CZ90495A3 - Process of combined recovery of mixed and contaminated waste plastics - Google Patents

Description

Method of combined evaluation of mixed and contaminated plastic waste

FIELD OF THE INVENTION The object of the invention is a method of combined recovery of mixed and contaminated plastic waste. BACKGROUND OF THE INVENTION

Plastics are used extensively in the home, business, crafts and industry. In particular, they are used as waste material and, in a short time, plastics fall away again as spent contaminated plastic waste. In waste, plastics are either mixed or contaminated. Sorting into individual types is rarely possible with a small expense. A large part of the plastics produced exists as a composite material with various types of plastics, paper, textiles or metals and is therefore not easy to recycle.

some of the plastic waste is now domestic waste or incinerated in waste incineration, Since it is difficult to biodegrade because of its low degree of efficacy to increase COp, and furthermore there is a high probability of dioxin formation.

A big deposit in women's plastic; / there is a sewing issue that will be

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DE 40 29 830 proposes plastics and waste containing plastic shreds to liquefy at elevated temperatures by degradation of polymers and injected into the combustion chambers of gasification reactors. processed with combined materials. These limitations are at the expense of large-scale use.

Three of this method proposes to separate mechanical impurities in the liquefaction process. The possible use for scrapping waste from the treatment of old car material is in doubt, as it usually contains 20 µl of mineral and metal impurities. Possibilities of recovery of these residues can not be

L2 40 17 035 describes a method and apparatus for the gasification of plastics for the production of synthesis gas. For the liquefaction of plastics, worm kneading machines or double worms are designed which operate at> 400 ° C and> 100 bar. Before liquefaction, substances are added to the plastics to accelerate catalytic degradation of molecules. Mechanical impurities are separated from the plastics during liquefaction. and due to the expected abrasion at this high mechanical engineering load, the proposed method is not suitable for liquefying contaminated plastics. Some mechanical impurities, which are supplemented by molten plastics, do not show any possibility of recovery, so they are likely to turn out as a deposition product. The metal oxide class prior to introduction into the gasification reactors presents a disadvantage in that these may form undesirable slags which can lead to disrupt the lining of reactors or gas outlet systems.

The design of D2 40 23 999 requires the recovery of metals from the combined materials by the porn separation of non-metallic components with defined solvents under defined process conditions. This process is technically very expensive and requires more process steps to obtain species-pure individual components. The extent to which large-scale use leads to economically and technically applicable products remains an open question.

Despite the proposed method of DE 40 29 379, only part of the plastic waste is to be incinerated with oxygen and the other part is to be gasified or liquefied and then injected into the flue gas jet. This process is disadvantageous because multiple process steps have to be operated simultaneously with strictly defined process parameters in order to obtain a useful synthesis gas.

It has also been known that plastic wastes, in particular foils, should not be melted and compacted. The drawback of this process is that high energy costs are required for melting and that the necessary compaction devices such as an extruder exhibit high wear .

It has also been known that plastic wastes are recovered by hydrogenation. Another disadvantage of this process is the non-residential energy-intensive and costly treatment for the hydrogenation process. The liquid hydrocarbon fraction produced must be treated very costly for further evaluation. Dři hydrogenation

-4 of the process, the hydrogenation residue containing heavy metals and chlorine is eliminated and must be treated separately.

The method for the recovery of contaminated and mixed plastic waste is not available today in sufficient capacity, so methods have already been proposed, for example as described in D3 41 07 023 for interim storage? This method suggests interim storage of plastic waste mixed with non-combustible materials to reduce fire risk. This method has the drawback that the plastic waste must again be costly to separate, more polluted than before, and a large amount of storage is required.

SUMMARY OF THE INVENTION

It is an object and object of the present invention to provide a recovery process which allows the environmentally compatible mixed and contaminated plastic waste to be recovered by a gasification process. According to the invention, this object is achieved by introducing mixed and contaminated plastic wastes separately liquefied or mixed with hydrocarbons existing at the liquefied state at a temperature in the liquefied state into the buoyant gasifier. Furthermore, liquefied plastics can be used as carrier medium for problematic fine-grained mineral and / or organic solid residues such as contaminated filter dusts and fine-grained dried lacquers

In carrying out the processes, the feedstocks are returned through one or more of the burner blower tubes and do not react to CO-containing gases and, wherein the fine-grained, solid mineral constituents of the feedstocks contained in the feedstock are contained in the burner. They are used as slag-forming substances and cause binding of inorganic impurities and pollutants contained in liquefied plastics such as heavy metals. In the proposed new process, the mineral and metal impurities of plastic waste with a size > 5 mm before the quenching are optionally pulverized to less than 5 mm. Particularly when introducing liquefied plastics through a separate blower tube, the proportion of impurities in the plastic and the proportion of problematic fine-grained mineral and / or organic solid residuals can be up to 40. and / or organic residuals of up to 15%. Fine-grained mineral and / or organic residual substances may have a maximum grain size of 5 am.

R AC combined total method is characterized in that the residual substances are separated prior to liquefaction or p ^r i liquefaction separately add value to the process of a pressurized gasification fixed bed. In this new process, the energy for melting mixed and contaminated plastic waste is obtained from their conversion product

The resulting synthesis gas can be used directly as an energy supplier. The energy supplier can also be steam, obtained from reaction heat or electricity. The advantage lies in the energy autarchy and in the generally increased degree of conversion efficiency.

The advantage of the process is in particular that liquid and solid residues can be recovered simultaneously by a single process step and that the heat generated by the conversion of mixed or contaminated plastic waste liquefied separately or mixed with hydrocarbons existing at normal temperature in the liquid state The fluidized bed gasifier converts solid, simultaneously entrained residuals into syngas and slag, and the heavy metals contained in the liquid and solid residues are bound to the mineral constituents of the solid residues in an ineligible manner. No waste is produced in combination with fixed bed pressure gasification. which must be deposited or destroyed in a waste incineration plant.

DETAILED DESCRIPTION OF THE INVENTION

The invention is to be explained in more detail by means of two exemplary embodiments.

Example 1

In the stirrer boiler 3, mixed or contaminated plastic wastes 1 are liquefied by the introduction of heat from the power supply or by using spent oil heated in the heated apparatus 21 at a temperature of 400 ° C of 3 t / h. kg of solid residues per hour that are fed to a fixed bed gasifier mixed with coal for gasification. The liquefied plastic waste is fed to a gasification reactor 10 via a separate burner discharge tube via a conveyor 20.

As a further feed product, spent gas 2 at a rate of 8 t / h through the agitator tank 7 is fed into the gasification reactor 10 as a base load. Spent oil 2 contains the following concentrations of pollutants:

TCB 150 mg / kg

Ou 2500 mg / kg and 2000 mg / kg

In 2000 mg / kg

At the same time, about 13,000 bP / oxygen 11 and 4 t / h of gasification steam 12 are fed to the gasification reactor 10 via the main burner 8. In the temperature range of 1300 to 2000 ° C, the fission gas 16 is formed from the organic feedstocks. in an amount of 40,000 m < 3 > / h, after quenching to 195 [deg.] C. by quenching with water 14, gas treatment occurs. The composition of fission gas is as follows:

C0 ₂ 6.0 fi

47.0 H _2/0

CO 45.7

-3CH ₄ 0.3 7>

κ ₂ 1.0 7

Upon conversion and purification of the gas, conversion to methanol is carried out.

The heavy metals are weighed into the slag produced in the gasification reactor and dropped in the cooling tank 13 as a non-pelletized granulate 17 in an amount of 0.4 t / h. The carbon black water 18, the hydrogen free carbon, is fed to a simple treatment.

Example 2

Besides prosktu batch corresponding to example 1 was introduced 1 t / h through a clarifying sludge silo £ 4, mixed in a mixing device 6 3 t / h of waste oil .2 and through the second mixing tank ^with liquefied plastic přesoddělený ® burner into the gasification reactor 10. The clarifying sludge contains 90 / solids, of which 1,000 ng ΤΞ dioxin / kg and 2000 mg Cr / kg. In addition to 9 t / h spent oil, 17,000 m m / h of oxygen and 5 t / h of gasification steam are fed to the gasification reactor 10 via the main burner. In the gasification reactor 10, dioxin and organic components of the plastic / clarifying sludge mixture are converted to 51,000 m @ 2 of dioxin-free fission gas 16 per hour. The amount of non-elucible slag granulate 17 is increased to 0.7 t / h.

Claims (1)

A method for the combined recovery of mixed and contaminated plastic waste in a gasification process, in particular a fluidized bed gasification and pressure gasification process, characterized in that the contaminated plastic waste is liquefied, separated or mixed with hydrocarbons existing at normal temperature in the liquid state and / or With a proportion of fine-grained mineral and / or organic solids of less than 40%, one or more of the burner blower pipes are introduced into the gasifier, which is suspended in a gasifier, where they are reacted to gases containing carbon monoxide and hydrogen; they are liquefied and converted into slag, prior to liquefaction and introduction of said substances into a fluidized bed gasifier, the mineral and metallic impurities of plastic waste larger than 5 mm are separated and, if necessary, crushed to a maximum of 5 µm, and they are fed separately to a fixed bed pressure gasifier, whereupon the plastic waste is further liquefied by supplying heat from the fluidized bed gasification and / or fixed bed gasification processes using directly the heat generated from the process, the gas or the heat of the steam leaving the cooling process or electrical energy produced by gas.