RU2250239C1 - Rubber-containing waste processing - Google Patents

Abstract

FIELD: rubber industry.

SUBSTANCE: invention, in particular, relates to reusing worn out motor car tires and mechanical rubber ware by processing them into fuel oil and liquid and solid matters that can be used as raw material for various production processes. Processing of rubber-containing waste comprises fluidization of waste in hydrocarbon solvent (benzene) at 280-320°C, separation of liquid fraction, and distillation thereof to produce desired products. According to invention, prior to be fluidized, waste is treated, in atmosphere of gas, which is inert to initial waste, with destruction products in excess benzene until complete swelling is attained, after which excess benzene is separated and recycled to the head of process. Thermal fluidization is conducted in the same gas atmosphere, while simultaneously separating liquid fraction and obtaining fuel oil as target product and benzene, a part of which being returned into process. Inert gas is preferably carbon dioxide and heating to 280-320°C is provided by high-frequency currents at thermal fluidization pressure up to 2 atm.

EFFECT: reduced expenses and improved environmental safety of processing due to wasteless technology.

4 cl

Description

The invention relates to the field of organic waste processing, in particular to methods for processing rubber-containing waste, and can be used for the disposal of worn-out tires and rubber products by processing them into boiler fuel, as well as liquid and solid wastes that can be used as raw materials for various industries.

The constantly growing amount of waste rubber products, in particular worn-out tires, creates the problem of their disposal and recycling. The burning or disposal of these wastes leads to environmental pollution, as well as the loss of organic raw materials and metal. Deep complex processing of these waste products allows you to get products that can be used as boiler fuel and as chemical raw materials for various industries.

There is a method for the thermal processing of used tires by loading whole products into a high-temperature reactor, supplying it with gaseous hydrocarbon and heating it to obtain liquid and gaseous hydrocarbon products and a solid residue, while the temperature in the lower part of the reactor is 250-425 ° C, and in the upper part 130-290 ° C. Get purified metal cord and hydrocarbon products of the following composition,%: liquid products - 58-62; gaseous products - 7-10; solid residue - 31-32 (RU, patent No. 2128196, C 08 J 11/06, 1999).

The disadvantage of this method is the use of natural gas in high-temperature conditions, which increases the explosiveness of the reactor, and also complicates and increases the cost of its hardware design.

The closest in technical essence to the proposed one is a method of processing organic industrial and household polymer waste into motor fuel and chemical raw materials used in organic and inorganic synthesis, which consists in thermal fluidization of waste at 270-420 ° C and a pressure of 1-6 MPa in a hydrocarbon solvent, representing one or more alkylbenzenes, which use the product of the distillation of “crude benzene” with a mass ratio of solvent and waste 2-4: 1 in the presence of rare earth metal or intermetallic compounds based on rare-earth metals, or in the presence of titanium hydride, taken in an amount of 0.5-10% by weight of the reaction mixture (RU, patent No. 2110535, C 08 J 11/04, 1998).

The disadvantages of this method are the complexity of the hardware design due to the need to conduct the process under high pressure, as well as the use of expensive and scarce rare earth metals or intermetallic compounds based on rare earth metals that are difficult to extract from products obtained from processing.

The objective of the invention is to obtain an inexpensive, waste-free, reliable and environmentally friendly technology for processing rubber waste.

The technical result obtained from the use of the proposed method is to reduce the time of the process and reduce its energy intensity.

The problem is solved, and the technical result is achieved due to the fact that benzene is used as a hydrocarbon solvent in the method for processing rubber-containing wastes, including heat-liquefying wastes in a hydrocarbon solvent at temperatures of 280-320 ° C, separating the liquid fraction and its distillation to obtain the desired products , before thermal liquefaction, the waste is treated in a gas inert with respect to the initial rubber-containing waste and degradation products, in excess of benzene until completely swollen after which the excess benzene is separated and returned to the head of the process, thermal liquefaction is carried out in a gas medium inert to the initial rubber-containing waste and degradation products, with the simultaneous separation of the liquid fraction, and boiler fuel and benzene are obtained as the target distillation products, some of which are returned to the head of the process, while it is preferable that carbon dioxide is used as an inert gas, and heating to 280-320 ° C is carried out by high-frequency currents at a thermal fluidization pressure of up to 2 atmospheres.

The use of benzene as a hydrocarbon solvent determines the reliability and stability of the process for processing rubber-containing waste, since benzene, having a boiling point of 80 ° C, allows it to be separated from other thermal fluidization products in a narrow temperature range to obtain a marketable product and the possibility of its return to the process head, i.e. e. to the initial stage. The liquid fraction remaining after distillation of benzene is boiler fuel.

In the process of swelling in excess of benzene, the destruction of rubber-containing waste occurs, and the process of swelling in an inert gas environment, i.e., any gas inert to the starting rubber-containing waste and degradation products (for example, pure nitrogen, and preferably carbonic pelvis), prevents leakage various chemical reactions, including oxidative ones.

The temperature heating of the reactor can be carried out by any known methods, for example by induction heating, and preferably by heating with high frequency currents.

Maintaining heating with high frequency currents to a temperature of 280-320 ° C with the simultaneous separation of the liquid fraction helps to accelerate thermal liquefaction and increase the depth of destruction of rubber-containing waste.

The method can be carried out at normal or slightly elevated pressure, preferably up to two atmospheres, which helps to reduce the cost of the process due to the absence of the need to use complex and expensive equipment required for operation at high pressures.

The method is as follows.

Rubber-containing wastes are loaded into a high-temperature reactor equipped with devices for heating with high-frequency currents, which can be used as whole waste automobile tires, scraps of rubber-fabric plates and other wastes, the reactor is sealed and blown, for example, with carbon dioxide, and then excess hydrocarbon is introduced the solvent is benzene. Complete swelling of rubber-containing wastes in excess benzene in carbon dioxide occurs in 15 minutes, after which excess benzene is expelled from the reactor, which is returned to the process head, i.e. at the initial stage of the process, and served in a second reactor, similar to the first, for swelling the next portion of rubber waste. Under the influence of high-frequency currents, the contents of the reactor are heated to 280-320 ° C with the simultaneous separation of the liquid fraction, which is subjected to distillation. The power of the installation does not exceed 100 kW / h when using high frequency currents above 1500 Hz. At a temperature of 80 ° C, benzene is separated from other thermal liquefaction products, part of which is returned to the process head for processing new portions of rubber-containing waste. The liquid fraction remaining after distillation of benzene is boiler fuel. The solid fraction remaining in the reactor and containing coke and metal cord is discharged from the reactor, after which the reactor is again ready for loading. For the continuity of the process of processing rubber-containing waste, two or more high-temperature reactors are used.

An example implementation of the method.

An example is given in a laboratory experiment. In the reaction chamber V - 2 liters, 300 g of cut worn automobile tires are laid and 600 g of solvent, benzene, are poured. To create an inert atmosphere, the reaction chamber is purged with a gas inert with respect to the initial rubber-containing waste and degradation products — СО ₂ . After 15 minutes, the rubber completely swells, after which excess solvent, 510 g, is distilled off. Thus, the rubber absorbed 90 g of benzene (i.e., it took about one part of benzene to process three parts of rubber-containing waste). The reaction chamber is heated using high frequency currents to 320 ° C while distilling off the liquid hydrocarbon fraction. Heat liquefaction is carried out at a pressure of 1.2 atmospheres. Heat liquefaction time - 30 min. The solid fraction formed in the reaction chamber contains coke and metal cord, which are discharged at the end of the process.

Calculate the material balance.

Pledged: 300 g of rubber-containing waste;

90 g of benzene;

TOTAL: 390 g.

Received: 250 g of liquid hydrocarbons;

120 g - coke;

10 g - steel cord;

TOTAL: 380 g.

The resulting deficit - 10 g - are gaseous products - pyrogas.

Chromatographic analysis of the liquid hydrocarbon fraction showed a benzene content of 53%.

250 g of the liquid hydrocarbon fraction contains 132.5 g of benzene; of which 90 g - benzene, which was used to swell the processed rubber waste. Thus, an additional 42.5 g of benzene was obtained during the destruction of rubber. The sulfur content in benzene does not exceed 0.01%. The remaining 117.5 g is high-calorie boiler fuel with a flash point of 98-102 ° C. The sulfur content in boiler fuel does not exceed 0.8%.

130 g of solid fraction contains 120 g of coke and 10 g of steel cord. The sulfur content in coke is 1.5-2.0%.

Thus, from 300 g of rubber we get:

benzene - 42.5 g - 14.2%;

boiler fuel - 117.5 g - 39.2%;

Coke - 120 g - 40.0%;

metal cord - 10 g - 3.3% and

pyrogas - 10 g - 3.3%.

Thus, the proposed invention allows to utilize rubber-containing waste, including worn-out automobile tires, and to process them into materials suitable for further use.

Claims (4)

1. A method for processing rubber-containing wastes, including thermal fluidization of wastes in a hydrocarbon solvent at temperatures of 280-320 ° C, separation of the liquid fraction and its distillation to obtain the desired products, characterized in that benzene is used as the hydrocarbon solvent, and the waste is subjected to treatment in the medium before thermal liquefaction gas, inert with respect to the initial rubber-containing waste and degradation products, in excess of benzene to completely swell, after which the excess of benzene is separated and returned to the head about ECCA thermal liquefaction is carried out in the atmosphere gas inert to the starting rubber waste and degradation products, while separating the liquid fraction, and as target product distillation obtained fuel oil and benzene, a portion of which is recycled to the process head. 2. The method according to claim 1, characterized in that carbon dioxide is used as an inert gas. 3. The method according to claim 1 or 2, characterized in that the heating to 280-320 ° C is carried out using high frequency currents. 4. The method according to any one of claims 1 to 3, characterized in that the thermal liquefaction is carried out at a pressure of up to 2 atmospheres.