ES2437717A1 - Method and device for the manufacture of charcoal from biomass (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Method and device for the manufacture of charcoal from biomass. Method of manufacturing charcoal from vegetal biomass that comprises: a) heating the biomass contained in a carbonization reactor with gas exit until a minimum temperature of 400ºc is reached, b) increasing the temperature of the carbonization reactor to a minimum temperature of 600º c, by combustión of the gases expelled by the gas outlet of the carbonization reactor in stage a) with an external source of oxygen, c) carbonizing the biomass in the absence of oxygen maintaining the conditions established in stage b) until the evolution of gases ends, d) decrease the temperature of the carbonization reactor, and e) extract the charcoal obtained from the carbonization reactor. Device and its use of this device for obtaining charcoal from vegetable biomass. (Machine-translation by Google Translate, not legally binding)

Description

METHOD AND DEVICE FOR THE MANUFACTURE OF VEGETABLE CARBON FROM BIOMASS

TECHNICAL SECTOR

The present invention relates to a method of manufacturing charcoal from biomass, where the energy released in the combustion of emitted gases is used

10 by heating the biomass to reach and maintain the temperature necessary for carbonization. Additionally, this patent application also describes a device that allows to carry out the method of manufacturing charcoal of the invention.

STATE OF THE TECHNIQUE

15 The process of obtaining more widespread charcoal today is carried out with pyramidal earth and brick furnaces with external energy mainly and for an average period of 2 days.

20 Procedures for obtaining charcoal in which combustion of the gases emitted by biomass have also been described. In particular, European Patent EP671453 81 (Metallgesellschaft AG) describes a process for producing coal in a loose bed reactor, where the reactor is a tank through which hot gas flows. In this reactor, the starting biomass is introduced from the top, and the

25 carbon obtained is collected from the bottom. This document describes the release of volatile components of the wood when it is heated, as well as it is described that these components combustion exothermically in the reactor due to the oxygen content present in the biomass. The exotherm produced by this combustion is controlled with the countercurrent gases, preventing the reaction biomass from increasing

30 temperature too fast, which would be detrimental to the hardness of the coal obtained.

On the other hand, in European patent EP2125994 81 (Themya) a process for obtaining continuous charcoal is described. This procedure includes

35 the forced oxidation of the volatile compounds emitted with the objective of increasing the temperature (T2) of the lower part of the reactor to 600-750 ° C, accelerating the biomass mineralization process, consuming the oxygen present in the injection gases which circulate through the reactor column and progressively decrease the temperature of the injection gases (T1) to room temperature.

5 However, the procedures described to date are more complex processes and need more external fuel than the present invention. Thus, the method of manufacturing charcoal of the present invention provides considerable energy savings by using the energy of the gases released in the

10 carbonization of the material. Additionally, the device of the present invention requires fewer physical components than the devices described in the documents cited above. The gases released from the carbonization combustion outside the carbonization reactor and produce an increase in the temperature of this reactor, which can be regulated with the combustion chamber chimney. In this way, you can also

15 control the quality of the coal obtained in a simple way.

DESCRIPTION OF THE INVENTION

In a first aspect, the present invention relates to a method of manufacturing charcoal 20 from vegetable biomass comprising: a) heating the biomass contained in a carbonization reactor with gas outlet to reach a minimum temperature of 400 oC ,

b) increase the temperature of the carbonization reactor to a minimum temperature of 600 ° C, by combustion of at least part of the gases expelled by the gas outlet of the carbonization reactor in step a) with an external source of

oxygen, c) carbonize the biomass in the absence of oxygen maintaining the conditions established in stage b) until the evolution of gases is finished, d) decrease the temperature of the carbonization reactor, and 30 e) extract the charcoal obtained from the reactor of carbonization

This patent application means "vegetarian biomass any biodegradable fraction of products or residues of biological origin from gardening activities (garden waste), agricultural (agricultural waste), or forestry (forest waste). Preferably, the vegetable biomass used as a starting product are

garden, agricultural or forestry residues such as, for example, pruning or gardening remains. In this way, manufacturing costs are further reduced by revaluating waste material, transforming it into a product of commercial interest such as charcoal.

Currently, garden waste can represent a problem of uncontrolled collection and dumping, so the manufacturing method of the present invention gives this residue a new "life cycle", when used as raw material for obtaining charcoal . Therefore, the use of garden waste is especially preferred

10 as raw material in the method of the present invention.

Additionally, the vegetable biomass used is packaged, preferably in the form of square or rectangular bales.

In another preferred embodiment, the method of manufacturing charcoal from vegetable biomass described in this patent application takes place discontinuously, that is, by independent batches.

Step a) of the method of manufacturing charcoal described in this application for

20 patent, includes heating the biomass of plant origin to a minimum temperature of 400 ° C. To carry out this first heating stage, external fuel is used, such as methane, propane or butane, all of them commercial fuel gases.

By increasing the temperature of the carbonization reactor that contains the biomass of origin

Vegetable, preferably garden, agricultural or forestry residues, begins a chemical process known as pyrolysis. In this process, gases, mainly light hydrocarbons, are produced from the breakdown of the cellulose molecules of the biomass. Due to the overpressure inside the reactor, the gases produced are expelled from the reactor by the gas outlet (s). In this way, the carbonization of biomass has

30 within the reactor in the absence of oxygen, since the possible oxygen initially present in the carbonization reactor is expelled by the gas outlet (s) by overpressure as the system is heated in step a) of the method.

Once they have left the carbonization reactor, the gases come into contact with a

35 source of oxygen in a combustion chamber and, at temperatures of 400 ° C or higher, 4

They become inflamed by spontaneous combustion. This combustion of the gas coming from the biomass, produces an increase in the temperature of the carbonization reactor that contains the vegetable biomass and, thus, gas is returned to be expelled by pyrolysis of the biomass in the absence of oxygen. In this way it can be achieved, without using fuel

5 external, that the temperature reaches 600 oC, and even 700 ° C depending on the amount of gases emitted and oxygen.

Additionally, the energy released in the combustion of the biomass gases is also used to evaporate the water that contains the starting biomass.

In this way, the method of the present invention allows to obtain charcoal from vegetable biomass with an external contribution of calories from an external fuel and the heat capacity of the volatile gases of the biomass, which are released when heated and produced the feedback of the pyrolysis process getting the

15 carbonization of plant biomass inside the carbonization reactor. In this way the contribution of external energy necessary to carry out the manufacture of charcoal is approximately 30% of the total necessary.

Additionally, the method of the present invention allows to accelerate the process of

20 carbonization of biomass, since the temperatures achieved with the internal fuel, gases emitted by cellulose degradation, accelerate the expulsion of more gases and thus the process of obtaining charcoal.

The method of manufacturing charcoal of the present invention also makes it possible to use

25 part of the gases emitted from the pyrolysis of plant biomass, mainly light hydrocarbons, as a source of energy for other uses.

In another preferred embodiment, the same external source of oxygen is used in steps b) and c). Preferably, this external source of oxygen is selected from the group consisting

30 in air, oxygen enriched air, oxygen mixed with an inert gas such as argon, helium or nitrogen or compressed oxygen, the use of air as an oxygen source being even more preferable as it is more profitable.

In another preferred embodiment, step c) of carbonization of the biomass in the absence of oxygen comprised in the method of manufacturing charcoal from biomass

The vegetable described in this patent application takes place at a temperature between 600 'C and 800'C.

As described above, the temperature can be maintained at

Minimum temperature of 600 ° C due to the energy produced by combusting the gases emitted from the biomass pyrolysis process itself and an external source of oxygen, preferably air, outside the carbonization reactor. Thus, it is possible to control the temperature of the carbonization reactor by regulating the flow of the oxygen source, preferably by regulating the flow of air into the combustion chamber of the

10 device described below in this patent application. Additionally or alternatively to the regulation of the flow of the oxygen source, it is also possible to maintain the temperature within the established range, preferably between 600 and 800 ° C, by means of a conventional cooling system.

However, the method of the present invention also allows, if desired, that step c) of carbonization of the biomass take place by providing a small amount of external fuel.

In another preferred embodiment, in the method of manufacturing charcoal of the present

In the invention, part of the gases emitted by carbonization of plant biomass can be extracted from the device where the manufacture of charcoal takes place, thus allowing its use as a source of energy for other applications. Preferably, once the carbonization reactor has reached a temperature between 600 and 800 ° C, the flow of the oxygen source is cut off and the emitted gases are separated from the carbonization reactor of the

25 device where the method of the present invention takes place. More preferably, the gases are removed from the combustion chamber of the device described in the second aspect of the present invention, and these gases can be stored for later use,

or be used as a source of energy in another procedure that takes place simultaneously.

In this way, in addition to being able to control the temperature of the carbonization reactor within a preferred range, that is, between 600 and 800 'C, part of the gases emitted by the reaction can be used as an energy source for other uses.

In another preferred embodiment, the method of manufacturing charcoal of the present invention also makes it possible to take advantage of the residual heat obtained by combustion of the gases emitted with the oxygen source as an energy source for other applications.

5 Once the gas evolution in stage c) is finished, it is considered that the carbonization has ended and, therefore, the method of manufacturing charcoal that is described in this patent application comprises a step d) where the decrease in the temperature of the carbonization reactor to a temperature at which can be safely handled by the operator, preferably at a temperature

10 maximum of 40 ° C. This decrease can be made by allowing the system to cool on its own or by applying a cooling system such as, for example, inert gas cooling tunnel.

In another preferred embodiment, the method of making charcoal as it is

15 described in this patent application may comprise additional processing steps of the charcoal obtained after step e). In particular, it can comprise grinding, screening and selection stages of the size of the coal to obtain different grain measurements. Additionally, these grains can be pelletized, enriched or processed according to ways known to the person skilled in the art, depending on the use

20 that it is intended to be given, for example, as barbecue fuel.

In another preferred embodiment, the method of manufacturing charcoal described in this patent application takes place in a device as described in the second aspect of this invention.

In a second aspect, the present invention relates to a device for manufacturing charcoal from vegetable biomass, preferably according to the method described in the first aspect of the present invention, comprising: i) at least one reactor of carbonization with at least one gas outlet,

Ii) a combustion chamber in thermal contact with the at least one carbonization reactor, iii) at least one gas outlet from the combustion chamber to the outside, and iv) heating means.

Each of the carbonization reactors present in the device of the present invention is made of a temperature conductive material and resistant to maximum temperatures of 900 ° C such as, for example, metals such as rolled steel or stainless steel.

The device for making charcoal of the present invention may comprise one or more carbonization reactors. In any case, each of these carbonization reactors comprises at least one gas outlet and is in thermal contact with a combustion chamber. Preferably, the combustion chamber at least partially envelops the carbonization reactor.

In another preferred embodiment, any of the carbonization reactors, preferably all of them, can be completely removed from the device. In this way, the device of the present invention allows the loading of vegetable biomass and the discharge of charcoal more easily for the operator. Additionally, complete removal of the carbonization reactor will allow faster cooling of its contents. As well as it facilitates the work of cleaning the carbonization reactor.

In another preferred embodiment, the device for manufacturing charcoal of the present invention may comprise at least one system for extracting part of the gases generated by carbonization of the plant biomass, preferably light hydrocarbons from cellulose degradation, from the chamber of combustion. In this way the device of the present invention allows part of the emitted gases to be stored and / or used as an energy source for other applications.

In another preferred embodiment, the device for manufacturing charcoal of the present invention may comprise at least one refrigeration system.

In another preferred embodiment, the device for manufacturing charcoal described in this patent application comprises:

i) a carbonization reactor with several gas outlets, preferably the reactor can be completely removed from the device, for example, to carry out the loading and unloading of the material,

ii) a combustion chamber at least partially enveloping the carbonization reactor,

iii) a gas outlet from the combustion chamber to the outside, and iv) lighters as heating means.

The different carbonization reactors and combustion chambers can have several shapes, for example, they can be quadrangular, preferably square or rectangular, or they can be cylindrical, etc.

In another preferred embodiment, the combustion chamber is the space formed by the outer wall of the carbonization reactor and the inner wall of an oven, preferably a

10 conventional oven. In this case, it is preferred that the carbonization reactor has the same shape as the inner wall of the furnace, it being even more preferable that both are quadrangular. This combustion chamber comprises at least one chimney to allow the exit of gases towards the outside of the device.

The quadrangular shape of the furnace and carbonization reactor is preferred because the welding of the metallic materials that preferably make up the structure of the device is always more robust if it is carried out with said geometry. Additionally, the straight side walls characteristic of this geometry are also more robust since they withstand less stress and temperature influence than side walls with certain

20 degree of curvature.

On the other hand, in the method of manufacturing charcoal described in this patent application it is preferred that the vegetable biomass used as raw material is packaged, preferably in the form of square or rectangular bales. Thus,

It is also preferred that the carbonization reactor and the combustion chamber have a square or rectangular shape, since these geometries allow easily adding said matter to be carbonized, as well as optimizing the total space occupied by the device.

In another preferred embodiment, the carbonization reactor is a square compartment or

30 rectangular waterproof, with an opening in the upper part to allow the loading and unloading of the reactor. This compartment is provided with a cover of the appropriate size to allow a tight seal. Preferably, the cover comprises holes to allow the exit of gases. Even more preferably, the compartment and lid are metallic, for example, of rolled steel or stainless steel.

In an even more preferred embodiment, the device (1) for manufacturing charcoal as described in this invention, preferably by the procedure described in the first aspect of this patent application, comprises:

i) a carbonization reactor (2), comprising: a box and a lid with holes 5 (6), both of rolled steel or stainless steel, ii) a combustion chamber (4) formed by the external wall of the reactor of

carbonization and the inner wall of an oven, preferably a conventional oven, iii) a chimney (5) from the combustion chamber (4) to the outside, and V) lighters (7).

10 The lighters (7) allow the device to be heated by the application of external fuel, for example, methane, propane or butane, all of them commercial fuel gases.

In a third aspect, the present invention also relates to the use of the device as described in this patent application, both in its most general scope and in the different preferred embodiments mentioned, for manufacturing charcoal according to the method described. in the first aspect of this invention.

Additionally, the present invention also includes the use of gases generated by carbonization of plant biomass as a source of energy for other applications.

BRIEF DESCRIPTION OF THE FIGURE

Figure 1: Schematic diagram of the device used in the method of making charcoal according to a particularly preferred embodiment of the present invention. (1) Device, (2) carbonization reactor, (3) plant biomass, (4) combustion chamber, (5) chimney, (6) reactor holes, (7) lighters.

30 Figure 2: Photograph showing the combustion of the gases emitted by the pyrolysis of the biomass in the combustion chamber (4) formed by the outer wall of the carbonization reactor (2) and the outer wall of a conventional furnace.

35 10

Figure 3: Photos of charcoal from different sources:

to.

Coal palm tree trunk

b.

Coal palm leaf

C. Pine Leaf Vegetable Charcoal 5 d. Grass charcoal

and.

Branch charcoal

F.

Trunk Charcoal

EXAMPLE

Remains of pine branch of silvicultural work or gardening cleaning are collected. These branches are introduced into the carbonization reactor (2). Subsequently, the reactor is introduced into the oven (1) and it is closed. Next, the lighters (7) are lit to allow external fuel to enter the combustion chamber (4) until the temperature of the carbonization reactor (2) reaches a temperature of 400 oC. At this temperature the carbonization process inside the reactor begins, so that the external fuel input is reduced to 10% of the initial amount. The gases emitted during carbonization are collected in the combustion chamber (4), allowing their combustion to increase the temperature of the carbonization reactor (2) to 600 oC. 20 The reactor temperature is maintained between 600 and 700 ° C by controlling the entry of air into the combustion chamber. Once the emission of flammable gases from the pyrolysis is finished, the temperature is allowed to decrease to a maximum temperature of 40 oC. Subsequently, the carbonization reactor (2) is removed from the device (1) and the branch charcoal obtained from the reactor. Finally, the coal obtained is ground and screened to

25 get the grain of desired size.

Claims (8)

1. A method of manufacturing charcoal from plant biomass comprising: a) heating the biomass contained in a carbonization reactor with gas outlet 5 until a minimum temperature of 400 oC is reached, b) increase the temperature of the carbonization reactor to a minimum temperature of 600 oC, by combustion of at least part of the gases expelled by the gas outlet of the carbonization reactor in step a) with an external source of oxygen, 10 c) carbonize the biomass in the absence of oxygen while maintaining the conditions established in stage b) until the evolution of gases is finished, d) decrease the temperature of the carbonization reactor, and e) extract the charcoal obtained from the carbonization reactor. The method of manufacturing charcoal according to claim 1, wherein the method takes place discontinuously. 3. The method of manufacturing charcoal according to any one of the claims 1 or 2, where plant biomass is a garden waste, forest residue or forest residue. 4. The method of manufacturing charcoal according to any one of claims 1 to 3, wherein the external source of oxygen from steps b) and c) is air. The method of manufacturing charcoal according to any one of claims 1 to 4, wherein step c) of carbonization in the absence of oxygen takes place at a temperature between 600 and 800'C. 6. Device for manufacturing charcoal from vegetable biomass comprises: 30 i) at least one carbonization reactor with at least one gas outlet, ii) a combustion chamber in thermal contact with the at least one carbonization reactor, iii) at least one gas outlet from the combustion chamber outside , and iv) heating means.

7.

Device for manufacturing charcoal according to claim 6, wherein the at least one carbonization reactor is made of rolled steel or stainless steel.

8.

Device for manufacturing charcoal according to any one of claims 6 or

5 7, where any of the carbonization reactors can be completely removed from the device. 9. Device for manufacturing charcoal according to any one of claims 6 to 8, 10 i) a carbonization reactor with several gas outlets, ii) a combustion chamber at least partially enveloping the reactor carbonization, iii) at least one gas outlet from the combustion chamber outside, and iv) lighters. 10. The device for manufacturing charcoal according to any one of claims 6 to 9, comprising: i) a metal carbonization reactor, comprising: a metal box and a metal cover with holes, ii) a combustion chamber formed between the outer wall of the reactor of carbonization and the inside wall of an oven, iii) a chimney from the combustion chamber to the outside, and iv) lighters. 11. Use of the device as described in any one of claims 6 to 10, in the method of making charcoal as described in any one of claims 1 to 5.