Coal-oil slurry coke inhibitor suitable for mild liquefaction of coal in Hami region as well as preparation method and application of coal-oil slurry coke inhibitor

Abstract

The invention discloses a coal-oil slurry coke inhibitor suitable for mild liquefaction of coal in Hami region, and a preparation method and application thereof, and relates to the technical field of coal chemical industry. The preparation method comprises the following steps: firstly, distilling a raw material oil product to obtain distilled oil with a distillation range of 150-450 DEG C; carrying out hydrogenation reaction on distilled oil obtained by distillation through a hydrogenation reactor; sequentially adding an inhibitor and a passivator into the hydrogenated distilled oil; and finally, stirring the obtained mixed solution at a certain temperature. According to the characteristics of direct coal liquefaction of the coal-oil slurry, coking deposition of the coal-oil slurry in a reaction device can be effectively reduced, and the operation condition of coal under the mild liquefaction condition is improved; the method can be directly attached to a direct coal liquefaction project for production, is particularly suitable for the direct coal liquefaction process of high-quality coal liquefaction coal in the Hami region under the mild liquefaction condition, and plays an important role in prolonging the operation cycle of a direct coal liquefaction factory and reducing the production cost and the parking risk.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical industry, and in particular to an oil-coal slurry coke inhibitor, a preparation method and application thereof. Background Art

[0002] Direct coal liquefaction refers to the process of converting coal into liquid fuel through hydrocracking under the action of hydrogen and catalyst. It is an important technical approach to efficiently and cleanly utilize coal resources to convert them into liquid oil products, and is also one of the important coal chemical technologies to ensure national energy security.

[0003] There are many factors that affect the effect of direct coal liquefaction, including the type and quality of coal, catalyst, reaction temperature, reaction pressure and reaction time. Among them, the common direct coal liquefaction conditions are reaction temperature of 440-455°C and pressure in the reactor of 19MPa. Mild liquefaction conditions refer to the direct coal liquefaction reaction at a temperature lower than the reaction temperature, reaction pressure, or at the reaction temperature and pressure conditions.

[0004] Coking inhibitors are mainly used in delayed coking and other fields. By adding coking inhibitors, the polymerization and coking of heavy oil in the coking process are reduced, and while improving product quality, local overheating and blockage accidents caused by coking are reduced. Common causes of coking are asphaltene aggregation and deposition, olefins forming macromolecular organic matter, inorganic salt deposition and other factors. Under mild liquefaction process conditions, due to the reduction of hydrogen partial pressure and the increase of oil-coal slurry flow rate, it is easy to cause coking of the pipeline in the preheater, increasing the risk of pipeline blockage. It can be seen that the existing technology needs to be further improved. Summary of the invention

[0005] One of the purposes of the present invention is to provide a method for preparing an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in the Hami area. According to the characteristics of oil-coal slurry in direct coal liquefaction, the inhibitor can effectively reduce the coking deposition of oil-coal slurry in the reaction device and improve the operating conditions of coal under mild liquefaction conditions.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, comprising the following steps:

[0008] (1) distilling the raw oil product to obtain distilled oil with a distillation range of 150 to 450° C.; the raw oil product is selected from the oil product produced by direct coal liquefaction in Hami area;

[0009] (2) hydrogenating the distilled oil;

[0010] (3) adding an inhibitor to the distilled oil after hydrogenation in step (2);

[0011] (4) on the basis of step (3), further adding a passivating agent;

[0012] (5) Stirring the mixed solution obtained in step (4) to obtain the product.

[0013] The above-mentioned method for preparing an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in Hami area, in step (1), the raw oil product is a mixture of one or more of coal tar, diesel, coal liquefaction oil, and washing oil.

[0014] The above-mentioned method for preparing an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in the Hami area, in step (2), the distilled oil is hydrogenated by a hydrogenation reactor, the hydrogenation temperature is 300-400°C, the hydrogen pressure is 12-18MPa, the hydrogen-oil ratio is 400-600:1, and the hydrogenation time is 30-100min.

[0015] In the above-mentioned method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, in step (3), the amount of inhibitor added is 15-40% of the mass of the distilled oil after hydrogenation.

[0016] The above-mentioned method for preparing an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in Hami area, in step (3), the inhibitor is one or a mixture of several of aniline, naphthylamine, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and polyethylene glycol.

[0017] In the above-mentioned method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, in step (4), the amount of the passivating agent added is 0.5-3% of the mass of the hydrogenated distilled oil to which the inhibitor is added.

[0018] The above-mentioned method for preparing an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in Hami area, wherein the passivating agent is one or a mixture of several of organic phosphoric acid, carbonyl condensate and imidazole.

[0019] The above-mentioned method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, in step (5), the temperature is maintained at 40-200°C for stirring, the stirring speed is 1000-5000rpm, and the stirring time is 30-120min.

[0020] Another object of the present invention is to provide an oil-coal slurry coke inhibitor prepared by the preparation method of the above-mentioned oil-coal slurry coke inhibitor suitable for mild liquefaction of coal types in Hami area.

[0021] Another object of the present invention is to provide the use of the above-mentioned oil-coal slurry coking inhibitor, wherein the addition amount of the oil-coal slurry coking inhibitor is 0.01 to 0.05% of the mass of the oil-coal slurry.

[0022] Compared with the prior art, the present invention brings the following beneficial technical effects:

[0023] (1) The present invention proposes a method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, which comprises first distilling the raw oil product, hydrogenating the distilled oil obtained by distillation through a hydrogenation reaction, then adding an inhibitor and a passivating agent to the distilled oil after hydrogenation in sequence, and finally stirring to obtain the coke inhibitor. The preparation method of the present invention is simple to operate and has low cost.

[0024] (2) The present invention can be directly attached to the coal direct liquefaction project for production, and is particularly suitable for the coal direct liquefaction process of high-quality coal in the Hami area under mild liquefaction conditions. It plays an important role in increasing the operation cycle of the coal direct liquefaction plant and reducing production costs and shutdown risks. DETAILED DESCRIPTION

[0025] The present invention proposes an oil-coal slurry coke inhibitor suitable for mild liquefaction of coal in Hami area, a preparation method and an application thereof. In order to make the advantages and technical solutions of the present invention clearer and more specific, the present invention is further described below in conjunction with specific embodiments.

[0026] The inhibitor described in the present invention is one or a mixture of aniline, naphthylamine, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and polyethylene glycol.

[0027] The passivating agent mentioned in the present invention is: one or a mixture of organic phosphoric acid, carbonyl condensate, and imidazole.

[0028] A method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, comprising the following steps:

[0029] Step 1: distill the raw oil product to obtain distilled oil with a distillation range of 150-450° C. The raw oil product is selected from the coal direct liquefaction oil product in Hami area; specifically, the raw oil product is a mixture of one or more of coal tar, diesel, coal liquefaction oil, and wash oil.

[0030] Step 2: hydrogenate the distilled oil; hydrogenation is carried out in a hydrogenation reactor, and the specific hydrogenation reactor is preferably a fixed bed reactor, in which a hydrogenation catalyst is placed, and the hydrogenation catalyst is preferably alumina or silicon oxide as a carrier, and one or a mixture of molybdenum, nickel, tungsten oxide, sulfide. Preferably, the hydrogenation temperature is 300-400°C, the hydrogen pressure is 12-18MPa, the hydrogen-oil ratio is 400-600, and the hydrogenation time is 30-100min.

[0031] Step 3: adding an inhibitor to the distilled oil after hydrogenation in step 2; the amount of the inhibitor added is 15-40% of the mass of the distilled oil after hydrogenation.

[0032] Step 4: on the basis of step 3, further adding a passivating agent; the amount of the passivating agent added is 0.5 to 3% of the mass of the hydrogenated distilled oil with the inhibitor added;

[0033] Step 5: Stir the mixed solution obtained in step 4 at 100° C. for 30 to 120 minutes.

[0034] The oil-coal slurry coke inhibitor prepared by the invention is applied to the mild liquefaction process of coal in Hami area, and the addition amount of the oil-coal slurry coke inhibitor is 0.01-0.05% of the mass of the oil-coal slurry.

[0035] The present invention will be further described below in conjunction with specific embodiments.

[0036] Embodiment 1:

[0037] The direct liquefaction product oil of Hami coal A is selected, and the distillation oil has a distillation range of 200-350°C; the distillation oil is then hydrogenated, the hydrogenation temperature of the hydrogenation reactor is 350°C, the hydrogen pressure is 14MPa, the hydrogen-oil ratio is 400, and the hydrogenation time is 50 minutes; then inhibitors aniline and polyethylene glycol are added to the hydrogenated distillation oil, the amount of aniline added is 10% of the mass of the hydrogenated distillation oil, and the amount of polyethylene glycol added is 20% of the mass of the hydrogenated distillation oil; then a passivating agent imidazole is added thereto, the amount of imidazole added is 1% of the mass of the hydrogenated distillation oil with the inhibitor added, and the mixture is stirred for 100 minutes at a temperature of 100°C to obtain an oil-coal slurry coke inhibitor.

[0038] The application of the oil-coal slurry coking inhibitor prepared in this embodiment is specifically analyzed. The oil-coal slurry coking inhibitor of this embodiment is added to the oil-coal slurry of Hami coal A. The added amount of the oil-coal slurry coking inhibitor is 0.03% of the mass of the oil-coal slurry. In a 0.01 t / day coal direct liquefaction device, at a reaction temperature of 450°C and a reaction pressure of 10 MPa, the device is operated for 72 hours to compare the coking amount in the preheater pipeline before and after the addition of the coking inhibitor.

[0039] Table 1 Comparison of mild liquefaction effect of coal A in Hami area

[0040] Coking amount / g Focus state blank 80.5 Hard texture, sticks to the pipe wall, difficult to clean Example 1 Scorch inhibitor 24.2 Soft texture, easy to clean

[0041] It can be seen from Table 1 that under mild liquefaction conditions of a reaction temperature of 450°C and a reaction pressure of 10 MPa, after using the oil-coal slurry coke inhibitor of this embodiment, the amount of coking in the preheater is reduced by 69.9% compared with the oil-coal slurry without adding the coke inhibitor, which can effectively extend the operating time of the device.

[0042] Embodiment 2:

[0043] A washing oil in Hami area is selected, and the distillation range of the distillation oil is 250-300°C; then the distillation oil is hydrogenated, the hydrogenation temperature of the hydrogenation reactor is 300°C, the hydrogen pressure is 15MPa, the hydrogen-oil ratio is 600, and the hydrogenation time is 60 minutes; then the inhibitor tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester is added to the distillation oil after hydrogenation, and the addition amount of tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester is 35% of the mass of the distillation oil after hydrogenation, and then the passivating agent organic phosphoric acid is added thereto, and the addition amount of the organic phosphoric acid is 0.5% of the mass of the distillation oil after hydrogenation with the inhibitor added, and the oil-coal slurry coke inhibitor is obtained at a temperature of 80°C and stirred for 50 minutes.

[0044] The application of the oil-coal slurry coking inhibitor prepared in this embodiment is specifically analyzed. The oil-coal slurry coking inhibitor of this embodiment is added to the oil-coal slurry of Hami coal B. The amount of the oil-coal slurry coking inhibitor added is 0.01% of the mass of the oil-coal slurry. In a 0.01 t / day coal direct liquefaction device, at a reaction temperature of 430°C and a reaction pressure of 16 MPa, the device was operated for 72 hours. The coking amount in the preheater pipeline was compared before and after the addition of the coking inhibitor, as shown in Table 2.

[0045] Table 2 Comparison of mild liquefaction effect of coal A in Hami area

[0046] Coking amount / g Focus state blank 67.2 Hard texture, difficult to clean Example 2 Scorch inhibitor 18.9 Soft texture, easy to clean

[0047] It can be seen from Table 2 that under mild liquefaction conditions of a reaction temperature of 430°C and a reaction pressure of 16 MPa, after using the coke inhibitor of this embodiment, compared with the oil-coal slurry without adding the coke inhibitor, the amount of coking in the preheater is reduced by 48.3 g, which can effectively extend the operating time of the device by more than 3 times and has a good coke inhibition effect.

[0048] Embodiment 3:

[0049] The direct liquefaction product oil of Hami coal C is selected, and the distillation oil has a distillation range of 200-350°C; the distillation oil is then hydrogenated, the hydrogenation temperature of the hydrogenation reactor is 300°C, the hydrogen pressure is 12MPa, the hydrogen-oil ratio is 400, and the hydrogenation time is 60 minutes; inhibitors naphthylamine and polyethylene glycol are then added to the hydrogenated distillation oil, and the amount of naphthylamine added is 20% of the mass of the hydrogenated distillation oil, and the amount of polyethylene glycol added is 15% of the mass of the hydrogenated distillation oil; passivating agents imidazole and organic phosphoric acid are then added thereto, and the amounts of imidazole and organic phosphoric acid added are respectively 1% of the mass of the hydrogenated distillation oil to which the inhibitors are added, and the mixture is stirred for 100 minutes at a temperature of 200°C to obtain an oil-coal slurry coke inhibitor.

[0050] The application of the oil-coal slurry coking inhibitor prepared in this embodiment is specifically analyzed. The oil-coal slurry coking inhibitor of this embodiment is added to the oil-coal slurry of Hami coal C, and the addition amount of the oil-coal slurry coking inhibitor is 0.02% of the mass of the oil-coal slurry. In a 0.01 ton / day coal direct liquefaction device, under the conditions of reaction temperature of 450°C and reaction pressure of 10MPa, the operation is carried out for 72 hours, and the coking amount of the preheater pipeline before and after the addition of the coking inhibitor is compared. The coking amount of the preheater pipeline before and after the addition of the coking inhibitor is compared, as shown in Table 3.

[0051] Table 3 Comparison of mild liquefaction effect of coal C in Hami area

[0052] Coking amount / g Focus state blank 70.6 Hard texture, not easy to clean Example 3 Scorch inhibitor 16.7 Soft texture, easy to clean

[0053] It can be seen from Table 3 that under mild liquefaction conditions of a reaction temperature of 450°C and a reaction pressure of 10 MPa, after using the coke inhibitor of this embodiment, compared with the oil-coal slurry without adding the coke inhibitor, the amount of coking in the preheater is reduced by 53.9 g, which can effectively extend the operating time of the device and has a good coke inhibition effect.

[0054] Embodiment 4:

[0055] Hami coal D coal tar is selected, and the distillation range of the distilled oil is 250-350°C; then the distilled oil is hydrogenated, the hydrogenation temperature of the hydrogenation reactor is 400°C, the hydrogen pressure is 15MPa, the hydrogen-oil ratio is 600, and the hydrogenation time is 40 minutes; then the inhibitor naphthylamine is added to the hydrogenated distilled oil, and the amount of naphthylamine added is 15% of the mass of the hydrogenated distilled oil; then the passivating agent carbonyl condensate is added thereto, and the amount of carbonyl condensate added is 3% of the mass of the hydrogenated distilled oil with the inhibitor added, and the mixture is stirred for 60 minutes at a temperature of 80°C to obtain an oil-coal slurry coke inhibitor.

[0056] The application of the oil-coal slurry coking inhibitor prepared in this embodiment is specifically analyzed. The oil-coal slurry coking inhibitor of this embodiment is added to the oil-coal slurry of Hami coal D, and the addition amount of the oil-coal slurry coking inhibitor is 0.05% of the mass of the oil-coal slurry. In a 0.01 ton / day coal direct liquefaction device, under the conditions of reaction temperature 440°C and reaction pressure 12MPa, the coking amount of the preheater pipeline is compared before and after the addition of the coking inhibitor. As shown in Table 4.

[0057] Table 4 Comparison of mild liquefaction effect of coal D in Hami area

[0058] Coking amount / g Focus state blank 65.2 The texture is hard, adheres to the pipe wall, and is difficult to clean Example 4 Scorch inhibitor 15.8 Soft texture, easy to clean

[0059] It can be seen from Table 4 that under mild liquefaction conditions of a reaction temperature of 440°C and a reaction pressure of 12 MPa, after using the coke inhibitor of this embodiment, compared with the oil-coal slurry without adding the coke inhibitor, the amount of coking in the preheater is reduced by 49.4 g, which can effectively extend the operating time of the device and has a good coke inhibition effect.

[0060] Under the guidance of the above-mentioned Examples 1 to 4, those skilled in the art can also obviously obtain other inhibitors and passivators.

[0061] Parts not described in the present invention can be implemented by those skilled in the art by referring to the existing technology.

[0062] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present application and are not intended to be limiting of the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments should fall within the scope of protection of the claims of the present application.

Claims

1. A method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, characterized in that: The following steps are involved: (1) distilling the raw oil product to obtain distilled oil with a distillation range of 150 to 450° C.; the raw oil product is selected from the oil product produced by direct coal liquefaction in Hami area; (2) hydrogenating the distilled oil; (3) adding an inhibitor to the distilled oil after hydrogenation in step (2); (4) on the basis of step (3), further adding a passivating agent; (5) Stirring the mixed solution obtained in step (4) to obtain the product.

2. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 1, characterized in that: In step (1), the raw oil product is a mixture of one or more of coal tar, diesel, coal liquefied oil, and wash oil.

3. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 1, characterized in that: In step (2), the distilled oil is hydrogenated by a hydrogenation reactor, the hydrogenation temperature is 300-400° C., the hydrogen pressure is 12-18 MPa, the hydrogen-oil ratio is 400-600:1, and the hydrogenation time is 30-100 min.

4. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 1, characterized in that: In step (3), the amount of inhibitor added is 15-40% of the mass of the distilled oil after hydrogenation.

5. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 4, characterized in that: In step (3), the inhibitor is one or a mixture of aniline, naphthylamine, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and polyethylene glycol.

6. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 1, characterized in that: In step (4), the amount of the passivating agent added is 0.5 to 3% of the mass of the hydrogenated distilled oil to which the inhibitor is added.

7. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 6, characterized in that: The passivating agent is one or a mixture of organic phosphoric acid, carbonyl condensate and imidazole.

8. The method for preparing a coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area according to claim 1, characterized in that: In step (5), the temperature is maintained at 40 to 200° C. for stirring, the stirring speed is 1000 to 5000 rpm, and the stirring time is 30 to 120 min.

9. A coke inhibitor for oil-coal slurry suitable for mild liquefaction of coal in Hami area, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. The use of a coal-oil slurry coke inhibitor according to claim 9, characterized in that: The addition amount of the oil-coal slurry coke inhibitor is 0.01-0.05% of the mass of the oil-coal slurry.