KR101840058B1 - Method of Preparing Modified Red Mud Using hydrochloric acid and phosphoric acid - Google Patents

Abstract

(B) adding hydrochloric acid and phosphoric acid to the slurry red mud; and (c) mixing the red mud with the red mud through the step (b). And then filtering it to obtain an end product. The present invention also relates to a method for producing a modified red mud.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preparing modified red mud using hydrochloric acid and phosphoric acid,

The present invention relates to a process for producing a modified Red mud in which the activity of the catalyst is improved through an acid treatment method of Red mud. More particularly, the present invention relates to a process for preparing red mud modified with hydrochloric acid and phosphoric acid. Further, the present invention relates to a method of using the modified red mud as a hydrocracking catalyst for decompression residual oil.

The Vacuum Residue (VR) in heavy oil is a very complex compound containing a large amount of substances causing serious degradation of the catalyst, and when it is treated, the presence of metal (Ni, V) contained in the heavy oil Calm can cause many problems. Therefore, catalyst selection plays a very important role in treating such heavy oil. Since most of the catalysts used in the slurry hydrocracking reaction are expensive, difficulty in using the catalyst and recovering the catalyst is a problem, and a method for recovery and treatment of the catalyst is required.

Red mud is an industrial by-product derived from the Bayer process that produces alumina from bauxite, and a significant amount of about 5.5 million tons is produced annually, which is advantageous in that it is inexpensive and does not need to be recovered after the reaction. In addition, components such as K, Cr, V, Ni, Cu, Mn and Zn as well as Fe2O3, Al2O3, SiO2, TiO2, Na2O, CaO and MgO are contained in the red mud and have activity as a catalyst. The red mud can be reacted even without the pretreatment process, but the activity of the red mud can be enhanced by controlling the physical properties.

Previously, the Pratt and Christoverson method was used to increase the activity of red mud. It is known that Na and Ca in red mud cause pore plugging phenomenon in the hydrocracking reaction and cause deactivation of the catalyst. Therefore, the above method increased surface area and pore size by removing Na and Ca contained in red mud using HCl. When the pore size is small, the pore plugging phenomenon occurs at the pore inlet, thereby deteriorating the performance of the catalyst. On the other hand, when the pore size is increased, the pore plugging phenomenon is relatively small and the deactivation of the catalyst is reduced . Also, molecules having a large molecular weight can easily contact with active sites in large pores, thereby improving the conversion rate of the cracking reaction.

At present, most of the catalysts used in the decompression residual oil reaction are expensive, so that it is difficult to use the catalyst and recover the catalyst. When the red mud is used without the pretreatment, the reactivity is low. There is still a need to develop a modified red mud which has a conversion ratio similar to that of a conventional commercial catalyst as a hydrocracking catalyst for decompression residual oil.

One embodiment of the present invention is to provide a red mud which is improved in catalytic activity by economically controlling physical properties through treatment of red mud which is a low-priced waste catalyst with hydrochloric acid and phosphoric acid, and a method for producing the same.

Another embodiment of the present invention is to provide a modified red mud having a conversion ratio similar to that of a conventional commercial catalyst in a hydrocracking reaction of a decompression residue having the largest molecular weight among heavy oils.

In one embodiment of the present invention, a process for preparing a modified Redmud catalyst comprises the steps of (a) mixing red mud and water to produce a slurry red mud, (b) adding hydrochloric acid and phosphoric acid to the slurry red mud , And (c) adding ammonia water to the red mud through the step (b), followed by filtration to obtain an end product.

Further, the method may further include a step of drying or calcining the final product after the step (c), or calcining the dried product.

In one embodiment of the present invention, red mud refers to sludge remaining from bauxite raw mineral by a beer method (a method of extracting aluminum hydroxide by adding sodium hydroxide to a raw mineral having a large amount of alumina and extracting aluminum hydroxide) , Generally a fine powder having a size of 5 to 20 mu m, and is usually produced in the form of a slurry having a water content of about 30%. In the present invention, various types of red mud such as dried red mud, red mud containing water, and red mud having increased water content by supplying water to dried red mud powder can be used. For example, Although red mud sludge is produced in a pulverized state, the pulverized red mud can be used by dry pulverization or wet pulverization because it is present in a lump state with each other.

In one embodiment of the present invention, the slurry red mud is treated with an acid by adding hydrochloric acid and phosphoric acid, wherein the hydrochloric acid treatment can utilize an aqueous hydrochloric acid solution with a concentration of 20% to 35% And the pore structure is developed.

In addition, the amount of phosphoric acid added may be 3 to 10 wt% based on phosphorus, and more specifically, phosphoric acid at 50 to 85% concentration may be added in an amount of 3 to 10 wt% based on phosphorus. Appropriate amounts of phosphoric acid are added considering the interaction with added phosphorus and inorganic catalysts, and when the phosphorus content is exceeded, excess phosphorus may act as catalyst poison of active sites of inorganic catalysts. When phosphoric acid is treated with hydrochloric acid, the stability of the inorganic support is secured and the dispersion degree of the active phase is improved, thereby increasing the hydrocracking conversion rate of the decompression residue. Due to the phosphoric acid treatment, phosphorus is carried in the red mud, and the pore size is increased by more than 10 nm.

In one embodiment of the present invention, the modified red mud prepared according to the process of the present invention can be used as a hydrocracking catalyst for vacuum residue oil. Red mud prepared according to one embodiment of the present invention exhibits a higher conversion rate than that of thermal cracking without a catalyst. Redmud treated with hydrochloric acid and phosphoric acid has a change in basic physical properties such as surface area increase These changes increase the reaction conversion rate in the hydrocracking reaction of the decompressed residual oil. Therefore, when Red Mud is treated according to the production method of the present invention, a hydrocracking catalyst having a good residual activity is produced.

Red mud prepared according to one method of the present invention has high pore size, pore volume, and specific surface area, and thus has excellent catalytic activity.

In addition, the red mud prepared according to one method of the present invention has an advantage of exhibiting a conversion rate through hydrocracking reaction under reduced pressure equivalent to that of a conventional commercial catalyst.

In addition, the red mud prepared according to one method of the present invention ensures stability of the inorganic support, improves the dispersibility of the active phase, increases the pore size, pore volume, and surface area, It is possible to increase the activity and prevent the phenomenon of for-plugging of the catalyst.

1 shows X-ray diffraction (XRD) pattern results of Red Mud according to Production Example 1 (A), Production Example 2 (B), Production Example 3 (C), and Production Example 5 Fig.
2 is a graph showing the pore structure analysis results of the red mud catalyst according to Production Examples 1 to 4 by nitrogen adsorption.
3 is a graph showing NH 3-TPD (ammonia temperature desorption) results of Red Mud catalysts according to Production Examples 1 to 3.
FIG. 4 is a graph showing changes in reaction pressure with time in the hydrocracking reaction of reduced-pressure residues of various kinds of red mud catalysts.
FIG. 5 is a graph showing the results of hydrocracking reaction of reduced-pressure residues of various kinds of red mud catalysts in terms of the distribution of gaseous, liquid and solid products and conversion rates.
FIG. 6 is a graph showing the results of GC-SIMDIS analysis of the distribution of liquid product in the reaction results of various kinds of red mud catalysts.
FIG. 7 is a graph showing conversion ratios and specific product distributions of respective catalysts as a result of hydrocracking reaction of reduced-pressure residues of various kinds of red mud catalysts.

Hereinafter, a method for producing red mud according to the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited by the following examples.

Preparation Example 1: Preparation of unmodified red mud (RM)

Aluminum hydroxide was extracted by bait process to produce alumina from bauxite and the dried sludge remaining was used.

Manufacturing example  2: treated with hydrochloric acid Red Mud  catalyst ( ARM )

190 g of H ₂ O was added to 10 g of Red Mud of Production Example 1 and stirred to prepare a slurry. To the red mud slurry was added 18 g of 35% hydrochloric acid, and the mixture was heated for 30 minutes. Thereafter, distilled water was added to the solution so that the total volume became 800 cm < ³ > and NH ₄ OH was added thereto so that the pH of the solution became 8. The resulting precipitate was filtered and the precipitate was washed three times with distilled water at about 40 ° C. The washed red mud was dried at about 110 ° C for 24 hours and then aerosolized at about 500 ° C for 2 hours to prepare Activated Red Mud (ARM) treated with hydrochloric acid.

Manufacturing example  3: Hydrochloric acid and phosphoric acid treated Red Mud  catalyst ( PARM  4%)

190 g of H ₂ O was added to 10 g of Red Mud of Production Example 1 and stirred to prepare a slurry. To the red mud slurry was added 18 g of hydrochloric acid at a concentration of 35% and 85 g of phosphoric acid at a concentration of 1.5 g, followed by heating for 30 minutes. Thereafter, distilled water was added to the solution so that the total volume became 800 cm < ³ > and NH ₄ OH was added thereto so that the pH of the solution became 8. The resulting precipitate was filtered and the precipitate was washed three times with distilled water at about 40 ° C. The washed red mud was dried at about 110 DEG C for 24 hours and then aerosolized at about 500 DEG C for 2 hours to prepare a red mud catalyst (PARM 4%) treated with hydrochloric acid and phosphoric acid.

Manufacturing example  4: Hydrochloric acid and phosphoric acid treated Red Mud  catalyst( PARM  8%)

Was prepared in the same manner as in Production Example 3 except that the content of phosphoric acid was doubled.

Manufacturing example  5: Sulfated Red Mud  catalyst ( SARM )

190 g of H ₂ O was added to 10 g of Red Mud of Production Example 1 and stirred to prepare a slurry. To the red mud slurry was added 18 g of 35% hydrochloric acid, and the mixture was heated for 30 minutes. Thereafter, distilled water was added to the solution so that the total volume became 800 cm < ³ > and NH ₄ OH was added thereto so that the pH of the solution became 8. The resulting precipitate was filtered and the precipitate was washed three times with distilled water at about 40 ° C. The washed red mud was dried at about 110 ° C for 24 hours and then aerated at about 500 ° C for 2 hours. The red mud of Preparation Example 2 was sulfided while flowing a mixed gas of H ₂ S: H ₂ : Ar mixed at a ratio of 5:50:45 at 400 ° C. for 2 hours at a rate of 60 ml / min, (SARM).

Table 1 below shows the results of EDX (Energy Dispersive X-ray Spectroscopy) component analysis of Red Mud.

Production Example 1
(RM) Production Example 2
(ARM) Production Example 3
(PARM 4%) Production Example 5
(SARM) Fe 23.32 22.84 25.11 28.78 O 42.78 50.38 48.24 30.95 Al 10.39 12.20 11.26 13.81 Si 4.73 4.10 3.93 5.14 Na 6.18 0.29 0.41 0.23 Ca 4.03 1.47 2.91 1.62 Ti 4.25 3.82 4.29 4.71 P - - 3.84 - S - - - 14.77

As can be seen from Table 1, Fe is the most basic component of red mud, and the amount of Na and Ca is remarkably reduced as a result of activation by hydrochloric acid treatment. On the other hand, as a result of simultaneous treatment with hydrochloric acid and phosphoric acid, it was confirmed that not only the amount of Na and Ca was significantly reduced but also the amount of phosphorus was increased. Indicating that phosphorus was supported in the red mud as a result of phosphoric acid treatment. As a result of the sulfuration treatment, sulfur was supported in the red mud.

Table 2 shows the basic properties of red mud according to each production example.

Production Example 1
(RM) Production Example 2
(ARM) Production Example 3
(PARM 4%) Production Example 4
(PARM 8%) Pore Diameter (nm) 25.49 7.48 12.78 16.60 Specific surface area (m < 2 > / g) 21.87 127.71 104.83 97.03 Pore volume (cm < 3 > / g) 0.14 0.23 0.31 0.39

As can be seen from FIG. 2 showing the results of the pore structure analysis by nitrogen adsorption of Red Mud according to each production example and Table 2 showing the basic physical properties of each Red Mud, the Red Mud of Production Example 1 basically has a large pore size It has a low specific surface area. In the case of the hydrochloric acid-treated Preparation Example 2, the pore structure was evolved as Na and Ca escaped, and the pore size was decreased to 10 nm or less, and the specific surface area was increased. On the other hand, in Production Examples 3 and 4 treated with hydrochloric acid / phosphoric acid, the pore size was larger than that of Production Example 2 in which conventional hydrochloric acid treatment was performed, and the specific surface area was slightly reduced. Thus, it was confirmed that the physical properties of the catalysts of Production Examples 3 and 4 were improved as compared with those of Production Examples 1 and 2.

1 is a graph showing XRD patterns of Red Mud according to Production Examples 1 to 3 and 5 (wherein A: Preparation Example 1, B: Preparation Example 2, C: Preparation Example 3, D: being). The basic components and crystal structure of red mud are iron oxide series, and it can be confirmed that basic components and crystal structure are not changed by acid treatment (hydrochloric acid and phosphoric acid treatment). However, as in Production Example 5, it can be confirmed that they are changed to the iron sulfide structure upon sulfiding treatment.

FIG. 3 is a graph showing the results of NH 3-TPD experiments performed to confirm changes in acid sites of Red Mud catalysts according to Production Examples 1 to 3. The TPD patterns of each red mud are typical results, and it has been confirmed that the acid point greatly increases after the acid treatment. However, there was no significant difference in the acid point change between hydrochloric acid treatment and hydrochloric acid / phosphoric acid treatment.

Hydro cracking  Reaction experiment

HCK reactor (model name: R-201), and a batch-type high-pressure autoclave having an internal volume of 100 ml was used as the reactor. In order to maintain the reaction temperature at a high temperature, a heater for raising the temperature to 600 ° C was installed outside the reactor. Cooling is designed to cool the water down into the U-shaped tube when the set temperature is exceeded. The reactor was equipped with two inlet and outlet gas lines, the inlet line used for hydrogen and nitrogen injection and the outlet line used for pressure vent .

Example  1 (pressure change)

 In a reactor having an internal volume of 100 ml, 1.2 g of red mud catalyst was added together with 30 g of vacuum residue, and hydrogen was flowed into the reactor using a mass flow controller (MFC) so that the initial hydrogen pressure of the reaction was 90-95 bar. After checking the pressure Leak, the temperature was raised to 490 ° C using a heating device, the pressure was maintained at about 150 bar, and the reaction was carried out for 2 hours. At the end of the reaction, the pressure at the reaction temperature was recorded, cooled to room temperature, and compared to the initial pressure, and ΔP was measured.

Here, except for changing the Redmud catalyst using Production Examples 1 to 4 and an oil-soluble catalyst (1.2% = 4,000 ppm Mo in 10% Mo naphthanate), the catalyst was not used (blank) And the rest were repeatedly experimented under the same conditions, and the results of the pressure changes are shown in FIG.

4 is a graph showing reaction pressure changes in the reactor during the hydrocracking reaction of various red mud catalysts of various kinds. In order to confirm the performance of the catalyst in terms of hydrocracking reaction rate and hydrogen consumption as a hydrocracking catalyst, Redmud experimented the change of the reaction pressure in the reactor during the hydrocracking reaction of each catalyst. In the case of non-preprocessed red mud and oil-soluble catalysts, hydrocatalysts are not used because the hydrogenation reaction does not proceed and the pyrolysis reaction occurs mainly. The hydrogenation reaction is progressed with the cracking, so that the pressure decrease due to the consumption of hydrogen occurs. In the case of acid-treated Red mud catalyst, it consumes a similar amount of hydrogen and consumes more hydrogen than the oil-soluble catalyst (10% Mo naphthanate 1.2 g = 4,000 ppm Mo) The speed is estimated to be relatively high.

Example  2 (conversion rate and selectivity)

After completion of the reaction of Example 1, hydrogen was evacuated for analysis of the product, the pressure was lowered to atmospheric pressure, and the amount of product was measured to determine conversion and selectivity to confirm the activity of the catalyst. The product is divided into liquid, gas, and solid (residue + red mud + coke). The conversion and selectivity (yield) of each product gas phase, liquid phase, and solid phase product were determined by weighing using a balance. The results of the above conversion and selectivity are shown in Fig. 5 and Fig.

Liquid selectivity (wt%) = [weight of solid product] / [amount of decompression residue input] × 100

Solid phase selectivity (wt%) = [solid phase weight in reactor] / [injection amount of vacuum residue] × 100

The gas selectivity (wt%) = {[amount of decompression residual oil input] - [weight of liquid and solid product]} / [amount of decompression residual oil] x 100

Total conversion (wt%) = 100 - (liquid phase selectivity + gas selectivity)

5 is a graph showing the results of hydrocracking reaction of decompression residue of various red mud catalysts of various kinds. The reaction proceeded in a batch reactor and a blank test was also performed to compare with thermal cracking. Reaction condition 490 캜 was a sufficiently high reaction temperature that cracking due to pyrolysis occurred, resulting in a reaction conversion of about 60% and a liquid product of 45%. On the other hand, when the red mud catalyst was used, the conversion of the reaction was improved and the yield of the liquid product was also increased. In the case of the reaction conversion rate, it was confirmed that the conversion rate of the PARM catalyst (Example 1) with higher phosphorus was higher than that of the ARM catalyst treated with hydrochloric acid (Comparative Example 1) rather than Red Mud (RM) without the pretreatment have. That is, the reaction conversion rate was increased by hydrochloric acid treatment and hydrochloric acid / phosphoric acid treatment. In addition, the yield of the liquid product was highest in the hydrochloric acid / phosphoric acid-treated catalyst (PARM 4%), and when the redmud was modified through various acid treatments, the decompression residue hydrocracking reaction efficiency was increased due to the modified properties . On the other hand, for comparison, the reaction results were shown under the same conditions using an oil-soluble catalyst (1.2% of Mo naphthanate = 4,000 ppm Mo).

Example  3 ( GC - SIMDIS  analysis)

Particularly, the liquid mixture is composed of various oil components, and GC-SIMDIS analysis is further performed to analyze it more precisely. The results of the above GC-SIMDIS analysis are shown in Fig.

FIG. 6 is a graph showing the results of GC-SIMDIS analysis of the distribution of liquid products in the reaction results of the respective catalysts. First, since relatively large amounts of naphtha and diesel are produced in a relatively large amount of pyrolysis in the absence of a catalyst, and the hydrocracking reaction by the catalyst proceeds relatively in the presence of a catalyst, diesel and VGO Gas Oil) was relatively generated.

FIG. 5 shows the conversion rates of various red mud catalysts and the yields of gaseous, liquid, and solid products, and FIG. 6 shows GC-SIMDIS results of the liquid product. FIG. 7 shows the results obtained by integrating the results of FIGS. 5 and 6 again. In FIG. 7, the conversion rate of each catalyst is lowered because the residue of the liquid phase observed by GC-SIMDIS is subtracted again. The reaction conversion ratios in FIGS. 5 and 7 were higher than that of Preparation Example 1 (RM), that of Redmud (ARM) of Preparation Example 2 was higher than that of Preparation Example 1 (RM) And the yield of liquid product was also the same. In addition, in the analysis of the liquid phase component, VGO (Vacuum Gas Oil) was generated in a large amount due to the addition of phosphoric acid, which is presumed to promote the hydrocracking reaction.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

Claims (5)

(a) mixing red mud and water to prepare a slurry red mud,
(b) adding hydrochloric acid and phosphoric acid to the slurry red mud, and
(c) adding ammonia water to the red mud after the step (b) and filtering it to obtain an end product,
Wherein the phosphoric acid is added in an amount of 3 to 10 wt% based on phosphorus.
The method according to claim 1,
Wherein the step (c) further comprises a step of drying or firing or drying the final product after the step (c).
delete A modified red mud produced by the manufacturing method according to claim 1 or 2.
The method of claim 4,
Wherein the modified red mud is a hydrocracking catalyst of reduced-pressure residual oil.

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