WO2011047696A1

WO2011047696A1 - Process for converting biomass and device therefor

Info

Publication number: WO2011047696A1
Application number: PCT/EP2009/007534
Authority: WO
Inventors: Hans-Gerd RÜCKER; Nic Haagen; Oliver Weiss
Original assignee: Bioethika Umwelttechnologien Ag
Priority date: 2009-10-21
Filing date: 2009-10-21
Publication date: 2011-04-28

Abstract

The invention relates to a process for converting biomass of municipal, agricultural and/or industrial origin into carbonaceous substances of a different composition. The biomass is prewarmed before and after occurrence of the thermal reaction outside the pressurized reactor, wherein the reaction in the pressurized reactor is initiated by the prewarmed and catalyst-enriched biomass, and wherein the biomass continuously passes through the pressurized reactor, in that the preheated part of the biomass is surrounded by a remaining part of the biomass situated in the pressurized reactor. A device for carrying out the process comprises at least one pressurized reactor (2) which is composed of at least one inner reactor (2.1) and an outer reactor (2.2), wherein the outer reactor is provided with at least one discharge opening (14.1, 14.2). At least one heatable mixing vessel (1) is connected upstream of the inner reactor. An outer screw (5) is arranged on a shell (3) of the inner reactor and an inner screw (4) is arranged within the inner reactor. The inner and outer screws (4; 5) are rotatable reversibly.

Description

Process for the conversion of biomass and apparatus therefor

The invention relates to a process for the conversion of biomass of municipal, agricultural and / or industrial origin into carbonaceous substances of other composition, in which the biomass is mixed with water, the water-containing biomass is added to a catalyst, the water-and catalyst-enriched biomass in a pressure reactor a thermal reaction under pressure, exclusion of air and dehydration is subjected.

Furthermore, the invention relates to a device for carrying out the method.

A method of the type mentioned is given in DE 196 31 201 C2. A disadvantage of the known method is that the heating of the biomass takes place within the pressure reactor with the aid of an external heat source, in the present case via generators for generating microwave radiation. The process is energy intensive and therefore not economically efficient.

CONFIRMATION COPY It is known to produce fuels by means of so-called hydrothermal carbonization ("coalification") from biomass with the release of heat energy.Published patent applications, inter alia WO 2008/095589 AI,

EP 1 970 431 AI, WO 2008/113309 AI, DE 10 2007 022 840 AI invoke the already explored in 1913 by Friedrich Bergius chemical process, without mentioning any further prior art concretely. In the process, the biomass consisting of biowaste, grass, leaves and other plant residues is slurried with water, treated with a catalyst such as citric acid and transferred in a pressure reactor under elevated temperature and pressure over a few conversion stages emission-free in a carbonaceous material. There will be no carbon dioxide released during the process.

A device for the carbonization of organic substances, preferably garbage, shows DE 34 24 373 AI. The device consists of a pressure chamber, called carburizing chamber, whose one wall is arranged displaceable so that the waste can be continuously compressed. The compressive forces are to be increased during compression until the resulting from these forces molecular friction in the organic matter, which are located in the Kolohlungskammer, has generated so much heat that under the simultaneous action of pressure and heat, while approximately exclusion of Oxygen, these organic substances are subjected to a coalification.

EP 0 204 354 B1 describes a process for the production of hydrocarbons containing liquids from biomass, in which the biomass is brought into a reaction zone at elevated temperature and pressure.

Furthermore, EP 0 052 334 B2 discloses a device for obtaining solid, liquid and gaseous fuels from organic material, therein sewage sludge, in which within a heated reactor tube a screw conveyor is arranged. Here, biomass is heated under exclusion of air to a temperature of 200 to 600 degrees Celsius, but without the involvement of reduction and oxidation processes.

The processes for the conversion of biomass, which are described in the above-mentioned documents, have the great disadvantage that the pressure reactor must be constantly reheated, otherwise the process comes to a standstill. This requires a very high energy consumption.

The object of the invention is to design a method of the type mentioned in the preamble, which is more energy efficient and with the aid of which the process can be performed on an industrial scale. Another object of the invention is to develop a device for carrying out the method.

This object is achieved by a generic method in which the biomass is preheated before and after the occurrence of the thermal reaction outside the pressure reactor and is supplied to the pressure reactor in the preheated state, the reaction in the pressure reactor is initiated by the preheated and catalyst-enriched biomass, the biomass continuously passes the pressure reactor, wherein the preheated part of the biomass is surrounded by another part of the biomass located in the pressure reactor.

Biomass is understood to mean an organic material which is preferably biological, water-containing residues and waste. These materials usually come from households (biowaste), from industrial plants (breweries, Food processing, paper mills, pharmaceutical industry etc) and as sewage sludge biological wastewater treatment. The materials also include agricultural and forestry waste and the remainder of renewable raw materials containing cellulose. The biomass can also be added to wood and wood-based panels if they have been shredded accordingly beforehand.

The reaction proceeds in the presence of at least one acidic catalyst and is exothermic. Preferably, the catalyst used is citric acid, which reacts with the cellulosic material of the biomass. Besides citric acid and other organic acids, such as acetic, formic, succinic, tartaric u. a., in question.

It is advantageous that the biomass passes through the pressure reactor at least at predetermined time intervals in opposite directions of flow. It is particularly advantageous to put the biomass at the same time in a rotational movement, which can be done in one or simultaneously in two opposite directions of rotation. These measures improve the heat exchange of the biomass streams.

The preheating of the biomass outside the pressure reactor can take place in a heatable mixing container. The biomass can be preheated to a temperature of up to about 200 ° C., preferably it should be preheated between 95 ° C. and 135 ° C. It is advantageous that the preheating of the biomass in the mixing vessel is assisted by the waste heat obtained from the pressure reactor.

At the beginning of the process, called start-up phase, at least part of the biomass in the pressure reactor is heated by at least one external heat source, such as the heating cartridge. The warm-up cartridges may be placed at multiple locations of the indoor and / or outdoor reactor. Otherwise the process runs without power from the outside, so that it can be run independently after the start-up phase.

The process is continuous, as if in a cycle where new material (biomass) can be fed in and processed material (product) can be removed again and again. Due to the exothermic reaction, excess energy is generated which, in the form of steam, can drive at least one steam engine with an electric generator. The advantage is that apart from the start-up phase no heat must be supplied from the outside and that the heat-related fluctuations of the process can be compensated thanks to the available energy surplus.

The output of the processed mass from the pressure reactor can be made in stages by successively opening and closing several drain valves. This gives carbonaceous products of varying consistency and density.

It is of great advantage that the conversion of organic materials according to the invention can be carried out in such a way that the calorific value of the biomass used can be largely utilized.

An apparatus for carrying out the method consists essentially of the following listed parts: at least one pressure reactor, which consists of an outer reactor and at least one inner reactor, and at least one, the inner reactor upstream, heatable mixing vessel.

Preferably, both the inner reactor and the outer reactor are cylindrical, the two having a common Have longitudinal axis, so that an uninterrupted tube in-tube arrangement arises.

The inner reactor is rotatably arranged with respect to the outer reactor, wherein the rotational movement can be realized in one or in two opposite directions of rotation about said longitudinal axis.

Furthermore, the cylindrical inner reactor may be provided with an inner screw and / or with an outer screw. The internal screw can be arranged rotatably with respect to a jacket of the internal reactor or rigidly connected to a jacket inside the rotatable internal reactor. Instead of the inner screw or outer screw several separate stirring arms can be used.

Preferably, the rotational movements of the inner screw

and / or the jacket of the inner reactor reversible.

The mixing container may be equipped with at least one agitator whose drive axis is vertical, d. H. can be arranged perpendicular to the longitudinal axis of the pressure reactor or horizontally or inclined. It is important that the mixing vessel, as well as the pressure reactor is made airtight and thermally insulated in order to minimize the heat losses.

The pressure reactor can rest on a suitably solidified substrate, for example on a concrete floor or a platform lying above the ground. It is conceivable to set up the entire device or at least the pressure reactor for the purpose of mobility of the system on a vehicle platform.

The device works emission-free and binds C0 ₂ and CO. The products resulting from metabolism can be used as required used for energy production or as a soil conditioner and fertilizer.

The object of the invention is described below with reference to

Drawing explained in more detail. The figures show:

1 shows a pressure reactor with connected mixing container, in a schematic side view;

Fig. 2 shows the pressure reactor of FIG. 1 in a schematic

Front view;

FIG. 3 shows the pressure reactor according to FIG. 1 in a longitudinal section; FIG.

4 shows the entire device in a perspective, schematic representation;

Fig. 5 shows the pressure reactor of FIG. 1 in an enlarged

Representation, with a sketchy hinted armature;

Fig. 6 shows a detail "C" according to Fig.l;

Fig. 7 is a schematic division of the outer reactor in

several fields.

The device 100 shown in FIG. 4 or plant consists essentially of a pressure reactor 2 with two connected mixing vessels 1.1 and 1.2, a steam boiler 16, two power generators 17, a condensation water tank 19, a reagent tank 20, a heater 21 and a collecting container 22. The steam boiler 16 is connected via a line 30 and a pressure relief valve 18 to the pressure reactor 2.

The pressure reactor 2 is shown in detail in FIGS. 3 and 5. It consists of a cylindrical outer reactor 2.2 and an nem also cylindrical inner reactor 2.1 together. The outer reactor 2.2 has a jacket 9 and two end walls 31.1 and 31.2, on which the inner reactor 2.1 is mounted. The inner reactor 2.1 in turn has a jacket 3 which is longer than the jacket 9 of the outer reactor. The outer reactor 2.2 has a chamber 39 whose effective volume is limited by the jacket 9 and by the inner reactor 2.1 and by the outer screw 5.

The inner reactor 2.1 or its jacket 3 is rotatably disposed within the outer reactor 2.2. Inside the inner reactor 2.1, an inner screw 4, which is rotatable about a shaft 25 and extends almost as far as a casing inner side 32, runs. H. it slides during the rotational movement over the jacket-inner side 32. The rotational movement of the inner screw 4 is reversible.

The jacket 3 of the inner reactor 2.1 is of an outer screw

5, which is rigidly connected to the jacket. The rotational movement of the jacket 3 of the inner reactor 2.1 and thus of the outer screw 5 can take place in one or in two opposite rotational directions D1, D2 (see FIG. Reference is made here to a gear 33 shown in FIGS. 1 and 3, which is part of a tooth drive (not shown).

The mixing container 1 is through a cylindrical double jacket

6, which has a space 7 filled with oil. A heating device 8 in the form of a heating coil (see FIGS. 1 and 6) is also accommodated in the space 7. Furthermore, the mixing container 1, a stirrer 24 and an airtight sealable, domed lid 12 on which an equally closable filler neck 13 is introduced. An unillustrated drive for the agitator 24 is omitted because of simplification of the drawing. The mixing container 1 tapers conically downward and closes via a controlled Ven- til 23 (flap) to a filling opening 34 of the inner reactor 2.1 at.

The mixing container 1 and the inner reactor 2.1 including inner and outer screws are made of a bronze alloy. The jacket 9 and end walls 31.1, 31.2 of the outer reactor 2.2 are made of a corrosion-resistant steel alloy and vacuum-insulated similar to the mixing container 1.

On the jacket 3 of the inner reactor 2.1, two closable outlets 10.1, 10.2 are provided (cf., Fig. 5), of which the outlet 10.1 leads directly into the outer reactor 2.2. The second outlet 10.2 is connectable to a collecting container 22. This allows the discharge of the product located in the inner tube either in the outer reactor 2.2 or in the collecting container. As shown in FIG. 5, the inner reactor 2.1 is provided at its end facing away from the mixing container 35 with a hydraulic piston 11, by means of which a drain valve 36 can close and open the arranged on the jacket 3 outlet 10.1.

On the jacket 9 of the outer reactor 2.2, a discharge opening 14.1 is arranged for discharging the finished product. An additional discharge opening 14.2 is located immediately in front of the rear end wall 31.1.

The pressure reactor 2 is equipped with conventional fittings, such as thermometer 26, pressure gauge 27, pH meter 28 and sampling point 29. The parts of the fitting are each provided at several points of the shell 9.

Function of the device (see Figures 5 and 6)

The following parameters of the process and the device were predetermined: Classification of running around inner reactor 2.1 outer screw 5 in nine fields 38;

Each field shown schematically in Fig. 7 corresponds to a volume V2 of the inner reactor 2.1; This results in a total volume V3 of the outer reactor:

V3 = 9 x V2

The volume V2 of the inner reactor should not be exceeded by a volume VI of the mixing container, d. H.

V2 <VI

The boiler pressure in the steam boiler 16 should be between 18 and 20 bar;

In the heated mixing vessel there is a pressure between 1010 and 1015 mbar;

The PJ value of the dry matter is on average 17,000 kJ / kg;

The residence time of the biomass in the inner reactor is about 1 hour.

At the beginning of the up to 8 hours lasting start-up phase, two warming cartridges 15.1, 15.2 heated to about 170 ° C. with thermal oil are introduced into the empty pressure reactor 2. The heating cartridges are made of bronze alloy and each have a volume of about 0.7 m ³ . The warming cartridges

15.1, 15.2 are accommodated in an inlet 37 (see Fig. 7) of the inner reactor 2.1 and at the opposite end of the outer reactor 2.2 at its end 31.1 (see Fig. 7) or via the outlet 14.2 shown in Fig. 5 in the outer reactor. The number and arrangement of the heating cartridges 15.1, 15.2 am Pressure reactor is chosen only as an example and can be made differently if required.

Biomass and about 15% by weight of water are pumped into two mixing vessels 1.1, 1.2 (see FIG. 4) via the inlet connection 13 on the cover 12 until the mixing vessels are filled. With the agitator 24, the mixture is processed to a homogeneous mass. The heating of the mixing container 1.1, 1.2 to a temperature of 120 ° C and thus the biomass by means of the heater shown in Fig. 2 8. The excess of preheated biomass in both mixing vessels 1.1, 1.2 is sufficient for the filling of the inner reactor 2.1 and for portionwise charging of the outer reactor.

The division of a chamber 39 of the outer reactor 2.2 in nine fields and the assignment of the capacity of the inner reactor 2.1 only a field 38 (volume section) is clear from the given performance. A field 38 corresponds to the volume V2 of the inner reactor (see Fig. 7). The portions of the biomass (in the present case 9 portions) will pass from the inner reactor 2.1 gradually into the chamber 39 of the outer reactor 2.2 via the outlet 10.1 (left side Fig.5), which is opened by means of hydraulic piston 11 and draining slide 36 each time , This ensures that the mass in the chamber 39 is not mixed with each other and the calorific value of the mass located in a field can be fully utilized. The process, which is carried out under exclusion of air, is continuous and can take months as required.

It is also possible to refill the mass from the mixing containers 1.1, 1.2 as needed, because the available biomass does not always have the same calorific value. Through the supply of materials, the process can be be controlled better. It is aimed at a uniform reaction in each field.

The residence time of the predetermined amount of biomass in the inner reactor 2.1 is about 1 hour, d. H. Each hour, another portion of the preheated biomass is fed from the mixing vessel into the inner reactor without having to stop the process. The inner screw 4 turns left and right and thereby homogenizes the mass.

After one hour, the mass is discharged from the inner reactor in the flow direction Rl via the outlet 10.1 in the outer reactor 2.2 and at the same time a reagent, here: citric acid and water supplied from the reagent tank 20, wherein the weight ratio of water to reactant is about 20. The reactant initiates the exothermic process already at a temperature of 170 ° C, which produces water vapor. At a temperature of 210 ° C creates an overpressure of 20 bar. The generated steam also has a pressure of 20 bar.

In order to make maximum use of the calorific value of the mass, in particular for steam production, the water is supplied in mist form in order to achieve the greatest total surface area.

Every hour the mass moves around a field in the flow direction R2 and after 9 hours it reaches the last field where the outlet 14.2 is. The processed mass is discharged and the first field is filled with the mass from the inner reactor 2.1 via the outlet 10.1. Immediately thereafter, the inner reactor is again filled with the pre-heated in the mixing container 1.1 or 1.2 mass and mixed. Overall, the biomass in the outer reactor lingers for about 9 hours at a temperature between 200 and 210 ° C until the calorific value of the mass is used up. The outlet of the mass is carried out in two stages as needed. The outlets 14.1, 14.2 (drain valves) on the outer reactor are then opened sequentially, so that no air enters the process.

Depending on the desired residence time, usually 9 hours, the rotational movement of the outer screw 5 is set or a very slow rotation of the outer screw and thus of the shell 3 is made.

The steam passes via the pressure relief valve 18 and thermo-insulated line 30 into the steam boiler 16, to which two power generators 17 connected in series are connected.

With the electric current generated in this way are in turn operated parts of the device, such as agitator 24, heater 8 in the mixing containers 1.1, 1.2, emptying slide 36 and other movable elements.

The rest of the electricity is fed into the public grid.

Claims

Claims:

1. A process for the conversion of biomass of municipal, agricultural and / or industrial origin in carbonaceous materials of other composition, in which the biomass is mixed with water, the catalyst is added to hydrous biomass, the biomass enriched with water and catalyst in a pressure reactor (2 ) is subjected to a thermal reaction under pressure, exclusion of air and dehydration until a carbonaceous end product is formed, characterized in that the biomass is preheated before and after the occurrence of the thermal reaction outside the pressure reactor (2) and is supplied to the pressure reactor in the preheated state , the reaction in the pressure reactor (2) is initiated by the preheated and catalyst-enriched biomass, the biomass continuously passes the pressure reactor (2), wherein the preheated part of the biomass is surrounded by a part of the biomass located in the pressure reactor (2) t.

2. The method according to claim 1, characterized in that the biomass favoring the heat exchange, at least temporarily in opposite directions of flow (Rl, R2) passes the pressure reactor (2).

3. The method according to claim 1, characterized in that the preheating of the biomass takes place in at least one heatable mixing container (1.1, 1.2).

4. The method according to any one of claims 1 to 3, characterized in that the biomass is preheated to a temperature up to 200 ° C, but preferably between 95 ° C and 125 ° C.

5. The method according to claim 1, characterized in that in the pressure reactor (2) treated biomass coaxially pass the pressure reactor and the rotational movement in the pressure reactor (2) is subjected.

6. The method according to claim 5, characterized in that the rotational movement of the biomass in the pressure reactor (2) in a rotational direction (Dl) or simultaneously in two opposite directions of rotation (Dl, D2).

7. The method according to claim 1 and 3, characterized in that the preheating of the biomass in the mixing vessel (1.1, 1.2) is supported by waste heat recovered from the pressure reactor (2).

8. The method according to any one of claims 1 to 7, characterized in that the start-up process of the conversion by means of at least one, in the pressure reactor (2) placed, filled with thermal oil and heated cartridge (15.1, 15.2) takes place.

9. The method according to any one of claims 1 to 8, characterized in that the biomass water is supplied in mist form.

10. Device (100) for carrying out the method according to claim 1, comprising at least one pressure reactor (2), which consists of at least one inner reactor (2.1) and an outer reactor (2.2), wherein the outer reactor (2.2) with at least one discharge opening (14.1, 14.2) is provided, at least one, the inner reactor (2.1) upstream, heatable mixing container (1.1, 1.2) having a gas-tight sealable lid (12) and at least one on the lid (12) arranged filler neck (13).

11. The device according to claim 10, characterized in that the inner reactor (2.1) and outer reactor (2.2) are cylindrical.

12. The device according to claim 10 and 11, characterized in that the inner reactor (2.1) and the outer reactor (2.2) is arranged coaxially to each other.

13. Device according to claims 10 to 12, characterized in that the inner reactor (2.1) has a jacket (3), which is surrounded by a jacket attached to the outer screw (5).

Apparatus according to claim 13, characterized in that the inner reactor (2.1) together with outer screw (5) is arranged rotatably movable relative to the outer reactor (2.2).

15. The apparatus according to claim 13, characterized in that within the shell (3) of the inner reactor (2.1) an inner screw (4) is arranged.

16. The apparatus of claim 13 and 15, characterized in that the inner screw (4) is rigidly connected to the jacket (3).

17. The apparatus of claim 13 and 15, characterized in that the inner screw (4) relative to the jacket (3) is arranged rotatably.

18. The apparatus according to claim 17, characterized in that the rotational movement of the inner screw (4) is reversible.

19. The apparatus according to claim 10, characterized in that the mixing container (1.1, 1.2) has a double jacket (6) which forms a fillable with oil space (7), wherein the double jacket (6) or in the space (7) a Heating device (8) is arranged.

20. The apparatus of claim 10 and 19, characterized in that at least the double jacket (6) of the mixing container (1.1, 1.2) and a jacket (9) of the outer reactor (2.2) are vacuum-insulated.

21. Device according to one of claims 10 to 20, characterized in that on the jacket (3) of the inner reactor (2.1) at least one outlet (10.1) to the outer reactor (2.2) and at least one outlet (10.2) to at least one collecting container ( 22) are provided.

22. Device according to one of claims 10 to 21, characterized in that the inner reactor (2.1) with at least a fluidically driven piston, preferably hydraulic piston (11) is equipped with which the position of at least one on the jacket (3) of the inner reactor (2.1) arranged drain slide (36) can be changed.

23. Device according to one of claims 10 to 24, characterized in that at least the inner reactor (2.1) is made of a material of high thermal conductivity, preferably of a bronze alloy.

24. The device according to claim 11, characterized in that the pressure reactor (2) at least one steam engine or steam boiler (16) is connected, which drives at least one power generator (17).