WO2015199562A1

WO2015199562A1 - Process for recycling waste hydroinsulation materials

Info

Publication number: WO2015199562A1
Application number: PCT/PL2014/000117
Authority: WO
Inventors: Izabella Bogacka; Stanisław LEWANDOWSKI; Bartosz SZCZYTOWSKI
Original assignee: Laboratorium Czystych Technologii Acren Sp Z OO
Current assignee: Laboratorium Czystych Technologii Acren Sp Z OO
Priority date: 2014-06-26
Filing date: 2014-10-24
Publication date: 2015-12-30
Anticipated expiration: 2016-12-26
Also published as: PL231670B1; PL408675A1

Abstract

The process according to the invention consists in that the waste hydroinsulation materials, optionally preliminarily crushed to pieces not larger than 70 mm, are set in a sliding rotary motion and treated with an organic solvent having a boiling point up to 200°C in the form of liquid and vapour in a reverse flow. A solution of bituminous materials in the solvent is separated from the insoluble residue and subjected to distillation until a dense bituminous mass is obtained. The insoluble residue, consisting of the topping, mechanical impurities and fibre tissue, is administered to the sieving apparatus. The topping, in the form of stones, falls to the bottom of the apparatus and is moved to the topping tank. The mechanical impurities, which are larger than the openings on the sieve, remain in the sieve. The topping tank is filled with the same solvent that was used for the extraction of bituminous materials. The topping, moving to the topping tank, extrudes its solvent to the sieving apparatus, which prevents penetration of the bituminous material solution in the solvent to the topping tank. Other undissolved components of the hydroinsulation materials, i.e. fibre tissue, are treated with the solvent in a reverse flow and then dried. The organic solvent is xylene or 1,2-dichloroethane or a mixture of xylene and butyl acetate or a fraction of a pyrolysate with a boiling point ranging between 70- 110°C, obtained in a pyrolysis of polyethylene, containing approx. 67% by weight of olefins, 5% by weight of aromatic compounds and saturated hydrocarbons.

Description

Process for recycling waste hydroinsulation materials

The invention relates to a process for the recovery of raw materials out of hydroinsulation materials, used for protection against water or moisture, and particularly out of tar paper.

Hydroinsulation materials are, due to their function, produced in a sequential process and belong to the group of composite materials.

Formerly used coverings, which consisted of tar paper and tar, did not present special difficulties. Nowadays, hydroinsulation materials are composed of several layers: glass fibre or cardboard tissue, nonwoven fabric or polyester-glass composite and optionally a mixture of the listed components. They are covered on both sides with a mass of regular or modified bitumen, or asphalt mass. As is known, it is a mixture of water-insoluble hydrocarbons and is mostly produced of tars, adhesives and asphalts, often fortified with additives such as waste from the production of plastics and rubbers, including used tires. Very high quality, specialised hydroinsulation products additionally comprise an addition of substances of SBS type (styrene-butadiene-styrene) or APP type (atactic polypropylene), which enhance elasticity.

As the bituminous mass protects the insulated surface, it must adhere well, and therefore be characterised by very good adhesion, uniform fluidity in the molten state and resistance to cracking at low temperatures. This mass, as mentioned above, is used in the manufacture of tar paper and insulation materials, but also to cover the upper part of constructed roads in the form of various types of asphalts. Technical requirements and economical issues imply that in addition to the mixture of hydrocarbons, which do not dissolve in water, these masses contain different kinds of fillings. They are mostly mineral materials, a finely ground, light rock. This kind of mass is less expensive, and at the same time, it does not tend to separate during use. Insulation and roofing layers are additionally sprinkled with aggregate or talc, which protect the rolls against sticking together.

90 million square metres of tar paper are traded in Poland every year. As 1 m² with a thickness of 5.2 mm weighs 6 kg, this equals 50,000 tonnes/year. The production waste is estimated at 2%. As with any product, these materials also become waste over time, and this waste is extremely bothersome.

According to official data, 10-13% of tar paper is removed every year, which, together with production waste, is equal to 5% of the amount of tar paper delivered to the market every year.

The problem of waste insulation materials is their quality. The better they fulfilled their task, the more difficult their recycling is, because the applied materials are assumed not to be biodegradable, as they would not fulfil their insulation function.

Legal regulations allow this type of waste to be incinerated in boilers; however, this method is highly dangerous for the environment owing to the emission of sulphur and other impurities contained in bitumen. At the same time, the economic effect is small, due to the fact that the only profit is heat, and its percentage is low. It is obvious that this method should be withdrawn due to environmental reasons and the saving of raw material.

A method for recycling tar paper into road construction bitumen is known. The method is based on the separation of debris and other constructional contaminations and the subsequent defibration of tar paper and separation of fibres. The advantage is that the resulting intermediate product for the manufacture of asphalt emulsions is less expensive and less troublesome. Studies have shown that this type of addition increases the tightness of the asphalt mass. Unfortunately, this phenomenon is temporary. While intensively used, pavement under the pressure of moving vehicles is susceptible to cracking, especially in adverse weather conditions. This is due to the freezing of water absorbed and accumulated in the residues of fibres present in the intermediate product. The maintenance of such pavement requires frequent and expensive repairs. The addition of waste to the production processes always poses a risk of deterioration of the final product quality, as evidenced by the cracking of road pavement, sometimes even before their use is started.

The description of DE 102006009205 discloses a process in which the granulated waste is transported and heated. At least a part of the granules undergoes melting and can be removed from the system.

The description of US 2014/0034762 discloses a process for the crushing of asphalt and mechanical separation, wherein the freezing of asphalt is used.

The publication WO2005/087380 discloses a process based on the melting of asphalt in order to recover the cardboard in contact with a liquid heat delivery agent. During the heating, the gases are removed from the tank, filtered and discharged to the atmosphere. The molten asphalt and cardboard are removed from the tank and cooled.

The publication WO2008/103035 discloses a device for the recycling of roof coverings. It consists of a system of conveyor belts, blades and screens. The processing is mechanical.

The publications WO02/28610 and WO00/43184 disclose processes in which bitumen and tar are separated from the other components contained in bituminous materials using pressure and extrusion.

According to the description of EP1757672, bituminous waste along with a polar liquid which does not dissolve the bitumen are loaded into the reactor, the components inside the reactor are heated to a temperature higher than the melting point of the bitumen, the components are mixed and the resulting fractions are separated.

The description of EP1534434 discloses a device for melting bituminous materials, whose size and shape can be adjusted depending on the characteristics and size of the pieces of membranes that undergo recycling.

Patent application PL Z-374595 discloses a process that is based on the defibring of the preliminarily cleaned, cracked tar paper into small chips not larger that 4x50 mm at a temperature not higher that 100°C. The resulting crushed material, in the form of tar paper chips, is added to the cement-emulsion mixture for the bedding of road pavements, consisting of mineral aggregate, pulverised minerals, adhesives and an addition of the crushed asphalt produced as a result of pavement milling in an amount up to 5% by weight of the aggregate in the mixture.

Most of the known methods are based on the crushing of material and smelting of bitumen or its extrusion using force. One of the methods involves the addition of a high boiling solvent, which does not dissolve tar.

None of the abovementioned methods leads to the obtaining of isolated, individual components that can be fully used as a raw material for production of hydroinsulation materials. The lack of possibility for separation of bituminous materials from the topping, i.e. small stones and from the cardboard, which is the main component of the fibre tissue, seems to be of particular importance.

The process according to the invention consists in that the waste hydroinsulation materials, optionally preliminarily crushed to pieces not larger than 70 mm, are set in a sliding rotary motion and treated with an organic solvent having a boiling point up to 200°C in the form of liquid and vapour in a reverse flow. A solution of bituminous materials in the solvent is separated from the insoluble residue and subjected to distillation until a dense bituminous mass is obtained. The insoluble residue, consisting of the topping, mechanical impurities and fibre tissue, is administered to the sieving apparatus. The topping, in the form of stones, falls to the bottom of the apparatus a id is moved to the topping tank. The impurities, which are larger than the openings in the sieve, remain in the sieve. The topping tank is filled with the same solvent that was used for the extraction of bituminous materials. The topping, moving to the topping tank, extrudes its solvent to the sieving apparatus, which prevents penetration of the bituminous material solution in the solvent to the topping tank. Other undissolved components of the hydroinsulation materials, i.e. fibre tissue, are treated with the solvent in a reverse flow and then dried.

The preferred organic solvent is xylene or 1 ,2-dichloroethane or a mixture of xylene and butyl acetate or a fraction of a pyrolysate with a boiling point ranging between 70-1 10°C, obtained in a pyrolysis of polyethylene, containing approx. 67% by weight of olefins, 5% by weight of aromatic compounds and saturated hydrocarbons.

The process of the invention allows for the obtaining of pure bituminous materials, a pure topping and fibre tissue liberated from troublesome bituminous contaminations. The fibre tissue obtained in this way is suitable for ecological use by incineration. The obtained pure topping can be re-used to produce hydroinsulation materials, and the bituminous material is a fully useful raw material for re-use in the production of said hydroinsulation materials.

The process according to the invention allows for full recycling of all components of waste hydroinsulation materials.

The subject of the invention is presented in the illustration, in which Fig. 1 illustrates a diagram of an installation used for the process according to the invention. Example 1. The test was carried out using xylene as a solvent, prepared in a tank 8. The waste of tar paper of an average composition: 67.0% by weight of bitumen, 21.1 % by weight of topping, 1 1.7% by weight of cardboard and 0.2% by weight of water, was used as a raw material. The waste was crushed into pieces not larger than 50 mm. After checking the apparatus, the valves under the topping tank 5 and clarifier 7 were closed. The apparatus was purged with carbon dioxide supplied to a reloading tube 13, and then the valves under the tank 7a and evaporator 10 and the valve isolating the distillation system of the topping tank 5 were closed. Xylene in an amount of 5,000 kg was then pumped into the apparatus through a washing device 11 from the tank 8, which was followed by switching on the rotation of the baskets and stirrers of the concentrator 2 of a sieving apparatus 3, extractor 6, concentrator 9, washing device 11 and apparatus 12 as well as the heating and cooling of the entire apparatus. Eventually, the stirrer of the evaporator 10 was switched on, and after nearly an hour, the apparatus 1 was started, and a mixture of air and exhaust fumes at a temperature of 65-70°C was supplied to its outlet, and the raw material at a rate of 200 kg/h was administered to its inlet. After approximately one hour, when it was observed that the first pieces of tar paper were falling into the feeding hopper of the apparatus 2, the stirrer mounted in the hopper was switched on, and an increase of the temperature in the clarifier 7 was observed, which meant that the whole apparatus was filled with xylene vapours. The heating of the topping tank 5 was reduced, so that the temperature inside would not exceed 100°C, and after one hour, the administration of the pure solvent from the clarifier 7 to the apparatus 11 at a rate of 250 kg/h and to the topping tank 5 at a rate of 45 kg/h was started. Two hours later, the rotations of a screw 14 were switched on, and half an hour later, the reloading tube 13 was provided with water at a rate of 1.8 kg/h. After approximately half an hour, it was observed that the insoluble residue reached the screw 14, because the screw started to push the insoluble residues from the apparatus. 25 hours after the start of the administration of raw material to the apparatus 1 , the administration was stopped, and the apparatus 1 and the stirrer of the hopper were switched off when pieces of tar paper stopped falling into the feeding hopper of the apparatus 2. 3 hours later, the administration of the pure solvent to the topping tank 5 and washing device 11 was switched off, and the valve over the diffuser 4 was closed, while the inlet valve of the distillation system of the topping tank 5 was open, which was followed by the maximising of its heating. The stirrer of the sieving apparatus 3 and the rotation of baskets of the apparatuses 2 and 6 were switched off, and then a non-visualised relief valve under the cone of the sieving apparatus 3, draining liquid to the apparatus 9, was opened. Xylene, distilled in the apparatus, accumulated in the clarifier 7, and therefore, after approximately an hour, the valve situated in the bottom of this apparatus was opened, and the water was drained to a separate vessel, while xylene was pumped to the tank 8 to prevent the overfilling of the clarifier 7. In turn, a non- visualised valve draining the washing device 11 to the extractor 6 was opened, and after 30 minutes, a non-visualised valve draining the content of the concentrator 9 to the evaporator 10 was opened. After the following 3 hours, when the temperature in the evaporator 10 reached 220°C and the screw 14 did not push the insoluble residues out any longer, the apparatus was switched off. In the meantime, all xylene was distilled from the intensively heated topping tank 5. The heating of the apparatus was switched off, and the removal of the solvent residues from the evaporator 10 through the gentle, slow production of a vacuum inside it was undertaken. Half an hour after a vacuum of less than 180 mm Hg was obtained, the process was ended. The whole apparatus was switched off and left for 9 hours, which was followed by the switching off for a few minutes of the evaporator 10, which was thoroughly emptied, including a removal of the bitumen contained inside. The sample was balanced.

Used

Raw material 25 x 200 kg = 5,000 kg

Water 26 x 1.8 kg = 46.8 kg

Recovered

Water 49.0 kg

Topping 1 ,055.0 kg

Bitumen 3,350.0 kg

Fibre tissue 590.0 kg - contained approx.

0.85% of water, i.e. 5 kg

Example 2

The apparatus and the process were as described in Example 1 except that the straight tube of the diffuser 4 was replaced with a 1 ,150 mm long tube, which was helicoidally bent, i.e. formed as a spring with a stroke of 600 mm. 1 ,2-dichloroethane was used as a solvent. The raw material and the dosing rate were as in Example 1. After 25 hours of administration of the raw material, the following amounts were used:

Raw material 25 x 200 kg = 5,000.0 kg

Water 26 x 1.8 kg = 46.8 kg

Recovered Water 49.0 kg

Topping 1055.0 kg

Bitumen 3,350.0 kg

Fibre tissue 590.0 kg

Example 3

The apparatus was as described in Example 1 , but instead of a circular tube, used there as a diffuser, a 660 mm long tube of a rectangular section, ended with flanges on both sides, was applied. A construction resembling two vertical racks arranged opposite one another was placed inside it. Each rack had 15 shelves. This tube was closed with tight lids on both sides. Stub pipes were placed in the central part of the lids. The test was conducted similarly as in Example 1 , and xylene containing 6% by weight of butyl acetate was used as a solvent. The raw material was a waste of postconsumer tar paper containing: 72.0% by weight of bitumen, 16.5% by weight of topping, 10.8% by weight of ground, 0.5% by weight of nails and 0.2% by weight of water, cut into pieces not larger than 60 mm administered at a rate of 400 kg/h. The test was carried out for 12 hours, at an administration rate of 400 kg/h, and then balanced:

Used

Raw material 12 x 400 kg = 4,800.0 kg

Water 13 x 1 .8 kg = 23.4 kg

Recovered

Water 28.6 kg

Topping 792 kg

Bitumen 3,456 kg

Fibre tissue 522.8 kg - contained approx.

0.85% of water, i.e. 4.4 kg

Nails 24 kg; they were isolated with a

magnet from the topping tank 5. Example 4

The apparatus and the procedure were as in Example 1 except that a fraction of a pyrolysate with a boiling point ranging between 70-1 10°C, obtained in a pyrolysis of polyethylene, containing approx. 67% by weight of olefins, 5% by weight of aromatic compounds and saturated hydrocarbons, was used as a solvent. The raw material was a mixture of waste of postconsumer tar paper containing: 75.0% by weight of bitumen, 13.6% by weight of topping, 1 .0% by weight of fibre tissue, 0.3% by weight of water, 0.1 % by weight of nails and wires, crushed into pieces not larger than 27 mm. The raw material was administered into the apparatus at a rate of 150 kg/h. The test was carried out for 30 hours and then balanced to give the following result:

Used

Raw material 30 x 150 kg = 4,500.0 kg

Water 30 x 0.8 kg = 54.0 kg

Recovered

Water 65.0 kg

In the clarifier 1 16.5 kg

Bitumen 3,375.0 kg

Fibre tissue 497.5 kg

4.5 kg of nails and wires were isolated with a magnet from the mixture in the topping tank 5; the rest, i.e. 612.0 kg is topping. The ground contained 0.5% by weight of water.

Claims

The process for recycling of waste hydroinsulation materials characterised in that the waste hydroinsulation materials, optionally preliminarily crushed to pieces not larger than 70 mm, are set in a sliding rotary motion and treated with an organic solvent having a boiling point up to 200°C in the form of liquid and vapour in a reverse flow, and the resulting solution of bituminous materials in the solvent is separated from the insoluble residue and subjected to distillation until a dense bituminous mass is obtained, while the insoluble residue, consisting of the topping, mechanical impurities and fibre tissue, is administered to the sieving apparatus, wherein the topping falls to the bottom of the apparatus and is moved to the topping tank, wherein the impurities, which are larger than the openings on the sieve, remain in the sieve, while the topping tank is filled with the same solvent that was used for the extraction of bituminous materials, and the topping, moving to the topping tank, extrudes its solvent to the sieving apparatus, while other undissolved components of the hydroinsulation materials are treated with the solvent in a reverse flow and then dried.

A process, according to claim 1 , characterised in that the organic solvent is xylene or 1 ,2-dichloroethane or a mixture of xylene and butyl acetate or a fraction of a pyrolysate with a boiling point ranging between 70-110°C, obtained in a pyroiysis of polyethylene, containing approx. 67% by weight of olefins, 5% by weight of aromatic compounds and saturated hydrocarbons.