KR20080080264A - Three-stage catalytic pyrolysis process for recovering hydrocarbons from mixed synthetic resins. - Google Patents

Abstract

The present invention is a high-efficiency pyrolysis method of mixed synthetic resins, wherein pyrolysis is a reaction in which a polymer compound is heated at high temperature without contact with air, and is decomposed into low molecular weight by the action of a catalyst to be converted into fuel oil such as kerosene or an aliphatic or aromatic monomer. to be. However, vinyl chloride resin (PVC) is contained in the mixed waste plastics, and the material has a relatively low thermal decomposition temperature and releases a large amount of corrosive gas, hydrogen chloride, to decompose the generated fuel oil, thereby degrading its practicality. . The present invention is a successor of the patent application No. 16866 and the patent application No. 40640, the first invention, in order to prevent the contamination of the recycled fuel oil, firstly decomposes resins having low decomposition temperature such as vinyl chloride resin and polystyrene resin in one step , The product is quenched and recovered by hydrogen quenching and low boiling point, the molten mixed mixed resin is continuously fed to the two-stage catalytic pyrolysis, and the petroleum-grade hydrocarbons from which chlorine is contaminated are recovered continuously. The present invention relates to a multi-stage catalytic pyrolysis process in which point waxes are thermally decomposed in a final stage fixed catalyst and recovered as kerosene.

Description

3-Stage Catalytic Pyrolysis Process for the Hydrocarbon Recovery from Mixed Synthetic Resin}

The technical field of the present invention is a thermal decomposition method of a mixed synthetic resin, the thermal decomposition method is an aliphatic high molecular compound such as vinyl chloride resin (PVC), polyether (PE), polypropylene (PP), and polyether terephthalate ( A mixture of aromatic polymer compounds such as PET), polystyrene (PS), and acryronitrile butadiene styrene (ABS) resin is heated to high temperature without contact with air and decomposed into low molecular weight to be converted into fuel oil such as kerosene. It is an economical, high value-added process that can be recovered with monomers.

Patent application 16586, which is a prior invention of the present invention, is an unstirred thin film pyrolysis apparatus in which a fixed bed pyrolysis catalyst is filled in a tube, and this method melts a mixed waste synthetic resin and causes a liquid resin to flow down through a fixed bed catalyst, thereby causing a catalytic pyrolysis reaction. As a result, only the liquid thermoplastic resin can be reacted, and the solid matter is deposited on the surface of the catalyst and the fixed phase is likely to be blocked. Thereby, there is a limitation that the thermosetting resin cannot be treated by filtration.

        Patent application 40640 has developed a method suitable for the thermal decomposition of waste synthetic resin by improving the air flow transfer pyrolysis technique, which is a known pyrolysis method, for catalytic pyrolysis of solids that cannot be treated in the present invention. The reaction stage is divided into one-stage falling pyrolysis and two-stage falling pyrolysis, and in the first-stage falling pyrolysis step, firstly pyrolyzes the thermoplastic resin melted by high heat in the mixed waste synthetic resin input to produce fuel oil mainly composed of kerosene. In the fall-fall pyrolysis step, a high-temperature catalyst is added to the reactor to increase the temperature, and thermally decompose the powdery thermosetting resin, which has not reacted in the previous step, to generate decomposition gas, which is a low molecular hydrocarbon, to form a liquid and powdery waste synthetic resin in a single reaction system. It is effective pyrolysis within.

       Conventionally known airflow pyrolysis methods continuously inject liquid or powdery waste synthetic resin into a vertical tubular airflow pyrolysis reactor which circulates the regenerated high temperature regenerated catalyst together with the reaction gas or the inert gas. Is a reaction apparatus that promotes catalytic pyrolysis by direct contact with heat transfer, and there are two methods of air transfer pyrolysis reactors, a rising type and a falling type, but the reaction time is very short as several seconds. It is difficult to pyrolyze the mixed synthetic resin as a single reaction step. U.S. Patent No. 6,534,689 intends to complete the reaction by performing fluidized bed pyrolysis again in the bottom water of the falling air stream pyrolysis unit as a complementary solution. However, in order to form a fluidized bed, a reaction gas or an inert gas has to be blown to the lower part of the fluidized bed, which impedes practicality by impeding the recovery of the produced hydrocarbon or removing the hydrochloric acid.

Pyrolysis is a sensitive catalytic reaction in which high-temperature flammable vapors are generated. In addition, the pyrolysis reaction temperature exceeds the ignition point of low molecular hydrocarbons, and the pyrolysis reaction apparatus has a high risk of ignition and ignition. Due to the deterioration of activity due to excessive production of gas and tar phase carbides, mechanical fragility of the device and the high level of operation have not been practical. In addition, vinyl chloride resin (PVC) is contained in the mixed waste plastics, which accounts for about half of the amount of plastics produced. This material has a relatively low thermal decomposition temperature and contaminates the fuel oil produced by releasing a large amount of corrosive gas, hydrogen chloride. In other words, it is a factor that hinders the recycling of recovered fuel oil.

The present invention is a successor of the patent application No. 16866 and the patent application No. 40640, the first invention, in order to prevent the contamination of the recycled fuel oil, firstly decomposes resins having low decomposition temperature such as vinyl chloride resin and polystyrene resin in one step , The product is quenched and recovered by hydrogen quenching and low boiling point, the molten mixed mixed resin is continuously fed to the two-stage catalytic pyrolysis, and the petroleum-grade hydrocarbons from which chlorine is contaminated are recovered continuously. The point waxes are then pyrolyzed in the final stage of the fixed catalyst bed to recover high quality kerosene in high yield.

1) By recovering kerosene practically from mixed synthetic resin containing vinyl chloride resin, waste synthetic resin of about 3 million tons / year can be recycled as alternative energy without end-processing, thus achieving environmental protection and crude oil import substitution effect. .

2) Vinyl chloride resin is one of four general-purpose resins, and hydrogen chloride and fuel oil are separated and recovered by three-stage cracking to achieve recycling practical use of waste vinyl chloride resin.

If described in detail by the accompanying drawings;

       1 is a three-stage catalytic pyrolysis method for recovering hydrocarbons from a mixed synthetic resin. (1) A pulverized mixed synthetic resin injected into a raw material hopper under nitrogen sealing, through a feeder, and (2) continuously pyrolyzed to a salt pyrolysis machine. The produced hydrochloric acid and the low boiling point are introduced into the (12) quench absorption tower through a steam pipe, quenched and absorbed into water, and stored in a recovery hydrochloric acid tank. By contact pyrolysis, the resulting kerosene which is not contaminated with chlorine is condensed into (5) the distillate, (6) cooled by the cooler (9) and stored into the recovery kerosene tank. The resulting wax (4) flows into the catalyst stationary phase, further pyrolyzes, is converted to kerosene, ascended into a still oil and recovered as kerosene. The cracked residue is mixed with the catalyst and discharged from the pyrolyzer simultaneously with the catalyst. Low-boiling fraction is discharged to the top of the distillation column and condensed through (7), (8) 1 and 2nd condensers, some are refluxed, and the recovered fraction is flown into and stored in the recovery fuel tank (11). (13) It is used as fuel of the heat heater and the heated fruit is used as a pyrolysis heat source.

       1 is a three-stage catalyst pyrolysis method for recovering hydrocarbons from a mixed resin.

(1) Raw material mixer (8) Secondary condenser

(2) salt crackers (9) recovery kerosene tanks

(3) catalytic crackers (10) recovered fuel tanks

(4) fixed bed catalyst (11) gas storage tank

(5) distillation tower (12) quench absorption tower

(6) Chillers (13) Fruit Heaters

(7) primary condenser

Claims (1)

To convert the mixed synthetic resin containing vinyl chloride resin (PVC) into hydrocarbons by catalytic pyrolysis under nitrogen sealing without air contact;         A) In the first step, resins having low decomposition temperatures such as vinyl chloride resin and polystyrene resin are pyrolyzed at 200 to 400 degrees Celsius to recover hydrogen chloride and low boiling point of the product through a quench absorption tower,         B) Continuously recover the kerosene from which chlorine is contaminated through the distillation column by rapid thermal cracking by direct contact with the catalyst preheated at 300 ~ 600 degrees Celsius by continuously adding mixed mixed resin melted in this stage to the catalytic pyrolysis machine.         3) recovering kerosene with improved quality and yield by pyrolyzing high boiling point waxes descending to the bottom of the distillation column in three stages at 200 ~ 500 degrees Celsius. A three-stage catalyst pyrolysis method characterized by the above three stages of selective catalytic pyrolysis process.

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