Pyrolysis gasification sludge incineration process

Abstract

The application discloses a pyrolysis gasification sludge incineration process, comprising the following steps: S1, pretreating oily sludge, and crushing straw; S2, putting the pretreated oily sludge, the crushed straw particles and calcium oxide powder into a mixer to be fully mixed to obtain a mixture; S3, putting the mixture obtained in the step S2 into a pyrolysis furnace to be subjected to anaerobic or anoxic pyrolysis treatment by taking potassium-modified ZSM-5 molecular sieve particles as an ex-situ pyrolysis catalyst; S4, performing condensation treatment on the pyrolysis gas obtained in the step S3 after purification, wherein liquid products are aromatic hydrocarbon oil, which is recycled and reused, and gaseous products are non-condensable gas, which is subjected to incineration treatment; and S5, recycling the pyrolysis solid product obtained in the step S3 to be reused as biomass charcoal. The application has a high resource recycling rate, can pyrolyze, gasify and recycle aromatic hydrocarbon oil, has a good overall economic benefit, and the catalyst can be repeatedly used, and basically no secondary pollution is caused.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solid waste treatment, in particular to a pyrolysis gasification sludge incineration process. BACKGROUND

[0002] Oil-containing sludge is a kind of special sludge, which mainly comes from the process of crude oil extraction, transportation, storage and refining, including tank bottom sludge, floor sludge, pool bottom sludge and refining sludge. Oil-containing sludge is an emulsion system composed of 20-80% of crude oil, 5-85% of water and 5-50% of solid particles, often containing aged crude oil, petroleum hydrocarbons, pathogens, acid gases, corrosive products and other toxic and harmful substances. In addition, during the processing of oil, flocculants, corrosion inhibitors, demulsifiers and other chemical additives are introduced, resulting in extremely complex composition. Oil-containing sludge has the characteristics of high viscosity, stable emulsification and difficult demulsification, and has been listed as a dangerous waste. It is a kind of solid waste that is difficult to handle and has great harm. Although oil-containing sludge is a dangerous waste, the oil phase contained in it is also a recyclable resource.

[0003] At present, a variety of treatment technologies for oil-containing sludge have been developed at home and abroad, including solidification, solvent extraction, bioremediation, incineration, pyrolysis, ultrasonic treatment, supercritical water treatment, etc. Among the above-mentioned numerous existing treatment technologies for oil-containing sludge, pyrolysis treatment has the advantages of high treatment efficiency, significant volume and mass reduction, and resource recycling, and is widely used in the treatment of oil-containing sludge. Pyrolysis treatment refers to a process in which oil-containing sludge is heated to a certain temperature under anoxic or hypoxic atmosphere, and organic matter is decomposed. The existing pyrolysis process of oil-containing sludge is divided into catalytic pyrolysis and ordinary pyrolysis. Catalytic pyrolysis is a pyrolysis process in which oil-containing sludge is heated to above 400℃ under the action of a catalyst, while ordinary pyrolysis is a pyrolysis process in which oil-containing sludge is heated to above 500℃. The products of the two processes are residual solid material, non-condensable gas and pyrolysis oil; the difference lies only in the composition of non-condensable gas and pyrolysis oil. Catalytic pyrolysis process can modify the gas produced by the action of catalyst, thereby changing the composition of non-condensable gas and pyrolysis oil.

[0004] However, the existing pyrolysis process also has a series of defects. Ordinary pyrolysis process has uncontrollable products, high pyrolysis temperature, high energy consumption, poor overall economic benefit and low resource recycling rate. Catalytic pyrolysis process has difficulty in recovering catalysts, and most of them use metal oxides as catalysts, which can cause secondary pollution. SUMMARY

[0005] In order to solve the above at least one technical problem, a sludge treatment process with high resource recycling rate, which can pyrolysis, gasification, recycling and preparation of aromatic oil, has good overall economic benefit, and basically no secondary pollution is developed, the application provides a pyrolysis gasification sludge incineration process.

[0006] The application provides a pyrolysis gasification sludge incineration process, comprising the following steps:

[0007] S1, the oil sludge is pretreated to a water content of 40% or less, and the straw is crushed to a particle size of 5mm or less;

[0008] S2, the oil sludge pretreated in step S1 and the crushed straw particles, and the calcium oxide powder, are mixed in a mass ratio of 65-70% of oil sludge, 25-30% of straw, and 5-10% of calcium oxide, and are fully mixed in a mixer to obtain a mixture;

[0009] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace, and potassium modified ZSM-5 molecular sieve particles are used as non-in-situ pyrolysis catalyst for anaerobic or anoxic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 5-10℃ / min to 180-200℃, then heating at a rate of 12-18℃ / min to 500-560℃, and then keeping the temperature at 500-560℃ for 10-30min; pyrolysis gas and pyrolysis solid product are obtained;

[0010] S4, the pyrolysis gas obtained in step S3 is purified and then condensed, the liquid product obtained by condensation is aromatic oil, which is recycled and reused, and the gaseous product obtained by condensation is non-condensable gas, which is incinerated and the heat is recovered for heating the pyrolysis furnace;

[0011] S5, the pyrolysis solid product obtained in step S3 is recycled and reused as biomass charcoal.

[0012] Optionally, in step S1, the oil sludge is pretreated to a water content of 30-35%, and the straw is crushed to a particle size of 1-3mm.

[0013] Further optionally, in step S1, the pretreatment of the oil sludge is carried out by heating and dewatering.

[0014] Further optionally, the heating temperature is controlled to be within 105℃.

[0015] Optionally, in step S2, the particle size of the calcium oxide powder is 50-500μm.

[0016] Optionally, in step S3, the preparation of potassium modified ZSM-5 molecular sieve particles comprises the following steps:

[0017] Sa, the potassium modified ZSM-5 molecular sieve, kaolin and anhydrous ethanol are mixed according to the mass ratio of 8:2:1-2 to prepare a mud;

[0018] Sb, the mud obtained in step Sa is placed in a granulator to prepare particles with a particle size of 2-10 mm;

[0019] Sc, the particles obtained in step Sb are placed in a vacuum furnace and calcined at a temperature of 560-580 DEG C to obtain potassium modified ZSM-5 molecular sieve particles.

[0020] Optionally, in the step S3, the pyrolysis furnace adopts the following structure: the pyrolysis furnace comprises a furnace body, the furnace body is provided with a raw material inlet, a pyrolysis gas conveying pipe for discharging pyrolysis gas and a protective gas input pipe for inputting protective gas, the furnace body is provided with a sludge loading area, and a catalytic bed is fixedly arranged in the area between the sludge loading area and the pyrolysis gas conveying pipe in the furnace body, the catalytic bed adopts a porous ceramic shell filled with potassium modified ZSM-5 molecular sieve particles.

[0021] Optionally, in the step S3, the pyrolysis treatment is carried out under nitrogen protection.

[0022] Further optionally, the input flow rate of the nitrogen is 120-140 mL / min.

[0023] Optionally, in the step S5, as a reutilization of the biomass charcoal, the biomass charcoal is used to prepare a biomass fuel by mixing with biomass raw materials, used as a biomass charcoal adsorbent and used as a soil conditioner for acid soil.

[0024] In summary, the present application has the following at least one beneficial technical effect:

[0025] 1. The present application adopts the process design of co-pyrolysis of oily sludge and straw, and calcium oxide powder is mixed as an in-situ pyrolysis catalyst, which can effectively improve the pyrolysis efficiency, change the composition of the gasification mixed gas, and further improve the yield of the pyrolysis oil phase product and improve the quality of the pyrolysis oil phase product; in addition, the use of calcium oxide as an in-situ pyrolysis catalyst can help the removal of water from the oily sludge, reduce the activation energy required for pyrolysis, promote the conversion of heavy organic matter to light organic matter, and the mixing of a small amount of calcium oxide in the solid product biomass charcoal obtained by pyrolysis can help the application of biomass charcoal in the field of soil conditioner, and will not cause secondary pollution to the environment.

[0026] 2. The application adopts a process combining in-situ catalytic pyrolysis and non-in-situ catalytic pyrolysis, uses calcium oxide as the catalyst for in-situ pyrolysis, and uses porous potassium-modified ZSM-5 molecular sieve particles as the catalyst for non-in-situ catalytic pyrolysis. The two catalytic modes are used in combination to promote the deoxygenation and dehydrogenation of the oily sludge and the generation of aromatic groups, greatly improve the yield of aromatic oil, and reduce the yield of low-benefit non-condensable gas.

[0027] 3. The application uses oily sludge and straw as raw materials, converts most of them into high-quality biomass charcoal and aromatic oil through pyrolysis for recycling, and incinerates the remaining small amount of non-condensable gas for recycling the incineration heat, has a high resource recycling rate, has good product quality, and has very excellent overall economic benefits.

[0028] 4. The process of the application can effectively reduce the volume of oily sludge, effectively reduce the emission of hazardous waste, and has a low yield of non-condensable gas, which can greatly reduce the emission of waste gas and effectively reduce environmental pollution. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a process flow diagram of the pyrolysis gasification sludge incineration process of the application;

[0030] Figure 2 It is an electron microscope image of the biomass charcoal obtained in Example 1 of the application;

[0031] Figure 3 It is a structural schematic diagram of the pyrolysis furnace used in the application;

[0032] In the figure: 1, furnace body; 2, sludge loading area; 3, catalytic bed; 4, raw material inlet; 5, pyrolysis gas conveying pipe; 6, protective gas input pipe. DETAILED DESCRIPTION

[0033] The application will be further described in detail below in combination with the drawings and examples.

[0034] As shown in the drawings, Figure 1 The application designs a pyrolysis gasification sludge incineration process, which includes the following steps:

[0035] S1, pretreat the oily sludge to a moisture content of 40% or less, and pulverize the straw to a particle size of 5 mm or less;

[0036] S2, mix the pretreated oily sludge and the pulverized straw particles of step S1, and the calcium oxide powder according to the mass fraction of 65-70% of oily sludge, 25-30% of straw, and 5-10% of calcium oxide, in a mixer to obtain a mixture;

[0037] S3, placing the mixture obtained in step S2 into a pyrolysis furnace, and performing anaerobic or anoxic pyrolysis treatment on the mixture by using the potassium-modified ZSM-5 molecular sieve particles as an ex-situ pyrolysis catalyst; the pyrolysis process is as follows: heating at a heating rate of 5-10℃ / min to 180-200℃, then heating at a heating rate of 12-18℃ / min to 500-560℃, and then keeping the temperature at 500-560℃ for 10-30min; pyrolysis gas and a pyrolysis solid product are obtained;

[0038] S4, purifying the pyrolysis gas obtained in step S3, and then performing condensation treatment on the pyrolysis gas; the liquid product obtained by condensation is an aromatic oil, which can be recycled and reused; the gaseous product obtained by condensation is non-condensable gas, which can be incinerated to recover heat for heating the pyrolysis furnace;

[0039] S5, recycling the pyrolysis solid product obtained in step S3 for reuse as a biomass charcoal.

[0040] The potassium-modified ZSM-5 molecular sieve particles of the present application can be prepared by using a potassium-modified ZSM-5 molecular sieve powder as a raw material and by using the following steps:

[0041] Sa, mixing the potassium-modified ZSM-5 molecular sieve, kaolin and anhydrous ethanol in a mass ratio of 8:2:1-2 to prepare a mud;

[0042] Sb, placing the mud obtained in step Sa into a granulator to prepare particles with a particle size of 2-10mm;

[0043] Sc, placing the particles obtained in step Sb into a vacuum furnace, and vacuum calcining the particles at a temperature of 560-580℃ to prepare the potassium-modified ZSM-5 molecular sieve particles.

[0044] In order to ensure that the prepared potassium-modified ZSM-5 molecular sieve particles have a high specific surface area and a low breakage rate, in step Sc, the vacuum calcining is performed by using the following process: heating at a heating rate of 4-8℃ to 220-240℃, then heating at a heating rate of 8-12℃ / min to 560-580℃, and then keeping the temperature at 560-580℃ for more than 2h, and finally cooling the furnace to room temperature.

[0045] The following are preparation examples and examples of the present application

[0046] The main reagents used in the preparation examples and examples of the present application are as follows:

[0047] Straw: corn straw collected in Hubei; calcium oxide powder: 100-400μm, purchased from Jingzhou Yinjie Chemical Co., Ltd.; potassium-modified ZSM-5 molecular sieve: potassium element loading of 2%, purchased from Zibo Julong Chemical Technology Co., Ltd.; anhydrous ethanol, purchased from Wuhan Beiguofeng Chemical Co., Ltd.

[0048] Preparation Example 1

[0049] The preparation of the potassium modified ZSM-5 molecular sieve particles of the present preparation example comprises the following steps:

[0050] Sa, the potassium modified ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 50, kaolin and anhydrous ethanol are fully mixed in a mass ratio of 8:2:2 to configure into a mud;

[0051] Sb, the mud obtained in step Sa is placed in a granulator to form particles with a particle size of 2-10 mm;

[0052] Sc, the particles obtained in step Sb are placed in a vacuum furnace, and heated to 230℃ at a heating rate of 5℃, then heated to 580℃ at a heating rate of 10℃ / min, and then kept at 580℃ for 2.5h, and finally cooled to room temperature by furnace cooling, to obtain the potassium modified ZSM-5 molecular sieve particles.

[0053] Preparation Example 2

[0054] The preparation of the potassium modified ZSM-5 molecular sieve particles of the present preparation example comprises the following steps:

[0055] Sa, the potassium modified ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 100, kaolin and anhydrous ethanol are fully mixed in a mass ratio of 8:2:2 to configure into a mud;

[0056] Sb, the mud obtained in step Sa is placed in a granulator to form particles with a particle size of 2-10 mm;

[0057] Sc, the particles obtained in step Sb are placed in a vacuum furnace, and heated to 230℃ at a heating rate of 5℃, then heated to 580℃ at a heating rate of 10℃ / min, and then kept at 580℃ for 2.5h, and finally cooled to room temperature by furnace cooling, to obtain the potassium modified ZSM-5 molecular sieve particles.

[0058] Preparation Example 3

[0059] The preparation of the potassium modified ZSM-5 molecular sieve particles of the present preparation example comprises the following steps:

[0060] Sa, the potassium modified ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 200, kaolin and anhydrous ethanol are fully mixed in a mass ratio of 8:2:2 to configure into a mud;

[0061] Sb, the mud obtained in step Sa is placed in a granulator to form particles with a particle size of 2-10 mm;

[0062] Sc, the granules obtained in step Sb are placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5h, and finally cooled to room temperature in the furnace, to obtain the potassium-modified ZSM-5 molecular sieve granules.

[0063] Preparation Example 4

[0064] The preparation of the potassium-modified ZSM-5 molecular sieve granules in this preparation example includes the following steps:

[0065] Sa, the potassium-modified ZSM-5 molecular sieve powder with a Si / Al ratio of 300, kaolin and anhydrous ethanol are thoroughly mixed in a mass ratio of 8:2:2 to prepare a mud;

[0066] Sb, the mud obtained in step Sa is placed in a granulator to prepare granules with a particle size of 2-10mm;

[0067] Sc, the granules obtained in step Sb are placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5h, and finally cooled to room temperature in the furnace, to obtain the potassium-modified ZSM-5 molecular sieve granules.

[0068] Preparation Example 5

[0069] The preparation of the potassium-modified ZSM-5 molecular sieve granules in this preparation example includes the following steps:

[0070] Sa, the potassium-modified ZSM-5 molecular sieve powder with a Si / Al ratio of 25, kaolin and anhydrous ethanol are thoroughly mixed in a mass ratio of 8:2:2 to prepare a mud;

[0071] Sb, the mud obtained in step Sa is placed in a granulator to prepare granules with a particle size of 2-10mm;

[0072] Sc, the granules obtained in step Sb are placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5h, and finally cooled to room temperature in the furnace, to obtain the potassium-modified ZSM-5 molecular sieve granules.

[0073] Comparative Example 1

[0074] The preparation of the potassium-modified ZSM-5 molecular sieve granules in this preparation example includes the following steps:

[0075] Sa, the ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 25, kaolin and anhydrous ethanol were mixed in a mass ratio of 8:1:3 to form a mud;

[0076] Sb, the mud obtained in step Sa was placed in a granulator to form particles with a particle size of 2-10 mm;

[0077] Sc, the particles obtained in step Sb were placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5 h, and finally cooled to room temperature by furnace cooling, to obtain potassium-modified ZSM-5 molecular sieve particles.

[0078] Comparative Example 2

[0079] The preparation of the potassium-modified ZSM-5 molecular sieve particles of the present comparative example includes the following steps:

[0080] Sa, the ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 25, kaolin and anhydrous ethanol were mixed in a mass ratio of 8:1:3 to form a mud;

[0081] Sb, the mud obtained in step Sa was placed in a granulator to form particles with a particle size of 2-10 mm;

[0082] Sc, the particles obtained in step Sb were placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5 h, and finally cooled to room temperature by furnace cooling, to obtain potassium-modified ZSM-5 molecular sieve particles.

[0083] Comparative Example 3

[0084] The preparation of the potassium-modified ZSM-5 molecular sieve particles of the present comparative example includes the following steps:

[0085] Sa, the ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 25, kaolin and anhydrous ethanol were mixed in a mass ratio of 8:1:3 to form a mud;

[0086] Sb, the mud obtained in step Sa was placed in a granulator to form particles with a particle size of 2-10 mm;

[0087] Sc, the particles obtained in step Sb were placed in a vacuum furnace, and heated to 230°C at a heating rate of 5°C, then heated to 580°C at a heating rate of 10°C / min, and then kept at 580°C for 2.5 h, and finally cooled to room temperature by furnace cooling, to obtain potassium-modified ZSM-5 molecular sieve particles.

[0088] Comparative Example 4

[0089] The preparation of the potassium-modified ZSM-5 molecular sieve particles of the present comparative example comprises the following steps:

[0090] Sa, potassium-modified ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 25, kaolin and anhydrous ethanol were mixed in a mass ratio of 8:2:2 to form a mud;

[0091] Sb, the mud obtained in step Sa was placed in a granulator to form particles with a particle size of 2-10 mm;

[0092] Sc, the particles obtained in step Sb were placed in a vacuum furnace, and heated to 230°C at a heating rate of 10°C, then heated to 580°C at a heating rate of 15°C / min, and then kept at 580°C for 2.5 h, and finally cooled to room temperature by furnace cooling, to obtain potassium-modified ZSM-5 molecular sieve particles.

[0093] Comparative Example 5

[0094] The preparation of the potassium-modified ZSM-5 molecular sieve particles of the present comparative example comprises the following steps:

[0095] Sa, potassium-modified ZSM-5 molecular sieve powder with a silicon-aluminum ratio of 25, kaolin and anhydrous ethanol were mixed in a mass ratio of 8:2:2 to form a mud;

[0096] Sb, the mud obtained in step Sa was placed in a granulator to form particles with a particle size of 2-10 mm;

[0097] Sc, the particles obtained in step Sb were placed in a vacuum furnace, and heated to 230°C at a heating rate of 10°C, then heated to 580°C at a heating rate of 15°C / min, and then kept at 580°C for 2.5 h, and finally cooled to room temperature by furnace cooling, to obtain potassium-modified ZSM-5 molecular sieve particles.

[0098] The potassium-modified ZSM-5 molecular sieve particles prepared in Preparation Examples 1-5 and the potassium-modified ZSM-5 molecular sieve particles prepared in Comparative Examples 1-5 were detected for particle breakage rate, and the specific surface area was detected by N2 adsorption instrument, and the results are shown in Table 1 below.

[0099] Table 1 Detection results of Preparation Examples 1-5 and Comparative Examples 1-5

[0100] Fragmentation rate (%) Specific surface area (m 2 / g) Preparation Example 1 Less than 1% 277.6 Preparation Example 2 Less than 1% 276.2 Preparation Example 3 Less than 1% 274.6 Preparation Example 4 Less than 1% 272.7 Preparation Example 5 Less than 1% 278.4 Comparative Example 1 7.8％ 286.8 Comparative Example 2 Less than 1% 179.2 Comparative Example 3 Less than 1% 255.6 Comparative Example 4 5.7％ 274.3 Comparative Example 5 1.9％ 259.8

[0101] As can be seen from the data in Table 1, the specific process steps and raw material ratio adopted in the present application for preparing the potassium-modified ZSM-5 molecular sieve particles can effectively prevent the particles from being broken during the preparation process, and a particle-type catalyst with a large specific surface area can be obtained.

[0102] The following are examples of the present application

[0103] As Figure 3 shown, the pyrolysis furnace used in the pyrolysis of oily sludge in the present embodiment adopts the following structure: a furnace body 1 is provided with a raw material inlet 4, a pyrolysis gas conveying pipe 5 for discharging pyrolysis gas, and a protective gas input pipe 6 for inputting protective gas. A sludge loading area 2 is provided in the furnace body 1, and a catalytic bed 3 is fixedly arranged in the area directly above the sludge loading area 2 in the furnace body 1, which completely separates the sludge loading area 2 from the pyrolysis gas conveying pipe 5. The catalytic bed 3 adopts a porous ceramic shell filled with potassium-modified ZSM-5 molecular sieve particles.

[0104] The oily sludge sample used in the examples of the present application is dehydrated oily sludge from Shengli Oilfield, with a water content of 32.4% and an oil content of 15.8%.

[0105] Example 1

[0106] The pyrolysis and gasification of sludge incineration process in the present embodiment includes the following steps:

[0107] S1, the straw is crushed to a particle size of 4-5 mm;

[0108] S2, the oily sludge and the crushed straw particles, and the calcium oxide powder are mixed in a mixer according to the mass fraction of 65% oily sludge, 30% straw, and 5% calcium oxide to obtain a mixture;

[0109] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: the temperature is raised to 180℃ at a rate of 5℃ / min, then the temperature is raised to 500℃ at a rate of 12℃ / min, and then the temperature is kept at 500℃ for 30 min; pyrolysis gas and pyrolysis solid products are obtained; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to the preparation example 1;

[0110] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then subjected to condensation treatment; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the heat for heating the pyrolysis furnace;

[0111] S5, the pyrolysis solid product obtained in step S3 is recovered to obtain biomass charcoal.

[0112] The treatment process of examples 2-5 of the present application is basically the same as example 1, the only difference is the different potassium modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace. The treatment process of examples 2-5, the potassium modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace, respectively uses the particles prepared by preparation examples 2-5.

[0113] Example 6

[0114] The pyrolysis gasification sludge incineration process of the present embodiment comprises the following steps:

[0115] S1, the straw is crushed to a particle size of 4-5 mm;

[0116] S2, the oil-containing sludge and the crushed straw particles, and the calcium oxide powder, are mixed in a mass ratio of 65% oil-containing sludge, 30% straw, and 5% calcium oxide, and are placed in a mixer for thorough mixing to obtain a mixture;

[0117] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 10℃ / min to 200℃, then heating at a rate of 18℃ / min to 560℃, and then keeping the temperature at 560℃ for 10 min; obtaining pyrolysis gas and pyrolysis solid product; the potassium modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace uses the particles prepared by preparation example 1;

[0118] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then subjected to condensation treatment; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the incineration heat for heating the pyrolysis furnace;

[0119] S5, the pyrolysis solid product obtained in step S3 is recovered to obtain biomass charcoal.

[0120] Example 7

[0121] The pyrolysis gasification sludge incineration process of the present embodiment comprises the following steps:

[0122] S1, the straw is crushed to a particle size of 4-5 mm;

[0123] S2, the oil-containing sludge and the crushed straw particles, and the calcium oxide powder, are mixed in a mass ratio of 65% oil-containing sludge, 30% straw, and 5% calcium oxide, and are placed in a mixer for thorough mixing to obtain a mixture;

[0124] S3, placing the mixture obtained in step S2 into a pyrolysis furnace to perform anoxic pyrolysis treatment; the pyrolysis process is as follows: heating at a heating rate of 8℃ / min to 195℃, then heating at a heating rate of 16℃ / min to 540℃, and then keeping the temperature at 540℃ for 30 min; obtaining pyrolysis gas and pyrolysis solid products; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to the preparation example 1;

[0125] S4, after dust removal and purification of the pyrolysis gas obtained in step S3, performing condensation treatment; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated, and the incineration heat is recovered for heating of the pyrolysis furnace;

[0126] S5, recovering the pyrolysis solid product obtained in step S3 to obtain biomass charcoal.

[0127] Example 8

[0128] The pyrolysis and gasification of sludge incineration process of the present example includes the following steps:

[0129] S1, crushing the straw to a particle size of 1-3 mm;

[0130] S2, placing the oily sludge, the crushed straw particles, and the calcium oxide powder into a blender according to a mass ratio of 65% oily sludge, 30% straw, and 5% calcium oxide, and mixing them thoroughly to obtain a mixture;

[0131] S3, placing the mixture obtained in step S2 into a pyrolysis furnace to perform anoxic pyrolysis treatment; the pyrolysis process is as follows: heating at a heating rate of 8℃ / min to 195℃, then heating at a heating rate of 16℃ / min to 540℃, and then keeping the temperature at 540℃ for 30 min; obtaining pyrolysis gas and pyrolysis solid products; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to the preparation example 1;

[0132] S4, after dust removal and purification of the pyrolysis gas obtained in step S3, performing condensation treatment; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated, and the incineration heat is recovered for heating of the pyrolysis furnace;

[0133] S5, recovering the pyrolysis solid product obtained in step S3 to obtain biomass charcoal.

[0134] Comparative Example 6

[0135] The pyrolysis and gasification of sludge process of the present comparative example includes the following steps:

[0136] S1, crushing the straw to a particle size of 5 mm or less;

[0137] S2, the oily sludge and the crushed straw, and the in-situ catalyst, are mixed in a mixer according to the mass fraction of 65% oily sludge, 30% straw, and 5% in-situ catalyst to obtain a mixture; the in-situ catalyst is prepared by mixing titanium white and ferrous sulfate according to a mass ratio of 1:1;

[0138] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating to 195℃ at a heating rate of 8℃ / min, then heating to 540℃ at a heating rate of 16℃ / min, and then keeping the temperature at 540℃ for 30 min; pyrolysis gas and pyrolysis solid products are obtained; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to the preparation example 1;

[0139] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then condensed; the liquid product obtained by condensation is pyrolysis oil which is recovered; the gaseous product obtained by condensation is non-condensable gas which is incinerated to recover the incineration heat for heating the pyrolysis furnace;

[0140] S5, the pyrolysis solid product obtained in step S3 is recovered to obtain biomass charcoal.

[0141] Comparative Example 7

[0142] The sludge pyrolysis and gasification process of the present comparative example comprises the following steps:

[0143] S1, the straw is crushed to a particle size of less than 5 mm;

[0144] S2, the oily sludge and the crushed straw, and the calcium oxide powder, are mixed in a mixer according to the mass fraction of 65% oily sludge, 30% straw, and 5% calcium oxide powder to obtain a mixture;

[0145] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating to 195℃ at a heating rate of 8℃ / min, then heating to 540℃ at a heating rate of 16℃ / min, and then keeping the temperature at 540℃ for 30 min; pyrolysis gas and pyrolysis solid products are obtained; no non-in-situ catalyst is arranged in the pyrolysis furnace;

[0146] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then condensed; the liquid product obtained by condensation is pyrolysis oil which is recovered; the gaseous product obtained by condensation is non-condensable gas which is incinerated to recover the incineration heat for heating the pyrolysis furnace;

[0147] S5, the pyrolysis solid product obtained in step S3 is recovered to obtain biomass charcoal.

[0148] Comparative Example 8

[0149] The pyrolysis gasification sludge incineration process of the present comparative example comprises the following steps:

[0150] S1, crushing the straw to a particle size of 1-3 mm;

[0151] S2, the oil-containing sludge and the crushed straw particles are mixed in a mixer according to a mass ratio of 70% oil-containing sludge, 30% straw, to obtain a mixture;

[0152] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 12℃ / min to 720℃, then heating at a rate of 5℃ / min to 600℃, and then keeping the temperature at 600℃ for 120 min; pyrolysis gas and pyrolysis solid products are obtained; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to the preparation example 1;

[0153] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then subjected to condensation treatment; the liquid product obtained by condensation is pyrolysis oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the incineration heat for heating the pyrolysis furnace;

[0154] S5, the pyrolysis solid product obtained in step S3 is recovered to obtain biomass charcoal.

[0155] Comparative Example 9

[0156] The pyrolysis gasification sludge incineration process of the present comparative example comprises the following steps:

[0157] S1, crushing the straw to a particle size of 1-3 mm;

[0158] S2, the oil-containing sludge and the crushed straw particles, as well as the calcium oxide powder, are mixed in a mixer according to a mass ratio of 65% oil-containing sludge, 30% straw, and 5% calcium oxide, to obtain a mixture;

[0159] S3, the mixture obtained in step S2 is placed in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 8℃ / min to 195℃, then heating at a rate of 16℃ / min to 540℃, and then keeping the temperature at 540℃ for 30 min; pyrolysis gas and pyrolysis solid products are obtained; the ex-situ catalyst in the pyrolysis furnace is zinc-modified ZSM-5 molecular sieve with a zinc element content of 2% and a silicon-aluminum ratio of 50;

[0160] S4, the pyrolysis gas obtained in step S3 is purified by dust removal and then subjected to condensation treatment; the liquid product obtained by condensation is pyrolysis oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the incineration heat for heating the pyrolysis furnace;

[0161] S5, recovering the pyrolysis solid product obtained in step S3 to obtain the biochar.

[0162] Process treatment effect detection:

[0163] Using the processes of embodiments 1-8 of the present application, and the processes of comparative examples 6-9, each 100 kg of oily sludge sample was treated, and the mass of the oil phase product, the mass of the non-condensable gas, the content of aromatic oil in the oil phase product, and the total carbon content and specific surface area of the biochar were detected.

[0164] Among them, the detection of the content of aromatic oil in the oil phase product was detected by the method recorded in SH / T 0118-1992 "Determination of aromatic hydrocarbon content in solvent oil";

[0165] The detection of the total carbon content of the biochar was detected by the method recorded in GB / T 28734-2012 "Determination of carbon and hydrogen in solid biomass fuel";

[0166] The specific surface area of the biochar was detected by the method recorded in GB / T 7702.20-2008 "Test method for coal particle activated carbon".

[0167] The detection results are shown in Table 2 below.

[0168] Table 2 Detection results of embodiments 1-8 and comparative examples 6-9

[0169] Oil phase (kg) Non-condensable gas (kg) Aromatic content (%) Total carbon (%) Specific surface area (m 2 / g) Example 1 14.8 1.25 91.4 72.3 24.6 Example 2 14.5 1.28 90.7 71.9 23.2 Example 3 14.1 1.32 89.6 71.4 22.1 Example 4 13.7 1.38 88.1 71.6 20.7 Example 5 15.0 1.12 92.1 71.5 25.4 Example 6 14.8 1.23 91.5 72.4 25.1 Example 7 14.9 1.20 91.7 72.7 24.8 Example 8 14.9 1.16 91.7 72.8 25.7 Comparative Example 6 12.2 3.42 66.2 73.8 13.4 Comparative Example 7 10.3 3.29 21.4 74.5 14.2 Comparative Example 8 9.2 4.58 74.6 75.2 10.6 Comparative Example 9 11.8 4.26 37.1 76.4 16.9

[0170] From the data in Table 1, the data of embodiments 1-8 and the data of comparative examples 6-9 can be seen that after the oily sludge is treated by the process of embodiments 1-8 of the present application, the mass of the oil phase obtained is significantly higher than that of the process of comparative examples 6-9, the mass of the non-condensable gas obtained is significantly lower than that of the process of comparative examples 6-9, and the content of aromatic hydrocarbon in the oil phase is also higher, and the quality is better; In addition, after the oily sludge is treated by the process of embodiments 1-8 of the present application, the total carbon content of the biochar obtained is slightly lower than that of the process of comparative examples 6-9, but the specific surface area of the biochar is significantly larger, and the quality is relatively better. Therefore, by using a specific catalyst and combining in-situ catalysis and non-in-situ catalysis, the oil recovery rate of the oily sludge can be greatly improved, the amount of non-condensable gas can be greatly reduced, the recovered oil product is aromatic oil with better quality, and better economic benefits can be obtained.

[0171] From the data in Table 1, it can be seen from the comparison of the data of Examples 1-5 that the lower the silica-alumina ratio of the potassium-modified ZSM-5 molecular sieve used in the process of the application, the better the process effect. It can be seen that the potassium-modified ZSM-5 molecular sieve particles used in the potassium-modified ZSM-5 molecular sieve particles of the application should have a silica-alumina ratio of less than 100.

[0172] The applicant also conducted electron microscope detection on the biomass char obtained by the process of Example 1 of the application, and the detection results are shown in Figure 2 Figure 2 It can be seen that the biomass char obtained by the process of Example 1 of the application has relatively rich pores and a relatively high porosity.

[0173] And from the detection data of the biomass char of Examples 1-8 in Table 1, it can be seen that the biomass char obtained by the process of the application has a relatively high specific surface area and a total carbon content of more than 70%. It can be seen that the biomass char obtained by the process of the application has excellent adsorption performance and also has a certain calorific value. Therefore, the biomass char obtained by the application can be used as an adsorbent, or can be blended with biomass raw materials to prepare biomass fuel.

[0174] The applicant further improved the process of the application in order to further improve the quality of the pyrolysis products. The following are Examples 9-14 of the application.

[0175] Example 9

[0176] The pyrolysis gasification sludge incineration process of this example includes the following steps:

[0177] S1, crushing the straw to a particle size of 1-3 mm;

[0178] S2, mixing the oil-containing sludge, the crushed straw particles, and the calcium oxide powder in a mass ratio of 65% oil-containing sludge, 25% straw, and 10% calcium oxide in a mixer to obtain a mixture;

[0179] S3, placing the mixture obtained in step S2 in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 8℃ / min to 195℃, then heating at a rate of 16℃ / min to 540℃, and then maintaining the temperature at 540℃ for 30 min; obtaining pyrolysis gas and pyrolysis solid products; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is the particle prepared in Preparation Example 5;

[0180] S4, purifying the pyrolysis gas obtained in step S3 by dust removal, and then condensing the purified gas; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the incineration heat for heating the pyrolysis furnace; ​

[0181] S5, recovering the pyrolysis solid product obtained in step S3 to obtain the biomass charcoal.

[0182] Example 10

[0183] The difference between this example and example 9 is that in step S2, the oil-containing sludge, straw and calcium oxide are mixed in a mass ratio of 70%, 25% and 5% respectively.

[0184] Example 11

[0185] The difference between this example and example 9 is that in step S2, the oil-containing sludge, straw and calcium oxide are mixed in a mass ratio of 66%, 26% and 8% respectively.

[0186] Example 12

[0187] The pyrolysis gasification sludge incineration process of this example comprises the following steps:

[0188] S1, crushing the straw to a particle size of 1-3 mm;

[0189] S2, mixing the oil-containing sludge, crushed straw particles and calcium oxide powder in a mass ratio of 66%, 26% and 8% respectively in a mixer to obtain a mixture;

[0190] S3, placing the mixture obtained in step S2 in a pyrolysis furnace for anaerobic pyrolysis treatment; the pyrolysis process is as follows: heating at a rate of 8℃ / min to 195℃, then heating at a rate of 16℃ / min to 540℃, and then keeping the temperature at 540℃ for 30 min; obtaining pyrolysis gas and pyrolysis solid product; the pyrolysis treatment is carried out under nitrogen protection, specifically: evacuating the air in the pyrolysis furnace with nitrogen before pyrolysis, continuously inputting nitrogen into the pyrolysis furnace during the pyrolysis process, and the input flow rate of nitrogen is 120 mL / min; the potassium-modified ZSM-5 molecular sieve particle catalyst in the pyrolysis furnace is prepared according to preparation example 5;

[0191] S4, purifying the pyrolysis gas obtained in step S3 by dust removal, and then condensing; the liquid product obtained by condensation is aromatic oil, which is recovered; the gaseous product obtained by condensation is non-condensable gas, which is incinerated to recover the heat for heating the pyrolysis furnace;

[0192] S5, recovering the pyrolysis solid product obtained in step S3 to obtain the biomass charcoal.

[0193] Example 13

[0194] The difference between this example and example 12 is that in step S3, the input flow rate of nitrogen is 130 mL / min.

[0195] Example 14

[0196] The difference between the present embodiment and embodiment 12 is that in step S3, the input flow of nitrogen is 140 mL / min.

[0197] The process of embodiments 9-14 of the present application is also subjected to process effect detection, and the results are shown in Table 3.

[0198] Table 3: Detection results of embodiments 9-14

[0199] Oil phase (kg) Non-condensable gas (kg) Aromatic content (%) Total carbon (%) Specific surface area (m 2 / g) Example 9 14.7 1.18 91.9 72.1 25.1 Example 10 14.3 1.21 91.6 72.4 24.9 Example 11 15.2 1.11 92.2 71.1 25.3 Example 12 15.9 1.02 93.2 70.5 25.7 Example 13 16.2 0.94 93.8 70.1 25.9 Example 14 16.0 0.99 93.4 70.4 25.5

[0200] As can be seen from the results in Table 3, by optimizing the mixing amount of straw and calcium oxide, the yield of pyrolysis oil phase can be further improved, and the quality of oil phase is also improved.

[0201] As can be seen from the results in Table 3, by using nitrogen protection during pyrolysis and continuously inputting nitrogen, nitrogen element can be effectively provided, and the content of oxygen element in the pyrolysis system can be reduced, which can further improve the yield of pyrolysis oil phase, and can also effectively reduce the generation amount of non-condensable gas, and the quality of obtained aromatic oil is further improved. In addition, the input of nitrogen will cause the total carbon content of the biomass charcoal obtained by pyrolysis to slightly decrease. In summary, the process of the present application uses nitrogen protection pyrolysis, and the overall economic benefit can be further improved.

[0202] The above are preferred embodiments of the present application, and do not limit the protection scope of the present application, so: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A process for pyrolysis gasification of sludge incineration, characterized by, The method comprises the following steps: S1, pretreating the oily sludge to a water content of 40% or less, and crushing the straw to a particle size of 5mm or less; S2, mixing the pretreated oily sludge, the crushed straw particles, and the calcium oxide powder in a mass ratio of 65-70% oily sludge, 25-30% straw, and 5-10% calcium oxide in a mixer to obtain a mixture; S3, pyrolyzing the mixture obtained in step S2 in a pyrolysis furnace under anaerobic or anoxic conditions using potassium-modified ZSM-5 molecular sieve particles as an ex-situ pyrolysis catalyst; the pyrolysis process comprises the following steps: heating at a rate of 5-10℃ / min to 180-200℃, then heating at a rate of 12-18℃ / min to 500-560℃, and then maintaining the temperature at 500-560℃ for 10-30min; pyrolysis gas and pyrolysis solid products are obtained; S4, purifying the pyrolysis gas obtained in step S3, and then condensing the purified pyrolysis gas; the condensed liquid product is aromatic oil, which is recycled and reused; the condensed gaseous product is non-condensable gas, which is incinerated to recover heat for heating the pyrolysis furnace; S5, recycling the pyrolysis solid product obtained in step S3 as a biomass charcoal for reuse. In step S3, the potassium-modified ZSM-5 molecular sieve particles are prepared by the following steps: Sa, mixing potassium-modified ZSM-5 molecular sieve, kaolin, and anhydrous ethanol in a mass ratio of 8:2:1-2 to prepare a mud; Sb, placing the mud obtained in step Sa in a granulator to prepare particles with a particle size of 2-10mm; Sc, placing the particles obtained in step Sb in a vacuum furnace and calcining at a temperature of 560-580℃ under vacuum to obtain potassium-modified ZSM-5 molecular sieve particles.

2. The process according to claim 1, characterized in that, In step S1, the oily sludge is pretreated to a water content of 30-35%, and the straw is crushed to a particle size of 1-3mm.

3. The process according to claim 2, characterized in that, In step S1, the oily sludge is pretreated by heating and dewatering.

4. The process according to claim 3, characterized in that, The heating temperature is controlled to be 105℃ or less.

5. The process according to claim 1, wherein the sludge is incinerated by a pyrolysis gasification sludge incineration process. In step S2, the particle size of the calcium oxide powder is 50-500μm.

6. The process according to claim 1, wherein the sludge is incinerated by a pyrolysis gasification incineration process. In step S3, the pyrolysis furnace has the following structure: the pyrolysis furnace comprises a furnace body (1) provided with a raw material inlet (4), a pyrolysis gas delivery pipe (5) for discharging pyrolysis gas, and a protective gas input pipe (6) for inputting protective gas; the furnace body (1) is provided with a sludge loading area (2); a catalytic bed (3) is fixedly arranged in the region of the furnace body (1) between the sludge loading area (2) and the pyrolysis gas delivery pipe (5); the catalytic bed (3) has a porous ceramic shell filled with potassium-modified ZSM-5 molecular sieve particles.

7. The process according to claim 1, wherein the sludge is incinerated by a pyrolysis gasification process. In step S3, the pyrolysis is carried out under nitrogen protection.

8. The process according to claim 7, c h a r a c t e r i z e d in that, The input flow rate of the nitrogen is 120-140mL / min.

9. The process according to claim 1, wherein the sludge is incinerated by a pyrolysis gasification sludge incineration process. In step S5, the biomass charcoal is reused by mixing with biomass raw materials to prepare a biomass fuel, and is used as a biomass charcoal adsorbent and an acid soil conditioner.

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