-70%, followed by drying of the residue in drum furnaces at 300-400 ° C with the addition of gravel or crushed stone in a mass ratio of from 1: 2 to 1 : 3. The result is "black" gravel - a building material with a hydrophobic coating, oil condensate and purified water (USSR Author's Certificate No. 1747400, publ. 15.07.92).

Closest to the proposed invention in technical essence is a method of processing oily waste (sludge) by pre-dewatering the sludge using a mechanical grinder, followed by heat treatment at a temperature of 300-400 ° C in a rotary tube mixer by mixing dehydrated "cold" oil sludge with crushed stone (gravel ) in a mass ratio of 1: 2 or 1: 3, preheated in a rotary drum furnace, and to maintain the heat treatment temperature in a rotary mixer in predetermined limits, flue gases from crushed stone (gravel) heating furnaces are fed into it (RF Patent No. 2156750, publ. 09.27.2000 - prototype).

A common disadvantage of this method is the long duration of the process of pre-dewatering the sludge and the need to clean the entire volume of the trapped and condensed vapor-gas phase from the toxic products of the pyrolysis of hydrocarbon and other organic components of the processed sludge, which inevitably form upon direct heating to 300-400 ° C in drum furnaces of the sludge mixture and crushed stone (gravel), the inability to separate highly resistant sludge into oil and water.

The proposed invention solves the problem of separation of highly stable oil sludge.

The problem is solved by the method of processing oil sludge, according to which oil sludge from the sludge collector is pumped at a pressure of up to 1.0 MPa and a flow rate of up to 10 m ³ / h to a tube furnace, heated to a temperature of 110-120 ° C, and fed to a coalescing device filled with coalescing material in in the form of crushed granite with a bulk density of 1.36-1.40 t / m ³ and a particle size of 5 to 50 mm, it is treated in a coalescing device with steam in the center and perimeter of the stream and water at the outlet, then the processing product is fed into a horizontal container sedimentation tank, defend in a decanter and separated into oil and aqueous phase.

SUMMARY OF THE INVENTION

The task of processing oil sludge is one of the most difficult due to the fact that oil sludge is a difficult to destroy oil emulsion that has gone through all stages of separation and remains after all this in the form of an oil emulsion. The proposed invention solves the problem of separation of difficult to separate oil sludge. The problem is solved using the device shown in Fig.1.

A device for processing oil sludge includes a sludge collector 1, a pump 2, a tube furnace 3, a coalescing device 4, a horizontal sump 5, an oil buffer 6, a pump 7, a sump with a hydrophobic liquid-phase layer 8, a pump 9, a tank 10,

The device operates as follows.

Oil sludge from sludge collector 1 is pumped 2 to a tube furnace 3. In furnace 3, oil sludge is heated by the heat of combustion of natural gas or associated petroleum gas. To speed up and improve the separation process, oil sludge heated in the furnace 3 is fed to a coalescing device 4 and then to a horizontal tank - sedimentation tank 5 for sludge. In the sump 5, the heated and coalescing oil sludge is divided into the oil phase (upper layer) and the aqueous phase (water sludge).

Sludge water from the lower part of the tank 5 enters the sump with a hydrophobic liquid-phase layer 8. The purified wastewater from the sump 8 is pumped out by pump 9 into the tank 10, where additional water sludge occurs. Next, the prepared water is fed into the reservoir pressure maintenance system. The oil caught in the sump 8, at the upper level serves in the "head of the process" in the feed line of sludge to the furnace 3.

The oil phase from the sump 5 is diverted at the upper level to the oil buffer tank 6. Next, the oil phase from the buffer vessel 6 is pumped out by a pump 7 to the oil treatment unit or, in case of unsatisfactory analyzes, it is sent to the furnace 3 for further heating.

Figure 2 presents a coalescing device. The device includes a housing 11, nozzles of the input 12 and output 13 of the products and coalescing material 14. Coalescing material 14 is a granite crushed stone with a bulk density of 1.36 - 1.40 t / m ³ and a particle size of from 5 to 50 mm. Near the inlet pipe 12 along the axis of the casing 11 there is a steam inlet pipe 15 directed along the oil sludge stream, in the central part of the casing 11 there are lateral steam inlets 16 located around the circumference, near the outlet pipe there is a water inlet pipe 17 directed towards the oil sludge stream, in the lower part case 11 posted by a drainage pipe 18.

Coalescing device operates as follows.

Oil sludge enters through the input pipe 12 into the housing 11, filled with coalescing material - crushed granite. Steam is introduced through a nozzle 15 into the center of the oil sludge stream and through the nozzles 16 around a circumference of the oil sludge flow with a pressure of up to 0.6 MPa and a temperature of up to 120-140 ° C. At the end of the housing 11 through the pipe 17 enter water up to 1-3% of the volume of oil sludge.

Oil sludge in the form of water and oil globules falls under the activating effect of the supplied steam and acquires additional acceleration, thereby creating conditions for collision with coalescing material. Oil sludge emulsion globules are enlarged, destroyed, divided into separate phases. At the end of the device, fresh water is supplied in front of the flow to improve coalescence.

To prevent clogging of particles of coalescing material, a washing of the apparatus is provided with a cessation of oil sludge supply and emptying through the drainage pipe 18.

Case Study

Oil sludge from sludge collector 1 with a temperature of 5 to 40 ° C is pumped 2 under pressure up to 1.0 MPa and flow rate up to 10 m ³ / h to the tube furnace 3. In furnace 3, oil sludge is heated by the heat of combustion of natural gas or associated petroleum gas. To speed up and improve the separation process, oil sludge, heated in furnace 3 to a temperature of 110-120 ° C, is fed to a coalescing device 4 and then to a horizontal tank - sump 5 with a volume of 200 m ³ for sludge. In the sump 5, the heated and coalescing oil sludge is divided into the oil phase (upper layer) and the aqueous phase (water sludge).

Sludge water from the lower part of the tank 5 enters the sump with a hydrophobic liquid-phase layer 8 with a volume of 100 m ³ . The purified wastewater from the sump 8 is pumped out by the pump 9 into the tank 10, where additional sludge of water occurs. Next, the prepared water is fed into the reservoir pressure maintenance system. The oil caught in the sump 8, at the upper level serves in the "head of the process" in the feed line of sludge to the furnace 3.

The oil phase with a temperature of about 90 ° C and with a water cut of up to 2% from the sump 5 is diverted at the upper level to the buffer tank of oil 6 with a volume of 100 m ³ . Next, the oil phase from the buffer tank 6 is pumped out by a pump 7 to the oil treatment unit or, in case of unsatisfactory analyzes, it is sent to the tank 3 for additional heating at the outlet of the tank 6.

As a result, it is possible to divide highly resistant oil sludge into oil and water.

The application of the proposed method will process highly resistant oil sludge.

Claims (1)

A method of processing oil sludge, according to which oil sludge from a sludge collector is pumped under a pressure of up to 1.0 MPa and a flow rate of up to 10 m ³ / h into a tubular furnace, heated to a temperature of 110-120 ° C, fed to a coalescing device filled with coalescing material in the form of granite crushed stone with a bulk density of 1.36-1.40 t / m ³ and a particle size of 5 to 50 mm, is treated in a coalescing device with steam in the center and perimeter of the stream and water at the outlet, then the processing product is fed into a horizontal settling tank defend in the sump and ra Dividing by the oil and aqueous phase.

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