BRPI1004634A2 - installation and process in multistage vertical retort for gasification, carbonization and activation of waste tires and rubber waste - Google Patents

Abstract

INSTALLATION AND PROCESS IN VERTICAL RETURNING MULTIPLE STAGES FOR GASIFICATION, CARBONIZATION AND ACTIVATION OF INSERVABLE TIRE AND RUBBER WASTE. Comprising an industrial plant for the production of activated charcoal, pyrolytic oil and scrap metal, energetically self-fed, using as a waste tire. The system enables economical and non-polluting production, with the generation of high added value products.

Description

VERTICAL RETURNING INSTALLATION AND PROCESS OF MULTIPLE STAGES FOR GASIFICATION, CARBONIZATION AND ACTIVATION OF INSERVABLE TIRE AND RUBBER WASTE.

The present invention relates to a process for transforming waste tires into products such as:

· Burning oil (low sulfur and high calorific value)

• Activated coal for water and wastewater treatment.

• Generation of non-condensable gases for burning in furnaces and boilers.

• Metallic scrap.

The components present in the largest amount of tire rubber are styrene butadiene rubber (SBR), natural rubber (NR) and polybutadiene rubber (BR). Also appear: smoke, oils, sulfur, accelerator, stearic acid and zinc oxide. Smoke black is used to give rubber resistance, softness to rubber and increase its workability during tire making. Sulfur is used to bind the polymer chains within the rubber and also to harden to prevent excessive deformation by high temperatures. The accelerator is typically an organo sulfuric compound that acts as a catalyst for the vulcanization process. Zinc oxide and stearic acid also act to control vulcanization and enhance the physical properties of rubber.

During normal use of the tire, there is wear, basically of the tread. When the tire reaches its half-life, the carcass is still in good condition, and it still has economic value and is considered serviceable as it can be recycled by the retreading process. However, if for some reason the carcass is in poor condition and does not allow retreading, the tire is considered unusable and literally becomes waste (garbage). The accumulation of these residues provides the accumulation of rainwater and consequently the attraction of rodents and mosquitoes transmitting disease such as dengue, yellow fever and others. In addition, open-air smoldering will generate emissions of toxic air pollutants. To stop the progress of accumulation of this waste is necessary to recycle them.

It is known that the reuse of vulcanized rubbers is currently one of the main problems in the area of recycling, as they are thermally rigid, as a consequence of chemical cross-links between polymer chains, which prevent melting and re-processing. Among the alternatives for the reuse of these materials are.

1. Retreading or retreading: After fuel, tires are the most costly item to use in vehicles. Due to this the retreading was developed with the objective of reforming a used tire, replacing and vulcanizing the upper layer of tread rubber. For this it is necessary that the overall structure of the tire is conserved, showing no cuts or deformations, and the tread still has the grooves and projections that allow its adherence to the ground.

2.Recovery: Recovery consists of simply grinding the tires and grinding the waste. The rubber contained in the waste, in vulcanized form, does not change and is not separated from other compounds. Recovered tires generally follow two types of use:

2.1. In mix with asphalt for paving roads and parking yards.

After grinding, particles smaller than 5 mm and with a maximum moisture content of 2% are mixed with asphalt at a ratio of 1% to 3% by weight.

2.2.In cement factories. The ground material with particles from 1 mm to 6 mm is incinerated in the kilns as fuels and the soot from the burning gases is incorporated into the cement.

3. Regeneration or devulcanization: Tire housings fall under the classification of wastes containing high fiber content. Regeneration can be done by various processes - alkaline, acidic, mechanical, and saturated steam. In regeneration, the waste undergoes modifications that make it more plastic and able to receive new vulcanization, but do not have the same properties as raw rubber, being generally mixed with it for the manufacture of artifacts.

4.Protection of buildings by the sea: on the dikes and quays; dams and slope containment where the tires are usually placed whole.

5. Energy recovery by burning in furnaces.

6. Pyrolysis is the process of thermoconversion carried out under an oxygen-free atmosphere and provided by the addition of heat to a carbonaceous material.

Despite all these recycling processes, there is still a considerable excess of this waste, that is, the generation of waste tires is greater than the quantities processed in the mentioned destinations. It is well known that these destinations add little value to the generated products, on the other hand the technologies that generate products with more attractive values are extremely costly making the products economically unviable.

In view of this opportunity (using waste material to generate high value-added products at low cost) a three-stage destructive distillation system (the first two in neutral environment and the third in oxidizing environment) was developed that will generate two-phase products. (one gas and one solid) which will be processed under different temperatures and atmospheres.

The invention is based on the process of breaking the chemical bonds of the organic chains by heat (endothermic reaction) and destructive distillation, which aims to reuse the tire components as raw materials and fuels.

In the present invention occurs the optimization and joining of three operations in the same apparatus:

Gasification in neutral environment.

Indirect heating carbonization and low oxygen content.

Activation of carbonaceous waste in oxidizing atmosphere.

Still having the advantage of being a thermally self-sufficient system.

The system consists of the use of an initial gasification area (up-draft) where the extraction of gas and pyrolytic oil will be done. In this area we work with lower temperatures in order to generate higher amounts of oil and the generation of lower amounts of SO2. The system works in a neutral atmosphere, and since the reactions (due to the non-occurrence of burning) are endothermic, the energy to trigger the reactions (breakdown of the chemical bonds of the organic chains) is provided by the posterior zone.

Subsequent azone is where carbonization occurs, also in this zone the energy supply is partly supplied externally and partly by the gases from activation, and the neutral atmosphere comes from the gases generated during activation (from C + 2H20 reactions). -> CO2 + H2)

It is a material preparation step where volatile components and light gases (CO, H2, CO2 and CH4) are removed, producing a fixed carbon mass and a primary porous structure that favors further activation.

Activation in an oxidizing environment (using 920 ° C high temperature steam) which consists of subjecting the carbonized material to secondary reactions, aiming at increasing the surface area. This reaction is essentially endothermic, and the energy supply is all external (using the gases generated in the system itself).

Upon arrival in the industry, the raw material (waste tires) will be discharged into the crushing area, where crushing of the material in 50x50 mm fractions will immediately begin.

Crushed material is conveyed by a conveyor system to the vertical retort feed hopper. Said apparatus is composed of 5 areas.

Generated Products

The pyroactivation system will enable us to obtain (from the waste tire raw material) the following products (average percentages):

• 36% pyrolytic oil

• 26% coal (20% activated carbon)

• 20% noncondensable gas

• Scrap of burnt wire 18% Pyrolytic oil. Pyrolytic oil, condensable fraction extracted together with the gases, is composed of heavy aromatics, light aromatics, alkanes, acetones, aldehydes.

Table 1: Basic characteristics of pyrolytic oil

Specific Weight 0.9481 a / ml PCI 9000 Kcal / kg FULGOR POINT 40 ° C ELEMENTARY COMPOSITION% Carbon 87 Hydrogen 10 Nitrogen 1.2 Oxygen 1.4 Sulfur 0.8

Source: CEMPRE, 2003

Table 2. Typical elemental composition of tire oil.

ELEMENTARY COMPOSITION% MASS Carbon 82.73 Hydrogen 10.84 Sulfur 1.70 Nitrogen 0.40 Oxygen 4.33

Source: CEMPRE, 2003

This product can be given two destinations: burning and distillation. In the case of distillation the following products can be obtained: Table 3.Products generated during fractional distillation of pyrolytic oil

PERCENT PRODUCTS USE Light naphtha 10% Chemical industry (solvent) d-Limonene 6% Chemical industry Light oil 10% Chemical industry Heavy oil (distillation residue) 74% Burning

Source: C. Roy, H. Darmstadt, B. Benallal, A. Chaala. 1995. Activated charcoal.

Activated carbons are porous carbonaceous materials that have a non-granitic microcrystalline form that have been processed to increase internal porosity. Once activated, coal has an internal porosity comparable to a network of tunnels that branch into smaller channels and so on. This differentiated porosity is classified according to size in macro, meso and micro porosity.

Activated Carbon Production

Activated carbons are obtained through two basic steps: carbonization by precursor pyrolysis and activation itself.

Activation, a process subsequent to pyrolysis, consists in subjecting the charred material to secondary reactions, aiming at increasing the surface area. It is the fundamental stage in which the increase in coal porosity will be promoted. It is desired in the activation process to control the basic characteristics of the material (pore distribution, specific surface area, surface chemical activity, mechanical strength etc.) according to the configuration required for a given specific application.

Physical Activation - Physical activation is the reaction of coal with gases containing combined oxygen.

Due to the endothermic nature of activation reactions, coal particles must be kept in close contact with oxidizing gases. Power for the activation process can be supplied directly or indirectly depending on the type of furnace employed.

For the process of physical activation, they are generally used as oxidants, water vapor and CO2. The gas-solid reactions involved in the process are described through the following steps.

1. Diffusion of reagent to outer surface of solid;

2. Diffusion of the reagent through the internal pores of the solid;

3. Adsorption of the reagent by the inner surface of the solid; 4. reaction on the surface of the solid;

5. Desorption of products from the inner surface of solid;

6. Diffusion of products by the internal pores of the solid; 7. Diffusion of the products from the solid outer surface. Physicochemical Properties of Activated Carbon

Porosity

The porosity of activated charcoals is one of the most important aspects for evaluating their performance. Differences in adsorption characteristics are related to the pore structure of the material. Based on the adsorption properties, the International Union of Pure and Applied Chemistry (IUPAC) establishes a porous classification summarized as follows:

Shape: The term open pore or closed pore is used to denote holes in solid materials, the former corresponding to holes communicating with the outer surface and the latter corresponding to an isolated hole. If an open pore is such as to allow a fluid to flow, the pore is said to be a transport pore, which may have arms that do not contribute to the transport phenomenon.

Regarding pore size: Based on the adsorption properties, IUPAC proposes the following pore classification as presented in Table 4.

Table 4: Classification of pores according to IUPAC

Pore Type Average Diameter Main Function Micropores ιτιθ <2 nm They contribute to most of the surface area that provides high adsorption capacity for small size molecules such as gases and common solvents. Mesopores 2 nm <m0 <50nm They are important for the adsorption of large molecules such as dyes and provide most of the surface area for chemical impregnated coals. Macropores m0> 50 nm They are normally considered unimportant for adsorption and their function is to serve as a transport medium for gaseous molecules. 10

Textural Characterization

Control of pore size distribution and surface affinity of activated charcoal are important aspects in its preparation.

Active charcoal is one of the best adsorbents known due to its huge inner surface, made up of thousands of microscopic pores.

The metal-free carbonaceous waste will be used as activated carbon for effluent and water treatment in public and industrial supply systems.

Specific characteristics and typical properties of activated carbon for water treatment obtained from waste tires.

Table 5. Characteristics and properties of activated carbon obtained from tire waste.

SPECIFICATIONS

Sludge number mg / g 800 minimum PH Alkaline Bulk density g / cm 0.20 - 0.75 Mesh through size # 100 99% Mesh through size # 200 95% Mesh through size # 325 90% Phenol index g / l 2.5 max. Humidity 8% max. Ash 12% max.

Source: Direct Search 2010

Noncondensable gas.

The gas generated will be used to power the carbonization system itself, and it has a PCI of 7000 kcal / kg. Table 5: Basic gas composition.

COMPONENT

% BY WEIGHT

% BY VOLUME

Methane

Ethane

Propane

Iso-Butane

n-Butane

NitrogenO

16.1% 32.6% 7.6% 1.2% 33.1% 9.4%

31.5% 34.1% 5.4% 0.6% 17.9% 10.5%

H2S

0.0% *

0.0% *

Source: Direct Research, 2010. Metals

The use of radial tires generates, after magnetic separation, a considerable percentage of wire remains, which after being compacted will be sold to scrap dealers in the region.

Description of the pyroactivation system.

The whole system will be built in refractory material (metallic or not) thermally insulated.

Figure 1 schematically illustrates said system and process. As shown in the above figure and in accordance with the description given herein, reference is made to the present patent application for a VERTICAL RETURN INSTALLATION AND PROCESSING OF MULTIPLE STAGES FOR GASIFICATION, CARBONIZATION AND REPLACEMENT OF TIRE .

Zone 5. Combustion and heating, average temperature 1100 ° C; shall have one or more burners ±. In this zone will be burned the noncondensable gases exhausted by zone 1 (after passing through the separation tower for the removal of condensables) and part of the gases generated in the activation zone. The hot gases (result of burning) will be directed to the steam generator2 in order to make use of the waste heat. The gases after passing through the heat recovery boiler will pass through a gas scrubber 3 and then released into the environment.

Zone 1 Heating of raw material 4 (average temperature 150 ° C, residence time 8 minutes, heating rate 15 ° C / min, flow rate 0.3 m / min). In this zone the retort will be fed and the raw material (shredded waste tires) will be heated (countercurrent) by the gases (condensable and non-condensable) generated in zone 2. Both gas fractions5 will be aspirated into a fractionation tower system. where the condensables will be separated from the non-condensable gas. The first (pyrolytic oil) will go to tanking and the second (CNG) will return to feed zone 5 (combustion and heating), and the excess will be consumed in high performance combustor 7

Zone 2 Gasification8 (average temperature 400 ° C, residence time 28 minutes, heating rate 25 ° C / min, flow rate 0.1 m / min). In this zone will start to reduce the volume and weight of the material; Two non-condensable and one condensable gas fractions will be generated which will pass to zone 1 where they will exchange heat with the raw material. Zone 3 Carbonization9 (average temperature 600 ° C, residence time 20 minutes, heating rate 20 ° C / min, flow rate 0.3 m / min). In this zone due to the high temperature the gasification will be finished and the carbonization of the raw material will occur, and the gases generated will go to the heating of zone 2.

Zone 4 Activation10 (average temperature 900 ° C, residence time 28 minutes, heating rate 20 ° C / min, flow rate 0.1 m / min). In this zone the atmosphere will be oxidizing and indirect heating. From the 50% generated gases will pass to zone 3 and will heat it, the retainer will go to the combustion zone complement the heating of the zone itself. In this zone superheated steam (950 ° C) 11 will be injected for the generation of the oxidizing atmosphere. The activated carbon residue will be extracted through a lock system.

Example.

Waste tires were shredded into 50 χ 50 mm pieces and were continuously introduced into the vertical retort (at a rate of 100kg / h over a 24 hour period) in the pilot oven. During this period 2400 kg of scrap tire pieces were introduced and exhausted by the upper part 480 kg CNG and 860 kg pyrolytic oil having the following characteristics.

PIROL TICO OIL SPECIFIC WEIGHT 0.95 g / ml PCI 9000 kcal / kg FLOOR POINT 41 ° C SULFUR CONTENT 0.8%

NON CONDENSIBLE GAS PCI 7000 kcal / kg

In the lower part of the retort, 400 kg of activated charcoal and 240 kg of scrap metal were extracted. The extracted activated carbon had the following characteristics.

CARBON A "RIVER, IODINE NUMBER 800 PH Alkaline APPEARANT DENSITY 0.20 g / cm

25

Claims (3)

VERTICAL RETURNING INSTALLATION AND PROCESS OF MULTIPLE STAGES FOR GASIFICATION, CARBON | IZATION AND ACTIVATION OF INSERVABLE TIRE AND RUBBER WASTE. 1. Characterized by the fact that it comprises an industrial plant with a particle size homogenization system with a multistage vertical retort top feed system comprising a 5 zone composite system. Zone 5 Combustion and heating, average temperature 1100 ° C; will have one or more burners (1). In this zone will be burned the noncondensable gases exhausted by zone 1 (after passing through the separation tower for the removal of condensables) and part of the gases generated in the activation zone. Hot gases (as a result of burning) will be directed to the steam generator (2) in order to make use of the waste heat. The gases after passing through the heat recovery boiler will pass through a gas scrubber (3) and then released into the environment. Zone 1 Heating of the raw material (4) (average temperature 150 ° C1 residence time 8 minutes, heating rate 15 ° C / min, flow rate 0.3 m / min). In this zone the retort will be fed and the raw material (shredded inoperable tires) will be heated (countercurrent) by the gases (condensable and non-condensable) generated in zone 2. Both gas fractions (5) will be aspirated to a tower system of plate fractionation (6) where the condensables will be separated from the non-condensable gas. The first (pyrolytic oil) will go to tanking and the second (CNG) will return to feed zone 5 (combustion and heating), the excess will be consumed in high performance combustor (7} Zone 2. Gasification (8) (temperature 400 ° C, residence time28 minutes, heating rate 25 ° C / min, flow rate 0.1 m / min) In this zone the volume and weight reduction of the material will start, two gas fractions will be generated one not condensable and other condensable that will pass to zone 1 where they will exchange heat with the raw material Zone 3. Carbonization (9) (average temperature 600 ° C, residence time20 minutes, heating rate 20 ° C / min, flow rate of 0.3 m / min) In this zone due to the high temperature the gasification will be finished and the carbonization of the raw material will occur, and the gases generated will go to the heating of zone 2. Zone 4. Activation (10) (average temperature 900 ^ C, residence time 28 minutes os, heating rate 20 ° C / min, flow rate 0.1 m / min). In this zone the atmosphere will be oxidizing and indirect heating. From the 50% generated gases will pass to zone 3 and will heat it, the retainer will go to the combustion zone complement the heating of the zone itself. In this zone superheated steam (950 ° C) (11) will be injected for the generation of the oxidizing atmosphere. The activated carbon residue will be extracted through a lock system. 2. Characterized by the fact that this facility is intended for the generation of high value-added products from waste products. 3. According to claim 1, characterized in that it is a three-stage destructive distillation system (the first two in a neutral environment and the third in an oxidizing environment) which will produce two-phase products (one gaseous and one solid). will be processed under different temperatures and atmospheres.