CN102092907B - Oil-containing sludge resource treatment method - Google Patents

Abstract

The invention relates to an oil-containing sludge resource treatment method, which comprises the following steps of: flushing the oil-containing sludge by using sewage after electric air flotation, and separating out crude oil by using electric air flotation; delivering the flushed oil-containing sludge to a flow curtain type extraction tower, and performing extraction at the temperature of between 10 and 80 DEG C, wherein the volume ratio of an extraction solvent to the oily sludge is 1-15:1, the extraction solvent is a mixture of No.6 solvent oil and aromatic hydrocarbon, the boiling point of the extraction solvent is 60 to 150 DEG C, or the extraction solvent is oilfield gas condensate or petroleum ether; feeding the extraction mixed solution into a sedimentation tank, and performing natural sedimentation to separate an oil phase and an aqueous phase; delivering the oil phase to a fractionating tower to fractionate the extraction solvent and the crude oil; and washing the extracted muddy sand, wherein the oil content of the muddy sand is less than 3,000mg/kg of the standard, and the dipping water can be recycled after the electric air flotation.

Description

A kind of method of oily sludge recycling treatment

Technical field

The present invention relates to the processing of the oily sludge in oil field, especially relate to crude oil and electric floating recovery oily sludge Central Plains oil treatment process in a kind of solvent extraction sump oil mud.

Background technology

The source of oily sludge mainly is that the oily sludge, the oil field gathering and transportation process that produce in the oil extraction process produce the sump oil mud of oily sludge and the generation of refinery's sewage disposal system.These oily sludges also contain the stratum silt that carries in the extraction liquid except that containing crude oil, the flco that forms in the sewage disposal process of disposing polluted water in oil station, corrosive pipeline product, heavy metal salt and paraffin, asphalitine etc. and certain moisture content.

The oily sludge that produces in the oil extraction process is mainly derived from Ground Processing System, and the oily sludge that produces in the oil extraction-generated waste water processing procedure is added flco that water purification agent that sewage purification adds in handling forms etc. and formed oily sludge.

The oil field gathering and transportation process produces oil tank that oily sludge is mainly derived from block station, multi-purpose station, settling tank, sewage jar, oil interceptor bed mud, oil product storage tank when storing oil product; A small amount of mechanical admixture in the oil product, the grains of sand, earth, heavy metal salt and heavy oil property components such as paraffin and asphalitine are deposited on tank bottom, form tank bottom oil sludge.The blowdown of settling tank, secondary settlement jar, well-flushing water recycling can also can produce oily sludge in addition.

Through analyze these oily sludges form different, usually oil content between 10%～60%, solids 10-60% such as silt, and water 15-60%.Under the situation that petroleum resources growing tension and environmental problem are on the rise, effectively reclaim the crude oil in the sump oil mud, not only practice thrift valuable crude resources, and eliminated environmental pollution.

Relatively the method for processing oily sludge commonly used has at present: solidify and bury, burn hot washing method, solvent extraction, chemical demulsification method, solid-liquid isolation method, pyrogenic process etc.But wherein many methods all exist some problems, are not suitable for very much for practical application.Like big, the easy generation secondary pollution of burning method power consumption, crude resources waste; Biological treatment need last length, and same crude resources also can not get recycling; Chemical demulsification method need add demulsifier and heating in addition to the serious oily sludge of emulsification, and post processing is difficult; Solid-liquid isolation method is low for the oil recovery rate that contains innage, with serious pollution oily sludge.

Solvent extraction is the effective ways that reclaim crude oil, and the body refuse after the extraction is prone to reach the national standard of landfill or stacking, thereby causes people's attention.On September 8th, 2004 disclosed patent CN1526797A; Use extraction and from oily sludge, reclaim fuel oil, this patent adopts general extraction tower, when the oily sludge layering is slow; The diluted acid that needs to add 1-3% carries out breakdown of emulsion, and this can cause corrosion on Equipment and second environmental pollution.

Summary of the invention

The purpose of this invention provides a kind of processing method of oily sludge, at first sloughs through electrochemical method and is rich in emulsified water in the oily sludge, makes sewage reach the re-injection requirement, and oily sludge is moisture after this method is handled reduces to below 1%; Second step was reclaimed a large amount of aging crude oil in the oily sludge, and the contained aging sump oil of oily sludge is reduced to below 1% after this method is handled; The 3rd step was the oily sludge processing that organises; After processing such as microbial fermentation, oily sludge is organised, reach innoxious discharging, last sump oil content is less than 3 ‰; Satisfy country's " agricultural pollutant emission " standard, the organic fertilizer that can be used as planting technique uses.

Technical scheme of the present invention is: treatment facility comprises electric floating device, stream curtain formula extraction tower, settling tank.

Concrete steps:

1) at first oil-containing dirt water is pumped into electric floating device, dissolved air flotation goes out the contained crude oil of part, the effluent cycle utilization after the air supporting, and the sewage flushing after the remaining sump oil mud electricity consumption air supporting, oil-polluted water electricity consumption dissolved air flotation again goes out crude oil;

2) will be promoted to stream curtain formula extraction tower through the sump oil mud after the sewage flushing, the crude oil in the sump oil mud dissolved fully with extractant; Extraction conditions: temperature 10-80 ℃, extractant and greasy filth volume ratio are 1-15: 1; The extraction mode adopts batch (-type);

2) will extract mixed liquor pumps into the settling tank natural subsidence and isolates oil phase and water;

3) oil phase is pumped into fractionating column, fractionate out extractant and crude oil;

4) the silt particle washing back oil-containing after the extraction reach national stacking standard (＜3000mg/kg), embathe water and after electric floating processing, can be recycled.

Suitable extractant should satisfy following requirement:

1) high selectivity, only dissolving crude oil wherein;

2) can dissolve crude oil wherein fully;

3) boiling point low (＜150 ℃), condensation point low (＜-10 ℃);

4) be convenient to store and conveying;

5) viscosity, density, specific heat capacity, evaporation latent heat are low;

6) heat, nothing corrosion good, nontoxic with chemical stability;

7) low price is abundant with the source.

According to above-mentioned extractant alternative condition, the slective extraction agent is mixed solvent (mixture of 6# solvent naphtha and aromatic hydrocarbons, boiling point 60-150 a ℃), extractant also but field condensate or benzinum.Dissolubility and the selectivity of utilizing extractant is with oil and silt, separated form water.

Extraction conditions: temperature 10-80 ℃, extractant and greasy filth volume ratio are 1-15: 1.The extraction mode adopts batch (-type), and stream curtain formula extraction tower is adopted in extraction, and extractant recycles.

The most outstanding technical characterictic of the present invention is shale greasy filth, and mud is difficult to gravity settling separation and adopts stream curtain formula extraction tower, can adapt to the sump oil mud processing that different regions sump oil mud processing, particularly shale or natural sedimentation is difficult to be separated.

Description of drawings

Fig. 1 is a process chart of the present invention.

The specific embodiment

Treatment facility comprises electric floating device, stream curtain formula extraction tower and settling tank.

Embodiment 1

Oilfield sewage station accident pool contains sewage and sump oil mud.The detailed process that adopts the present invention to handle: at first oil-containing, dirt water are pumped into electric floating device, dissolved air flotation goes out contained crude oil, the effluent cycle utilization after the air supporting; Sewage flushing after the sump oil mud electricity consumption air supporting, oil-polluted water electricity consumption dissolved air flotation again goes out crude oil; Oily sludge 2m after the flushing ³Be promoted to stream curtain formula extraction tower and extract the about 2m of extractant ³Temperature is about 40-50 ℃ after the heat exchanger preheating of destilling tower top; Pump into stream curtain formula extraction tower and carry out spraying and extracting, the extraction mixed liquor pumps into the settling tank natural subsidence and isolates oil phase and water, and oil phase pumps into fractionating column; Fractionate out extractant and crude oil, extractant recycles; Water recycles behind the crude oil through electric floating isolating wherein.

Embodiment 2

Present embodiment improves extraction process among the embodiment 1, has increased reextraction, and other step is identical with the others of embodiment 1.

The greasy filth of single extraction is that 0.5: 1 ratio is carried out reextraction in extractant and sump oil mud again.

Embodiment 3

Present embodiment improves extraction process among the embodiment 2, has increased extracting the water wash step of back greasy filth, and other technology is identical with the others of embodiment 2.

Greasy filth behind the reextraction is used water wash, washing water directly pump into electric floating-electric flocculation plant handles, the oil phase that air supporting goes out mixes with the oil phase of single extraction and carries out the fractionation processing.

Claims (1)

1. the method for an oily sludge recycling treatment is characterized in that: treatment facility comprises electric floating device, a stream curtain formula extraction tower, settling tank;

Concrete steps:

1) at first oil-containing, dirt water are pumped into electric floating device, dissolved air flotation goes out the contained crude oil of part, the effluent cycle utilization after the air supporting, and the sewage flushing oily sludge after the electricity consumption air supporting, oil-polluted water electricity consumption dissolved air flotation again goes out crude oil;

2) will be promoted to stream curtain formula extraction tower through the oily sludge after the sewage flushing, the crude oil in the oily sludge dissolved fully with extractant;

Extraction conditions: temperature 10-80 ℃, extractant and greasy filth volume ratio are 1-15: 1; The extraction mode adopts batch (-type); Extractant is the mixture of 6# solvent naphtha and aromatic hydrocarbons, boiling point 60-150 ℃, or extractant is field condensate or benzinum;

2) will extract mixed liquor pumps into the settling tank natural subsidence and isolates oil phase and water;

3) oil phase is pumped into fractionating column, fractionate out extractant and crude oil;

4) washing of the silt particle after extraction back oil-containing reaches national stacking standard＜3000mg/kg, embathes water and after electric floating processing, can be recycled.

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