阅读说明：本技术 一种含油污泥资源化处理方法 (Oily sludge recycling treatment method ) 是由 王新军 于 2021-07-26 设计创作，主要内容包括：本发明提供了一种含油污泥资源化处理方法,涉及危险废物处理技术领域。本发明将含油污泥进行脱水预处理,得到预处理油泥；将预处理油泥与改性剂混合进行油泥改性,得到改性油泥；将改性油泥进行深度脱水,得到脱水油泥；将脱水油泥造粒或却条后进行低温干化,得到干化污泥。本发明通过脱水预处理、深度脱水和低温干化使含油污泥的含水率降低至10～30％,通过油泥改性提高含油污泥的燃尽率,含油污泥经过处理后成为疏松、多孔、干燥的干化污泥,热值≥3000Kcal/kg,能够作为生物质燃料进行资源化利用。本发明提供的方法能够实现含油污泥的资源化、无害化处理,使含油污泥得到充分利用。(The invention provides a resource treatment method for oily sludge, and relates to the technical field of hazardous waste treatment. The method comprises the steps of carrying out dehydration pretreatment on oil-containing sludge to obtain pretreated oil sludge; mixing the pretreated oil sludge with a modifier to modify the oil sludge to obtain modified oil sludge; deeply dehydrating the modified oil sludge to obtain dehydrated oil sludge; and granulating or cooling the dehydrated oil sludge, and then drying at low temperature to obtain dried sludge. According to the invention, the moisture content of the oily sludge is reduced to 10-30% through dehydration pretreatment, deep dehydration and low-temperature drying, the burnout rate of the oily sludge is improved through oil sludge modification, the oily sludge becomes loose, porous and dry dried sludge after treatment, the calorific value is not less than 3000Kcal/kg, and the oily sludge can be used as biomass fuel for resource utilization. The method provided by the invention can realize resource and harmless treatment of the oily sludge, so that the oily sludge is fully utilized.)

1. A resource treatment method for oily sludge is characterized by comprising the following steps:

(1) carrying out dehydration pretreatment on the oily sludge to obtain pretreated oil sludge; the water content of the pretreated oil sludge is 75-80%;

(2) mixing the pretreated oil sludge with a modifier to modify the oil sludge to obtain modified oil sludge; the modifier comprises 10-40 wt% of demulsifier, 20-35 wt% of dispersant and the balance of flocculant;

(3) deeply dehydrating the modified oil sludge to obtain dehydrated oil sludge; the water content of the dehydrated oil sludge is 65-70%;

(4) granulating or cooling the dehydrated oil sludge, and then drying at low temperature to obtain dried sludge; the low-temperature drying temperature is 65-75 ℃; the water content of the dried sludge is 10-30%.

2. The method for recycling oily sludge according to claim 1, wherein the sludge concentration of the oily sludge in the step (1) is 0.2-3.0 wt%.

3. The method for recycling oily sludge according to claim 1, wherein the dehydration pretreatment in the step (1) is performed in a stack screw dehydrator.

4. The resource treatment method of the oily sludge according to claim 1, wherein the demulsifier in the step (2) is poly (methacryloyloxyethyl trimethyl ammonium chloride); the dispersant is volcanic ash; the flocculant is a mixture of a dimethyl diallyl ammonium chloride/acrylamide copolymer and sodium carboxymethyl cellulose, and the mass ratio of the dimethyl diallyl ammonium chloride/acrylamide copolymer to the sodium carboxymethyl cellulose is 5-30: 15-30.

5. The method for recycling the oily sludge according to claim 1 or 4, wherein the mass ratio of the pretreated oily sludge to the modifier in the step (2) is 100: 5-15.

6. The method for recycling oily sludge as claimed in claim 1 or 4, wherein the mixing in the step (2) is performed in a gravity-free mixing agitator.

7. The method for recycling oily sludge according to claim 1 or 4, wherein the mixing time in the step (2) is 1-3 min.

8. The method for recycling oily sludge according to claim 1, wherein the deep dehydration in the step (3) is performed in a high-pressure belt filter press.

9. The method for recycling the oily sludge according to claim 1, wherein the low-temperature drying in the step (4) is performed in a drying machine.

10. The method for recycling the oily sludge according to claim 1 or 9, wherein the heat value of the dried sludge in the step (4) is more than or equal to 3000Kcal/kg, the burn-out rate in 2min is more than or equal to 97%, the burn-out time is less than or equal to 5min, the ash content is less than 20%, and the ignition temperature is more than or equal to 268 ℃; the dried sludge is used as biomass fuel.

Technical Field

The invention relates to the technical field of hazardous waste treatment, in particular to a resource treatment method for oily sludge.

Background

The oily sludge is a concomitant product of petroleum production, is one of main pollution sources of petroleum production, and is a great problem influencing the quality of oil fields and surrounding environments. The oily sludge is an extremely stable suspended emulsion system, the composition of the oily sludge is extremely complex, and the oily sludge contains a large amount of aged crude oil, wax, asphaltene, colloid, suspended solid, bacteria, salts, acidic gas, corrosion products, heavy metals and the like, and the oily sludge has an oil content of 10-50% and a water content of 40-90% in total. At present, the annual production amount of oily sludge in China reaches more than 300 million tons, the annual production of oily sludge in three oil fields of Daqing, Shengli and Liaohe is about 200 million tons, the annual production of oil fields in Xinjiang is 4-5 million tons, and the stockpiling amount is about 22 million tons.

The oily sludge may have certain influence on the environment if discharged without being treated: if the material is stored in the open air, hydrocarbon substances such as petroleum and the like volatilize, and the quality of the atmospheric environment is affected; surface water quality may be affected by surface runoff if adjacent to the surface. China pays more attention to the discharge of oily sludge, and at present, the oily sludge which is not treated is clearly regulated and willingly discharged to be subject to a certain amount of fine, so that the problem can not be fundamentally solved although the discharge of partial pollutants is limited. In recent years, researchers have conducted a great deal of research on the treatment technology of oily sludge, but from the viewpoint of end treatment, the resource utilization of oily sludge cannot be achieved or the degree of resource utilization is low.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for recycling oily sludge, which can realize the recycling and harmless treatment of oily sludge, so as to make full use of the oily sludge.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a resource treatment method of oily sludge, which comprises the following steps:

(1) carrying out dehydration pretreatment on the oily sludge to obtain pretreated oil sludge; the water content of the pretreated oil sludge is 75-80%;

(2) mixing the pretreated oil sludge with a modifier to modify the oil sludge to obtain modified oil sludge; the modifier comprises 10-40 wt% of demulsifier, 20-35 wt% of dispersant and the balance of flocculant;

(3) deeply dehydrating the modified oil sludge to obtain dehydrated oil sludge; the water content of the dehydrated oil sludge is 65-70%;

(4) granulating or cooling the dehydrated oil sludge, and then drying at low temperature to obtain dried sludge; the low-temperature drying temperature is 65-75 ℃; the water content of the dried sludge is 10-30%.

Preferably, the sludge concentration of the oily sludge in the step (1) is 0.2-3.0 wt%.

Preferably, the dehydration pretreatment in the step (1) is performed in a stack screw dehydrator.

Preferably, the demulsifier in step (2) is polymethacryloxyethyltrimethyl ammonium chloride; the dispersant is volcanic ash; the flocculant is a mixture of a dimethyl diallyl ammonium chloride/acrylamide copolymer and sodium carboxymethyl cellulose, and the mass ratio of the dimethyl diallyl ammonium chloride/acrylamide copolymer to the sodium carboxymethyl cellulose is 5-30: 15-30.

Preferably, the mass ratio of the pretreated oil sludge to the modifier in the step (2) is 100: 5-15.

Preferably, the mixing in step (2) is performed in a gravity-free mixing blender.

Preferably, the mixing time in the step (2) is 1-3 min.

Preferably, the deep dewatering in step (3) is carried out in a high pressure belt filter press.

Preferably, the low-temperature drying in the step (4) is performed in a drying machine.

Preferably, the heat value of the dried sludge in the step (4) is more than or equal to 3000Kcal/kg, the burnout rate in 2min is more than or equal to 97%, the burnout time is less than or equal to 5min, the ash content is less than 20%, and the ignition temperature is more than or equal to 268 ℃; the dried sludge is used as biomass fuel.

The invention provides a resource treatment method of oily sludge, which comprises the following steps: (1) carrying out dehydration pretreatment on the oily sludge to obtain pretreated oil sludge; the water content of the pretreated oil sludge is 75-80%; (2) mixing the pretreated oil sludge with a modifier to modify the oil sludge to obtain modified oil sludge; the modifier comprises 10-40 wt% of demulsifier, 20-35 wt% of dispersant and the balance of flocculationAn agent; (3) deeply dehydrating the modified oil sludge to obtain dehydrated oil sludge; the water content of the dehydrated oil sludge is 65-70%; (4) granulating or cooling the dehydrated oil sludge, and then drying at low temperature to obtain dried sludge; the low-temperature drying temperature is 65-75 ℃; the water content of the dried sludge is 10-30%. According to the method, the water content of the oily sludge is reduced to 10-30% through dehydration pretreatment, deep dehydration and low-temperature drying, the burnout rate of the oily sludge can be improved by adding a modifier to modify the oily sludge, the oily sludge is treated by the method provided by the invention to become loose, porous and dry dried sludge, the heat value is more than or equal to 3000Kcal/kg, and the sludge can be used as biomass fuel for resource utilization. Moreover, the burnout rate of combustible substances of the obtained dried sludge is more than or equal to 97 percent in 2min, and the burnout rate of combustible substances of coal is only 56 percent; the burnout time of the obtained dried sludge is less than or equal to 5min, most organic components are decomposed after incineration, the ash content is less than 20%, and coal can be burnt out after more than 10 min; meanwhile, NO generated by combustion of the obtained dried sludge_X、SO₂The emission indexes of pollutants such as HCl and flue gas are superior to those of coal; in addition, the ignition characteristic of the obtained dried sludge belongs to an extremely easy stable region, the ignition temperature is more than or equal to 268 ℃, and the dried sludge is safe to store and transport. The method provided by the invention can realize the recycling and harmless treatment of the oily sludge, so that the oily sludge is fully utilized; the method provided by the invention is simple, efficient, low in energy consumption and low in cost.

Detailed Description

The invention provides a resource treatment method of oily sludge, which comprises the following steps:

(1) carrying out dehydration pretreatment on the oily sludge to obtain pretreated oil sludge; the water content of the pretreated oil sludge is 75-80%;

(2) mixing the pretreated oil sludge with a modifier to modify the oil sludge to obtain modified oil sludge; the modifier comprises 10-40 wt% of demulsifier, 20-35 wt% of dispersant and the balance of flocculant;

(3) deeply dehydrating the modified oil sludge to obtain dehydrated oil sludge; the water content of the dehydrated oil sludge is 65-70%;

(4) granulating or cooling the dehydrated oil sludge, and then drying at low temperature to obtain dried sludge; the low-temperature drying temperature is 65-75 ℃; the water content of the dried sludge is 10-30%.

According to the invention, the oily sludge is subjected to dehydration pretreatment to obtain the pretreated oil sludge. The present invention does not require a particular source for the oily sludge, and oily sludge from sources well known to those skilled in the art are suitable for use in the present invention. In the invention, the sludge concentration of the oily sludge is preferably 0.2-3.0 wt%; the invention controls the sludge concentration of the oily sludge within the range, thereby ensuring the subsequent dehydration performance of the oily sludge and improving the dehydration efficiency on one hand, and ensuring that the oily sludge has enough fluidity and stability on the other hand. In the present invention, the dehydration pretreatment is preferably performed in a stack screw dehydrator; the invention has no special requirements on the stacked spiral dehydrator, and the stacked spiral dehydrator known by the technical personnel in the field can be adopted. In the invention, the water content of the pretreated oil sludge is 75-80%; in the specific implementation process, the oily sludge can be directly dewatered to the water content of 75-80% by a spiral-stacked dewatering machine; alternatively, the oily sludge having a high water content may be dehydrated by a screw-stacking dehydrator, and then the dehydrated oily sludge may be mixed with the oily sludge having a low water content to adjust the water content of the mixed oily sludge to 75 to 80%, for example, the oily sludge having a high water content, such as scum produced by a sewage treatment plant and excess activated sludge, may be dehydrated by a screw-stacking machine, and then mixed with the oily sludge having a low water content, such as tank bottom sludge and falling sludge. In an embodiment of the invention, the pretreated oil sludge is temporarily stored in a sludge hopper.

After the pretreated oil sludge is obtained, the pretreated oil sludge is mixed with a modifier for modifying the oil sludge to obtain modified oil sludge. In the invention, the modifier comprises 10-40 wt% of demulsifier, 20-35 wt% of dispersant and the balance of flocculant, and further preferably comprises 20-35 wt% of demulsifier, 20-25 wt% of dispersant and the balance of flocculant. In the present invention, the demulsifier is preferably polymethacryloxyethyltrimethyl ammonium chloride; the dispersant is preferably volcanic ash; the flocculating agent is preferably a mixture of dimethyl diallyl ammonium chloride/acrylamide copolymer and sodium carboxymethyl cellulose, and the mass ratio of the dimethyl diallyl ammonium chloride/acrylamide copolymer to the sodium carboxymethyl cellulose is preferably 5-30: 15-30, and more preferably 20-30: 15-25. The sources of the demulsifier, the deflocculant and the flocculant are not particularly required in the present invention and may be commercially available or prepared by methods well known to those skilled in the art. In the invention, the mass ratio of the pretreated oil sludge to the modifier is preferably 100: 5-15, and more preferably 100: 8-12. In the present invention, the mixing is preferably carried out in a gravity-free mixing blender; the present invention does not require a gravity-free blender, as is well known to those skilled in the art, and in particular embodiments of the present invention, the pre-treated sludge held in the sludge hopper is preferably transported to the gravity-free blender via a shaftless screw conveyor for blending. In the present invention, the mixing time is preferably 1 to 3min, and more preferably 2 min. The oil-containing sludge is seriously emulsified and presents a highly emulsified viscous liquid in the form of water-in-oil and oil-in-water, the pretreated oil sludge is mixed with the modifier, and the dispersant in the modifier can lighten the weight of the oil sludge fuel block, increase the specific surface area of the oil sludge fuel block and enable the oil sludge fuel block to be easily combusted; after the demulsifier and the flocculant in the modifier react with the oil sludge, the heat productivity of the oil sludge is improved, and the fly ash in the combustion process is obviously reduced; the pretreated oil sludge is modified by oil sludge to generate a substance with good combustion performance.

After the modified oil sludge is obtained, the modified oil sludge is subjected to deep dehydration to obtain dehydrated oil sludge. In the present invention, the deep dewatering is preferably carried out in a high-pressure belt filter press; the invention has no special requirements on the high-pressure belt filter press, and can adopt corresponding equipment well known by the technical personnel in the field; in a specific embodiment of the invention, the modified oil sludge is conveyed to the high-pressure belt filter press by a gravity-free mixing stirrer through a belt or a flood dragon conveying device. In the invention, the water content of the dehydrated oil sludge is 65-70%; meanwhile, the reaction time of the oil sludge and the modifier is further prolonged in the deep dehydration process, so that the modification of the oil sludge is fully carried out.

After the dehydrated oil sludge is obtained, the dehydrated oil sludge is granulated or cooled and then dried at low temperature to obtain dried sludge. The present invention does not require any particular method for granulation or slugging, and may be carried out by granulation or slugging methods known to those skilled in the art, such as granulation or slugging of the dewatered sludge by means of a granulation or slugging apparatus. In the invention, the low-temperature drying temperature is preferably 65-75 ℃, namely the peripheral temperature of the dehydrated oil sludge is kept at 65-75 ℃, so that most of water in the oil sludge can be effectively separated, and the safety and reliability of the oil sludge drying process can be ensured. In the invention, the low-temperature drying is preferably carried out in a drying machine, and the drying machine has no special requirement and can be a drying machine well known by a person skilled in the art; the specific process of the low-temperature drying is preferably as follows: the dehydrated oil sludge enters a mesh belt transmission device of a drying machine, a mesh belt continuously works, dry hot air is fed from the bottom of the mesh belt (the air supply temperature is 65-75 ℃), moisture in the dehydrated oil sludge is continuously vaporized after absorbing heat, a large amount of saturated vapor is brought back to the top of the mesh belt, the hot air is circulated from the top to an evaporator of the drying machine (the air return temperature is 40-60 ℃), and vapor (evaporated vapor, volatile organic gas and the like) is collected and discharged in a condensation dehumidification mode; at the moment, the water vapor with low saturation is heated to 65-75 ℃ through a condenser of the drier, is changed into dry high-temperature hot air, is sent back to the bottom of the mesh belt, and enters periodic circulation, wherein the whole period is 90-120 min, so that the purposes of drying and dewatering the sludge are achieved; in the low-temperature drying process, the latent heat of water vaporization in the oil sludge is equal to the latent heat of water condensation, and no external heat needs to be introduced in the drying process.

In the invention, the water content of the dried sludge is 10-30%. In the invention, the dried sludge is loose, porous and dry, has a unit heat value of more than or equal to 3000Kcal/kg, and can be used as biomass fuel for resource utilization. Moreover, the burnout rate of combustible substances of the obtained dried sludge is more than or equal to 97 percent in 2min, while coal can be usedThe burnout rate of the fuel is only 56%; the burnout time of the obtained dried sludge is less than or equal to 5min, most organic components are decomposed after incineration, the ash content is less than 20%, and coal can be burnt out after more than 10 min; meanwhile, NO generated by combustion of the obtained dried sludge_X、SO₂The emission indexes of pollutants such as HCl and flue gas are superior to those of coal; in addition, the ignition characteristic of the obtained dried sludge belongs to an extremely easy stable region, the ignition temperature is more than or equal to 268 ℃, and the dried sludge is safe to store and transport. In the present invention, the dried sludge is preferably used as a biomass fuel.

The method provided by the invention can realize the recycling and harmless treatment of the oily sludge, so that the oily sludge is fully utilized; the method provided by the invention is simple, efficient, low in energy consumption and low in cost.

The method for recycling oily sludge according to the present invention will be described in detail with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1

The oil-containing sludge is scum, the water content is 77.23%, the oil content is 20.12%, and the slag content (mainly sludge and other impurities) is 2.65 wt%. The method for recycling the oily sludge comprises the following steps:

pumping oily sludge to a screw-stacking dehydrator from a sludge pump for dehydration pretreatment, wherein the water content of the pretreated oil sludge obtained after screw-stacking dehydration is 75.1%, and temporarily storing the pretreated oil sludge in a sludge hopper;

conveying the pretreated oil sludge to a gravity-free mixing stirrer through a shaftless screw conveyor, conveying the modifier to the gravity-free mixing stirrer through a shafted screw conveyor, and mixing and modifying the modifier and the pretreated oil sludge (the mixing time is 2.5min) to obtain modified oil sludge; the modifier comprises the following components: the method comprises the following steps of (1) taking polymethacryloxyethyltrimethyl ammonium chloride (32 wt%) as a demulsifier, taking dimethyldiallylammonium chloride/acrylamide copolymer (28 wt%) and sodium carboxymethyl cellulose (19 wt%) as flocculants, taking volcanic ash (21 wt%) as a dispersion agent, and taking the mass ratio of pretreated oil sludge to a modifier as 100: 12;

conveying the modified oil sludge to a high-pressure belt filter press through a belt for deep dehydration to obtain dehydrated oil sludge, wherein the water content of the dehydrated oil sludge is 66%;

after being granulated by a granulating device, the dewatered oil sludge is conveyed into an oil sludge low-temperature drying machine by a shaftless screw conveyor for drying treatment: the granulated oil sludge enters a mesh belt transmission device of a drier, a mesh belt continuously works, dry hot air is fed from the bottom of the mesh belt (the air supply temperature is 70 ℃), moisture in the sludge is continuously vaporized after absorbing heat, a large amount of saturated vapor is brought back to the top of the mesh belt, the hot air is circulated from the top to an evaporator of the drier (the air return temperature is 58 ℃), and the moisture is collected and discharged in a condensation dehumidification mode; at the moment, the water vapor with lower saturation is heated to 75 ℃ through a condenser of the drier to become hot air with high drying temperature, the hot air is sent back to the bottom of the mesh belt to enter periodic circulation, the purpose of drying and dehydrating the sludge is achieved, the dried sludge is finally obtained, the water content is 26%, and the tail gas generated in the drying process can enter a tail gas treatment device through a fan to be subjected to advanced treatment.

The obtained dried sludge is a loose and porous substance, and the obtained dried sludge is tested, wherein the content of solid combustible substances is 19.74% (determined according to GB/T213-1996' method for measuring calorific value of coal), the content of ash is 19.784%, the content of fixed carbon is 15.474%, the content of volatile substances is 52.311%, the calorific value is 4822Kcal/kg, the burnout ratio is 98.5% in 2min, the burnout time is 4.8min, and the ignition temperature is 271 ℃, so that the obtained dried sludge can be used as solid biomass fuel for resource utilization.

Example 2

The oil-containing sludge is tank bottom oil sludge, the water content is 78.55%, the oil content is 19.78%, and the slag content (mainly sludge and other impurities) is 1.67 wt%. The method for recycling the oily sludge comprises the following steps:

pumping oily sludge to a screw-stacking dehydrator from a sludge pump for dehydration pretreatment, wherein the water content of the pretreated oil sludge obtained after screw-stacking dehydration is 75.8%, and temporarily storing the pretreated oil sludge in a sludge hopper;

conveying the pretreated oil sludge to a gravity-free mixing stirrer through a shaftless screw conveyor, conveying the modifier to the gravity-free mixing stirrer through a shafted screw conveyor, and mixing and modifying the modifier and the pretreated oil sludge (the mixing time is 2.6min) to obtain modified oil sludge; the modifier comprises the following components: polymethyl acryloyloxyethyl trimethyl ammonium chloride (31 wt%) is a demulsifier, dimethyl diallyl ammonium chloride/acrylamide copolymer (28 wt%) and sodium carboxymethyl cellulose (20 wt%) are flocculants, volcanic ash (21 wt%) is a dispersion agent, and the mass ratio of the pretreated oil sludge to the modifier is 100: 10;

conveying the modified oil sludge to a high-pressure belt filter press through a belt for deep dehydration to obtain dehydrated oil sludge, wherein the water content of the dehydrated oil sludge is 65.5%;

after being granulated by a granulating device, the dewatered oil sludge is conveyed into an oil sludge low-temperature drying machine by a shaftless screw conveyor for drying treatment: the granulated oil sludge enters a mesh belt transmission device of a drier, a mesh belt continuously works, dry hot air is fed from the bottom of the mesh belt (the air supply temperature is 68 ℃), moisture in the sludge is continuously vaporized after absorbing heat, a large amount of saturated vapor is brought back to the top of the mesh belt, the hot air is circulated from the top to an evaporator of the drier (the air return temperature is 59 ℃), and the moisture is collected and discharged in a condensation dehumidification mode; at the moment, the water vapor with lower saturation is heated to 74 ℃ through a condenser of the drier to become hot air with high drying temperature, the hot air is sent back to the bottom of the mesh belt to enter periodic circulation, the purpose of drying and dehydrating the sludge is achieved, the dried sludge is finally obtained, the water content is 22%, and the tail gas generated in the drying process can enter a tail gas treatment device through a fan to be subjected to advanced treatment.

The obtained dried sludge is a loose and porous substance, and tests on the obtained dried sludge show that the content of solid combustible substances is 18.24%, the content of ash is 19.98%, the content of fixed carbon is 9.37%, the content of volatile components is 52.41%, the heat value is 4908Kcal/kg, the burnout rate is 97.9% in 2min, the burnout time is 4.9min, and the ignition temperature is 268 ℃, so that the obtained dried sludge can be used as a solid biomass fuel for resource utilization.

The embodiment shows that the method provided by the invention can realize the resource and harmless treatment of the oily sludge, so that the oily sludge is fully utilized; the method provided by the invention is simple, efficient, low in energy consumption and low in cost.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.