KR20030035638A - Preparation of catalysts from used fcc catalysts for the liquid-phase degradation of waste polymer, and catalytic degradation process using the same - Google Patents

Abstract

PURPOSE: Provided are a method for fabricating catalyst for use in a liquid-phase decomposition process at low cost, and a liquid-phase decomposition process with high profitability by using the same. CONSTITUTION: The method comprises the steps of (a) reflux-heating waste catalyst of FCC process with 0.2-2.0N of hydrochloric acid, 0.1-1.0N of sodium hydroxide and potassium hydroxide at a temperature 60-80°C for 2-6 hours, and mixing the acid or base treated catalyst of the step (a) with FAU or MFI zeolite catalyst by below 100g. The liquid-phase degradation process comprises the step of degrading a polymer such as PE, PP and waste vinyl by using 10-100g of the catalyst prepared by the method above at 350-550°C to be hydrocarbon.

Description

Process for the preparation of catalysts for the liquid phase decomposition of waste polymers from FPC process waste catalysts and methods for decomposition of waste polymers using this catalyst THE SAME}

The present invention relates to a method for producing a catalyst that can be used in the liquid phase decomposition of waste polymer materials and a liquid phase decomposition process using the catalyst. In more detail, the present invention is a catalyst preparation method of the process of decomposing the polyolefin-based waste polymer material by using a catalyst to convert to a low-molecular hydrocarbon mixture that can be used as a raw material for liquid fuel or petrochemical industry, and waste polymer using such a catalyst Provided are methods for decomposing materials into low molecular hydrocarbons.

As the types of polymer materials are diversified and their physical properties are improved, their usage increases rapidly. On the other hand, polymer materials are inexpensive, weak in durability, and have a short lifespan. Therefore, polymer materials that are discarded are also increasing. In 1998, the production of high-molecular materials in China reached 7.5 million tons, and the waste of high-molecular materials reached 3 million tons. About 16% of the discarded polymer is used to manufacture containers or pipes through physical recycling, but most of the waste polymer is disposed of as it is because there is no proper recycling method. The method of incineration to recover heat is also very efficient in terms of energy, but since incineration generates harmful gases such as dioxins, the operation of incinerators is strictly regulated. Polymer materials are not easily decomposed in the natural state, so landfilling will not only cause soil pollution, but it is also difficult to secure proper landfill due to the aversion atmosphere. As such, the waste of polymer materials is rapidly increasing, but there is no proper recycling method or disposal method, so the disposal of waste polymer materials is a serious social problem.

Since most polymers are made of carbon and hydrogen, the most likely way to decompose them into low-molecular hydrocarbon mixtures and recycle them into fuel or petrochemical industry is most applicable in terms of scale, processing costs, and product utilization. The pyrolysis process that decomposes a polymer material at high temperature by applying heat is simple and easy to operate, but requires a lot of energy, and has a low carbon quality because the carbon number distribution of the produced liquid fuel is wide. The use of catalysts is advantageous in that the decomposition temperature can be lowered and the carbon number distribution of the product can be controlled, but the profitability is lowered due to the catalyst cost. The gas phase catalytic cracking process, which reacts the vaporized polymer with the catalyst through primary pyrolysis, is convenient to operate, but it is less profitable considering energy and catalyst costs. On the other hand, the liquid phase catalytic cracking process which directly adds a catalyst to the molten waste polymer material and decomposes it is preferable because a large amount of liquid products can be obtained at a low temperature. Therefore, there is a disadvantage in that the amount of catalyst used increases because only one catalyst is used. Because of this, a high catalyst cost is required, and therefore, the catalyst cost is very important in determining the profitability of the waste polymer material decomposition process in the liquid phase catalytic cracking process.

Catalysts used in the liquid catalytic cracking process of waste polymer materials should have high activity so as to decompose polymer materials even at low temperatures. However, the degree of decomposition is so severe that the degree of decomposition can be controlled so that a lot of liquid is not generated. do. In particular, it is highly profitable when the activity is high and the activity deterioration is slow so that a small amount of catalyst can be used but a large amount of waste polymers can be processed. When the acid strength is high, the decomposition reaction activity of the polymer material is high, but carbon deposition is severe. The higher the acid point, the faster the decomposition reaction, but also faster carbon deposition. Therefore, the acidity is high, but the acid concentration is not too high, the production of high-boiling compounds, which are precursors of carbon deposition, must be suppressed to decrease the activity decrease due to carbon deposition, thereby reducing the amount of catalyst used. In addition, it is more effective if the outer surface area is large and the possibility of contact with the polymer material is high. Moreover, since the catalyst for the liquid phase decomposition process can be used only once, the production cost must be very low to reduce the catalyst cost. In other words, high-activity and long-life long catalysts must be manufactured at a low price, thus increasing the profitability of the liquid phase catalytic cracking process and commercializing them.

Many zeolite catalysts have been studied as catalysts for the decomposition process of waste polymer materials [1]. In the bent pores of MFI or BEA zeolites, long hydrocarbons are less likely to be produced due to space limitations, and the diffusion is slow due to large resistance when the polymer material moves in the pores. As a result, it is difficult to produce long hydrocarbons, which are carbon deposition precursors, in the pores. Therefore, the catalyst deterioration is slowed by carbon deposition, and thus the catalyst activity is excellent in the liquid phase decomposition reaction of the polymer material. In addition, when the zeolite particles are small, the outer surface area in which the initial decomposition reaction of the polymer material proceeds is wide and the diffusion distance in the particles is short, thereby further increasing the decomposition activity. Small particles of MFI and BEA zeolite catalysts degrade polymer materials such as polyethylene (PE) wax and high density polyethylene (HDPE) quickly. However, even if zeolites with the same crystal structure are large, their decomposition activity is very low [2].

Since the polymer material is very large, it is difficult to enter into the zeolite pores as it is, and is primarily decomposed at the outer surface than the pores. However, since there is no limitation of pore structure on the outer surface, very long hydrocarbons, which are precursors of carbon deposition, can be produced, so that deactivation by carbon deposition is relatively fast. In particular, if the acid surface on the outer surface is too much, the carbon deposit is severe and the activity itself may be lost by covering the carbon to the pore inlet. Putting all these properties together, zeolite catalysts that can be used for liquid-phase catalytic cracking have desirable pores to prevent the formation of long hydrocarbons, and at the same time, the outer surface area is large due to the small particles, and the strong acid point is not too high. Do [3].

Since the catalyst for the liquid phase decomposition reaction should be high in activity and inexpensive, a method of enhancing the activity by further treating MFI zeolite synthesized without expensive organic template material has been devised [4]. Although the manufacturing cost is greatly lowered because the organic template is not used, it is difficult to manufacture the zeolite very cheaply because both the step of hydrothermal synthesis and the ion exchange and activation process are expensive. Since the price of the product produced by decomposing the waste polymer material can only be used as an alternative fuel, the price cannot be higher than the product produced by distilling the oil directly from crude oil, so the cost of producing the catalyst must be very low to increase profitability.

In the Fluidized Catalytic Cracking (FCC) process, diesel or diesel oil produced during crude oil distillation is contacted with a catalyst in a fluidized bed reactor to decompose the gasoline or naphtha fraction. As the number of automobiles increases, the demand for gasoline increases, and the naphtha demand increases due to the development of the petrochemical industry. The FCC process uses a spherical catalyst made of zeolite Y mixed with silica-alumina. Zeolite particles are contained in the large pores of the silica-alumina so that the large reactants are first decomposed at the silica-alumina acid point and then diffused into the zeolite pores to be converted into branched hydrocarbons having a high octane number. Recently, ultra stable zeolite Y (Ultra Stable Y; USY) prepared by partially eluting aluminum to improve thermal stability of the zeolite and to reduce the carbon deposition in the decomposition process to make the catalyst of the FCC process. However, this catalyst has a severe deterioration of activity due to carbon deposition despite only a few seconds of contact time. Therefore, the catalyst is recovered by a cyclone after the first use, sent to a regenerator, burned with carbon, and then used again. Thermal fatigue accumulated during use and regeneration and wear during the flow process cause particles to break down and carbon deposits in the pores are not completely removed, resulting in a gradual decrease in catalyst activity. The catalyst activity is kept constant by the removal method.

The spent FCC process catalyst is usually calcined in air to remove deposited carbon and then used as cement raw material. Recycling is considered as a brick manufacture or other zeolite synthetic raw material, but it is generated and mixed with limestone because of its high generation and low economic efficiency. The waste catalyst of FCC process has little other components besides silica and alumina, so there is no fear of pollution and it is suitable as cement raw material because of its excellent mechanical strength. However, significant amounts of zeolite remain in the FCC process waste catalyst. Although the structure is broken during use and carbon activity is lost much as an acid catalyst, the remaining zeolite component is likely to be a catalyst for decomposition of waste polymer materials. Since not too strong an acid point is more effective for the polymer decomposition reaction, the waste catalyst and the waste polymer material can be efficiently recycled at the same time as long as the FCC process waste catalyst can be properly treated and recycled.

The present invention provides a technique for inexpensively producing a catalyst that can be used for liquid phase catalytic cracking which converts waste polymer material into a low molecular hydrocarbon mixture. Catalysts that can be used in liquid phase cracking processes should be inexpensive but have a suitable acid point to decompose the polymer material. At the same time, the concentration of acid sites should not be too high so that carbon deposition will be fast, and the amount of catalyst used should increase profitability. To this end, the spent FCC process waste catalyst used in the fluidized bed catalyst decomposition process was first fired to remove the deposited carbon, and then further treated with acid and other methods to adjust the acidity and pore structure to suit the liquid phase decomposition process of the waste polymer material. . The collected FCC process waste catalyst is very active against decomposition of waste polymers containing polyolefin waste polymers such as PE and PP and low density polyolefins (LDPE) and ethylene vinyl acetate (EVA) such as waste agricultural vinyl. Because of their weakness and their activity only at very high temperatures, their use in liquid phase cracking requires significant increases. Along with this, there are differences depending on the composition and scale in the liquid phase decomposition of waste polymer material, but the throughput of waste polymer material per unit time is also very important in terms of productivity. Since the catalytic activity is limited even if the activity of the FCC process waste catalyst is increased, it is necessary to increase the treatment speed by using a catalyst mixed with a highly active synthetic zeolite. In the present invention, the mixed FCC process waste catalyst and the alkali-treated synthetic MFI zeolite are mixed and used, thereby increasing the operating capacity, thereby reducing the burden of facility costs, and thus improving the profitability.

In order to achieve the above technical problem, the present invention improves the activity and lifespan by effectively treating the FCC process waste catalyst so that it can be used in the process of decomposing the waste polymer material at low temperature into a low molecular hydrocarbon mixture which can be used as gas and liquid fuel. The focus was on. Since the spent catalyst itself does not have a price, even if the catalyst is used a lot, if a useful material is produced, the profitability of the liquid decomposition process of the waste polymer material may be greatly increased, thereby enabling commercial operation.

That is, the present invention is a waste polymer material characterized in that the waste catalyst is heated and refluxed at 60-80 ° C. for 2-6 hours with 0.2-2.0N hydrochloric acid and oxalic acid or 0.1-1.0N sodium hydroxide and potassium hydroxide solution. It is to provide a method for producing a catalyst for liquid phase decomposition of.

The present invention also provides a catalyst for liquid phase decomposition of waste polymer materials by mixing 10 to 100 g of an FCC process waste catalyst or a synthetic FAU or MFI zeolite catalyst treated with an acid or an alkali with respect to 1 kg of the waste catalyst treated with an acid and an alkali. It is to provide a method of manufacturing.

Further, the present invention is a liquid decomposition process characterized in that the decomposition of the low molecular hydrocarbon mixture in the range of 350 ~ 550 ℃ using 10 to 100g of the catalyst prepared in claims 1 and 2 per kg of PE, PP, waste agricultural vinyl To provide.

1 is an X-ray diffraction pattern of an acid treated FCC waste catalyst.

2 is an electron micrograph of an acid-treated FCC process waste catalyst.

3 is an apparatus diagram used for the experiment.

FIG. 4 is a yield distribution diagram of components of liquid products obtained from HDPE, LDPE, PP, and DAMP using an FCC process waste catalyst treated with 0.5N oxalic acid.

FIG. 5 is a yield distribution diagram of components of a liquid product obtained in DAMP using a mixed catalyst. FIG.

The present invention provides a method for enhancing activity by treating the FCC process waste catalyst so as to be used in the process of converting polyolefin waste polymer materials such as PE, polypropylene (PP), LDPE and EVA vinyl mixtures into low molecular hydrocarbon mixtures, It can be used alone or mixed with alkaline FAU or MFI zeolite to decompose the waste polymer material to provide a method of promoting the decomposition reaction and improving the yield of the liquid product.

The waste catalyst of FCC process contains 5-30% of ultra-stable zeolite Y, but the zeolite content is low, the structure is broken during use, and the deposited carbon pores are partially blocked. The catalytic activity is very low. In addition, silica-alumina, which is the main component of FCC process catalyst, has a lot of strong acid point, amorphous pore, and very large carbon deposit, so it is easy to decrease the activity in the decomposition of waste polymers.

In the present invention, the activity of the FCC catalyst waste catalyst which removes deposited carbon by firing in air is treated with acid to enhance activity. When treated with 0.2-3N hydrochloric acid, oxalic acid, or the like, aluminum of silica-alumina is eluted, and most of the strong acid points distributed in large pores disappear. At the same time, some of the aluminum in the ultra-stable zeolite Y is also removed, resulting in larger pore openings for faster material transfer. Therefore, the treatment concentration and time are set appropriately, which lowers the acidity of the large pores and widens the pores of the ultra-stable zeolite Y to promote the decomposition of the polymer material, while suppressing excessive decomposition in the zeolite pores, thereby making it possible to use a liquid product that is suitable for use as fuel. Could manufacture a lot.

The spent catalyst of the FCC process varies from manufacturer to manufacturer, but superstable zeolite Y is incorporated into silica-alumina. The green X-ray diffraction pattern after acid treatment of the spent catalyst is shown in FIG. 1. It can be seen from the diffraction peaks appearing in the spent catalyst that ultra stable zeolite Y is mixed. The diffraction peak is weak due to the low zeolite content and some breakdown of the structure during use. However, when treated with acid, the diffraction peak becomes larger. Hydrochloric acid treatment dissolves and removes amorphous materials such as silica and alumina, so that the zeolite content is relatively high and the diffraction peak becomes larger.

The catalysts used in the fluidized bed collide with each other in the flow process and are thus spherical to improve wear resistance. FCC process waste catalysts have broken down due to wear and thermal fatigue during the regeneration process during use, but they are also quite uneven in size, but are also spherical. However, treatment of the spent catalyst with hydrochloric acid dissolves the amorphous silica-alumina and turns the spherical catalyst into a very fine grain. As shown in FIG. 2, the waste catalyst recovered for disposal has a particle size of 50 to 100 μm, which is broken down to 1 to 20 μm when treated with 2.0N hydrochloric acid. This smaller particle size from acid treatment results in higher activity in the liquid phase catalytic cracking reaction. This is because the smaller the particles, the wider the outer surface on which the molten polymer material and the catalyst can react. Since the polymer material is first decomposed at the outer surface of the catalyst and then further decomposed into the zeolite pores, the decomposition activity of the catalyst is greatly enhanced when the particle size is reduced and the outer surface area is widened by acid treatment.

Treatment of spent catalysts with acids or alkalis enhances activity but limits the degree of enhancement. The efficiency of facility investment is increased by treating a lot of waste polymer materials with the same facility. Therefore, catalyst price and activity should be optimized in consideration of operating cost and facility investment cost. In the present invention, since the FCC process waste catalyst and the organic template material, which are appropriately treated and greatly improve the catalytic activity, are manufactured at low cost without mixing, the alkali-treated MFI and FAU zeolite are mixed with each other, so that the decomposition reaction is greatly promoted. Increased throughput of sugar waste polymer material.

Synthesis of MFI zeolite without the use of an organic template material greatly saves manufacturing costs, but generally results in larger particles. Since there is no organic template material, it is difficult to form the basic structure and secondary unit structure of zeolite, so the core concentration of zeolite in synthetic mother liquor is low. Because they grow long until they are big decisions. Compared with the core, the reactants are relatively large and can grow into large particles. However, in the liquid phase decomposition of the waste polymer material, the catalyst particles are small so that the outer surface area is large, so that the activity is high. Therefore, if the particles are synthesized without using the organic template material, the decomposition activity is low, and thus it is not useful for the decomposition reaction of the waste polymer material. However, when the large particle MFI zeolite is treated with an alkali solution to partially dissolve the surface, the particle size remains the same but the outer surface area becomes very large. To 20 g of MFI zeolite, 100 ml of 0.05-4.0 N sodium hydroxide or potassium hydroxide aqueous solution is added and treated at 60-80 ° C. for 0.5-8 hours to partially dissolve the zeolite surface to form mesoporous pores, thereby widening the outer surface area. If the treatment is performed at a temperature lower than 60 DEG C, the treatment time is long, and if it exceeds 80 DEG C, the catalyst recovery rate is lowered.

Alkaline treated MFI zeolite or FAU zeolite prepared in this way can greatly increase the rate of liquid phase catalytic cracking reaction by adding only a small amount to the FCC process waste catalyst. In this case, 100 ppm or less of a synthetic FAU or MFI zeolite catalyst treated with an acid or an alkali is mixed with an FCC process waste catalyst or 1 kg of a waste catalyst treated with an acid and an alkali to prepare a catalyst for liquid phase decomposition of waste polymer materials. It is preferable. Mixing 100 g or more thereof is not preferable because the production cost of the catalyst increases and the amount of waste catalyst generated increases.

In particular, when the activity of the catalyst decreases due to the generation of organic acid, such as decomposition of waste polymer containing EVA, such as waste agricultural vinyl, the organic acid is mainly adsorbed to the spent catalyst of the FCC process to protect the alkali-treated MFI zeolite catalyst, thus maximizing the catalyst mixing effect. .

Zeolite Y (FAU) has large pores and is connected three-dimensionally, but long and large hydrocarbons are formed in large supercages formed at intersections of pores, and thus, carbon deposits are likely to occur. In addition, the Si / Al molar ratio of 2 to 4 is low, and there is a lot of aluminum, so the acid point is very high. The acid strength is weak, but the concentration of the acid is high, and large hydrocarbons can be formed in large nests, so carbon deposition is very fast. For this reason, when FAU zeolite is used as it is for waste polymer material decomposition, its activity is very low. However, by treating the FAU zeolite with an alkaline solution, the pore inlet is shortened to shorten the residence time in the pores, and partial acid eluting inhibits the decrease in activity and increases the product yield. In particular, the acid strength is weakened, and the liquid product increases because the product quickly exits the pore from the three-dimensional pores and does not decompose to the gas. However, unlike the MFI zeolite, FAU zeolite has a weak crystal structure, so that the catalytic activity is enhanced by treatment with a weak sodium hydroxide or potassium hydroxide solution at 0.05 to 2.0 N. Treatment with the same strength as the MFI zeolite breaks the structure and lowers the catalytic activity.

The amount of catalyst used in the liquid phase decomposition of waste polymer materials using the catalyst prepared by the method of the present invention is low molecular hydrocarbon by decomposing and reacting at 350 to 550 ° C. using 0.01 to 0.2% by weight of the waste polymer material to be treated. Can be converted to a mixture. At this time, the reaction proceeds by pyrolysis if it exceeds 550 ° C., which is not preferable.

EXAMPLE

Hereinafter, an Example is given and this invention is demonstrated further more concretely.

Example 1

20 g of FCC waste catalyst was added together with 400 ml of 2.0 N oxalic acid solution and treated at 60-70 ° C. for 8 hours. After treatment, the mixture was washed with distilled water, filtered and placed in a dryer at 100 ° C. to remove moisture. Thereafter, the mixture was heated in an electric furnace at 550 ° C. for 6 hours to prepare an FCC process waste catalyst treated with oxalic acid.

FCC waste catalyst and catalyst treated with oxalic acid, HDPE with molecular weight of 250,000 manufactured by Honam Petrochemical Co., Ltd., LDPE with molecular weight of 150,000 manufactured by Hyundai Petrochemical, PP with molecular weight of 250,000, waste farming from Damyang Resources Reclamation Corporation. The liquid phase catalytic decomposition of waste vinyl (DAMP) prepared by washing the vinyl after melting was investigated.

The liquid phase catalytic cracking process of the waste polymer material was tested with the apparatus shown in FIG. 3. The reactor capacity was 100 ml, and a polymer material and a catalyst were added thereto, and the reaction was carried out after removing air with a nitrogen stream. The reactor was heated with a mantle and the reactor temperature was controlled with a PID controller. Gas is generated when the reactor temperature reaches around 300 ° C. When the reactor temperature reaches 380 ° C., a liquid product is obtained. The product was collected by liquefying in a condenser maintained at -4 ° C. Nitrogen gas was also flowed during the decomposition reaction to prevent contact with air and to keep the product flow smoothly. Table 1 below summarizes the results of liquid phase catalytic decomposition of these polymer materials.

Table 1. Liquid Phase Catalytic Degradation of Polymers from FCC Process Waste Catalysts and Catalysts Treated with Oxalic Acid

HDPE LPDE PP DAMP catalyst % Conversion Liquid yield (%) % Conversion Liquid yield (%) % Conversion Liquid yield (%) % Conversion Liquid yield (%) FCC Process Waste Catalyst 53 41 42 28 99 86 18 8 Waste catalyst treated with 0.5N oxalic acid 91 69 95 74 99 89 24 16

Reaction temperature-410 ℃

Reactant / Catalyst-10 g / 0.4 g

Response time-120 minutes

Even if the FCC waste catalyst is used as it is, if the reaction temperature is increased to 410 ° C, HDPE, LDPE, and PP are decomposed into liquid or gaseous products. In particular, PP readily decomposed and almost completely decomposed within 120 minutes. After the reaction is completed, the gaseous residue remaining in the reactor is cooled and condensed in the catalyst and the reactor, so the conversion rate is not 100%. Therefore, if the conversion rate is 90% or more, it is almost completely decomposed. On the other hand, the waste agricultural vinyl had a very low conversion rate of 18% and the liquid product yield of 8% under the same conditions. However, treating the FCC process waste catalyst with 0.5 N oxalic acid significantly increases the catalytic activity. The conversion rate of HDPE increased from 53% to 91%, and the LDPE conversion rate increased from 42% to 95%. In comparison, the conversion rate of DAMP, a waste vinyl, increased slightly from 18% to 24%. In DAMP, an organic acid that causes a decrease in catalytic activity was produced, resulting in little activity enhancing effect.

The product was analyzed by gas chromatography. The product distribution was similar regardless of the polymer type. The gaseous products were mostly hydrocarbons having 2 to 5 carbon atoms, of which C ₄ hydrocarbons were the most. The liquid product was mostly C ₅ -C ₁₂ hydrocarbons, with few hydrocarbons above C ₁₂ . The liquid product component distribution composition obtained from the oxalic acid treated FCC catalyst is shown in FIG. 4. The distribution of these hydrocarbon components differs slightly depending on the type of polymer material, but they are all similar. These may be used as fuels without further treatment, or may be used as naphtha or industrial solvents through purification processes such as decolorization treatment.

Example 2

10 g of the FCC waste catalyst was put in 100 ml of 0.3 N, 0.5 N, 1.0 N, 2.0 N hydrochloric acid and treated at 60 to 70 ° C. for 8 to 10 hours. After treatment, the filtrate was washed with distilled water and dried in a 100 ° C. dryer for one day. It was heated in a 550 ° C. kiln to activate the catalyst. The liquid phase decomposition of waste agricultural vinyl (DAMP) was investigated in a catalyst prepared by treating the FCC process waste catalyst with hydrochloric acid using the apparatus described in FIG. 3. HDPE, LDPE, PP, and so on decompose faster than DAMP, so only the results of DAMP decomposition are summarized in Table 2.

Table 2. Liquid Phase Degradation of DAMP in FCC Process Waste Catalysts Treated with Hydrochloric Acid

Hydrochloric acid concentration (N) - 0.3 0.5 1.0 2.0 % Conversion 18 27 35 39 18 Liquid yield (%) 8 15 22 16 9 Gas yield (%) 10 12 13 23 9

Reaction temperature-410 ℃

Reactant / Catalyst-10 g / 0.4 g

Response time-120 minutes

Compared to the untreated FCC waste catalyst, the catalyst treated with 1.0 N hydrochloric acid had a 39% conversion and a double liquid yield of 18%. The activity was much improved compared to before treatment, but 100% conversion was not obtained. In the liquid phase decomposition of the waste polymer material, it is difficult to separate and process the molten polymer material and the catalyst after use, so that the reactants should not remain. In the process of decomposing DAMP, the catalytic activity decreases due to the generation of organic acid, and the conversion is lower than that of HDPE, LDPE, and PP. Therefore, the amount of catalyst used should be increased in consideration of the catalyst poisoned by organic acid. Thus, by increasing the amount of catalyst per 10g of the polymer material to 0.6g to investigate the decomposition reaction of DAMP summarized in Table 3.

Table 3. Liquid Phase Decomposition of DAMP in FCC Process Waste Catalysts Treated with Hydrochloric Acid

Hydrochloric acid concentration (N) - 0.5 1.0 % Conversion 29 72 92 Liquid yield (%) 19 54 69 Gas yield (%) 10 18 23

Reaction temperature-410 ℃

Reactant / Catalyst-10g / 0.6g

Response time-120 minutes

The conversion was low at 39% when 0.4g of the FCC process waste catalyst treated with 1.0N hydrochloric acid was added to 10 g of DAMP, but the conversion was almost deteriorated to 92% when the catalyst usage was increased to 0.6 g. Although the catalyst usage is only one third more, the conversion rate is twice as high. This is because the activity of the catalyst is reduced by the organic acid generated during the DAMP decomposition process. When the amount of the catalyst used increases, the activity is not lowered by the organic acid, and a significant amount of the catalyst remaining in the activity remains, so that the conversion rate is increased.

Example 3

Emission of silica or alumina from the FCC process waste catalyst with alkali to form mesopores increases the external surface area, accelerates the diffusion of the polymer material, and significantly increases the catalytic activity in the liquid phase catalytic decomposition of the polymer material. However, since zeolite Y is weak to alkali, if the treatment concentration is not properly adjusted, the zeolite component dissolves first and the catalytic activity is lowered.

100 g of 0.1 N, 0.5 N, 1.0 N, 2.0 N sodium hydroxide solution was poured into 10 g of FCC waste catalyst and treated at 60 to 70 ° C for 2 hours. After treatment, the filtrate was washed with distilled water and dried in a 100 ° C. dryer for one day. The sodium cation was exchanged for protons by treatment with 0.5N hydrochloric acid to convert to an acidic catalyst. It was heated in a 550 ° C. kiln to activate the catalyst. Table 4 summarizes the results of the liquid phase decomposition of DAMP irradiated on the catalyst treated with sodium hydroxide solution.

Table 4. Liquid Phase Decomposition of DAMP in FCC Process Waste Catalyst Treated with Sodium Hydroxide

Sodium hydroxide concentration (N) - 0.1 0.5 1.0 2.0 % Conversion 29 21 68 35 20 Liquid yield (%) 19 11 51 21 12 Gas yield (%) 10 10 17 14 8

Reaction temperature-410 ℃

Reactant / Catalyst-10g / 0.6g

Response time-120 minutes

Alkaline treated FCC waste catalysts also degrade HDPE and PP quite well, so only the results of DAMP are poor. The conversion rate was significantly higher in the waste catalyst treated with 0.5 N sodium hydroxide solution compared to the untreated waste catalyst. This can be explained by the increase in degradation activity due to mesoporous formation and the effect of acid concentration. In acid treatment, the conversion was the highest when treated with 1.0 N hydrochloric acid. However, among the alkali treated waste catalysts, treatment with a lower concentration of 0.5 N resulted in higher catalytic activity. When treated with hydrochloric acid, only aluminum is eluted, whereas when treated with alkali, both silica and alumina are eluted. Therefore, in order to maintain zeolite structure and increase catalyst activity, treatment with dilute alkali is effective. In fact, treating the FCC process waste catalyst with 1.0 N sodium hydroxide solution eliminated all of the zeolite diffraction peaks, indicating that all remaining zeolite crystals in the spent catalyst were broken. This results in a lower conversion of DAMP in the FCC process waste catalyst treated with 2.0N sodium hydroxide solution than 29% in the waste catalyst not treated with 20%. Alkaline treatment produces mesopores, but all of the zeolite structure is broken, resulting in lower catalytic activity in the liquid phase decomposition reaction.

Example 4

FCC process catalysts are diesel catalysts for hydrocarbon cracking and react in a fluidized bed so that the zeolite content is usually controlled to within 30%, taking into account mechanical strength and conversion. Therefore, because the FCC process waste catalyst is a waste, only the treatment cost may be considered, but it is very advantageous in terms of cost, but there is a limit in catalytic activity even if the zeolite component is low and some structures are broken due to its use, thereby enhancing the activity by further treatment. For this reason, when a large amount of catalyst is used, many carbon-deposited spent catalysts are generated, but the throughput per unit time is not so high. This problem can be overcome by using a combination of the FCC process waste catalyst which maximizes the activity by the additional treatment and the synthetic zeolite having high activity per unit mass. Unlike high-molecular materials such as HDPE, LDPE, and PP, the decomposition reaction of waste agricultural vinyl mixed with EVA, which generates organic acids in the decomposition process, can significantly increase the decomposition reaction rate while reducing the catalyst cost by using a mixed catalyst. This is because the generated organic acid is mainly deposited in the FCC process waste catalyst, thereby preserving the catalytic function of the highly active synthetic zeolite.

Table 5 summarizes the results of the liquid phase decomposition of DAMP in synthetic MFI and FAU zeolite treated with a suitable alkaline solution. Since HDPE, LDPE, and PP are all decomposed using only 1/2 of the catalysts shown in this table, only the results of DAMP are difficult to digest.

Table 5. Liquid Phase Decomposition of DAMP on MFI and FAU Zeolites and Alkali Treated Catalysts

Reaction temperature (℃) Catalyst amount (g) Response time (minutes) % Conversion Liquid yield (%) Gas yield (%) MFI 380 0.3 60 20 10 10 MFI- 0.5N Sodium Hydroxide Treatment 380 0.3 40 98 52 46 FAU 410 0.2 200 74 60 14 FAU- 0.05N Sodium Hydroxide Treatment 410 0.2 160 90 66 24

Reactant-10 g

The synthesized MFI zeolite itself is not very active and the conversion is very low at 20% at 380 ° C. By comparison, the catalyst treated with 0.5N sodium hydroxide solution has a very high conversion rate of 98%. In particular, the reaction proceeds so quickly that the decomposition reaction is terminated within 40 minutes. The FAU zeolite has a high conversion temperature of 410 ° C. and a high conversion rate of 74% using only 0.2 g. It takes about 200 minutes to complete, but the liquid product yield is quite high, 60%. When treated with 0.05 N sodium hydroxide solution, the conversion rate is increased to 90% and the time required for the decomposition reaction is shorter than 160 minutes. These synthetic zeolites have a very high catalytic activity compared to FCC process waste catalysts. 0.6g of FCC process waste catalyst treated with 1.0N hydrochloric acid solution at 410 ° C is almost completely decomposed, so the amount of catalyst used is 0.2g or 0.3g. However, due to the low economic value of hydrocarbon mixtures produced by the decomposition of waste polymers, the use of synthetic zeolites as such is not practical and therefore unprofitable.

Example 5

In the liquid phase decomposition of waste agricultural vinyl, the amount of catalyst is inevitably increased because the catalyst loses a certain amount of activity by the organic acid. Therefore, using a mixed catalyst containing a small amount of a high activity but an expensive catalyst with a low activity but a low cost, or a FCC catalyst waste catalyst subjected to primary acid treatment, all organic acids are decomposed, and then a synthetic zeolite is added to decompose the polymer material. To maximize catalyst utilization.

Table 6. DAMP Decomposition in Mixed Catalysts

catalyst Response time (minutes) Usage (g) % Conversion FCC Process Waste Catalyst 120 0.4 18 0.5N Oxalic Acid Treated FCC Process Waste Catalyst 120 0.4 24 0.5N oxalic acid treated FCC process waste catalyst (A) + FAU zeolite (B) 100 (A) 0.4+ (B) 0.1 91 0.5 N oxalic acid FCC process waste catalyst (A) + 1.0 N sodium hydroxide treated MFI zeolite (B) 100 (A) 0.4 + (B) 0.05 93

Reaction temperature-410 ℃

Reactant-10 g

When the FCC process waste catalyst shown in Table 6 is used alone, the conversion rate is as low as 24%. However, adding 0.1 grams of FAU zeolite will triple the conversion rate. In Table 5, 0.2g is required to decompose 90% of DAMP using FAU zeolite alone, but 0.1g can be sufficiently decomposed when used in combination with the FCC process waste catalyst. In particular, when only 0.05 g of MFI zeolite treated with alkali is added, the conversion is very high at 93%. In other words, by appropriately treating the FCC process waste catalyst to enhance the catalytic activity, and using a mixture of high-activity FAU or MFI zeolite catalyst to reduce the amount of catalyst used and cost, while significantly increasing the throughput of waste polymer material per unit time Can be.

Using a mixed catalyst has the effect of controlling the composition of the liquid product in addition to increasing conversion. Figure 5 shows the yield of each hydrocarbon component of the liquid product obtained in the liquid phase decomposition process of Table 6. The FCC process waste catalysts themselves have very low yields, but when treated with 0.5 N oxalic acid and mixed with synthetic FAU or MFI zeolites, the yields are very high. Of these, many hydrocarbons having 10 to 14 carbon atoms are generated in the catalyst used in combination with the FAU zeolite. The higher boiling hydrocarbons result in greater convenience and stability when used as a liquid fuel. Therefore, if the amount and proportion of the mixed catalyst is properly adjusted, the quality of the liquid fuel can be greatly improved.

As described above, according to the present invention, an appropriate acid treatment of the waste catalyst of the FCC process provides high activity and low carbon deposition to rapidly decompose waste polymer materials into low molecular hydrocarbons and at the same time to inexpensively prepare catalysts having high yields of liquid products. Provide a method. Since the catalyst is used alone or in combination with FAU or alkaline MFI zeolite catalysts, it is possible to efficiently convert polyolefin waste polymer materials into low molecular hydrocarbon mixtures that can be used as fuel or petrochemical raw materials.

[references]

[1] J.-S. Shim, YS You, J.-H. Kim and G. Seo: “ Liquefaction of Polyethylene Wax over Solid Acid Catalysts” Studies in Surface Science and Catalysis, 82 , 465-466 (1998).

[2] YS You, J.-H. Kim and G. Seo: "Liquid-Phase Catalytic Degradation of Polyethylene Wax over MFI Zeolite with Different Particle Sizes", Polymer Degradation Stability, 70 , 365-371 (2000).

[3] YS You, J.-H. Kim and G. Seo: "Liquid-Phase Catalytic Degradation of Polyethylene Wax over Silica-Modified Zeolite Catalysts", Polymer Degradation Stability, 72 , 329-336 (2001).

[4] Seogon, Kim Jong-ho,: 제조 Method for preparing liquid phase decomposition catalyst for waste polymer materials and decomposition method using the same.〃, Korean Patent Application No. 75515 (Dec. 12, 2000).

Claims (3)

FCC process waste catalyst is a liquid catalyst for liquid phase decomposition of waste polymer materials, characterized by heating and refluxing at 0.2 to 2.0 N hydrochloric acid and oxalic acid or 0.1 to 1.0 N sodium hydroxide and potassium hydroxide for 2 to 6 hours at 60 to 80 ° C. Manufacturing method. The catalyst for liquid phase decomposition of waste polymer materials is prepared by mixing 100 g or less of a synthetic FAU or MFI zeolite catalyst treated with an acid or an alkali with respect to an FCC process waste catalyst or 1 kg of a waste catalyst treated with an acid and an alkali. How to manufacture. PE, PP, liquid decomposition process characterized in that the decomposition of the low molecular hydrocarbon mixture in the range of 350 ~ 550 ℃ using 10 ~ 100g of the catalyst prepared in claim 1 per kilo of vinyl for agricultural waste.