CN1178777A

CN1178777A - Process for treating oil containing sludge

Info

Publication number: CN1178777A
Application number: CN 97118778
Authority: CN
Inventors: 张腾云; 李小龙; 路胜旗; 陈国琪; 韩德奇
Original assignee: OIL REFINERY HENAN PETROLEUM EXPLORATION BUREAN
Current assignee: OIL REFINERY HENAN PETROLEUM EXPLORATION BUREAN
Priority date: 1997-10-16
Filing date: 1997-10-16
Publication date: 1998-04-15

Abstract

The treatment process of the present invention is especially suitable for treating oil containing sludge from oil refinery. Pre-dewatered oil containing sludge is treated in decompressing distilling still, where residual pressure and distilling temperature are controlled, so that the stable system of oil, water and sludge is destroyed, all water and partial oil are distilled out and the residual oil and sludge after decompressing distillation may be deposited and separated naturally. Sludge after washing has its oil containing amount reaching exhaust standard. The said treatment process is simple, low in power consumption and short in treatment period and can recover partical oil in oil containing sludge.

Description

A kind of process for treating oil-containing sludge

The present invention relates to a kind of treatment process of oily sludge, be particularly suitable for the processing of refinery oily sludge.

The oily sludge of refinery is mainly derived from the pond bed mud of various water treating ponds and the jar bed mud of oil tank etc., and its oleaginousness is generally 30～50%, and water ratio is 40～70%, and contains the solid matter (mud, sand etc.) about 10%.General middle-size and small-size refinery is produced mud per year and is reached thousands of tons of, and mud constantly accumulates, and can't stack and handle, and objectionable impurities wherein and petroleum hydrocarbon are understood with rainwash contaminated soil and water source.Form highly stable emulsification system because oil, water and solid matter in the oily sludge mix, be difficult to its separation.Therefore, the processing of oily sludge is a great problem of refinery always.

Handle the method for oily sludge at present both at home and abroad, biological treatment and physicochemical treatment method are arranged usually, the former is long the treatment time, and the oil in the oily sludge can not get recycling, and that the latter's key step has is concentrated, dehydration, drying and burning etc., not only handles the energy consumption height, burns a large amount of discharging gas contaminate environment that produce, and oil products are wasted in a large number, can not obtain recycling.

United States Patent (USP) (patent No. 4990237) disclose a kind of from oily sludge the method for refiltered oil, mainly be to adopt under normal pressure or little negative pressure, by low temperature and two evaporator sections of high temperature, the oil in the mud is all evaporated.This method technical process and equipment complexity, the operational condition harshness, energy consumption is big.

The object of the present invention is to provide a kind of treatment process that is particularly suitable for the refinery oily sludge, by the oil in the oily sludge, water, body refuse are separated substantially, reduce the oleaginousness in the body refuse, and make the oleaginousness of body refuse reach emission standard through washing.

The treatment process that realizes the object of the invention is:

Make oily sludge stoste remove a part of free oil and water by mechanical separation device, the mixed solution of free oil and water enters water-and-oil separator and carries out settlement separate processing; The oily sludge of another part after through the pre-dehydration of mechanical separation device distills with being pumped into the underpressure distillation still, and the heavy constituent oil that fractionation by distillation goes out enters fuel tank with the settlement separate oil that goes out; Light constituent oil and water that fractionation by distillation goes out are isolated light constituent oil and water after condenser enters water-and-oil separator, light constituent oil enters high-quality oil product pond or freshening, and isolated water enters treatment tank or makes softening water; The oil-containing body refuse that fractionation by distillation goes out enters washing tank, divides water outlet and body refuse respectively after the water lotion washing, and the water decontaminated water treating pond of telling, the body refuse of telling are discharged and carried out conventional processing.

Residual voltage in the underpressure distillation still is generally 0.1kPa～50kPa, and finally steaming temperature is 105 ℃～200 ℃; Water lotion in the washing tank is made up of water and additive, and the additive add-on is 1～15%; The additive of water lotion is made up of dilute sulphuric acid and ethanol, and wherein the alcoholic acid add-on is 0.5～20%.The add-on of water lotion is 0.5～3.0 times of oil-containing body refuse weight in the washing tank, and wash temperature is 20 ℃～80 ℃, and washing time is 10～30 minutes.

Because present method at first makes mud stoste dewater in advance, enter the underpressure distillation still then and carry out underpressure distillation, in certain residual voltage and steaming under the temperature, can steam the oil of water whole in the mud and part, thereby oil in the oily sludge, water, the formed stabilising system of body refuse have been destroyed, but remaining oil separates with the body refuse natural subsidence after making underpressure distillation, and remaining oil can be realized separating more completely after the washing device washing with body refuse.

Implement the method that the present invention proposes for realization the object of the invention, not only can solve the environmental protection problem that oily sludge brings, and treatment scheme is simple, energy consumption is low, and the treatment time is short, and can recycle the part oil product of oily sludge.

Introduce embodiments of the invention below in conjunction with accompanying drawing.

Fig. 1 is a process flow sheet of the present invention.

Oily sludge stoste pumps into mechanical separation device 1 (as pressure filter, centrifuge separator etc.) by pipeline 7, carries out pre-separation, and the free mixed solution oily and water that goes out through mechanical separation is undertaken settlement separate by pipeline 9 input water-and-oil separators 6; The settlement separate water that goes out is by pipeline 11 decontaminated water treating ponds, and the settlement separate oil that goes out goes fuel tank with the mixed solution from the mink cell focus of pipeline 15 by pipeline 22 from pipeline 10, can be underpressure distillation thermal source is provided.The mud that contains oil and water of discharging from mechanical separation device 1 pumps into underpressure distillation still 2 by pipeline 8.Underpressure distillation still 2 vacuumizes by pipeline 13, to keep decompression operation.Material according to mud is formed and character, and generally between 0.1kPa～50kPa, suitable residual voltage is 15kPa～30kPa to the residual voltage in the underpressure distillation still 2; The temperature that finally steams of underpressure distillation still 2 is 105 ℃～200 ℃, and suitable final boihng point is 120 ℃～150 ℃.Under such residual voltage and temperature, oil, water, the formed stabilising system of body refuse obtain destroying in underpressure distillation still 2 in the oily sludge, and oil in the oily sludge, water, body refuse are separated.The light component oil product and the whole water that steam from underpressure distillation still 2 pass through pipeline 12, after condenser 3 carries out heat exchange, entering water-and-oil separator 4 by pipeline 14 carries out settlement separate, the light-end products that come out from separator 4 remove high-quality oil product pond or freshening by pipeline 17, and the water that comes out from separator 4 is by pipeline 18 decontaminated water treating ponds or do the softening water use.Stop distillation when the vaporization temperature of underpressure distillation still 2 reaches when finally steaming temperature, then through the cooling sedimentation, isolated heavy constituent oil product is mixed together through pipeline 15 and settlement separate oil from pipeline 10 and enters pipeline 22 and go fuel tank; The less body refuse of isolated oil-contg is discharged underpressure distillation still 2 with mechanical means, and removes washing tank 5 through pipeline 16.Water lotion adds the washing tank 5 from pipeline 19.Water lotion is made up of water and additive, and the additive add-on is 1～15%.The add-on of water lotion is 0.5～3.0 times of oil-containing body refuse weight, and wash temperature is between 20～80 ℃.Additive is made up of 10% dilute sulphuric acid and ethanol, and wherein ethanol content is between 0.5～20%.The washing time of oil-containing body refuse in washing tank 5 is 10～30 minutes, and the sewage after the washing (oil-containing) is handled through pipeline 20 decontaminated water treating ponds, and the body refuse after the washing is discharged through pipeline 21, can carry out conventional processing (as burning or landfill).

Claims

1. process for treating oil-containing sludge, make oily sludge stoste remove a part of free oil and water by mechanical separation device (1), the mixed solution of free oil and water enters water-and-oil separator (6) through pipeline (9) and handles, it is characterized in that: enter underpressure distillation still (2) through the oily sludge after the pre-dehydration of mechanical separation device (1) through pipeline (8) and distill, isolated heavy constituent oil goes fuel tank through pipeline (15,22); Isolated light constituent oil and water are told light constituent oil and water after condenser (3) enters water-and-oil separator (4), light constituent oil removes high-quality oil product pond or freshening through pipeline (17), and water is through pipeline (18) decontaminated water treating pond or make softening water; Isolated oil-containing body refuse enters washing tank (5) through pipeline (16), and the water of telling after the washing of pipeline (19) adding water lotion is through pipeline (20) decontaminated water treating pond, and the body refuse of telling is discharged through pipeline (21) and carried out conventional processing.

2. a kind of process for treating oil-containing sludge according to claim 1 is characterized in that: the residual voltage in the underpressure distillation still (2) is 0.1kPa～50kPa, and finally steaming temperature is 105 ℃～200 ℃.

3. a kind of process for treating oil-containing sludge according to claim 1 and 2, it is characterized in that: the water lotion that adds in the washing tank (5), its add-on is 0.5～3.0 times of oil-containing body refuse weight, and wash temperature is 20 ℃～80 ℃, and washing time is 10～30 minutes.

4. a kind of process for treating oil-containing sludge according to claim 3 is characterized in that: water lotion is made up of water and additive, and water is clear water, and the additive add-on is 1～15%.

5. a kind of process for treating oil-containing sludge according to claim 4 is characterized in that: additive is made up of dilute sulphuric acid and ethanol, and wherein the alcoholic acid add-on is 0.5～20%.