Device and method for the pyrolytic treatment of biomass or other carbonaceous product

Abstract

Title: Device and method for pyrolytic treatment of biomass or other carbonaceous product. The present invention relates to an installation for the treatment of biomass or other carbonaceous product comprising a pyrolysis furnace (1) equipped with a pyrolysis chamber (4), a combustion chamber (19) configured to heat the biomass in said pyrolysis chamber (4), and a pyrolysis outlet (5) configured to discharge gases produced by the pyrolysis reaction, characterized in that it further comprises a distillation column (2) comprising a distillation chamber (7) connected directly by a distillation inlet (6) to said pyrolysis outlet (5) so as to receive said gases produced by the pyrolysis reaction, said distillation chamber (7) comprising a high distillation outlet (9) in its upper part so as to allow gas to exit from the top, a temperature sensor,a cooling means (8) and a control means configured to control a predetermined temperature at the upper distillation outlet, and a lower distillation outlet at its lower part, so as to allow liquid to exit from the bottom. The present invention also relates to a process for treating biomass or other carbonaceous product that can be implemented in the installation of the invention. Figure of the abstract: Figure No. 1,

Description

Title of the invention: Device and method for pyrolytic treatment of biomass or other carbonaceous product

[0001] The present invention relates to the field of pyrolysis. It relates more particularly to an installation and a method for the pyrolytic treatment of biomass or other carbonaceous product.

[0002] Wood chemistry by pyrolysis dates from the end of the 19th century and was represented by a few players whose main business was to produce vegetable charcoal for the iron and steel industry.

[0003] At the time, some were interested in the condensation of pyroligneous juices to extract mainly acetic acid (the molecule predominantly present in these juices).

[0004] A handful have been interested in developing other molecules of interest. The complexity of the operation has limited the number of operators.

[0005] The advent of petrochemicals, which made it possible to produce these molecules at a lower cost, had the effect of stopping these activities.

[0006] The global context of environmental and climate paradigm change has now evolved, and the IPCC (Intergovernmental Panel on Climate Change) indicated at the last COP (Conference of the Parties) the production of Biocarbon (charcoal from the pyrolysis of biomass) as one of the seven solutions to climate disruptions.

[0007] Beyond the context, there is a growing demand from manufacturers wishing to replace petroleum-based products with bio-based products.

[0008] However, existing systems face problems of complexity and separation cost, which makes them incompatible with market prices.

[0009] To simplify the process, some companies have decided to burn these molecules to generate energy. Such a process is called "pyro-gasification".

[0010] However, regulations that are unfavorable to the burial and open burning of biomass force producers to find other solutions.

[0011] There is therefore a need for a system and process for processing biomass, which makes it possible to valorize all types of biomass, including biomass which is currently underutilized (such as fruit pits, coffee grounds, pruning wood, etc.) in an efficient and economical way, by transforming them into biocarbon (carbon of plant origin) and bio-oils (chemical molecules of plant origin).

[0012] The present invention provides a process and a device for processing biomass, making it possible to obtain biocarbon and several liquids at a lower cost. separated according to their nature.

[0013] To this end, it proposes a biomass or other carbon product treatment installation comprising a pyrolysis furnace equipped with a pyrolysis chamber, a combustion chamber configured to heat the biomass in said pyrolysis chamber, and a pyrolysis outlet configured to evacuate gases produced by the pyrolysis reaction.The said installation further comprises a distillation column connected directly by a distillation inlet to the pyrolysis outlet so as to receive the gases produced by the pyrolysis reaction, the distillation column comprising a high distillation outlet in its upper part so as to allow gas to exit from the top, a temperature sensor, a cooling means and a control means configured to control a predetermined temperature at the high distillation outlet, and a low distillation outlet in its lower part, so as to allow liquid to exit from the bottom.

[0014] Thanks to these arrangements, the installation makes it possible to separate the pyrolysis gases produced into at least two fractions, the two fractions being controlled by the temperature control at the level of the high distillation outlet.

[0015] According to other characteristics: - the distillation column may include at least two tanks connected to said lower outlet, intended to receive at least two distinct liquids at two different times during the treatment of biomass or other carbonaceous product, allowing for increased fractionation of the products recovered from pyrolysis, - the distillation column may include a heating element in its lower part, preferably positioned lower than the distillation inlet, thus allowing the release of uncondensed gases carried along with the condensed liquid at the bottom of the distillation chamber, - said installation may further include a condenser comprising a cooling means, an outlet at the top for non-condensable gases, an inlet connected to the upper distillation outlet, and a lower outlet for the discharge of condensed liquids, thus allowing for further separation of the products obtained by the pyrolysis gases, - said pyrolysis outlet may include a bypass configured to close the connection to said distillation column and open the connection to a water outlet, thus preventing the distillation column and the condenser from becoming clogged during a pyrolysis phase that releases essentially or even exclusively water vapor. - said installation may further include a gas recirculation line connected to said combustion chamber, and in which said outlet of pyrolysis includes a configured bypass capable of closing the connection to said distillation column and opening the connection to said gas recirculation line, thus enabling the recovery by combustion of pyrolysis gases when they do not contain gases that can be recovered otherwise.

[0016] The present invention further relates to a process for treating biomass or other carbonaceous product, comprising the following steps: • loading a batch of biomass or other carbonaceous product into a pyrolysis furnace comprising a pyrolysis chamber, then closing it, then starting the mixing of the batch, for example by rotating the pyrolysis chamber,

[0017] The following steps can take place simultaneously: • heating of said batch up to a first temperature plateau, • recovery of pyrolysis gas in a distillation chamber, via a distillation inlet, said distillation chamber having a high distillation outlet disposed in its upper part, • temperature control at the level of said upper distillation outlet by cooling the gases inside the part located higher than the distillation inlet of said distillation chamber, • outlet of at least a first liquid through a lower outlet of said distillation chamber to a first reservoir, and outlet of non-condensed gases through said upper distillation outlet.

[0018] Thanks to these arrangements the process makes it possible to separate the pyrolysis gases produced into at least two fractions, the two fractions being controlled by the temperature control at the level of the high distillation outlet.

[0019] According to other characteristics: - the process may also include the following steps: • heating said batch to a second temperature stage, • recovery of pyrolysis gas in said distillation chamber via a distillation inlet, • temperature control at the level of said upper distillation outlet by cooling the gases inside the part located higher than the distillation inlet of said distillation chamber, • outlet of at least a second liquid via a lower distillation outlet to a second tank, and outlet of uncondensed gases via a high distillation outlet

[0020] allowing for increased fractionation of the products recovered from pyrolysis, - the process may further include a heating step of the part located below the distillation inlet of the distillation chamber, allowing thus releasing uncondensed gases carried along in the condensed liquid in the distillation chamber, - the process may also include the following steps: • during at least one temperature plateau of the batch, the gases exiting through the upper distillation outlet are directed to a condenser, • outlet of at least one liquid via a low condensation outlet to a separate reservoir at each of at least one temperature stages of the batch

[0021] thus allowing for further separation of the products obtained by pyrolysis gases.

[0022] The present invention will be better understood upon reading the following detailed description, with reference to the accompanying figures in which: - Figure [1] is a schematic view of an installation according to a particular embodiment of the invention

[0023] Fig. 1 represents a biomass processing installation according to the invention.

[0024] “Biomass” means organic matter of biological origin, that is, any matter derived from plants, animals, or microorganisms. This organic matter can be used as a source of renewable energy or in the production of various chemicals and materials.

[0025] Biomass includes in particular wood waste, agricultural crop residues (such as straw and sugarcane bagasse), energy plants (such as miscanthus and willow), forest biomass, food industry waste, such as fruit and vegetable peels, algae and aquatic plants, and waste of animal origin, such as manure.

[0026] The installation according to the invention can be suitable for other carbon-based products such as polymers and rubbers. In the following description, the example of biomass will be used, but the invention is not limited to the processing of biomass, and is suitable for any carbon-based product, in particular one containing carbon chains that pyrolysis can reduce.

[0027] The installation according to the invention comprises a pyrolysis oven 1 and a distillation column 2.

[0028] The pyrolysis furnace 1 is configured to perform high-temperature heating of biomass in the absence of oxygen.

[0029] The pyrolysis oven 1 includes a pyrolysis chamber 4, which is for example made of steel resistant to high temperatures and corrosion.

[0030] Thermal insulation can surround the pyrolysis chamber 4, to minimize heat loss and maintain optimal pyrolysis temperatures.

[0031] A feed hopper allows the controlled introduction of biomass, into The pyrolysis chamber 4 is connected via an inlet 3. The pyrolysis chamber 4 is then closed to prevent gas leaks during the pyrolysis process. It has a pyrolysis outlet 5, through which the gases produced by the pyrolysis reaction can exit the pyrolysis chamber 4.

[0032] The pyrolysis oven 1 includes a combustion chamber 19, configured to heat the pyrolysis chamber 4.

[0033] The temperatures reached by the biomass are controlled by at least one temperature sensor and a control module, so as to allow temperature increases and maintenance at chosen plateau temperatures.

[0034] The distillation column 2 comprises a distillation chamber 7, preferably with a vertical dimension greater than its horizontal dimensions. The pyrolysis outlet 5 is connected to a distillation inlet 6 of the distillation chamber 7.

[0035] It further comprises a cooling means 8 arranged higher than the distillation inlet 6.

[0036] The distillation chamber 7 is equipped with a high distillation outlet 9, allowing uncondensed gases to exit.

[0037] At least one temperature sensor is located at the upper distillation outlet 9; it controls the cooling means 8 to obtain the predetermined temperature at the upper distillation outlet 9. A wired or wireless connection is established with a control means, through which the predetermined temperature can be entered. Such a predetermined temperature can be fixed for a given processing step, or it can vary slightly during a step, depending on the elapsed time and, for example, the gas flow rate at the upper distillation outlet 9.

[0038] The distillation column 2 may further include a heating means disposed lower than the distillation inlet 6, allowing for example the release of gases which would have been carried along in the condensed liquid; the quality of the separation carried out in the distillation chamber 7 can thus be improved.

[0039] The distillation chamber 7 is further equipped with a lower distillation outlet 10, through which the liquids formed by condensation of the gases can exit.

[0040] The distillation column 2 includes at least two reservoirs 11, configured to collect pyroligneous juices discharged through the lower distillation outlet 10.

[0041] The distillation chamber 7 may include at least one packing or at least one perforated tray, to improve the efficiency of the separation, according to solutions well known in the prior art. Such a distillation chamber then becomes a rectification chamber.

[0042] The process according to the invention may consist of carrying out the following steps: • loading biomass into the pyrolysis chamber 4, • closing, then starting a mixing process, for example by rotation of pyrolysis chamber 4, • raising the temperature of the pyrolysis chamber 4 to a first temperature plateau of the biomass, • setting a first distillation temperature at the top of distillation chamber 7, • recovery of gases produced by pyrolysis in distillation chamber 7, • separation of these gases into pyroligneous juice, collected in a first reservoir, and into uncondensed gases, which exit from the top, • raising the temperature of pyrolysis chamber 4 to a second biomass temperature stage, • setting a second distillation temperature at the top of the distillation chamber 7 • recovery of gases produced by pyrolysis in the distillation chamber 7 • separation of these gases into pyroligneous juice, collected in a second tank, and into non-condensed gases, which exit from the top, • if necessary, increase the temperature of the pyrolysis chamber 4 to a third biomass temperature stage, to complete the pyrolysis reaction, then decrease the temperature, • opening of pyrolysis chamber 4, and recovery of pyrolysis residues, for example biocarbon.

[0043] Two distinct liquid products can thus be obtained in addition to biocarbon in two separate reservoirs 11 with two temperature stages in the pyrolysis chamber 4.

[0044] For the recovery of pyrolysis residues, the closed pyrolysis chamber can be allowed to cool, then opened to extract the residues. Alternatively, the hot residues can be removed under an inert atmosphere and then allowed to cool in another closed container, thus enabling rapid refilling of the pyrolysis chamber.

[0045] It is of course possible to operate with more than two temperature steps, to obtain more than two distinct liquid products.

[0046] These products can be a single component, but also mixtures. The advantage of the process according to the invention is that it produces less mixed products, which can then be more easily separated into single-component products.

[0047] According to a preferred embodiment of the invention, the installation may further include a condenser 12 of which a condensation inlet 13 is connected to the high type of distillation 9.

[0048] The condenser 12 includes a cooling means.

[0049] The condenser 12 is equipped with a high condensation outlet 14, allowing uncondensed gases to exit.

[0050] The condenser 12 is further equipped with a lower condensation outlet 15, through which Liquids formed by condensation of gases can escape.

[0051] The installation further comprises one or more pyroligneous juice tanks 11, connected to the lower condensation outlet 15 so as to collect the liquids formed.

[0052] According to this preferred mode, the biomass treatment process can be presented as follows: • loading of biomass into pyrolysis chamber 4, • closure, then starting a mixing process, for example by rotating the pyrolysis chamber 4, • raising the temperature of the pyrolysis chamber 4 to a first temperature plateau of the biomass, • setting a first distillation temperature at the top of distillation chamber 7, • recovery of gases produced by pyrolysis in distillation chamber 7, • separation of these gases into pyroligneous juice, collected in a first reservoir 11 connected to the lower outlet of distillation 10, and in non-condensed gases, which exit from the top, • recovery, where applicable, of said non-condensed gases in the condenser 12 • separation of these gases into pyroligneous juice, collected in a third reservoir 11 connected to the lower condensing outlet 15, and uncondensed gases, which exit from the top of the condenser 12, • raising the temperature of pyrolysis chamber 4 to a second biomass temperature stage, • setting a second distillation temperature at the top of distillation chamber 7, • recovery of gases produced by pyrolysis in distillation chamber 7, • separation of these gases into pyroligneous juice, collected in a second reservoir 11 connected to the lower outlet of distillation 10, and in non-condensed gases, which exit from the top, • recovery, where applicable, of said uncondensed gases in condenser 12, • separation of these gases into pyroligneous juice, recovered in a fourth reservoir 11 connected to the lower condensing outlet 15, and uncondensed gases, which exit from the top of the condenser 12, • opening of pyrolysis chamber 4, and recovery of pyrolysis residues, for example biocarbon.

[0053] Four distinct products can thus be obtained with two temperature stages in the pyrolysis chamber 4.

[0054] One can imagine a second distillation column 2 allowing the treatment of the non-condensed gases in the first distillation column 2, and whose non-condensed gases are sent to condenser 12 in the case where several distillation temperatures allow the separation of several gases released by pyrolysis during the same temperature plateau of the biomass.

[0055] The uncondensed gases in the condenser 12 can be recycled to the pyrolysis furnace 1, where they constitute a supplementary fuel for the combustion chamber 19.

[0056] When the temperature rise begins in the pyrolysis chamber 4, a first temperature plateau is generally established at around 105 - 160°C. At this temperature, water vapor is released and goes towards the pyrolysis outlet 5. Water vapor is generally of no use, and is therefore prevented from reaching the distillation chamber 7. For this purpose, a connecting valve allows the distillation inlet 6 to be closed, and a tube 17 dedicated to the water vapor to be opened, which is generally allowed to escape.

[0057] It can also happen that at certain temperature levels, a gas is released that cannot be utilized or for which there is no market. It is then possible to nevertheless establish a temperature plateau at such a biomass temperature level, but as with water vapor, to prevent the gas from entering the distillation chamber 7. Here again, a connecting valve allows the distillation inlet 6 to be closed and a tube 18 to be opened dedicated to such a gas, which can, for example, be recycled as fuel for the combustion chamber 19 of the pyrolysis furnace 1.

[0058] An opening 16 at the top of the combustion chamber 19 allows combustion fumes to be evacuated.

[0059] Example of treatment of hardwoods (oak, beech, hornbeam): • A batch of hardwood is loaded into pyrolysis chamber 4, • The pyrolysis chamber 4 is closed and stirred or rotated. • The inlet of distillation chamber 7 is closed and a steam vent is opened; the temperature is raised to 125°C; the gas produced is steam; this temperature is maintained until the steam flow rate falls below a predetermined threshold. • The inlet of distillation chamber 7 is opened, and the temperature is raised to 290°C; the head of distillation chamber 7 is set at 85°C, and the temperature plateau is maintained until the flow rate at the head of distillation chamber 7 is below a predetermined threshold; water vapor is collected at the head of distillation chamber 7, and methanol, ethanol, and acetic acid, mixed in a first tank 11, are collected at the bottom of distillation chamber 7; the condenser 12 is not active; the water vapor produced can either be passed through the condenser 12 or discharged directly. • The temperature is raised to 350°C, and the head of distillation chamber 7 is set to 290°C and the temperature plateau is maintained until the flow rate at the head of distillation chamber 7 is below a predetermined threshold; phenolic slices (syringol, guaiacol, ...) are recovered at the top of the column, and light tars of the creosol type are collected at the bottom of the column in a second reservoir 11, • The phenolic wafers arrive in the condenser 12, where they are collected in a third tank 11; the gases not condensed in the condenser 12 are returned to the combustion chamber 19, • The inlet of distillation chamber 7 is closed, the temperature is raised to 450°C, and this temperature is maintained for 2 hours to ensure the quality and homogeneity of the Biocarbon cooking; the gases produced are directed to combustion chamber 19 to serve as fuel; these are heavy tars, • We allow it to cool, then we open the pyrolysis chamber 4, and we recover the biocarbon, for example by rotating the chamber in the opposite direction to its production direction.

[0060] For biomasses of other kinds, or other carbon products, similar or different temperature steps and temperatures at the top of the distillation chamber 7 are defined, and other products or mixtures of products can be obtained.

[0061] The installation according to the invention is thus particularly flexible and can be adapted to a wide variety of carbonaceous product feeds. For each type of biomass or other carbonaceous product input, it is sufficient to define the temperature plateaus in the pyrolysis chamber 4 and the temperatures at the top of the distillation chamber 7, and thus two, three, or more distinct mixtures can be recovered.

[0062] These mixtures are fairly simple mixtures, with few products mixed, which means that they will be much simpler, and therefore less expensive, to separate and purify afterwards by one of the complementary processes known to the person skilled in the art, than if all the gases produced by pyrolysis had been recovered mixed in a single tank 11 as proposed by the prior art.

[0063] The expression "temperature plateau" should be understood in the present invention as maintaining the temperature of the pyrolysis chamber 4 for a certain time; the temperature then varies little during this time, but may still increase by a few degrees during the duration of the maintenance; in the context of the present invention, a temperature plateau is defined by the fact that the rate of temperature rise is at least twice as low as the maximum rate of temperature rise that preceded it.

[0064] The distillation temperature set at the top of the distillation chamber 7 can also vary during a plateau, for example according to the gas flow rate at the top outlet of distillation 9, to optimize the separation obtained; such control of the distillation temperature at the top of the distillation chamber 7 is within the reach of a person skilled in the art.

[0065] The production of biocarbon has various applications, such as cosmetics, supplements for animal feed, plastics, paint, but also applications as a replacement for graphite, carbon black (petroleum), etc.

[0066] The juices from pyrolysis will, in turn, be used to produce, among other things, chemical molecules, flavorings, solvents and precursors of plastics.

[0067] The process for treating biomass or other carbon products according to the invention makes it possible to make much better use of the gases released by pyrolysis, by separating them efficiently in separate tanks 11.

[0068] Although the above description is based on particular embodiments, it is in no way limiting to the scope of the invention, and modifications may be made, in particular by substituting technical equivalents or by a different combination of all or part of the features described above. The scope of the invention is defined by the following claims.

Claims

Claims

1. Installation for treating a biomass or other carbon product comprising a pyrolysis furnace (1) provided with a pyrolysis enclosure (4), a combustion chamber (19) configured to heat the biomass or other carbon product in said pyrolysis enclosure (4), and a pyrolysis outlet (5) configured to evacuate gases produced by the pyrolysis reaction, characterized in that it further comprises a distillation column (2) comprising a distillation chamber (7) connected directly by a distillation inlet (6) to said pyrolysis outlet (5) so as to receive said gases produced by the pyrolysis reaction, said distillation chamber (7) comprising a high distillation outlet in its upper part so as to allow gas to exit from the top, a temperature sensor, a cooling means (8) and a control means configured to control a predetermined temperature at the high distillation outlet,and a low distillation outlet in its lower part, so as to allow liquid to exit from the bottom.

2. Installation according to the preceding claim, in which the distillation column (2) comprises at least two tanks (11) connected to said lower outlet, intended to receive at least two separate liquids at two different times during the treatment of the biomass.

3. Installation according to one of the preceding claims, in which the distillation chamber (7) is provided with at least one perforated tray or at least one packing element.

4. Installation according to one of the preceding claims, in which the distillation column (2) comprises a heating means in its lower part, preferably arranged lower than the distillation inlet (6).

5. Installation according to one of the preceding claims, further comprising a condenser (12) comprising a cooling means, an outlet in the upper part intended for non-condensable gases, an inlet connected to the upper distillation outlet, and a lower outlet intended for the evacuation of condensed liquids.

6. Installation according to one of the preceding claims, further comprising a gas recirculation pipe (18) connected to said combustion chamber (19), and in which said pyrolysis outlet (5) comprises a bypass configured to close the connection to said distillation column (2) and open the connection to said pipe

7.

8. gas recirculation. Process for treating biomass or other carbon product, comprising the following steps: loading a batch of biomass or other carbon product into a pyrolysis furnace (1) comprising a pyrolysis chamber (4), then closing, then starting mixing or rotating the pyrolysis chamber (4), the following steps can take place simultaneously: heating said batch to a first temperature level, recovery of pyrolysis gas in a distillation chamber (7), via a distillation inlet (6), said distillation chamber (7) comprising a high distillation outlet (9) arranged in its upper part, controlling the temperature at said high distillation outlet (9) by cooling the gases inside the part located higher than the distillation inlet (6) of said distillation chamber (7), outlet of at least a first liquid via a low distillation outlet 10 of said distillation chamber (7) towards a first reservoir (11), and outlet of the non-condensed gases via said high distillation outlet (9). A method of treating a biomass or other carbon product according to the preceding claim, further comprising the following steps: heating said batch to a second temperature level, recovery of pyrolysis gas in said distillation chamber (7) via a distillation inlet (6), controlling the temperature at said upper distillation outlet (9) by cooling the gases inside the part located higher than the distillation inlet (6) of said distillation chamber (7), outlet of at least a second liquid via a lower distillation outlet (10) to a second reservoir (11), and outlet of the non-condensed gases via the upper distillation outlet (9).

9. A method of treating a biomass according to one of claims 7 or 8, further comprising a step of heating the part located lower than the distillation inlet (6) of the distillation chamber (7).

10. Method for treating a biomass according to one of claims 7 to 9, further comprising the following steps: • during at least one temperature level of the batch, supplying the gases exiting via the upper distillation outlet (9) to a condenser (12), • outputting at least one liquid via a lower condensation outlet (15) to a separate reservoir (11) at each of the at least one temperature level of the batch.

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