CN114804556B

CN114804556B - Non-stratified oil pit harmless treatment method and oil sludge fuel block prepared by same

Info

Publication number: CN114804556B
Application number: CN202210465414.6A
Authority: CN
Inventors: 薛岩
Original assignee: Harbin Gongda Huanneng Technology Co ltd
Current assignee: Harbin Gongda Huanneng Technology Co ltd
Priority date: 2019-07-05
Filing date: 2019-07-05
Publication date: 2023-03-17
Anticipated expiration: 2039-07-05
Also published as: CN110255838B; CN114804556A; CN110255838A

Abstract

The invention relates to a non-stratified oil pit harmless treatment method and an oil sludge fuel block prepared by the method. The method comprises the following steps: screening the homogeneous oily sludge to remove solid waste to obtain oily sludge; carrying out dehydration treatment on the oil sludge to obtain dehydrated oil sludge and oily wastewater, and carrying out oil-water separation on the oily wastewater to obtain waste oil and wastewater; carrying out sewage treatment on the wastewater; mixing the dehydrated oil sludge and the waste oil to obtain primary mixed oil sludge, adding an oil sludge modifier, and uniformly mixing to obtain pretreated oil sludge; the oil sludge modifier comprises 66.5 percent of auxiliary materials, 15 to 18 percent of curing agent, 5 to 7 percent of calcium oxide, 8.5 to 9.5 percent of bentonite and 1 to 2.5 percent of cement by mass percentage; and (3) placing the pretreated oil sludge at room temperature after molding to obtain the oil sludge fuel block. The invention can realize harmless, clean and resource treatment of the oil sludge in the non-layered oil pit, and the content of substances such as heavy metal, dioxin and the like which are leached from the fly ash of the combustion product of the prepared oil sludge fuel block is extremely low.

Description

Non-stratified oil pit harmless treatment method and sludge fuel block prepared by same

The application is a divisional application of patent applications with the application date of ' 7/5.2019, application number of ' 201910602549.0 ' and the invention name of ' a non-stratified oil pit harmless treatment method and an oil sludge fuel block prepared by the method '.

Technical Field

The invention relates to the technical field of oily sludge treatment, in particular to a non-stratified oil pit harmless treatment method and an oily sludge fuel block prepared by the method.

Background

With the development of the petroleum industry, the yield of the oily sludge is more and more. The oily sludge, namely oily silt, refers to a large amount of oily solid wastes generated in the processes of crude oil and natural gas exploration, exploitation, gathering, transportation, refining and the like, and is generally divided into oily sludge in oil fields and oily sludge generated in petrochemical industries (mainly oil refineries). The oily sludge of the oil field comprises the oily sludge on the ground generated in the oil field development process, the oily waste centralized stacked in an oil pit, the oily sludge generated at the bottom of a tank in the production operation of a combined station and the oily sludge generated in the operation of a sewage station.

The oily sludge refers to a mixture of various forms in which crude oil or product oil is mixed into soil or other media, oil content therein cannot be directly recovered and may cause environmental pollution, and the oily sludge is mainly generated in oil fields and oil refineries.

The oil-containing sludge generally has an oil content of about 15-20%, a water content of about 60-70% and a solid content of about 15-20%. The oily sludge is huge in volume, if the oily sludge is directly discharged without treatment, not only a large amount of cultivated land is occupied, but also the surrounding soil, water and air are polluted, along with the generation of malodorous gas, the sludge contains a large amount of pathogenic bacteria, parasites, heavy metals such as copper, zinc, chromium, mercury and the like, and also contains salts, polychlorinated biphenyl, dioxin, radioactive nuclides and other refractory toxic and harmful substances, and the wastes can influence the growth and development of crops, so that the toxic substances enter a food chain and influence the physical health of people. The treatment of oily sludge is always a difficult problem in the petroleum and petrochemical industry.

The oily sludge is a precious secondary resource, and if the oily sludge is not treated and is discharged randomly, the oily sludge causes huge damage to the environment and also causes huge waste to resources. With the increasingly strict and perfected environmental regulations, the harmless, clean and recycling treatment technology of the oily sludge becomes a necessary trend for the development of the sludge treatment technology.

The existing method for treating the oily sludge mainly comprises the following steps: incineration, coking, landfill, extraction, pyrolysis, solidification, chemical emulsion breaking, biological treatment, etc., which can recycle useful substances of oil sludge to some extent, but cause secondary environmental pollution and require a large investment in cost, and have problems of large investment in oil-containing sludge pit treatment and low treatment efficiency. Chinese patent application CN201710309039.5 discloses an oil sludge modifier and a method for converting modified oil sludge thereof into a novel regenerated solid fuel, wherein although the oil sludge can be subjected to chemical modification treatment, the oil sludge is converted into a solid fuel after the modification treatment, the regenerated solid fuel generated in the application has high content of leached heavy metals and generated toxic and harmful substances such as dioxin in fly ash generated after later combustion, and still has the problem of causing secondary pollution to the environment; fundamentally, the prior art does not achieve the harmless treatment and resource utilization of the oil sludge.

Aiming at the existing oily sludge pit with a plurality of oil-water sludge mixed and homogeneous phases, a harmless treatment method for modifying non-stratified oily sludge is very necessary to realize harmless treatment and resource utilization of the non-stratified oily sludge.

Disclosure of Invention

The invention aims to provide a non-stratified oil pit harmless treatment method and a sludge fuel block prepared by the non-stratified oil pit harmless treatment method, so as to solve the technical problems in the prior art. The method can treat the homogeneous oily sludge pit, can effectively separate the oily sludge to obtain dehydrated oil sludge and waste oil, reduces the pollution of oil to the waste water and solid wastes in the treatment process, effectively reduces the treatment load of the waste water, contributes to the design of the proportion of the calorific value and the forming of oil sludge fuel, and is favorable for improving the quality of resource products; meanwhile, the oil sludge obtained from the non-stratified oil sump is modified by the novel oil sludge modifier to prepare the oil sludge fuel block, the oil sludge modifier can realize harmless, clean and recycling treatment of the oil sludge in the non-stratified oil-containing sludge sump, and the oil sludge fuel block prepared by the oil sludge modifier through treatment has extremely low content of heavy metals leached by fly ash generated after combustion and toxic and harmful substances such as dioxin, and the like, does not need secondary treatment, and can completely reach the emission standard.

In order to achieve the above object, the present invention provides in a first aspect a method for innocent treatment of non-stratified oil pits, comprising the steps of:

(1) Screening the oily sludge in the non-layered oil pit to remove solid waste to obtain oily sludge;

(2) Performing dehydration treatment on the oil sludge obtained in the step (1) to obtain dehydrated oil sludge and oily wastewater, and then performing oil-water separation on the obtained oily wastewater to obtain waste oil and wastewater;

(3) Carrying out sewage treatment on the wastewater obtained in the step (2);

(4) Mixing the dehydrated oil sludge obtained in the step (2) with the waste oil to obtain primarily mixed oil sludge, and then adding an oil sludge modifier into the primarily mixed oil sludge and uniformly mixing to obtain pretreated oil sludge; the oil sludge modifier comprises 50-66.5% of auxiliary materials, 13-27.5% of curing agent, 3-10% of calcium oxide, 3-15% of bentonite and 0.3-5% of cement by mass percentage, wherein the auxiliary materials are agriculture and forestry organic waste and/or industrial solid waste;

(5) And (3) placing the pretreated oil sludge at room temperature after molding to obtain the oil sludge fuel block.

Preferably, the harmless treatment method of the non-stratified oil sump further comprises the step of cleaning the solid waste removed in the step (1) to obtain clean solid waste and waste oil water.

Preferably, the non-stratified oil pit innocent treatment method further comprises the steps of separating oil and water from the waste oil water to obtain oil and water, then subjecting the water to sewage treatment, and mixing the oil with the dehydrated oil sludge and the waste oil to obtain the initially mixed oil sludge.

Preferably, the water content of the dehydrated oil sludge is 5-25%; and/or the oil content of the primary oil sludge is 10-50%; and/or the mass ratio of the initial mixed oil sludge to the oil sludge modifier is 100: (5-20).

Preferably, the curing agent comprises 25 to 50% of methacryloyloxyethyl chloride, 10 to 30% of dimethyldiallyl chloride, 15 to 30% of acrylamide and 5 to 15% of carboxymethyl cellulose by mass percent.

Preferably, the oil sludge modifier comprises 66.5% of auxiliary materials, 15-18% of curing agents, 5-7% of calcium oxide, 8.5-9.5% of bentonite and 1-2.5% of cement in percentage by mass; the curing agent consists of, by mass, 40% of methacryloyloxyethyl chloride, 25% of dimethyldiallyl chloride, 25% of acrylamide and 10% of carboxymethyl cellulose.

Preferably, the agricultural and forestry organic waste is straw or rice husk; and/or the industrial solid waste is pulverized coal.

Preferably, the oil sludge modifier further comprises 0-5% of an oil absorbent by mass percent.

Preferably, the oil absorbent is a hydrogenated styrene-butadiene-styrene elastomer and/or high density polyethylene; and/or the content of the oil absorbent is 0.5 to 1.5 percent.

In a second aspect, the invention provides a sludged fuel block produced by the non-stratified oil pit decontamination process of the first aspect of the invention.

Compared with the prior art, the invention at least has the following beneficial effects:

(1) The non-layered oil pit harmless treatment method disclosed by the invention is wide in application range, small in treatment investment and high in treatment efficiency, can treat homogeneous oily sludge pits, can effectively separate oily sludge to obtain dehydrated oil sludge and waste oil, reduces oil pollution of waste water and solid wastes in a treatment process, effectively reduces the treatment load of the waste water, contributes to the design of the ratio of the calorific value of oil sludge fuel to the forming, and is favorable for improving the quality of resource products.

(2) The method can extract available components from homogeneous oil-containing sludge for producing the oil sludge fuel, improves the availability ratio of the oil-containing sludge, adopts a new oil sludge modifier to provide a new method for preparing the oil sludge fuel block by using oil sludge, relates to a harmless treatment method and a resource utilization process of oil sludge in a non-layered oil-containing sludge pit, and solves the problems of large investment and low treatment efficiency of the existing oil-containing sludge pit treatment.

(3) According to the invention, the oil sludge is modified into oil sludge fuel blocks (oil sludge coal), resources are recycled, and three purposes of environmental protection, energy conservation and emission reduction of oil sludge treatment and disposal are realized; the oil sludge contains petroleum components, and is converted into a solid gel structure after polymerization, so that the loss of the petroleum components is low, and the fuel effect of the oil sludge is good; the oily sludge coal converted from the polymerized oily sludge has good thermal stability and high burnout rate, and the environmental-friendly emission index is superior to that of coal burning; the sludge fuel block prepared by the invention has the basic characteristics of solid fuel: the material has a stable solid structure, is irreversible, and does not generate secondary argillization; the grain diameter is less than 4cm and less than the feeding caliber; the surface area is large, the contact surface with oxygen is large, and combustion is facilitated; the ignition temperature is about 270 ℃, the calorific value is more than 4000kcal/kg, and the dry ash-free base volatile fraction index is 92.98, so that the fuel belongs to an extremely easy stable region; the flammability discrimination index and the stable combustion discrimination index both belong to an extremely stable region.

(4) The process of converting the oil sludge into the oil sludge fuel block is operated and reacted at normal temperature and normal pressure; no waste water, waste gas and waste residue are generated in the treatment process; the whole process is safe and harmless, and has the advantages of simple operation, low investment, low requirement on environment and capability of realizing automatic production; meanwhile, the method has the advantages of small occupied area, short input period and quick response.

(5) The auxiliary material contained in the sludge modifier is agricultural and forestry organic waste and/or industrial solid waste which are hollow inside, so that the aim of resource recycling is fulfilled, the hollow structure of the auxiliary material can be used for increasing the specific surface area and the structural strength of the sludge fuel block, enabling the sludge fuel block to be easy to burn, and improving the calorific value of the prepared sludge fuel block, and in the invention, the addition of the auxiliary material can also make up for the defect that the combustion value of the sludge fuel block is reduced after the bentonite and the cement are added.

(6) The oil sludge modifier comprises bentonite and cement at the same time, the content proportion of the bentonite and the cement is reasonable, the content of heavy metals leached from fly ash or residues generated after the combustion of the oil sludge fuel block can be reduced to the maximum extent, and more importantly, the inventor finds that the content of toxic and harmful substances such as dioxin contained in the fly ash generated after the combustion of the oil sludge fuel block can be obviously reduced by matching the bentonite and the cement.

(7) The oil sludge modifier can completely realize harmless, clean and recycling treatment of the oil sludge in the non-stratified oil-containing sludge pit in the oil sludge modification treatment, and the fly ash generated after the combustion of the oil sludge fuel block prepared from the oil sludge treated by the oil sludge modifier has extremely low content of toxic and harmful substances such as leached heavy metal, dioxin and the like, and can be directly discharged without secondary treatment.

(8) In some preferred embodiments of the present invention, the components of the curing agent and the content of each component are optimized, and the inventors found that the curing agent in the present invention can significantly increase the adhesion effect of the oil sludge during the modification treatment process, can shorten the time for the curing reaction of the oil sludge at room temperature during the modification treatment process, and is beneficial to improving the efficiency of preparing the oil sludge fuel block.

Drawings

The drawings of the present invention are provided for illustrative purposes only, and the proportion and the number of the respective parts in the drawings do not necessarily correspond to those of an actual product.

FIG. 1 is a flow chart of a method for treating non-stratified oil puddles without harming the oil puddles according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a non-stratified sludge treatment system as used in one embodiment of the present invention.

In the figure: 1: a first sludge storage tank; 2: a screening device; 3: a second sludge storage tank; 4: a centrifuge; 5: a material storage tank; 6: an oil-water separator; 7: a sewage treatment facility; 8: an oil storage tank; 9: a blender; 10: an oil sludge modifier stirring tank; 11: a forming machine; 12: a dryer; 13: an exhaust gas purifier; 14: provided is a sewage treatment plant.

Detailed Description

To make the objects, technical solutions and advantages of the present invention clearer and more clear, the technical solutions of the present invention will be described clearly and completely in the following with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The invention provides in a first aspect a method for non-stratified oil pit innocent treatment, the method comprising the steps of:

(1) Screening the oily sludge in the non-layered oil pit to remove solid waste to obtain oily sludge; in the present invention, the non-stratified oil-containing sludge is also referred to as a non-stratified oil-containing sludge pit or a homogeneous oil-containing sludge pit; the oily sludge in the non-layered oil pit is non-layered oily sludge (homogeneous oily sludge) with homogeneous oil-water sludge.

(2) Performing dehydration treatment on the oil sludge obtained in the step (1) to obtain dehydrated oil sludge and oily wastewater, and then performing oil-water separation on the obtained oily wastewater to obtain waste oil and wastewater; preferably, the dehydrated sludge has a water content of 5 to 25% (e.g., 5%, 10%, 15%, 20%, or 25%).

(3) Carrying out sewage treatment on the wastewater obtained in the step (2); in the present invention, the wastewater may be subjected to the sewage treatment, for example, sequentially through a sewage treatment facility and/or a sewage treatment plant.

(4) Mixing the dehydrated oil sludge obtained in the step (2) with the waste oil to obtain primarily mixed oil sludge, and then adding an oil sludge modifier into the primarily mixed oil sludge and uniformly mixing to obtain pretreated oil sludge; the oil sludge modifier comprises 50-66.5% (such as 50%, 52.5%, 55%, 58.5%, 60%, 62.5%, 65% or 66.5%) of auxiliary materials, 13-27.5% (such as 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21%, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5%, 25%, 25.5%, 26%, 26.5%, 27% or 27.5%) of curing agents, 3-10% (such as 3%, 3.5%, 4%) of calcium oxide 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%), bentonite 3-15% (e.g., 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, or 15%) and cement 0.3-5% (e.g., 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%), the auxiliary materials are agricultural and forestry organic wastes and/or industrial solid wastes; in the present invention, the bentonite may be, for example, calcium bentonite; in the present invention, when the auxiliary materials consist of agricultural organic waste and industrial solid waste, the mass ratio of the agricultural organic waste to the industrial solid waste may be, for example, 1; in the present invention, it is preferable that the oil content of the initial oil sludge is 10 to 50% (e.g., 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%); in the present invention, it is preferable that the mass ratio of the initially mixed oil sludge to the sludge modifier is 100: (5-20) (e.g., 100; of course, in the present invention, the sludge modifier may only contain 100% of the auxiliary material, and when all the components contained in the sludge modifier are the auxiliary material, the mass ratio of the initial mixed sludge to the auxiliary material may be, for example, 100: (5-40).

(5) After the pre-treated oil sludge is formed, for example, the pre-treated oil sludge is placed at room temperature for 2 to 7 days (for example, 2, 3, 4, 5, 6 or 7 days), preferably 5 to 7 days, so as to prepare an oil sludge fuel block; in the invention, the oil sludge fuel block is placed at room temperature for 2-4 days, so that the water content of the oil sludge fuel block is not more than 10%; in the present invention, the water content of the dehydrated sludge, the oil content of the initially mixed sludge, the sludge modifier, and the blending ratio of the initially mixed sludge and the sludge modifier jointly determine the performance of the sludge fuel block, and when the water content of the dehydrated sludge, the oil content of the initially mixed sludge, and the blending ratio of the initially mixed sludge and the sludge modifier are the same, the performance of the sludge fuel block is determined by the sludge modifier.

The method can treat homogeneous-phase oily sludge pits, can effectively separate oily sludge to obtain dehydrated oily sludge and waste oil, can extract available components from the homogeneous-phase oily sludge for producing oily sludge fuel, improves the utilization rate of the oily sludge, reduces the oil pollution of the wastewater and solid wastes in the treatment process, effectively reduces the wastewater treatment load, contributes to the design of the ratio of the calorific value of the oily sludge fuel to the forming, and is favorable for improving the quality of resource products; meanwhile, the invention adopts a novel oil sludge modifier to modify oil sludge to prepare the oil sludge fuel block, the auxiliary material contained in the oil sludge modifier adopts agriculture and forestry organic waste and/or industrial solid waste which are hollow inside, the aim of resource recycling is achieved, the hollow structure of the auxiliary material can lighten the weight of the oil sludge fuel block, can increase the specific surface area and the structural strength of the oil sludge fuel block and enable the oil sludge fuel block to be easy to burn, the calorific value of the prepared oil sludge fuel block can be improved, and in the invention, the addition of the auxiliary material can also make up the defect that the burning value of the oil sludge fuel block is reduced after the bentonite and the cement are added, in the invention, the mass percentage of the auxiliary material in the oil sludge modifier is required to be as high as 50-66.5%, so that the defect that the burning value of the oil sludge fuel block is reduced after the bentonite and the cement are added can be effectively compensated; in the invention, the bentonite and the cement with proper proportion are added, so that the content of heavy metals leached from fly ash or residues generated after the combustion of the prepared oil sludge fuel block can be reduced to the maximum extent, and more importantly, the inventor surprisingly discovers that the content of toxic and harmful substances such as dioxin and the like in the fly ash generated after the combustion of the oil sludge fuel block can be obviously reduced by matching the bentonite and the cement with each other. The oil sludge modifier can completely realize harmless, clean and resource treatment of oil sludge in a non-stratified oil-containing sludge pit, and the content of heavy metals leached from fly ash generated after combustion of an oil sludge fuel block prepared by the treatment of the oil sludge modifier and the content of toxic and harmful substances such as dioxin are extremely low, secondary treatment is not needed, and the emission standard can be completely met.

According to some preferred embodiments, the method for harmless treatment of the non-stratified oil sump further comprises a step of washing (e.g. steam hot water washing) the solid waste removed in step (1) to obtain clean solid waste and waste oil water; preferably, the harmless treatment method of the non-stratified oil pit further comprises the step of burying the clean solid waste.

According to some preferred embodiments, the method for innocent treatment of a non-stratified oil sump further comprises the steps of subjecting the waste oil water to oil-water separation to obtain oil and water, then subjecting the water to sewage treatment and mixing the oil with the dehydrated sludge and the waste oil to obtain the initially mixed sludge; in the invention, preferably, the non-layered oil pit harmless treatment method can separate and recover the oil contained on the surface of the solid waste, so that the utilization rate of the oil in the oily sludge is improved, the problem that the oil contained in the solid waste pollutes the surrounding soil, water, air and the like is effectively avoided, and the removed solid waste can be directly buried; in the present invention, the oil is waste oil, and the water is waste water.

According to some preferred embodiments, the non-stratified oil sump innocent treatment method is carried out using a non-stratified sludge treatment system, for example as shown in fig. 2; the non-stratified oil sludge treatment system comprises a first sludge storage pool 1 for storing oil-containing sludge; a screening device 2 for removing solid waste contained in the oily sludge to obtain the oily sludge; the second sludge storage tank 3 is connected with the first sludge storage tank 1 through the screening device 2 and is used for collecting oil sludge; a centrifuge 4 (for example, a horizontal screw centrifuge) connected to the second sludge storage tank 3 for performing dehydration treatment on the oil sludge to obtain dehydrated oil sludge and oily wastewater; an oil-water separator 6 connected with the centrifuge 4 and used for carrying out oil-water separation on the oily wastewater; an oil storage tank 8 connected with the oil-water separator 6; a sewage treatment device 7 connected with the oil-water separator 6; the non-layering oil sludge treatment system further comprises an agitator 9 (such as a double-horizontal-shaft forced agitator), an oil sludge modifier stirring tank 10 for stirring and mixing an oil sludge modifier, and a forming machine 11 (such as a full-automatic forming machine) connected with the agitator 9; the centrifuge 4, the oil storage tank 8 and the sludge modifier stirring tank 10 are all connected with the stirrer 9; in the present invention, the stirrer 9 is used for uniformly mixing the oil content (waste oil) in the oil storage tank 8, the dehydrated oil sludge obtained by centrifugal dehydration of the oil sludge by the centrifuge 4, and the sludge modifier in the sludge modifier stirring tank 10 to obtain the pretreated oil sludge; in the present invention, it is preferable that the sewage treatment apparatus 7 is further connected to a sewage treatment plant 14; in the present invention, it is preferred that the non-stratified sludge treatment system is also in fluid communication with a waste gas cleaner 13; preferably, the waste gas purifier 13 is a low-temperature plasma waste gas purifier, and is configured to purify waste gas generated in the process of treating oily sludge by the non-stratified oil sludge treatment system, so that the purified waste gas can be directly discharged into the air; in the invention, preferably, the centrifuge is a centrifuge with a drying device, and the drying device is more favorable for reducing the water content in the dehydrated oil sludge, and can further ensure that the water content of the dehydrated oil sludge is reduced to 5-25%, so that the dehydrated oil sludge can achieve the purpose of adjusting the water content and the heat value when being subsequently applied to the production of oil sludge fuel, and the heat value of the oil sludge fuel can be greatly improved; when the non-stratified oil sludge treatment system further comprises the drying device (low-temperature drying mode), the drying device can be provided with a heat source by a gas-fired heat conduction oil boiler, so that the temperature of the dehydrated oil sludge is kept between 40 and 50 ℃.

In the present invention, the first sludge storage tank 1 is also referred to as an outdoor sludge storage tank when it is located outdoors, and the second sludge storage tank 3 and the oil storage tank 8 are also referred to as an indoor sludge storage tank and an indoor oil storage tank when they are located indoors, respectively. In the invention, the screening device 2 (such as a drum-type screening machine) separates massive solid waste in the oily sludge, and the separated oily sludge enters the second sludge storage tank 3; in the present invention, the connections between the components comprised in the non-stratified sludge treatment system may be connected, for example, by pipe connections or by conveying; in the present invention, the non-stratified sludge treatment system may include components for pumping the material to be treated, for example, with a pump as a power source; in the present invention, for example, the second sludge storage tank 3 pumps the collected oil sludge from the screening device 2 by using a pump as a power source, and the screening device 2 pumps the oil-containing sludge from the first sludge storage tank 1 by using a pump as a power source. In the present invention, the sludge modifier agitation tank 10 may be connected to, for example, a raw material tank, and each raw material component contained in the sludge modifier may be stored in a different raw material tank by an elevator or by direct transfer; in the present invention, the feed ratio of each raw material component of the sludge modifier may be integrally controlled by a computer, for example.

In the invention, the centrifuge 4 is used for dehydrating the oil sludge to obtain dehydrated oil sludge and oily wastewater, the oily wastewater is treated by the oil-water separator 6, the separated waste oil is temporarily stored in the oil storage tank 8 and then reused for production, the separated wastewater is treated by the sewage treatment equipment 7 and then is discharged into the sewage treatment plant 14 according to the water inlet index of the sewage treatment plant 14, the effluent of the sewage treatment plant 14 is subjected to the primary standard B standard of pollutant discharge Standard of urban Sewage treatment plant (GB 18918-2002), and finally the sewage containing body is Xinglong bubble.

According to some preferred embodiments, the non-stratified sludge treatment system further comprises a holding tank 5 for collecting solid waste, the holding tank 5 being connected to the screening device 2 and the decanter 6; the storage tank 5 is provided with a cleaning system for cleaning oil and water on the surface of the solid waste. In the present invention, the screening device 2 may be connected to the storage tank 5, for example, in a conveying manner; in the present invention, the cleaning system is used for steam hot water cleaning of solid waste, clean solid waste (clean solid waste) is transported to a landfill site by a transport vehicle for landfill, waste oil water (oily wastewater) from the cleaning is collected and pumped to the oil-water separator 6 for oil-water separation, oil (waste oil) separated is pumped to the oil storage tank 8, and water (wastewater) separated is pumped to the sewage treatment device 7. In the invention, the non-stratified oil sludge treatment system is preferably capable of separating and recovering the oil contained on the surface of the solid waste, so that the utilization rate of the oil contained in the oil-containing sludge is improved, the problem that the oil contained in the solid waste pollutes surrounding soil, water, air and the like is effectively avoided, and the removed solid waste can be directly buried.

According to some preferred embodiments, the non-stratified sludge treatment system further comprises a dryer 12 connected to the former 11; when the non-stratified oil sludge treatment system further comprises the dryer 12, the non-stratified oil sludge treatment system can convey the obtained pretreated oil sludge to a forming machine, the formed oil-containing sludge combustion block enters the dryer (a heat source is provided by a gas heat conduction oil boiler), is dried for 2 hours at a low temperature (45-50 ℃), is placed in a product storage area (a product warehouse) and stands for 12 hours, and for example, an oil sludge fuel block with a water content of which is finally removed to be below 5% can be obtained; in the present invention, it is preferable that the non-stratified oil sludge treatment system further includes a gas heat conduction oil boiler (for example, a 1000kW gas heat conduction oil boiler) for providing a heat source to the first sludge storage tank 1, the second sludge storage tank 3, the oil-water separator 6 and/or the oil storage tank 8, the stirrer 9 and/or the dryer 12; in the invention, the gas-fired heat conduction oil boiler is used for preserving the heat of the first sludge storage tank 1, the second sludge storage tank 3, the oil-water separator 6, the oil storage tank 8 and/or the stirrer 9, so that the temperature of oil and sludge can be kept at about 40 ℃; in the invention, the gas heat conduction oil boiler provides a heat source for the dryer 12, so that the temperature in the dryer 12 is kept at 45-50 ℃.

According to some preferred embodiments, the sewage treatment device 7 comprises a materialization triple box, an air flotation machine, a hydrolysis acidification box, a contact oxidation box and a sedimentation tank; the materialization triple box, the air flotation machine, the hydrolysis acidification box, the contact oxidation box and the sedimentation tank are connected in sequence; in the invention, the materialization triple box is connected with the oil-water separator 6, and the sedimentation tank is connected with the sewage treatment plant 14, so that the wastewater which is obtained by separating the oily wastewater through the oil-water separator 6 sequentially passes through the materialization triple box, the air flotation machine, the hydrolysis acidification box, the contact oxidation box and the sedimentation tank and then is discharged into the sewage treatment plant 14.

According to some preferred embodiments, a sieving device (not shown) is further arranged between the second sludge storage tank 3 and the centrifuge 4; in the present invention, the screening device is used for removing larger particle solid waste contained in the oil sludge; when the non-layered oil sludge treatment system comprises the sieving device, the sieving device is utilized to sieve out large-particle solid wastes in the oil sludge, then the sieved oil sludge is separated into oily wastewater and dehydrated oil sludge by a centrifuge 4, and the oily wastewater enters an oil-water separator 6 to separate the waste oil and the wastewater; in the present invention, the sieving means may be, for example, a sieving separation means having a sieve. In the present invention, it is preferable that the sieving device is further connected to the storage tank 5, so that the storage tank can also collect the solid waste sieved in the sieving device, and can utilize the cleaning system to clean the oil and water on the surface of the solid waste sieved from the sieving device, the oil and water (oily wastewater) washed off are also collected and pumped to the oil-water separator 6 for oil-water separation, the oil (waste oil) separated off is pumped to the oil storage tank 8, and the water (waste water) separated off is pumped to the sewage treatment device 7.

According to some preferred embodiments, the curing agent comprises, in mass percent, 25-50% (e.g., 25%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 48%, or 50%) methacryloyloxyethyl chloride (e.g., methacryloyloxyethyl trimethylammonium chloride), 10-30% (e.g., 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, or 30%) dimethyldiallyl chloride (e.g., dimethyldiallylammonium chloride), 15-30% (e.g., 15%, 18%, 20%, 22%, 25%, 28%, or 30%) acrylamide, and 5-15% (e.g., 5%, 8%, 10%, 12%, or 15%) carboxymethylcellulose.

The invention optimizes the components of the curing agent and the content of each component, and the inventor finds that the curing agent can obviously improve the adhesion effect of the oil sludge in the modification treatment process of the oil sludge, can shorten the time of curing reaction of the oil sludge at room temperature in the modification treatment process, and is beneficial to improving the preparation efficiency of the oil sludge fuel block. The present inventors have found that the bentonite and the cement of the present invention are well mixed with the components contained in the curing agent, and when the curing agent contains 25 to 50% by mass of methacryloyloxyethyl chloride, 10 to 30% by mass of dimethyldiallyl chloride, 15 to 30% by mass of acrylamide, and 5 to 15% by mass of carboxymethylcellulose, the bentonite and the cement can be made to have the best effect of reducing the content of heavy metals leached from fly ash or residues generated after combustion of sludge fuel blocks and the content of toxic and harmful substances such as dioxin in fly ash generated after combustion of sludge fuel blocks, and even if the simple components in the curing agent are changed, the performance of the sludge modifier in reducing the content of heavy metals leached from fly ash or residues and the content of toxic and harmful substances such as dioxin in fly ash can be adversely affected.

According to some preferred embodiments, the agricultural and forestry organic waste is straw or rice hulls.

According to some preferred embodiments, the industrial solid waste is pulverized coal.

According to some preferred embodiments, the sludge modifier comprises 66.5% by mass of an adjuvant, 15 to 18% by mass of a curing agent (e.g. 15%, 16%, 16.5%, 17%, 17.5% or 18%), 5 to 7% by mass of calcium oxide (e.g. 5%, 5.5%, 6%, 6.5% or 7%), 8.5 to 9.5% by mass of bentonite (e.g. 8.5%, 9% or 9.5%) and 1 to 2.5% by mass of cement (e.g. 1%, 1.5%, 2% or 2.5%); the curing agent consists of, by mass, 40% of methacryloyloxyethyl chloride, 25% of dimethyldiallyl chloride, 25% of acrylamide and 10% of carboxymethyl cellulose. The inventor obtains an optimal formula of the oil sludge modifier through a large number of thinking and creative tests, when the oil sludge modifier in the mass ratio is used for oil sludge modification treatment, the time of curing reaction of oil sludge at room temperature in the modification treatment process can be shortened, the preparation efficiency of an oil sludge fuel block is greatly improved, the prepared oil sludge fuel block has lower water content, higher fixed carbon content, higher calorific value (calorific value) and higher combustion efficiency, and meanwhile harmless, clean and resource treatment of the oil sludge in a layered oil-containing sludge pit can be better realized, so that the contents of toxic and harmful substances such as heavy metals leached from fly ash or residues (solid waste) generated after the combustion of the oil sludge fuel block and dioxin generation are lower; in the invention, the optimal formula of the oil sludge modifier consists of the following components in percentage by mass: 66.5 percent of auxiliary materials; 16.5 percent of curing agent; 6 percent of calcium oxide; 9% of bentonite; 2% of cement; the curing agent comprises the following components in percentage by mass: methacryloyloxyethyl chloride, 40%; 25% of dimethyldiallyl chloride; 25% of acrylamide; carboxymethyl cellulose, 10%.

According to some preferred embodiments, the sludge modifier further comprises 0-5% (e.g. 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%) by mass of an oil absorbing agent.

According to some preferred embodiments, the oil absorbent is a hydrogenated styrene-butadiene-styrene elastomer and/or a high density polyethylene, preferably the oil absorbent is formed from a blend of 1: (10-15) (e.g. 1; and/or the oil absorbent is present in an amount of 0.5 to 1.5% (e.g. 0.5%, 0.8%, 1%, 1.2% or 1.5%). The inventor finds that, in the invention, the oil absorbent is preferably added in a small amount of 0.5 to 1.5 percent, and the oil absorbent is preferably formed by mixing the following components in a mass ratio of 1: (10-15) (for example, 1, 11, 1, 12, 1, 13, 1. In the present invention, when the sludge modifier further comprises the oil absorbent, the optimal formulation of the sludge modifier consists of the following components in percentage by mass: 66.5 percent of auxiliary materials; 16.5 percent of curing agent; 6 percent of calcium oxide; 8.5 percent of bentonite; 2% of cement; oil absorbent, 0.5%; the curing agent comprises the following components in percentage by mass: methacryloyloxyethyl chloride, 40%; 25% of dimethyldiallyl chloride; 25% of acrylamide; carboxymethyl cellulose, 10%.

The invention will be further illustrated by way of example, but the scope of protection is not limited to these examples.

Example 1

(1) Screening the oily sludge in the non-layered oil pit to remove solid waste to obtain oily sludge; and carrying out dehydration treatment on the obtained oily sludge to obtain oily wastewater and dehydrated oil sludge with the water content of 15%, then carrying out oil-water separation on the obtained oily wastewater to obtain waste oil and wastewater, and carrying out sewage treatment on the obtained wastewater.

(2) Uniformly mixing the dehydrated oil sludge and the waste oil in the step (1) to obtain a primary mixed oil sludge with an oil content of 40%, and then adding an oil sludge modifier into the primary mixed oil sludge and uniformly mixing to obtain pretreated oil sludge; wherein the mass ratio of the initial mixed oil sludge to the oil sludge modifier is 100; the oil sludge modifier consists of 66.5 percent of auxiliary materials (straws), 16.5 percent of curing agent, 6 percent of calcium oxide, 9 percent of bentonite and 2 percent of cement in percentage by mass; the curing agent consists of 40 percent of methacryloyloxyethyl trimethyl ammonium chloride, 25 percent of dimethyl diallyl ammonium chloride, 25 percent of acrylamide and 10 percent of carboxymethyl cellulose in percentage by mass.

(3) And (3) feeding the pretreated oil sludge obtained in the step (2) into a brick making machine for molding, and standing at room temperature for 6 days to obtain the oil sludge fuel block.

The results of analyzing the coal quality of the sludge fuel block obtained in this example to obtain the water content and the calorific value (calorific value) of the sludge fuel block are shown in table 1; the contents of heavy metals leached from fly ash and residues, which are combustion products of the sludge fuel briquette, in the present example were measured, and the results are shown in tables 2 and 3, respectively; the dioxin content in the combustion product fly ash of the sludge fuel block in this example was measured, and the results are shown in table 4.

Example 2

Example 2 is essentially the same as example 1, except that:

in the step (2), the oil sludge modifier consists of 50% of auxiliary materials (straws), 27% of curing agent, 6% of calcium oxide, 12% of bentonite and 5% of cement in percentage by mass; the curing agent consists of 35 percent of methacryloyloxyethyl trimethyl ammonium chloride, 25 percent of dimethyl diallyl ammonium chloride, 25 percent of acrylamide and 15 percent of carboxymethyl cellulose in percentage by mass.

Example 3

Example 3 is essentially the same as example 1, except that:

in the step (2), the oil sludge modifier consists of 66.5 percent of auxiliary materials (straws), 16.5 percent of curing agent, 6 percent of calcium oxide, 8.5 percent of bentonite, 2 percent of cement and 0.5 percent of oil absorbent in percentage by mass; the curing agent consists of 40 percent of methacryloyloxyethyl trimethyl ammonium chloride, 25 percent of dimethyl diallyl ammonium chloride, 25 percent of acrylamide and 10 percent of carboxymethyl cellulose in percentage by mass; the oil absorbent consists of a hydrogenated styrene-butadiene-styrene elastomer and high-density polyethylene in a mass ratio of 1.

Example 4

Example 4 is essentially the same as example 3, except that:

the oil sludge modifier consists of 66.5 percent of auxiliary materials (straws), 16.5 percent of curing agent, 6 percent of calcium oxide, 8.5 percent of bentonite, 1.5 percent of cement and 1 percent of oil absorbent in percentage by mass; the oil absorbent consists of hydrogenated styrene-butadiene-styrene elastomer and high-density polyethylene in a mass ratio of 1.

Example 5

Example 5 is essentially the same as example 1, except that:

and (3) feeding the pretreated oil sludge obtained in the step (2) into a brick making machine for forming, and standing at room temperature for 3 days to obtain the oil sludge fuel block.

Comparative example 1

The comparative example is substantially the same as example 1 except that:

in the comparative example, the oil sludge modifier is prepared by mixing 31 mass percent of methacryloyloxyethyl trimethyl ammonium chloride copolymer, 14 mass percent of dimethyl diallyl ammonium chloride and acrylamide copolymer, 22 mass percent of sodium carboxymethyl cellulose and 33 mass percent of volcanic ash.

Comparative example 2

Comparative example 2 is substantially the same as comparative example 1 except that: and (3) feeding the obtained pretreated oil sludge into a brick making machine for molding, and standing at room temperature for 3 days to obtain the oil sludge fuel block.

Comparative example 3

Comparative example 3 is substantially the same as example 1 except that:

in the step (2), the curing agent consists of 46% of methacryloyloxyethyl trimethyl ammonium chloride copolymer, 21% of dimethyl diallyl ammonium chloride and 33% of sodium carboxymethyl cellulose in percentage by mass.

Table 1: the results of coal quality analysis of examples 1 to 5 and comparative examples 1 to 3.

Table 2: heavy metal content of fly ash leaching of sludge fuel briquette combustion products in examples 1 and 3 and comparative examples 1 and 3.

In table 2: ND represents that the detection result is smaller than the detection limit; the above samples were pretreated as required by HJ/T300-2007 acetic acid buffer solution method, a solid waste leaching toxicity leaching method.

Table 3: heavy metal content leached from the sludge fuel briquette combustion product residue in examples 1 and 3 and comparative examples 1 and 3.

In table 3: ND represents that the detection result is smaller than the detection limit; the above samples were pretreated as required by HJ/T300-2007 acetic acid buffer solution method, a solid waste leaching toxicity leaching method.

Table 4: dioxin content in fly ash of sludge fuel block combustion products in examples 1 and 3 and comparative examples 1 and 3.

Examples	Total amount of dioxins (PCDDs + PCDFs) (ugTEQ/kg)
		Example 1	0.077
Example 3	0.051
		Comparative example 1	3.61
Comparative example 3	2.42

Note: the pollution control standard GB 16889-2008 for the domestic garbage landfill site limits the content of dioxin to be lower than 3ug TEQ/kg.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A non-layered oil pit harmless treatment method is characterized by comprising the following steps:

(3) Carrying out sewage treatment on the wastewater obtained in the step (2);

(4) Mixing the dehydrated oil sludge obtained in the step (2) with the waste oil to obtain primarily mixed oil sludge, and then adding an oil sludge modifier into the primarily mixed oil sludge and uniformly mixing to obtain pretreated oil sludge; the oil sludge modifier comprises 66.5 percent of auxiliary materials, 15 to 18 percent of curing agent, 5 to 7 percent of calcium oxide, 8.5 to 9.5 percent of bentonite and 1 to 2.5 percent of cement in percentage by mass, wherein the auxiliary materials are agriculture and forestry organic wastes and/or industrial solid wastes; the curing agent consists of 40 mass percent of methacryloyloxyethyl trimethyl ammonium chloride, 25 mass percent of dimethyl diallyl ammonium chloride, 25 mass percent of acrylamide and 10 mass percent of carboxymethyl cellulose; the oil sludge modifier also comprises an oil absorbent with the mass percent of 0.5-1.5%; the oil absorbent consists of a hydrogenated styrene-butadiene-styrene elastomer and high-density polyethylene in a mass ratio of 1;

(5) And (3) placing the pretreated oil sludge at room temperature for 2-7 days after molding to obtain the oil sludge fuel block.

2. The non-stratified oil pit innocent treatment method according to claim 1, characterized in that:

the harmless treatment method of the non-layered oil pit further comprises the step of cleaning the solid waste removed in the step (1) to obtain clean solid waste and waste oil water.

3. The method for harmless treatment of non-stratified oil pits according to claim 2, characterized in that:

the non-layered oil pit harmless treatment method further comprises the steps of carrying out oil-water separation on the waste oil water to obtain oil and moisture, then carrying out sewage treatment on the moisture, and mixing the oil with the dehydrated oil sludge and the waste oil to obtain the primary mixed oil sludge.

4. The method for harmless treatment of non-stratified oil pits according to claim 1, characterized in that:

the water content of the dehydrated oil sludge is 5-25%; and/or

The oil content of the primary oil sludge is 10-50%; and/or

The mass ratio of the primary mixed oil sludge to the oil sludge modifier is 100: (5-20).

5. The method of innocent treatment of non-stratified oil pits according to any one of claims 1 to 4, characterized in that:

the agricultural and forestry organic waste is straw or rice husk; and/or

The industrial solid waste is pulverized coal.

6. An oil sludge fuel block produced by the non-stratified oil pit innocent treatment method of any one of claims 1 to 5.