WO2016042213A1

WO2016042213A1 - Pyrolysis apparatus and method

Info

Publication number: WO2016042213A1
Application number: PCT/FI2015/050623
Authority: WO
Inventors: Juha MÄKIPELKOLA
Original assignee: Adamatic Oy
Priority date: 2014-09-19
Filing date: 2015-09-17
Publication date: 2016-03-24
Also published as: FI126482B; EP3194532A4; FI20145827A; EP3194532A1

Abstract

The invention relates to a pyrolysis apparatus and a pyrolysis method. The pyrolysis apparatus is a continuous apparatus so that material to be pyrolysed is conveyed through the apparatus. The pyrolysis apparatus has at least two control parts, through which material to be pyrolysed is conveyed. In the at least two different control parts, the material is subjected to thermal effects of a different magnitude. In addition, gas evaporated from the material is recovered from the at least two control parts.

Description

Pyrolysis apparatus and method

Background of the invention

[0001] The invention relates to a pyrolysis apparatus and a pyrolysis method.

[0002] In pyrolysis, solid organic matter is disintegrated by heating, without oxygen being allowed to act on the process. Pyrolysis may also be referred to as dry distillation.

Summary of the invention

[0003] An object of this invention is to provide a novel pyrolysis apparatus and a novel pyrolysis method.

[0004] The solution according to the invention is characterized by what is disclosed in the independent claims. Some embodiments of the invention are presented in the dependent claims.

[0005] In the disclosed solution, a continuous pyrolysis apparatus is used, i.e. material to be pyrolysed is fed continuously into a reactor and conveyed through the apparatus. The apparatus comprises at least two control parts. The material to be pyrolysed is conveyed through the at least two control parts. In the at least two different control parts, the material is subjected to thermal effects of different magnitude. In addition, gas evaporated from the material is recovered from the at least two control parts.

[0006] Since the apparatus has at least two control parts, the temperatures of the different process phases may be controlled separately, taking into account the properties of the different materials to be pyrolysed. Gases separated from the material may be easily collected in different fractions already at an early stage of the process. The size of the reactors required can be kept reasonably small and thus durable apparatuses with long service life are obtained. Gases to be pyrolysed at each of the different temperatures may be divided into fractions already in the gas formation stage. Hence the gas fractions formed in the different control parts may be further distributed rapidly and in a simple manner, whereby the costs of further processing will be affordable. The different materials to be pyrolysed consist of different hydrocarbon fractions that evaporate at temperatures specific to each material. Using these known temperatures it is possible to separately determine the temperature of each control part and the formed gases may each be recovered in their specific control part. Gases formed at the lowest temperature may be recovered in a first control part and those formed at a higher temperature in a next control part after the first one, and so on, until all hydrocarbon gases have been formed. At the end of the process, non- pyrolyzable solids are discharged from the continuous pyrolysis apparatus.

[0007] According to an embodiment, the control parts are formed by dividing the pyrolysis reactor into sections. This type of structure is simple and operationally reliable.

[0008] According to a second embodiment, the control parts are formed of pyrolysis reactors arranged one after the other. In that case, a long conveyor is not needed in the apparatus. Moreover, thermal expansions do not cause major problems. Also a good temperature control in different parts of the process is achieved.

[0009] According to a third embodiment, the control parts are formed of pyrolysis reactors arranged one after the other, at least one of the reactors being divided into sections.

[0010] According to yet another embodiment, the direction of travel of the material is arranged to differ between at least two different control parts. The direction of travel of the material in the control parts may differ from one another by 90 degrees, for example. The apparatus can thus be arranged into a shorter space, for example, or in an otherwise optimal manner. The apparatus may be assembled into a compact whole.

List of figures

[0011] Some embodiments of the invention are explained in closer detail in the accompanying drawings, in which

Figure 1 is a schematic cross-sectional side view of a pyrolysis apparatus;

Figure 2 is a side view of the pyrolysis apparatus shown in Figure 1 ; Figure 3 shows the pyrolysis apparatus of Figure 2 cut along line A- A of Figure 2;

Figure 4 is a schematic side view of a second pyrolysis apparatus; Figure 5 is a schematic side view of a third pyrolysis apparatus; and Figure 6 is a schematic top view of a fourth pyrolysis apparatus.

Detailed description of embodiments

[0012] Figure 1 shows a pyrolysis apparatus 1 , which in this embodiment comprises one pyrolysis reactor 10. Material to be pyrolysed is fed into the pyrolysis apparatus 1 from an input 2. The pyrolysis apparatus 1 is a continuous apparatus, i.e. material to be pyrolysed is fed continuously into the apparatus and conveyed through it, the pyrolysed material, i.e. solid residue, being discharged from an output 3. The input 2 comprises an airtight shut-off feeder. Correspondingly, the output 3 is provided with an air lock.

[0013] During the pyrolysis, the material to be pyrolysed is conveyed in a pyrolysis channel by a conveyor 5. The conveyor 5 may be a screw conveyor, for example. The conveyor may also be a scraper conveyor or a chain conveyor or another kind of heat-resistant conveyor.

[0014] Above the pyrolysis channel 4, there is arranged a gas collection channel 6. When material in the pyrolysis channel 4 is heated, gas evaporates therefrom and travels into the gas collection channel 6. In other words, the gas collection channel 6 is separate from the pyrolysis channel 4.

[0015] Although the gas collection channel is separate from the pyrolysis channel 4, the connection from the pyrolysis channel 4 to the gas collection channel 6 may be fully open. On the other hand, between the pyrolysis channel 4 and the gas collection channel 6 there may be a net or a grid or a plate with holes or another similar structure, which is separates the pyrolysis channel 4 from the gas collection channel 6 also structurally, yet the structure allows gas to flow from the pyrolysis channel 4 into the gas collection channel 6.

[0016] The gas from the material to be pyrolysed typically contains an amount of fine particles. As the gas travels first from the pyrolysis channel 4 to the gas collection channel 6 and from the gas collection channel 6 through a gas discharge pipe 9 to recovery, the recovered gas contains less fine particles than gas recovered directly from the pyrolysis channel, for example.

[0017] In the pyrolysis reactor 10 the pyrolysis channel 4 and the gas collection channel 6 may be of an essentially equal length. The pyrolysis channel 4 mostly contains material to be pyrolysed and the gas collection channel 6 mostly gas consisting of said material.

[0018] The pyrolysis reactor 10 is divided into two or more sections 7a to 7c. In the embodiment of Figure 1 the pyrolysis reactor is divided into sections 7a to 7c by partition walls 8 arranged into the gas collection channel 6. There is thus a part of the gas collection channel 6 on either side of the partition wall 8. [0019] The partition wall 8 may be equal in size to the cross-section of the gas collection channel 6. In that case the partition wall 8 keeps the vaporized gas efficiently in a specific section. The partition wall 8 also helps a thermal effect to be directed to a desired section.

[0020] If desired, the partition wall 8 may also be smaller than the cross-section of the gas collection channel 6. Hence an apparatus with a simple and, at the same time, durable structure is obtained. However, even if the partition wall 8 is smaller than the cross-section, it still guides the formed gas and the thermal effect.

[0021] If desired, the apparatus may also be divided into sections without partition walls, in which the division into sections may result from different parts of the apparatus being subjected to a different thermal effect.

[0022] Each section 7a to 7c is provided with a gas discharge pipe 9. The gas discharge pipe 9 is arranged to the gas collection channel 6, i.e. gas formed from the material to be pyrolysed is removed from the gas collection channel 6 through the gas discharge pipe 9. The gas discharge pipe 9 may be arranged to the upper part of the gas collection channel 6, for example. Through the gas discharge pipe 9, gas separated from the material to be pyrolysed may be removed separately from each section 7a to 7c in the process step concerned.

[0023] As shown in Figure 2, at least one heater 15 is arranged for each section 7a to 7c. In the embodiment of Figure 2, section 7a is provided with two heaters 15. If the section is longer, more than two heaters may also be provided.

[0024] With a separate heater 15 provided for each section 7a to 7c, thermal effects of different magnitude may be directed to material to be pyrolysed in the different sections 7a to 7c. The first section 7a may be provided with the lowest temperature, the second section 7b may be provided with a temperature higher than that of the previous section, and the last section 7c may be provided with the highest temperature.

[0025] In the embodiment of Figures 1 and 2, the sections 7a to 7c form the control parts of the pyrolysis apparatus 1 .

[0026] Different gases are produced at different temperatures from the material to be pyrolysed. Hence gas formed at the lowest temperature may be recovered from the first section 7a. Gas formed at a slightly higher temperature may then be recovered from the next section, etc. [0027] The temperature at which gases are formed depends on the material to be pyrolysed. Hence the temperature in each section 7a to 7c may be set as desired, taking into account the properties of the material to be pyrolysed.

[0028] In principle, the material to be pyrolysed may consist of any organic matter. Examples of material to be pyrolysed include rubber, such as car tyres, different types of plastic, chicken manure, wood, biomass and soil contaminated by oil, or some other material suitable for pyrolysis.

[0029] Figure 2 shows schematically a control unit 1 1 for controlling the heaters 15. The control unit 1 1 is naturally provided with temperature data from inside the different sections 7a to 7c of the apparatus 1. However, for the sake of clarity, the arrangement in question is not shown in Figure 2.

[0030] The heater 150 may comprise a heating device 12 and a heating piping 13, for example. The heating device 12 may include e.g. a burner, fuel storage and supply devices and circulating equipment for circulating medium flowing in the heating piping. However, for the sake of clarity, the heating device 12 is only shown schematically in the accompanying figure. The fuel to be used may be gas or diesel, for example, or some other suitable fuel. If gas is used as fuel, the gas recovered from the pyrolysis apparatus during its operation may be utilized as fuel.

[0031] The medium circulating in the heating piping 13 may be hot air, for example. Another example of a medium is a hot saline solution, which enables a better efficiency to be achieved than with air, for example. The saline solution is obtained by liquefying salt in heat. With a saline solution, a temperature almost as high as 600°C may be achieved. The salt may be e.g. potassium nitrate, sodium nitrate, potassium chloride, sodium chloride or some other suitable salt or salt mixture. Due to its good heat emission coefficient, saline solution transfers heat extremely efficiently compared to conventional media, such as air or flue gases, for example.

[0032] The temperature of liquid salt may be adjusted with precision, and the salt does not cause thermal point stresses on the outer surface of the reactor. Consequently, the temperature of the different sections 7a to 7c may be adjusted extremely accurately. The temperature difference between two sections may be less than 10°C, for example. In addition, using a saline solution for heating enables to reduce the attachment to the heating piping 13 of any solids produced in the flue gases during heating. [0033] A heater using a saline solution as the medium may also be used in a pyrolysis apparatus not divided into sections. Moreover, this kind of heater may be used in any other apparatus or process because the heater allows a precise indirect heating to be produced. This disclosure thus presents a heater which is suitable for any apparatus and which is provided with means for heating a saline solution and a heating piping for conveying the thermal effect of the heated saline solution to heat a target to be heated. This disclosure also presents a method for heating a target to be heated by heating a saline solution and recirculating the heated saline solution in a heating piping to heat the target to be heated.

[0034] When desired, the heater 15 may also be e.g. a direct-fire heater or a heater heating indirectly with hot air, or a similar heater.

[0035] The heating piping 13 is fixed to a sheath 14 of the gas collection channel 6 and the pyrolysis channel 4 as shown in Figure 3. This way, heat from the heating piping 13 may be effectively and, on the other hand, also reliably transferred to heat the material to be pyrolysed.

[0036] As shown in Figure 3, the pyrolysis channel 4 and/or the gas collection channel 6 may have a circular cross-section. The pyrolysis channel 4 may thus be referred to as a pyrolysis pipe and the gas collection channel 6 as a gas collection pipe. With the tubular structure, a desired temperature distribution inside the channels is easy to obtain. In addition, this type of solution is structurally simple and strong. When the pyrolysis channel, i.e. the pyrolysis tube, is round, the conveyor 5 is preferably a screw conveyor.

[0037] In the embodiment of Figure 4, the pyrolysis apparatus 1 has three pyrolysis reactors 10a, 10b and 10c.

[0038] The input 2 of the first pyrolysis reactor 10a serves at the same time as the input of the pyrolysis apparatus 1 . The output of the first pyrolysis apparatus 10 is an intermediate output 3'. The intermediate output 3' of the first pyrolysis reactor 10a is connected to an input of the second pyrolysis reactor 10b, i.e. an intermediate input 2'. Correspondingly, the output of the second pyrolysis reactor 10b is an intermediate output 3', which is connected to an input of the third pyrolysis reactor 10c which is, correspondingly, an intermediate input 2'. The output of the third pyrolysis reactor 10c is also the output 3 of the pyrolysis apparatus 1 .

[0039] The pyrolysis reactors 10a, 10b and 10c form the control parts of the pyrolysis apparatus 1 . In this solution the pyrolysis apparatus does not need to be provided with one long conveyor. For this reason, the strength and deflection of the conveyor are easy to control although the conveyor is in a hot environment. In addition, the pyrolysis apparatus does not have a long uniform structure whose thermal expansion would be difficult to control. Further still, since the pyrolysis apparatus is formed of a plural number of pyrolysis reactors, the temperature in the different parts of the process can be controlled extremely well.

[0040] Figure 5 shows a solution that otherwise corresponds to that of Figure 4 except that in the pyrolysis apparatus 1 of Figure 5 the third pyrolysis reactor 10c is divided into sections 7a to 7c. In the embodiment of Figure 5 the control parts of the pyrolysis apparatus 1 are formed of the first pyrolysis reactor 10a, the second pyrolysis reactor 10b, the first section 7a of the third pyrolysis reactor 10c and the second section 7b of the third pyrolysis reactor 10c, and the third section 7c of the third pyrolysis reactor 10c. The pyrolysis apparatus 1 can thus be divided in a simple manner into a multitude of control parts.

[0041] Figure 6 shows a pyrolysis apparatus 1 from above. The pyrolysis apparatus of Figure 6 contains three control parts. The first pyrolysis reactor 10a forms the first control part, the second pyrolysis reactor 10b forms the second control part, and the third pyrolysis reactor 10c forms the third control part. In the first pyrolysis reactor 10a the material travels in a direction illustrated by arrow B. In the second pyrolysis reactor 10b the direction of travel C of the material deviates by about 90° from the direction of travel B of the material in the first pyrolysis reactor 10a. Furthermore, in the third pyrolysis reactor 10c the direction of travel D of the material deviates by about 90° from the direction of travel C of the material in the second pyrolysis reactor 10b and, at the same time, by about 180° from the direction of travel B of the material in the first pyrolysis reactor 10a. When the direction of travel of the material in at least two different control parts is arranged to differ from one another, the pyrolysis apparatus 1 may be provided with a layout of a desired design. This allows the apparatus to be arranged in an optimal manner into the space available. For example, Figure 6 illustrates that the pyrolysis apparatus 1 requires a significantly shorter space than a pyrolysis apparatus with an identical direction of travel of material in each control part. [0042] According to an embodiment, the direction of travel of material to be pyrolysed in two different control parts differs by at least 30 degrees from one part to the other.

[0043] It is obvious to a person skilled in the art that as technology advances, the basic idea of the invention may be implemented in many different ways. The invention and its embodiments are thus not restricted to the examples described above but may vary within the scope of the claims.

Claims

1 . A pyrolysis apparatus with at least one pyrolysis reactor having a pyrolysis channel, a gas collection channel separate from the pyrolysis channel, an input for supplying material to be pyrolysed into the pyrolysis channel, an output for removing pyrolysed material from the pyrolysis channel, and a conveyor for conveying material to be pyrolysed in the pyrolysis channel from the input to the output, the pyrolysis apparatus being a continuous apparatus with at least two control parts, at least one heater for each control part, wherein pyrolysed material in the two different control parts may be subjected to thermal effects of a different magnitude, the gas collection channel having a partition wall between the at least two control parts and the at least two control parts having a gas discharge pipe from the gas collection channel for recovering gas produced from the material to be pyrolysed.

2. An apparatus as claimed in claim 1 , wherein the pyrolysis channel and the gas collection channel are substantially equal in length.

3. A pyrolysis apparatus as claimed in claim 1 or 2, wherein the pyrolysis apparatus includes at least two pyrolysis reactors, the pyrolysis reactor forming a control part of the pyrolysis apparatus.

4. An apparatus as claimed in any one of the preceding claims, wherein the direction of travel of the material in the at least two different control parts is arranged to differ from one part to the other.

5. An apparatus as claimed in any one of the preceding claims, wherein the heater is provided with means for heating a saline solution and with a heating piping for circulating the heated saline solution to heat a target to be heated.

6. A pyrolysis method in which a continuous pyrolysis apparatus is used so that material to be pyrolysed is conveyed through the apparatus, the apparatus comprising at least one pyrolysis reactor with a pyrolysis channel and a gas collection channel separate from the pyrolysis channel, the apparatus having at least two control parts, through which material to be pyrolysed is conveyed, wherein the material in the at least two control parts is subjected to thermal effects of a different magnitude, said at least two different control parts being separated from one another by arranging a partition wall in the gas collection channel between the control parts and gas produced from the material to be pyrolysed is recovered from the at least two different control parts from the gas collection channel.

7. A method as claimed in claim 6, wherein the pyrolysis apparatus is provided with at least two pyrolysis reactors that are arranged to form the control parts of the pyrolysis apparatus.

8. A method as claimed in claim 6 or 7, wherein material in the at least two different control parts is conveyed in directions differing from one control part to another.

9. A method as claimed in any one of claims 6 to 8, wherein the material is subjected to a thermal effect by heating a saline solution and arranging the saline solution to circulate in the heating piping to heat the material to be pyrolysed.