WO2008138637A2

WO2008138637A2 - Method and device for hydrothermal carbonization (htc) of biomass using an htc system

Info

Publication number: WO2008138637A2
Application number: PCT/EP2008/003932
Authority: WO
Inventors: Tobias Wittmann; Hans-Joachim Von Massow
Original assignee: Suncoal Industries Gmbh
Priority date: 2007-05-11
Filing date: 2008-05-09
Publication date: 2008-11-20
Also published as: WO2008138637A3

Abstract

The invention relates to a method of process control of a system for the hydrothermal carbonization of biomass, including separation and usage of products, and to a corresponding device.

Description

Method and apparatus for the hydrothermal carbonization (HTC) of biomass with a HTC plant

description

A first inventive concept consists in a method and a device for controlling the preheating of biomass and cooling a reaction for hydrothermal carbonization (HTC) of biomass, wherein an HTC reactor via at least one pressure and / or temperature-controlled valve water vapor is removed, which subsequently can be used for preheating.

A second aspect of the invention consists in a method for the separation of the product mixture following a hydrothermal Karbonisierungsreaktion in a HTC system without prior relaxation to ambient pressure to perform the separation efficiently and can lead the separated water in a circle and reuse. Process for using this water to specifically increase the heat capacity of the reaction mixture for hydrothermal carbonization in order to better control the time of removal of the heat of reaction can. A method of using this water to selectively increase the water content of the reaction mixture for hydrothermal carbonation, in order to ensure complete envelopment of the biomass with water during the reaction can. Method of using this water to preheat the biomass. A method of utilizing the heat of reaction of an HTC reaction to evaporate the water discharged from the HTC plant to produce a liquid fertilizer.

State of the art

The reaction of the hydrothermal carbonization (dehydration followed by polymerization) converts biomass into humus or coal and water in an exothermic reaction between about 180 ⁰ C and 230 ⁰ C biomass. In order to achieve a complete conversion of the biomass, it must be preheated, during the subsequent reaction, the above-mentioned temperature window must be maintained for about four hours, then the temperature must be kept constant at about 180 ⁰ C between four and seven hours. In case of hypothermia, the biomass reacts only partially, overheating causes unwanted by-products.

This reaction was successfully tested in a batch reactor heated to the minimum reaction temperature by convention in an oven and then cooled by convection. Convective preheating and cooling allow only small dimensions on a pilot scale, as the control of the reactor temperature by the convective heat supply and removal over the required period of time are limited.

In addition to batch processes, it is further proposed in the literature to realize the reaction in a continuous plant consisting of a preheater, a reactor, a post-processor and other parts. Since the thermal conductivity of biomass is very low, there is a risk of local overheating in the preheating of the biomass or a local overheating or hypothermia in the cooling of the reaction when the heat supply and removal over

CONFIRMATION COPY Heat exchanger or heating and cooling coils is realized. The geometry of the reactor is further limited by the design of the heat exchanger. The resulting heat of reaction can not be used for an efficient preheating of the biomass beyond, since the temperature range in which the reaction takes place is too small to provide the necessary for a heat transfer with compact heat exchangers temperature differences, or a possibly necessary Temperature increase between reactor and preheater easy to implement.

The literature mentions that in the case of hydrothermal carbonization, in addition to coal or humus, a mineral-containing water is produced, which can be used in fertilized form as a fertilizer. In order to use one or both products economically, a separation is required. It is proposed in publications to realize this separation by squeezing the coal. For separation is a mechanical or thermal dewatering, or a thermal drying in question. The drying is characterized by a high energy input, since the water is evaporated. In the literature, the mechanical-thermal dewatering of brown coal is described in which the material to be dewatered is heated while increasing the pressure to about 200 ⁰ C. The increase in temperature leads to a reduction of the binding forces of the water to the coal. The simultaneous increase in pressure prevents evaporation of the water. The drainage is then carried out by pressing with a pressure of 40 - 100 bar. The mechanical-thermal drainage makes the heating of the material to be drained and their subsequent recovery required to minimize the use of energy.

Task and solution according to the invention

It is the object of the invention to find a solution for the economic implementation of the hydrothermal carbonization of biomass and to eliminate the known disadvantages of process control with the help of heating or cooling coils. According to the invention, the necessary uniformity in the preheating of the biomass, the cooling during the conversion process and the temperature during post-processing - and thus an efficient reaction control - achieved in that a controlled steam extraction takes place from the reactor and this steam then preferably for preheating the biomass in a preheater and temperature maintenance in a post-processor is introduced. Since the boiling temperature and the boiling pressure of the reacting mixture can not be selected independently of each other and energy must be expended for evaporation, the pressure reduction associated with removal of water vapor from the reactor triggers evaporation. The heat required for this purpose is removed from the reaction mixture and leads to a lowering of the temperature.

According to the invention, water vapor is thus removed from the reactor in order to control the internal reactor temperature of a reactor for the continuous or discontinuous hydrothermal carbonization of biomass. The water vapor can then be used to preheat the biomass. For efficient introduction of the steam, a pressure increase can take place between a preheater and the reactor. If the reaction regime requires a higher pressure or a higher temperature in the preheater than in the reactor, a pressure reduction must take place between the preheater and the reactor. The steam needs then first compressed and then introduced into the preheater. The steam extraction can be done via pressure and / or temperature controlled valves

Another object is to find a solution for the economic separation of the reaction products of the hydrothermal carbonization of biomass and thereby overcome the known disadvantages of thermal drying, mechanical, thermal or mechanical-thermal dewatering.

According to the invention, the product mixture is not relaxed to ambient pressure as soon as it reaches the desired quality, but is squeezed out at high temperature and pressure. Due to the pressure maintenance, the evaporation of the water present in the product and the associated lowering of the temperature of the mixture is at least partially avoided. Since the reaction mixture exits the reactor at a high temperature and under high pressure, the heating and heat recovery necessary in a mechanical-thermal dehydration are partially or completely avoided and the efficiency of separation is increased. The water thus separated may preferably be circulated and admixed with the biomass prior to or during the reaction. An admixture is made with the aim of a) increasing the heat capacity of the reaction mixture in order to better control the time of removal of the heat of reaction by means of a steam extraction from the reactor, b) the complete envelopment of the biomass with water during the reaction or at least until the time to ensure the commencement of steam extraction, since only fully water-enveloped biomass carbonates hydrothermally or c) preheat the biomass. Furthermore, the heat of the water not mixed with the biomass can preferably be used directly or indirectly via a second heat circuit by means of heat exchangers for preheating the biomass.

According to this concept of the invention, which is also to be implemented independently, an efficient separation of water and coal takes place after the hydrothermal carbonization without prior relaxation of the mixture to ambient pressure. A portion of the water can then be circulated at high temperature and pressure and mixed with the biomass prior to the start of the reaction or during the reaction. By mixing the water to the biomass, which is to be converted by means of hydrothermal carbonization in coal or humus a) targeted increases the heat capacity of the reaction mixture to better control the time of removal of the heat of reaction from the reactor or b) the complete enclosure of the Reactive biomass ensured or c) the biomass preheated.

With claim 1, the control of the internal temperature of a HTC reactor by the pressure-controlled or temperature-controlled removal of water vapor via e.g. one or more valves claimed. The pressure is adjusted in the reactor so that the boiling point of water corresponds to the desired internal reactor temperature. The liberated during the reaction heat is thus expended to evaporate water and removed in the form of water vapor from the reactor. The valve or valves will preferably be mounted on top of the reactor. If the steam can not be used immediately after removal, it can be temporarily stored in a corresponding device.

With claim 2 is claimed as a preferred process variant, such as the steam after removal for preheating the biomass in the preheater and / or Temperature is introduced into the post-curing. To do this, if the pressure in the reactor is less than in the preheater or post-processor or if the pressure differential between the point of removal in the reactor and the point of introduction into the preheater or post-conditioner is too low to trigger a flow, the steam must be compressed. If the pressure in the preheater is higher than in the reactor, a pressure reduction (eg cellular wheel or duck sluice) must be provided between the preheater and the reactor. A reduction in pressure between the preheater and the reactor can be particularly useful if a higher temperature is required to initiate the reaction for a short period of time than for its continuation. The introduction of the steam can preferably be realized via one or more valves, which - controlled by one or more temperature measurement in the preheater or follower - open when the desired temperature is not reached and allow the steam to flow in and close again as soon as the desired temperature is reached. The one or more valves are preferably mounted at the bottom of the preheater or follower. The pressure in the preheater and post-processor should be selected so that the water vapor condenses and releases its heat to the biomass. Preferably, the residence time of the biomass in the preheater is to be chosen so that the reaction is initiated even after the promotion in the reactor still continues to run independently. With claim 3 is claimed as a preferred variant of the method, as the water vapor can be introduced without additional compression in the preheater and / or post-conditioner. For this purpose, an increase in pressure (for example by an extruder screw or a pump) between preheater and reactor is preferably provided. The pressure in the preheater is adjusted so that the boiling point of water above the starting temperature of the reaction of about 180 - 230 ⁰ C. The steam introduced by, for example, one or more valves condenses and releases its heat to the biomass. The one or more valves can be controlled for example via one or more temperature measurement in the preheater. Open the valve (s) when the desired temperature is not reached and let steam flow in and close again when the desired temperature is reached. In addition, a pressure reduction can be realized between reactor and post-processor, for example by means of a throttle or a pressure lock. The pressure in the post-processor is adjusted so that the boiling point of water is above the temperature to be maintained. The introduced steam condenses and releases its heat to the biomass. The one or more valves can be controlled via a temperature measurement in the post-processor. Open the valve (s) when the desired temperature is not reached and let steam flow in and close again when the desired temperature is reached. The one or more valves are preferably mounted at the bottom of the preheater or follower. Preferably, the residence time of the biomass in the preheater is to be chosen so that the reaction is initiated even after the promotion in the reactor still continues to run independently.

Claim 4 claims as a preferred process variant that the abovementioned process can be used for a continuous, discontinuous or a combination of continuous and discontinuous operation of an HTC plant. Thus, for example, the preheating of the biomass can be carried out continuously, while the reaction and / or the post-treatment take place in a batch reactor. In another embodiment, for example, the preheating discontinuous and the reaction and / or the post-treatment can be carried out continuously. The method can be used in all possible ways Find combinations of continuous and discontinuous process control.

Claim 5 claims, as a preferred variant of the method, that the abovementioned method can also be used for a plurality of systems which are operated in parallel. If several continuous systems are operated in parallel, the extracted steam can be fed to a central steam rail and then withdrawn from there for preheating and post-processing for the same system or the other systems operated in parallel. If several discontinuous plants are operated in parallel and asynchronously undergo the operating states preheating, reaction and post-treatment, the steam withdrawn from the reactor of one or more HTC plants may be fed to preferably a central steam rail and for preheating or post-processing in one or more of the other HTCs Plants are used.

Claim 6 claims, as an independent process or as a preferred process variant, that the separation of coal and water after the hydrothermal carbonization does not take place after the mixture has been relieved to ambient pressure, but immediately after the completion of the hydrothermal carbonization. Since the product mixture is at a pressure above the ambient pressure and thus the boiling point is above the normal boiling point of water, the separation of coal and liquid water at a temperature of about 100 ⁰ C can take place. Since the viscosity, density and surface tension of the water decreases with increasing temperature, this also reduces the effort required for the separation. Thus, the advantages of mechanical-thermal dewatering can be used. The energy required for heating is reduced or not needed because the product mixture is available at a high temperature and under pressure following hydrothermal carbonization. In addition, separation of water and coal prior to relaxation entails the following advantages: The separated coal can be further dried by flash flash evaporation of part of the water not separated during the separation, resulting in subsequent expansion, and subsequently has a lower humidity than when first flash evaporation and then mechanical separation. The separated water is still available at high temperature and high pressure in liquid form, so that the heat for example by means of heat exchanger back into the HTC system eg for use in a first stage of preheating the biomass coupled by heat exchangers or externally as Use process heat

With claim 7 is claimed as a preferred process variant that the water separated from the coal completely or partially recirculated and the biomass is mixed before the reaction to, for example, the a) heat capacity of the reactor contents to increase, b) a complete enclosure of the biomass with water during the entire reaction or at least until the start of steam extraction or c) to use the heat of the water of reaction to preheat the biomass. This can in particular bring great efficiency advantages if the separation of water and coal after the reaction and before the relaxation of the mixture to ambient pressure and thus the water is available at high temperatures. The water can then be introduced directly into the reactor or preheater, for example with a pump. The introduction of the water is ideally carried out before the preheating by introducing water vapor. Claim 8 is claimed as a preferred variant of the method that of the coal separated water is completely or partially circulated and the biomass is added during the reaction to, for example, a) increase the heat capacity of the reactor contents, b) a complete enclosure of the biomass with water throughout the reaction or at least until the time of C) to use the heat of the water of reaction to preheat the biomass. This can in particular bring great efficiency advantages if the separation of water and coal after the reaction and before the relaxation of the mixture to ambient pressure and thus the water is available at high temperatures. The water can then be introduced directly into the reactor or preheater, for example with a pump.

With claim 9 is claimed as a preferred process variant that the heat capacity of the reactor contents, for example by the addition of fresh water or circulating water of reaction is increased so far that the heat of reaction by temporarily increasing the temperature of the reactor contents in the reactor can be cached until they actually can be used. For this purpose, an optimization of the added amount of water as a function of the cost of additional heat required to preheat the reaction mixture and the benefit of the better control of the withdrawal time is made.

Claim 10 is claimed as a preferred process variant that the removal of the heat of reaction from the reactor by steam extraction and thus the reactor cooling is delayed until the heat actually preheating the biomass, for temperature maintenance after completion of the exothermic reaction, for post-processing of the products or can be used elsewhere or would be exceeded by a further delay of heat removal, the maximum allowable internal reactor temperature. For this purpose, a control is provided, the dis heat dissipation if necessary but in any case triggers when would be affected by a further increase in temperature of the reaction mixture Reakiionsabiauf. This intermediate storage of the heat of reaction by the heating of the entire reactor contents may be necessary, for example when using the decoupled from a reactor heat for preheating or post-processing of the biomass in another reactor. Delaying the removal of heat from a reactor until completion of the reaction in, draining, and refilling of another reactor reduces the energy losses that would occur in an alternative external storage of the heat of reaction. Furthermore, this reduces the number of reactors required, which are combined by heat extraction and re-coupling, which could make the construction of smaller plants more economical.

With claim 11 is claimed as a preferred process variant that the biomass is mixed so much water before the beginning of the hydrothermal carbonization that it is completely enclosed by water throughout the Karbonisierungsprozesses or at least until the beginning of the steam extraction. Since the hydrothermal carbonization - at least in the first phase - can not be done in a steam atmosphere, this admixture is always required if the biomass does not bring enough self-moisture. For this purpose, for example, the separated from the coal water can be used. The admixture can take place, for example, in the preheater or immediately before the preheater or in the reactor. Claim 12 claims as an independent process or as a preferred process variant that the biomass, if a complete enclosure with liquid water prior to the start of the reaction is not appropriate, it is still preheated and moved to reaction temperature and thus repeatedly brought into contact with liquid water until, for example, the reaction is initiated to such an extent that it continues to run in a steam atmosphere, or the reaction is completely completed or the reaction is partially completed. This may be important, for example, when it is desired to minimize the water demand of an HTC unit or to minimize the water content during the reaction to minimize the expense of post-reaction separation. The movement of the biomass can be done, for example, in the preheater, in which a corresponding listed agitator or a rotating drum is installed. The biomass is heated in the preheater, for example by the injection of steam to the reaction temperature and continuously and discontinuously circulated. In order to guarantee the necessary contact with liquid water, a minimum quantity of it must be brought either together with the biomass or separately into the preheater.

Claim 13 is claimed as a preferred variant of the method that the water separated from the coal can be evaporated by the use of the heat released in the HTC system and thus processed into liquid fertilizer.

With claim 14 is claimed as a preferred variant of the method that the removal of the inert gases (CO ₂ , CH ₄ and others), which are released during the warming of the biomass and during the reaction takes place either in the preheater or between preheater and reactor in, for example, a degassing. Since water vapor is continuously removed from the reactor and this is circulated without condenser and introduced into the preheater, a separation of the water vapor from the inert gases is expensive. Only after condensation of the water vapor in the preheater, only the inert gases are present in gaseous form. Thus, they can only after demΕinbringen and the condensation of evti. with inert gases mixed water vapor can be removed in the preheater. Furthermore, the removal must take place before the reentry of the inert gases into the reactor space from which the water vapor to be recycled is removed.

Claim 15 a device for the hydrothermal carbonization of biomass is claimed, which is characterized in that for controlling the internal reactor temperature, a pressure-controlled valve is provided, which periodically or continuously deducts water vapor from the reactor and thereby adjusts the internal pressure so that the boiling temperature of the water in the reactor matches the desired internal reactor temperature.

With claim 16, a device for the hydrothermal carbonization of biomass is claimed, which is characterized in that this valve can be controlled via a temperature measurement in the reactor and periodically or continuously draws steam at the desired internal reactor temperature is exceeded.

With claim 17 is claimed as a preferred device variant, that the pressure and temperature control can also be combined so that the reactor internal temperature is even better controllable.

With claim 18 is claimed as a preferred device variant, that the control of the removal of inert gases by a pressure measurement (at the edge of the tube) and a temperature measurement (at the edge of the tube or directly in the biomass) in the Environment of the sampling point is done. If a high concentration of inert gases is present at the point of removal, the measured pressure can be far above the boiling pressure of water which corresponds to the measured temperature. A low concentration of inert gases is only present when the measured pressure is equal to or slightly above the boiling pressure of water corresponding to the measured temperature. Thus, from the measured temperature by means of a suitable algorithm at appropriate intervals to determine the corresponding boiling pressure of water. The removal must be continued until the measured pressure has approached the calculated pressure sufficiently.

embodiment

Fig. 1 shows a device variant for implementing the above-described method for steam extraction and its reintroduction for a continuous process control. Fig. 2 shows a device variant for implementing the above-mentioned method for steam extraction and its reintroduction for a continuous process control.

Fig. 3 shows a device variant for implementing the above-described method for steam extraction and its reintroduction for a discontinuous process.

Fig. 4 shows a device for controlling the reactor temperature over the reactor internal pressure.

Fig. 5 shows a device for controlling the reactor temperature over the reactor internal temperature. Fig. 6 shows a device variant for the implementation of the above-explained method for the separation of water and coal immediately after leaving the reactor.

Fig. 7 shows a device variant for implementing the above-explained method of recycling the separated water. Fig. 8 shows the algorithm for implementing the above-explained method of controlling the timing of steam extraction.

Fig. 9 shows a device variant for implementing the above-explained method of extracting inert gases between the point of introduction of the water vapor and the point of extraction of the water vapor. Fig. 10 shows an apparatus for controlling the extraction of inert gases.

A hydrothermal carburization plant for biomass, or HTC plant for short, comprises as main components (Fig. 1, Fig. 2) a reactor (4), a preheater (1) and a post-processor (9). The reactor (4) is designed so that it can rule in an internal pressure of the reactor, which is above an ambient pressure. The internal pressure of the preheater (1) and / or the post-processor (9) may be lower than the reactor internal pressure, corresponding to the ambient pressure or above. If the pressures in the preheater (1) and in the post-processor (9) below that of the reactor (4) (Fig. 1) between the preheater (1) and the reactor (4) a Device for increasing the pressure (5) and between the reactor (4) and the post-processor (9) a device for pressure reduction (11) is provided. If the pressure in the preheater (1) is above the pressure of the reactor (4) (FIG. 2), and the pressure of the reactor (4) is above that of the post-processor (9), then it is possible between the preheater (1) and the reactor (FIG. 4) a device for pressure reduction (5) or between the reactor (4) and post-processor (9) a device for pressure reduction (11) is provided. At least one valve (6) is mounted on the reactor (4), via which, for example, water vapor can escape from the interior of the reactor to the outside in its open state, as explained in more detail below. In continuous operation of an HTC plant (Fig. 1), the preheater (1) is filled with biomass (2). The biomass is heated inter alia by the introduction of steam through a valve (3) to the minimum reaction temperature depending on the biomass between 180 ⁰ C and 230 ⁰ C and conveyed into the reactor (4). Between preheater and reactor, the means for increasing the pressure (5) is provided to realize an increase in pressure between preheater (1) and reactor (4). During the hydrothermal carbonization of biomass, steam (7) is withdrawn from the reactor through at least one valve (6) to adjust the internal reactor pressure so that the reactor is cooled by the evaporation of water. The internal pressure is thus selected so that the evaporation temperature of water corresponds to the desired internal reactor temperature. The extracted steam (7) is completely or partially circulated and introduced via a valve (3) back into the preheater (1). Additionally, the steam may be introduced through a valve (10) for use in the post-processor (9). Between reactor (4) and post-processor (9), a device for pressure reduction (11) is provided. In addition, a device (8) for temporary storage of the steam can be provided. By increasing the pressure between preheater (1) and reactor (4), it is possible to supply the steam without compression directly to the preheater (1). Due to the pressure reduction between reactor (4) and post-processor (9), it is possible to supply the vapor (7) without compression directly to the post-processor (9). The product (12) is subsequently removed from the post-processor (9).

The pressure in the preheater of an HTC system can still be above the pressure in the reactor (Fig. 2). In continuous operation, the biomass (2) is introduced into the preheater (1). The biomass is, inter alia, by the introduction of steam by a valve (3) to the starting temperature of the reaction may, depending on the biomass is between 180 ⁰ C and 230 ⁰ C preheated. It is then introduced into the reactor (4). Provided between preheater (1) and reactor (4) a device for reducing pressure (5) to achieve a pressure reduction between preheater and reactor. During the reaction in the reactor (4), steam (7) is withdrawn via at least one valve (6), thereby adjusting the internal reactor pressure such that the heat of reaction is expended to evaporate the water. The extracted water vapor (7) is completely or partially circulated and compressed by a single or multi-stage compressor (13) and introduced via a valve (3) in the preheater (1). There, the biomass is preheated by the condensation of the introduced water vapor. Additionally, the steam may be introduced through a valve (10) for use in the post-processor (9). Between reactor (4) and post-processor (9), a device for pressure reduction (11) is provided. In addition, a device (8) for temporary storage of the vapor (7) can be provided. Due to the pressure reduction between the reactor (4) and post-processor (9), it is possible to Steam (7) without a compression directly to the post-processor (9) to supply. The product (12) is subsequently removed from the post-processor (9).

In the discontinuous operation of the HTC plant (Figure 3), the biomass (1) in the reaction vessel (2), which serves both as a preheater, reactor and as a post-processor, inter alia, by introducing steam (3) to the minimum reaction temperature heated. Due to the onset of the reaction, an independent further heating of the reactor takes place. From the reactor, steam (5) is withdrawn through at least one valve (4) and thereby the internal reactor pressure is adjusted so that the reactor is cooled by the evaporation of water. The internal pressure is thus selected so that the evaporation temperature of water corresponds to the desired internal reactor temperature. The extracted steam is completely or partially recirculated and used again for preheater. For this purpose, a device (6) for temporarily storing the steam is provided. If several reaction vessels are operated in parallel, steam can be taken or supplied from the storage device for all reaction vessels.

The device for controlling the temperature (Fig. 4) of the reactor (1) can be realized by a pressure-controlled valve (2). The opening pressure of the valve is adjusted by a controller so that the boiling point of water corresponds to the desired internal reactor temperature. By releasing heat of reaction, water within the reactor evaporates, the pressure rises, the valve opens and allows water vapor (3) to escape. The resulting pressure drop in the reactor also lowers the temperature. If the setpoint pressure falls below again, the valve closes. The removal of water vapor can also be carried out continuously, if the removal amount is metered so that the internal pressure of the reactor fluctuates around the setpoint. The released heat of reaction is spent in this way for the evaporation of water and removed from the reactor.

Alternatively, the device for controlling the temperature (FIG. 5) of the reactor (1) can also be designed such that the control of the valve (3) takes place via a temperature measurement. The valve control is then correspondingly connected to a temperature sensor for detecting the internal reactor temperature. As soon as the desired internal reactor temperature is exceeded, the valve control causes the valve to open and water vapor (3) is withdrawn until the desired internal reactor temperature has fallen below again. The valve closes again. The removal of water vapor can also be carried out continuously, if the removal amount is metered so that the internal temperature of the reactor fluctuates around the setpoint.

The separation of water and coal (Fig. 6) takes place in a separator (3) into which the reaction mixture (2) after exiting the HTC reactor (1) without prior relaxation to ambient pressure occurs. The separated coal (5) is then expanded in a pressure lock (4) to ambient pressure. The vapor (9) produced during the flash evaporation is removed from the lock. The separated water (8) is guided after exiting the separator (3) by a heat exchanger (6), cooled and via a throttle (alternatively a drive) (7), relaxed to ambient pressure. The separation can for example be inserted between the reactor (4 in Fig. 1 or 2) and the post-processor (9 in Fig. 1 or 2), the separated coal (5) - before or after the expansion in the pressure lock - in the follower (9 in Fig. 1 or 2).

The circulation of the water (Fig. 7) can be realized, for example, as follows The coal and water mixture (4) is removed after completion of the hydrothermal Karbonisierungsreaktion without relaxation to ambient pressure from the reactor (3) and introduced into the separator (5). There, the coal is dehydrated discharged from the separator (6) and relaxed via a pressure lock (7). The vapor (14) produced during the flash evaporation is removed from the pressure lock. The separated water (8) is also removed from the separator (5). A part of this (10) is then introduced by means of a pump (11) via a valve (12) in the preheater (1) (alternatively or additionally, the reactor (3)) and mixed with the incoming there biomass (14). The not circulated water (9) is via a throttle (alternatively a drive) (13) relaxed and discharged from the HTC system. The non-recirculated water can also be recooled as shown in Fig. 6 by a heat exchanger to bring the heat gained elsewhere in the HTC system again or otherwise use. The intermediate storage (FIG. 8) of the heat of reaction in a first reactor by heating the contents of the reactor until it can be used in another reactor is for example as follows: Reactor 1 is preheated (a), the reaction starts after the minimum reaction temperature has been exceeded and heats the reactor contents (b), wherein the cooling by heat extraction, for example via heat exchangers or a steam extraction does not start immediately. In parallel, reactor 2 is emptied and refilled (c). Only after completion of this work does the reactor cooling of the reactor 1 by a heat dissipation (d). The heat now extracted can be used directly to preheat the biomass in reactor 2 (e). If the internal reactor temperature of the first reactor exceeds the minimum reaction temperature, the heat is again temporarily stored by heating the entire contents of the reactor (f) until another reactor has a heat requirement, eg for temperature maintenance, post-processing or preheating, or the heat can be used elsewhere.

The point of removal of the inert gases is gewähit as shown in Fig. 9: The biomass (1) is introduced into the preheater and preheated by the condensation of the introduced through a valve (3) water vapor (8). The water vapor was previously removed from the reactor (5) through a valve (6). The degassing dome (4) is located between the point of introduction and condensation of the water vapor in the preheater and the removal of the water vapor from the reactor. The inert gases (9), which are discharged via a controllable valve (4), only have a low humidity between these two points and can thus be easily removed. The coal (7) withdrawn from the reactor (5) can, as shown in FIG. 1, continue to be introduced into a post-processor.

The device for removing the inert gases can be realized by a pressure- and temperature-controlled valve (5) (Fig. 10). From the temperature measured with the temperature sensor (3), the corresponding boiling pressure of water is determined at suitable intervals using a suitable algorithm. If the pressure measured with the pressure sensor (2) is not only marginally higher, the valve (5) opens and the inert gases (6) can flow out. It only closes again when the pressure recorded with the pressure sensor (2), the boiling pressure of water, which corresponds to the temperature recorded by the temperature sensor (3), has approached sufficiently.

Claims

claims

1. A method for operating a HTC plant for the production of coal or humus by hydrothermal carbonization of biomass in one

Reactor, characterized in that heat of reaction from the reactor in

Is discharged form of steam and so the internal reactor temperature is controlled.

2. The method according to claim 1, characterized in that the removed

Steam is compressed and then introduced into a preheater and / or in a post-curing.

3. The method according to one or more of the preceding claims, characterized in that the pressure in the preheater and / or in the

Post-processor is lower than in the reactor and the extracted water vapor is introduced without compression in the preheater and / or in the post-conditioner.

4. The method according to one or more of the preceding claims, characterized in that the HTC plant operates continuously or discontinuously or has continuous and discontinuous process steps.

5. The method according to one or more of the preceding claims, characterized in that a plurality of HTC systems are operated in parallel and derived heat in the form of different states of aggregation of the Pro¬ßvvassers between two or more parallel systems through pipes with the aim of further improving the energy balance or is supplied.

6. A process alone or according to one or more of the preceding claims, characterized in that a separation of coal and water following the hydrothermal carbonization in a HTC plant before the expansion of the water and coal mixture on

Ambient pressure takes place.

7. The method according to one or more of the preceding claims, characterized in that the separated in an HTC plant after the reaction of the coal water of the biomass is mixed before the start of the reaction.

8. The method according to one or more of the preceding claims, characterized in that in a HTC plant after the reaction of the coal separated water of the biomass is added during the reaction.

9. The method according to one or more of the preceding claims, characterized in that the heat capacity of the reactor contents is increased in order to control the time of use of the heat of reaction can.

10. The method according to one or more of the preceding claims, characterized in that during operation of a HTC plant, the heat of reaction in a reactor is temporarily stored by heating the reactor contents until it can be used elsewhere or exceeded by a further heating, the maximum permissible internal reactor temperature would.

11.Verfahren according to one or more of the preceding claims, characterized in that the biomass before the start of the hydrothermal

Carbonation reaction in a HTC plant as much water is added that it is enclosed in water.

12. A process alone or according to one or more of the preceding claims, characterized in that the biomass brought to the reaction temperature is repeatedly brought into contact with water by a circulation.

13. The method according to one or more of the preceding claims, characterized in that the heat released in an HTC plant is used to evaporate the water of reaction.

14. The method according to one or more of the preceding claims, characterized in that the point of extraction of inert gases between the point of condensation of introduced into the preheater

Steam and the point of removal of water vapor from the reactor takes place.

15. An apparatus for hydrothermal carbonization (HTC) of biomass with a HTC plant comprising a reactor, characterized by a controllable valve which is arranged and adapted to effect a discharge of steam from the reactor at a given internal reactor pressure, and a controller , which is connected to a pressure sensor for detecting the internal pressure of the reactor and designed to control the controllable valve in response to the detected pressure so that the

Reactor internal pressure does not exceed a maximum internal pressure of the reactor, which corresponds to the boiling pressure of water at the desired internal reactor temperature, wherein control is designed to control the internal pressure of the reactor via the removal of water vapor from the reactor.

16. An apparatus for hydrothermal carbonization (HTC) of biomass with a HTC plant, which has a reactor, characterized by a controllable valve which is arranged and adapted to effect at a predetermined internal reactor pressure, a discharge of steam from the reactor, and a controller , which is connected to a temperature measuring sensor for detecting the internal reactor temperature and is designed to control the controllable valve as a function of the detected temperature so that the internal reactor temperature does not exceed a maximum internal reactor temperature, wherein the controller is formed, the

Internal reactor temperature via the removal of water vapor from the Control reactor.

17. An apparatus for hydrothermal carbonization (HTC) of biomass with a HTC system, characterized by a combination of the described in claim 15 and 16, pressure and temperature-based control of

Internal reactor temperature with the aim of further narrowing the temperature window of the internal reactor temperature.

18. An apparatus for hydrothermal carbonization of biomass with a HTC plant according to one or more of the preceding claims, characterized by a controllable valve, which is arranged and adapted to effect a discharge of gas, and a controller, which with a temperature sensor for detecting the temperature in the immediate vicinity of the sampling point and a pressure sensor for detecting the pressure in the immediate vicinity of the sampling point is connected and designed to control the connected valve in response to the detected temperature and the detected pressure so that the measured pressure above that corresponding to the measured temperature Boiling pressure of water is.