DE102013013724A1 - Method for producing a homogeneous solid from biomass - Google Patents

Abstract

The invention relates to a method for producing a homogeneous solid from biomass by the biomass is subjected to a hydrothermal carbonization is mechanically dehydrated, optionally thermally dried, which decomposed in the mechanical dehydration of the solid separated filtrate by evaporation in a residue and a condensate is, residue and / or condensate proportionately recycled in the process and excess condensate preferably as wastewater and excess residue preferably be discharged as waste or fertilizer from the process.

Description

The aim of the method according to the invention is the generation of a homogeneous solid from biomass. Another object of the method according to the invention is to maximize the quality of the water which was in contact with the biomass during the process according to the invention and is separated from it and removed separately from the process.

Biomasses that can be used in the proposed method are referred to below with the terms feedstock or biomass. In the present context, the term "input material" or "biomass" is understood to mean plant and animal biomass and metabolites, in particular renewable raw materials, such as woodchips, green waste from landscape conservation, plants, straw, silage, and organic residues from agriculture and forestry, as well as from food, biorefinery, and Energy industry and waste management, as well as peat, lignite, paper and sewage sludge, molasses, vinasse, pomace and the like. Furthermore, biomass is understood as meaning sugar, starch, cellulose, hemicellulose, lignin and other constituents of the biomass.

If the solid produced in the process according to the invention are used as biofuel, then such biomasses are particularly suitable as feedstocks, due to their high ash content, their high content of chlorine, nitrogen or sulfur or other ingredients, or their poor ash melting behavior or only limited for a direct combustion or gasification are suitable and / or due to their physico-mechanical nature can not or only partially be used in Staubfeuerungen or Flugstromggasern and / or can not be transported due to their low bulk density or only at high cost and / or due to biological activity and the associated low degree of rotting are not storage-stable. In the prior art, the most widely used solid fuel is fossil brown and hard coal. Hard coal is mainly traded globally as a dry bulk material and is usually first ground at the point of use and then used in dust firing or entrained flow gasifiers. Lignite is burned as moist raw lignite mainly in the immediate vicinity of the opencast mine. Partly, a small portion of the flow rate is refined by drying and grinding to brown coal dust and then transported over distances of up to 1,000 km and used in dust firing. The advantage of using fossil coal as a fuel is the homogeneity in terms of material composition, which does not vary significantly within an assisted area and which, apart from a few outliers, varies significantly less compared to biomass Quality as well as the design, approval and operation of the corresponding combustion plants considerably simplified. Another advantage is the fluidizability of the dry, ground fossil coal, which allows a pneumatic transport into the combustion chamber and has led to the establishment of dust firing and Flugstromggasern. In addition, hard coal and lignite dust has a high bulk density of between 500 kg / m ³ and 1300 kg / m ³ and is storage-stable due to the lack of biological activity (degree of rotting I).

Biofuels, such as those in the DIN EN 14961-1 These advantages do not have any advantages because they vary considerably in their material composition, depending on their type and origin, compared to fossil coal. For example, the nitrogen content of biomass obtained from intensively used agricultural land is significantly higher than that of biomass from forestry, resulting in significant differences in NOx formation in combustion. Furthermore, stalk-like biomasses have a significantly higher proportion of potassium than woody biomasses, which leads to large differences in the ash melting behavior. The physical-mechanical properties of the biomass also vary depending on the type, origin and treatment, so that today very different firing systems such as grate firing, fluidized bed combustion, shaft firing, Vorofenfeuerung, etc. have been established, which have been optimized for individual types of biomass. A grinding of biomass with the aim to achieve a similar good fluidizability as that of fossil coal, is not possible in the prior art. Furthermore, the sometimes high water content promotes biological decomposition, so that a permanent storage of moist biomass can not be guaranteed. The low bulk density of fresh biomass, which is generally between 150 kg / m ³ to 300 kg / m ³ , also means that fresh biomass is usually only traded locally due to the resulting high transport costs.

The widely varying composition of biomass and its different physical-mechanical properties have led to the development of a relevant market for woody biomass only. Wood is traded mainly in the form of wood chips or pellets. Corresponding trading venues and quality standards are establishing themselves. The background to this is the material homogeneity of the wood, which is largely independent of type and origin, especially with regard to the small amount Ash content, the proportion of chlorine, sulfur and nitrogen, the low heavy metal content as well as the defined and good ash melting behavior, as well as the easy reprocessing by drying, comminution and possibly compaction. As a result, a sufficient storage stability and, in particular for pellets, a high bulk density of more than 500 kg / m ^{3 can be} ensured.

Effortless efforts have been made to establish not only wood but also straw, or fast-growing grasses such as Miscanthus as a biofuel. The high chlorine content, however, regularly leads to high-temperature corrosion, the undefined and poor ash-melting behavior leads to slagging, the high nitrogen content leads to high NOx emissions and the bad emissions to dust emissions. Also, the production of mixed pellets of various types of straw, fast-growing grasses and wood did not result in the required improvement of the above-mentioned problems, so that such a biofuel could not establish itself on the market.

Other biomass such as leaves, grass clippings and branches from the garden and landscape care, are currently only occasionally used regionally as a fuel, but create considerable problems in the combustion.

There are scientific bases for the conversion of input materials such as wood, straw, grass, green waste, landscape wood, vinage, fermentation residues, maize silage, whole plant silage and organic waste, as well as peat and lignite by hydrothermal carbonation at temperatures between 150 ° C and 300 ° C in the presence of liquid water in high-carbon and low-oxygen solids. Thereafter, during the reaction, the pressure must be at least equal to or above the saturated vapor pressure of the reaction mixture at the selected reaction temperature.

Hydrothermal carbonization involves a series of side reactions that cause, among other things, the formation of water-soluble hydrocarbons. A proportion of the water-soluble hydrocarbons are organic acids whose formation leads to a lowering of the pH. Although the carbonation reaction takes place even without a catalyst, the targeted choice of a suitable catalyst system for optimal process control is advantageous to set a meaningful combination of reaction temperature and residence time in conjunction with a high yield, optimized carbon balance and good product properties.

One of the first technical implementations of the hydrothermal carbonization of industrial pellets in pressure reactors at 250 ° C.-300 ° C. from the pulp industry was described by Friedrich Bergius in 1921 ( AT86234 ).

Furthermore, the disclosure US 3,552,031 a device for the separation of water from organic material together with liquid water using the example of lignite at temperatures between 100 ° C and 300 ° C in a horizontal pressure reactor which is charged by a conveyor and at the end of the dehydrated coal is withdrawn. The reactor is insulated and heated from the outside.

Also the US 3,992,784 discloses a process for the dehydration of organic material together with liquid water at more than 150 ° C using the example of lignite. The lignite is mixed with water and pumped by means of a pump in a pressure reactor. The mixture of water and lignite is preheated by heat exchangers / exchangers which utilize the heat of the product discharged from the reactor. Furthermore, the condensate of the dryer is again introduced together with the coal in the process. The heating of the educts takes place exclusively via an indirect heat transfer in heat exchangers / exchangers.

WO 2008081409 A2 discloses a method and apparatus for dehydrating biomass together with liquid water at temperatures above 150 ° C in a pressure reactor consisting essentially of a loop reactor into which the starting product is introduced. The reaction mixture in the reactor is circulated continuously and a part removed from the reactor and then dried. There are further ancillary units disclosed.

In addition revealed EP 1970431 A1 a method and apparatus for dehydrating biomass together with liquid water at temperatures above 100 ° C. The biomass is optionally preheated and introduced with a pump or lock in a horizontal pressure reactor through which it is moved by means of a screw conveyor. The pressure reactor is externally heated. The reacted biomass is discharged at the end of the pressure reactor either via a pump or a pressure lock.

Further disclosed WO 2008095589 A1 an S-shaped reactor for the dehydration of biomass in liquid water, which is in a bath of thermal oil, which can be cooled and heated if necessary.

In addition revealed WO / 2010/112230 an energetically optimized process for the hydrothermal carbonization of feedstocks.

The cited documents disclose various implementation of a hydrothermal carbonization and ancillary components. However, no method for securing the quality of the solid produced is disclosed.

Furthermore, scientific bases for the treatment of the effluent from a hydrothermal carbonation process water discharged by an anaerobic or aerobic biological treatment available. In addition, the treatment by activated carbon filters and a combination of these methods was investigated. Further describes EP 2 206 688 a pretreatment of the wastewater by wet oxidation.

The object of the invention when using the solid produced as biofuel is thus to offer a superior over the prior art method for processing biomass to a homogeneous, solid and dry biofuel, which is so homogeneous in terms of its material composition that the existing problems be overcome in the combustion of untreated biomass by z. B. the proportion of chlorine is reduced so much that no high-temperature corrosion takes place during combustion or gasification, the proportion of sulfur is reduced to the extent that a desulfurization can be used in the prior art, or eliminated, the proportion of nitrogen reduced so far is that a denitrification according to the prior art can be used or can be omitted, the ash defines melts and no slagging takes place at the usual operating temperatures of dry firing, the content of heavy metals is lowered so that the emissions into the ash and the Flue gas not differ from those in the use of fossil coal or wood and which is fluidizable in terms of its physico-mechanical properties after grinding, so that it can be used in dust firing or entrained flow gasification, directly or possibly after compaction one with fossil coal comparable bulk density and due to the no longer present biological activity and the low water content is storage stable. Another object of the invention is that the separated in the treatment process of the biomass water is cleaned so far that the remaining impurities are reduced to a subsequent biological treatment to the extent that a direct discharge into waters is possible.

If the solid produced in the process according to the invention is not to be used as an energetic substance, then the object of the invention is to reduce the constituents of the ash which are detrimental to the specific application or to reduce it itself to such an extent that the solid does not exceed the limit values applicable for the specific application.

• – in einer ersten Prozessstufe einer hydrothermalen Karbonisierung unterzogen wird,
• – in einer zweiten Prozessstufe mechanisch entwässert wird,
• – ggf. in einer dritten Prozessstufe thermisch getrocknet wird,
• – das in der mechanischen Entwässerung abgetrennte Filtrat in einer vierten Prozessstufe durch Eindampfung in einen Rückstand und ein Kondensat zerlegt wird,
• – Rückstand und/oder Kondensat anteilig in den Prozess zurückgeführt werden und
• – überschüssiges Kondensat als Abwasser aus dem Prozess ausgetragen wird.

The task is solved by the biomass

• Is subjected to hydrothermal carbonation in a first stage of the process,
• - mechanically drained in a second process stage,
• If necessary thermally dried in a third process stage,
• The filtrate separated off in the mechanical dehydration is decomposed by evaporation into a residue and a condensate in a fourth process stage,
• - Residue and / or condensate are proportionally attributed to the process and
• - Excess condensate is discharged as wastewater from the process.

• – in der zweiten Prozessstufe (mechanische Entwässerung) gewonnene Filtrat, welches nicht direkt in die erste Prozessstufe (hydrothermale Karbonisierung) zurückgeführt wird, in der vierten Prozessstufe (Eindampfung) durch Eindampfung in einen Rückstand und ein Kondensat zerlegt wird und
• – der Anteil des Rückstandes aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, und der Anteil des Kondensates aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, so gewählt wird,
• – dass der aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragene Feststoff mindestens einen Grenzwert nicht überschreitet,
• – wobei bei einer Überschreitung eines der Grenzwerte der Anteil an Rückstand aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird und/oder der Anteil an Kondensat aus der vierten Prozessstufe (Eindampfung) der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird.

Preferably, a combination of a hydrothermal carbonization, mechanical dewatering is proposed with an evaporation, wherein that

• - In the second stage of the process (mechanical dewatering) recovered filtrate, which is not directly in the first process stage (hydrothermal carbonation) is recycled, in the fourth process stage (evaporation) by evaporation into a residue and a condensate is decomposed and
• - The proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), and the proportion of condensate from the fourth process stage (evaporation), in the first process stage (hydrothermal carbonation) or second process stage (mechanical drainage) is entered, so selected
• - that the solid discharged from the second process stage (mechanical dewatering) does not exceed at least one limit value,
• - When exceeding one of the limits of the proportion of residue from the fourth process stage (evaporation), which is registered in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is reduced, and / or the proportion of condensate from the fourth process stage (evaporation) which is registered in the first process step (hydrothermal carbonization) and / or second process step (mechanical drainage) is increased.

The mode of action of this preferred process procedure according to the invention is that the amount of inorganic impurities in the solid produced is adjusted by discharging so many of the inorganic impurities introduced into the process according to the invention with the residue from the fourth process stage from the process, such as are required to comply with application-specific parameters for the use of the solid, wherein the amount of discharged from the process inorganic impurities by a proportional recycling of the residue and / or the condensate from the fourth process stage in the first and / or second process stage is set.

As a limit value for the solid may preferably be the ash content, the mass fraction of chlorine, sulfur, nitrogen, potassium or the mass fraction of a single heavy metal z. As lead, cadmium, chromium, iron, cobalt, copper, manganese, molybdenum, nickel, vanadium, zinc or tin are used in the total mass of the solid. In a preferred application of the solid as a support material of catalysts or as part of a catalyst may preferably be the mass fraction of a certain or more catalyst poins z. As heavy metals or halogens are used in the total mass of the solid as a limit. As a reference, the mass of the dry solid is usually selected. Depending on the application or industry-specific practices, however, the ashless, dry solid or the moist solid can also be used as a reference. If limits for other properties of the solid, z. B. its energy content, so a corresponding conversion to the mass fraction is required. As a measured variable, both the mass fraction of a substance or mixture of the total mass of the solid or the mass fraction of several substances or mixtures of the total mass of the solid can be used. If several limit values for the solid are defined, then the method according to the invention is usually already applied when only one of these limit values is exceeded. The limit values can define a maximum mass fraction, a minimum mass fraction and a bandwidth of the mass fraction of a substance or mixture of the total mass of the solid. When a limit value is exceeded, it is meant that the mass fraction of the substance or mixture of substances is already higher on the solid or threatens to be higher than the defined limit value. By falling below a limit is meant that the mass fraction of the substance or mixture of solids is already lower or threatens to be lower than the defined limit. The exceeding of one or more limits for the solid according to the invention directly after leaving the second process stage (mechanical dehydration), after exiting from any existing downstream process stages z. B. a thermal drying (third process step), a grinding or compaction or immediately before the occurrence of subsequent processes determined and applied in case of exceeding the inventive method.

• – in der zweiten Prozessstufe (mechanische Entwässerung) gewonnene Filtrat, welches nicht direkt in die erste Prozessstufe (hydrothermale Karbonisierung) zurückgeführt wird, in der vierten Prozessstufe (Eindampfung) durch Eindampfung in einen Rückstand und ein Kondensat zerlegt wird und
• – der Anteil des Rückstandes aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, und der Anteil des Kondensates aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, so gewählt wird,
• – dass das aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragen Filtrat oder der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragene Rückstand mindestens einen Grenzwert nicht überschreitet,
• – wobei bei einer Überschreitung eines der Grenzwerte der Anteil an Rückstand aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird und/oder der Anteil an Kondensat aus der vierten Prozessstufe (Eindampfung) der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird.

Preferably, another combination of a hydrothermal carbonization, mechanical dewatering is proposed with an evaporation, wherein that

• - In the second stage of the process (mechanical dewatering) recovered filtrate, which is not directly in the first process stage (hydrothermal carbonation) is recycled, in the fourth process stage (evaporation) by evaporation into a residue and a condensate is decomposed and
• - The proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), and the proportion of condensate from the fourth process stage (evaporation), in the first process stage (hydrothermal carbonation) or second process stage (mechanical drainage) is entered, so selected
• That the filtrate discharged from the second process stage (mechanical dewatering) or the residue introduced into the first process stage (hydrothermal carbonization) and / or second process stage (mechanical dehydration) does not exceed at least one limit value,
• - When exceeding one of the limits of the proportion of residue from the fourth process stage (evaporation), which is registered in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is reduced, and / or the proportion of condensate from the fourth process stage (evaporation) which is registered in the first process step (hydrothermal carbonization) and / or second process step (mechanical drainage) is increased.

The active principle of this preferred method according to the invention is that the amount of inorganic impurities introduced into the first and / or second process stage is adjusted by the fact that so many of the inorganic impurities added to the biomass in the process according to the invention are mixed with the residue from the fourth Process stage be discharged from the process, as required, to prevent improper enrichment of the inorganic impurities (which leads to, for example, a deposit), in the first and / or second process stage, wherein the amount of discharged from the process inorganic impurities by a proportionate recycling of the residue and / or the condensate from the fourth process stage in the first and / or second process stage is set.

As the limit value for the filtrate or the residue, a measured variable is selected, which ensures that in the first process stage, second process stage or fourth process stage to no accumulation of inorganic substances or mixtures that adversely affect the process management, z. B. attach themselves to pipes or container walls excessively. Suitable measures are, for example, the electrical conductivity or the dry matter content or a combination of these.

• – in der zweiten Prozessstufe (mechanische Entwässerung) gewonnene Filtrat, welches nicht direkt in die erste Prozessstufe (hydrothermale Karbonisierung) zurückgeführt wird, in der vierten Prozessstufe (Eindampfung) durch Eindampfung in einen Rückstand und ein Kondensat zerlegt wird und
• – der Anteil des Rückstandes aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, und der Anteil des Kondensates aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, so gewählt wird,
• – dass der aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragene Feststoff mindestens einen Grenzwert nicht überschreitet und
• – dass das aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragen Filtrat oder der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragene Rückstand mindestens einen Grenzwert nicht überschreitet,
• – wobei bei einer Überschreitung eines der Grenzwerte der Anteil an Rückstand aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird und/oder der Anteil an Kondensat aus der vierten Prozessstufe (Eindampfung) der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird.

Preferably, the two above erfindungsmäßen alternative process guides can be combined, wherein that

• - In the second stage of the process (mechanical dewatering) recovered filtrate, which is not directly in the first process stage (hydrothermal carbonation) is recycled, in the fourth process stage (evaporation) by evaporation into a residue and a condensate is decomposed and
• - The proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), and the proportion of condensate from the fourth process stage (evaporation), in the first process stage (hydrothermal carbonation) or second process stage (mechanical drainage) is entered, so selected
• - That discharged from the second process stage (mechanical dewatering) solid does not exceed at least one threshold and
• That the filtrate discharged from the second process stage (mechanical dewatering) or the residue introduced into the first process stage (hydrothermal carbonization) and / or second process stage (mechanical dehydration) does not exceed at least one limit value,
• - When exceeding one of the limits of the proportion of residue from the fourth process stage (evaporation), which is registered in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is reduced, and / or the proportion of condensate from the fourth process stage (evaporation) which is registered in the first process step (hydrothermal carbonization) and / or second process step (mechanical drainage) is increased.

Accordingly, in addition to the limit value for the solid discharged from the second process stage (mechanical dehydration), it is also preferred for the filtrate discharged from the second process stage (mechanical dewatering) or the first process stage (hydrothermal carbonization) and / or second process stage (mechanical Dehydration) residue defined at least one further limit, which is used to adjust the amount of recirculated residue or condensate. In this case, a reduction in the recirculation of residue or an increase in the recirculation of condensate according to the invention already takes place if such a measure would not be necessary if only one or more of the limit values for the solid or the limit value for the filtrate or the residue is considered.

• – bei einer Überschreitung des oder der Grenzwerte der Anteil an Rückstand aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird und/oder der Anteil an Kondensat aus der vierten Prozessstufe (Eindampfung) der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird und
• – bei einer Unterschreitung des oder der Grenzwerte der Anteil an Rückstand aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird und/oder der Anteil an Kondensat aus der vierten Prozessstufe (Eindampfung) der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird.

The method according to the invention can be improved by regularly monitoring the observance of the limit value (s) by the application of the method according to the invention by means of measurements, wherein after evaluation of the preferred measurement

• - When exceeding the limit or limits, the proportion of residue from the fourth process stage (evaporation), which is registered in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is reduced, and / or the proportion of condensate from the fourth process stage (evaporation), which is introduced into the first process stage (hydrothermal carbonization) and / or second process stage (mechanical drainage), is increased, and
• - If the limit value (s) fall below the limit, the proportion of residue from the fourth process stage (evaporation), which is introduced into the first process stage (hydrothermal carbonation) and / or second process stage (mechanical drainage), is increased and / or the proportion of condensate from the fourth process stage (evaporation) which is registered in the first process step (hydrothermal carbonization) and / or second process step (mechanical dewatering) is reduced.

If the limiting value (s) is exceeded, the proportion of residue from the fourth process stage (evaporation) which is introduced into the first process stage (hydrothermal carbonization) and / or second process stage (mechanical dehydration) is preferably first, preferably to a fraction of less than 50 % By weight of the entire residue from the fourth process stage (evaporation), more preferably to a fraction of less than 25% by weight of the total residue from the fourth process stage (evaporation), more preferably to a fraction of less than 10% by mass total residue from the fourth process stage (evaporation) more preferably reduced to a proportion of less than 5 wt .-% of the total residue from the fourth process stage (evaporation), before the proportion of condensate from the fourth process stage (evaporation) in the first Process step (hydrothermal carbonation) and / or second process step (mechanical drainage) is entered, increases w ill.

If the limit value (s) are not reached, the proportion of condensate from the fourth process stage (evaporation) which is introduced into the first process stage (hydrothermal carbonization) and / or second process stage (mechanical drainage) is preferably initially reduced to less than 40 Ma % of the total condensate from the fourth process stage (evaporation), more preferably to a fraction of less than 20 wt.% of the total condensate from the fourth process stage (evaporation), more preferably to a fraction of less than 10 wt.% of the total Condensate from the fourth process stage (evaporation) more preferably reduced to a proportion of less than 5 wt .-% of the total condensate from the fourth process stage (evaporation) before the proportion of residue from the fourth process stage (evaporation) in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical drainage) is registered is increased.

The proportion of the residue from the fourth process stage (evaporation) in the first process stage (hydrothermal carbonation) or in the second process stage (mechanical dehydration) is attributed between 0% and 100% based on the total amount of the fourth process stage (evaporation) produced residue and the proportion of the condensate from the fourth process stage (evaporation) in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is between 0% and 50% based on the total amount in the fourth Process level (evaporation) produced condensate are. Preferably, a minimum amount of preferably 5% by mass, more preferably of at least 3% by mass, of the total condensate from the fourth process stage (evaporation) is recycled to the first process stage (hydrothermal carbonization) and / or second process stage (mechanical dehydration).

If the process according to the invention comprises a third process stage (thermal drying), the residue from the fourth process stage (evaporation) can preferably also be introduced into the third process stage (thermal drying). Further preferably, the process steam generated in the third process stage can be introduced into the fourth process stage (evaporation) and condensed there, and the condensate thus produced can be used just like the condensate from the actual evaporation. If there is a third process step (thermal drying) and if the residue is returned to the third process step (thermal drying), the upper limit (s) for the solid is determined at the earliest after leaving the third process step (thermal drying).

The residue discharged from the process may preferably be used as fertilizer, if appropriate after further treatment.

• – die Biomasse ggf. zusammen mit Rückstand und/oder Kondensat aus einer vierten Prozessstufe, der Eindampfung, in einer ersten Prozessstufe, der hydrothermalen Karbonisierung, mit Druck beaufschlagt und bei einer Temperatur zwischen 150°C und 250°C und einem Druck, der mindestens dem Sattdampfdruck bei der gewählten Prozesstemperatur entspricht für mindestens dreißig Minuten einer hydrothermalen Karbonisierung unterzogen und das sich bildende Karbonisierungsprodukt zurückgekühlt und entspannt und aus der ersten Prozessstufe (hydrothermale Karbonisierung) ausgetragen und einer zweiten Prozessstufe, der mechanischen Entwässerung, zugeführt,
• – die Wasserbilanz der ersten Prozessstufe (hydrothermale Karbonisierung) durch die Zufuhr von Filtrat aus der zweiten Prozessstufe (mechanische Entwässerung) ausgeglichen,
• – das aus der ersten Prozessstufe (hydrothermale Karbonisierung) ausgetragene Karbonisierungsprodukt in der zweiten Prozessstufe (mechanische Entwässerung) ggf. zusammen mit Rückstand und/oder Kondensat aus der vierten Prozessstufe (Eindampfung) mechanisch auf einen TS-Gehalt von mindestens 40% entwässert, das hierbei gewonnene Filtrat aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragen und der ersten Prozessstufe (hydrothermale Karbonisierung) und/oder der vierten Prozessstufe (Eindampfung) zugeführt und der hierbei gewonnenen Presskuchen aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragen und einer dritten Prozessstufe, der thermischen Trocknung, zugeführt,
• – der aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragene Presskuchen in der dritten Prozessstufe (thermische Trocknung) thermisch auf einen TS-Gehalt von mindestens 80 Ma.-% getrocknet, das verdampfte Wasser aus der dritten Prozessstufe (thermische Trocknung) ausgetragen und der vierten Prozessstufe (Eindampfung) zugeführt und das Trockenprodukt aus der dritten Prozessstufe (thermische Trocknung) ausgetragen und ggf. nach Kompaktierung, Lagerung, Transport und Mahlung als Biobrennstoff in Staubfeuerungen oder Flugstromvergasern genutzt,
• – das aus der zweiten Prozessstufe (mechanische Entwässerung) ausgetragene und in die vierte Prozessstufe (Eindampfung) eingetragene Filtrat in dieser durch Verdampfung und Kondensation in Kondensat und Rückstand aufgespalten,
• – das aus der dritten Prozessstufe (thermische Trocknung) ausgetragene und in die vierte Prozessstufe (Eindampfung) eingetragene verdampfte Wasser in dieser kondensiert,
• – die so gewonnenen Kondensate aus der vierten Prozessstufe (Eindampfung) ausgetragen und der ersten Prozessstufe (hydrothermale Karbonisierung) und/oder der zweiten Prozessstufe (mechanische Entwässerung) zugeführt und/oder ggf. nach einer weiteren Aufbereitung indirekt oder direkt eingeleitet und der Rückstand aus der vierten Prozessstufe (Eindampfung) ausgetragen und der ersten Prozessstufe (hydrothermale Karbonisierung) und/oder der zweiten Prozessstufe (mechanische Entwässerung) zugeführt und/oder einer Verwertung zugeführt,
• – der Anteil des Rückstandes aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird und der Anteil des Kondensates aus der vierten Prozessstufe (Eindampfung), der in die erste Prozessstufe (hydrothermale Karbonisierung) oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, so gewählt, dass der erzeugte Biobrennstoff die für seinen Einsatz in der Vergasung oder Verbrennung geforderten Grenzwerte nicht überschreitet, wobei bei einer Überschreitung der Anteil an Rückstand, der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, reduziert wird und/oder der Anteil an Kondensat der in die erste Prozessstufe (hydrothermale Karbonisierung) und/oder zweite Prozessstufe (mechanische Entwässerung) eingetragen wird, erhöht wird.

In a preferred embodiment of the method according to the invention

• - The biomass optionally together with residue and / or condensate from a fourth process stage, the evaporation, in a first process step, the hydrothermal carbonization, pressurized and at a temperature between 150 ° C and 250 ° C and a pressure of at least the saturated vapor pressure at the selected process temperature is subjected to a hydrothermal carbonization for at least thirty minutes and the carbonation product which forms is discharged and expanded and removed from the first process stage (hydrothermal carbonization) and fed to a second process stage, the mechanical dehydration,
• - balanced the water balance of the first process step (hydrothermal carbonation) by the supply of filtrate from the second process step (mechanical drainage),
• - The carbonation product discharged from the first process stage (hydrothermal carbonization) in the second process stage (mechanical dehydration), if appropriate together with residue and / or condensate from the fourth process stage (evaporation) is mechanically dewatered to a TS content of at least 40% recovered filtrate discharged from the second process stage (mechanical dewatering) and the first process stage (hydrothermal carbonation) and / or the fourth process stage (evaporation) fed and thereby obtained press cake from the second process stage (mechanical dewatering) discharged and a third process stage, the thermal Drying, fed,
• - The pressed from the second process stage (mechanical dewatering) pressed cake in the third process stage (thermal drying) thermally dried to a TS content of at least 80 wt .-%, the evaporated water discharged from the third process stage (thermal drying) and the fourth Fed to the process step (evaporation) and discharged the dry product from the third process stage (thermal drying) and possibly used after compaction, storage, transport and grinding as biofuel in Staubfeuerungen or Flugstromvergasern,
• The filtrate discharged from the second process stage (mechanical dewatering) and introduced into the fourth process stage (evaporation) is split into the condensate and the residue by evaporation and condensation,
• The vaporized water discharged from the third process stage (thermal drying) and introduced into the fourth process stage (evaporation) condenses therein;
• - The condensates thus obtained from the fourth process stage (evaporation) discharged and the first process stage (hydrothermal carbonation) and / or the second process stage (mechanical dehydration) supplied and / or optionally after a further treatment indirectly or directly initiated and the residue from the discharged fourth stage of the process (evaporation) and fed to the first process stage (hydrothermal carbonization) and / or the second process stage (mechanical dewatering) and / or recycled,
• - the proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering) and the proportion of the condensate from the fourth process stage (evaporation), in the first process stage ( hydrothermal carbonation) or second process stage (mechanical dehydration) is selected, so selected that the biofuel produced does not exceed the limits required for its use in the gasification or combustion, wherein when exceeded, the proportion of residue in the first process stage (hydrothermal Carbonation) and / or second process stage (mechanical dewatering) is registered, is reduced and / or the proportion of condensate in the first process step (hydrothermal carbonation) and / or second process step (mechanical dewatering) is registered, is increased.

The operating principle of this preferred procedure is that the contaminants present in the biomass, which are partly converted into the water phase in the first process stage and partially separated with the filtrate from the press cake in the second process stage, are concentrated in a residue in a fourth process stage whereby a condensate which is clean in relation to the filtrate is obtained and is wholly or partially discharged from the process as waste water and the amount of residue to be discharged as waste from the fourth process stage is minimized by a proportionate recycling of the residue to the first or second process stage, to the extent This recycling does not impair the quality of the biofuel produced and, at the same time or alternatively, the condensate produced is proportionately returned to the first or second process stage in order to improve the quality of the biofuel produced, wherein d the proportion of the residue which is recycled is between 0% and 100% relative to the total amount of the residue produced in the fourth process stage and the proportion of the condensate is between 0% and 50% relative to the total amount produced in the fourth process stage Condensate can lie. Furthermore, it is ensured by the hydrothermal carbonization that the biofuel can be fluidized after mechanical dewatering, drying and grinding and can be used in Staubfeuerungen and Flugstromvergasern.

• – die Biomasse in einer der ersten Prozessstufe vorgelagerten Wäsche mit Waschwasser vermischt und von Mineralik befreit wird, wobei die Mineralik durch Schwerkrafttrennung auf einen Aschegehalt von mindestens 80 Massen-% bezogen auf die Trockenmasse und einem TS-Gehalt von mindestens 40 Massen-% bezogen auf die Gesamtmasse aufkonzentriert und aus der Wäsche ausgetragen wird und das verbleibenden Organik-Mineralik Gemisch mit einem Aschegehalt von maximal 20 Massen-% bezogen auf die Trockenmasse und einem Wassergehalt von maximal 85 Masse-% bezogen auf die Gesamtmasse aus der Wäsche ausgetragen und der ersten Prozessstufe zugeführt wird,
• – der TS-Gehalt des Waschwassers durch Vermischung mit Filtrat aus der zweiten Prozessstufe oder Kondensat aus der vierten Prozessstufe auf einem Wert zwischen 5 Massen-% bezogen auf die Gesamtmasse und 20 Massen-% bezogen auf die Gesamtmasse eingestellt wird,
• – das überschüssiges Waschwasser aus der Wäsche ausgetragen und der ersten Prozessstufe zugeführt wird.

According to the invention, when using biomass with a high ash content of more than 10% by mass, based on the dry mass, the process procedure may preferably be improved, with more than 20% by mass, based on the dry mass, by:

• - The biomass is mixed in a washing the first stage of the process upstream with wash water and freed from mineral, the mineral by gravity separation to an ash content of at least 80% by mass based on the dry matter and a TS content of at least 40% by mass based on concentrated the total mass and discharged from the laundry and the remaining organic-mineral mixture with an ash content of a maximum of 20 mass% based on the dry matter and a water content of 85 mass% based on the total mass discharged from the laundry and the first process stage is fed
• The TS content of the wash water is adjusted by mixing with filtrate from the second process stage or condensate from the fourth process stage to a value between 5% by mass based on the total mass and 20% by mass based on the total mass,
• - The excess washing water discharged from the laundry and the first process stage is supplied.

The operating principle of this improvement of the process control according to the invention is that the adhering to the biomass impurities such as stones, gravel and sand in a first process stage upstream laundry are transferred to the water phase and concentrated in this by a gravity separation and discharged separately from the process and not be entered in the first process stage, being used as wash water process water from the second or condensate from the fourth process stage and the wash water with increasing contamination by dissolved or fine organics of the first process stage fed and in this by hydrothermal carbonation again in - in relation to the wash water cleaner - filtrate is transferred.

A further improvement of the method according to the invention can be achieved by the drying of the press cake in the third process stage in a steam atmosphere and the heat of the discharged from the third process stage and registered in the fourth process stage evaporated water is used in this for heating the evaporation plant. Preferably, the evaporation plant is a single-stage or multi-stage forced circulation evaporator, wherein the first stage is preferably heated with the discharged from the third process stage and registered in the fourth process stage evaporated water.

If the solid produced in the process according to the invention is used as biofuel, the limit values and permissible ranges of the limit values differ depending on the application. If, for example, biofuel replaces wood pellets, the limit values of APEX-Endex, Amsterdam can be used as a guide. If lignite dust is substituted by the biofuel, the composition of the Rhenish and Lusatian lignite dust can be taken as a guide to the limit values. Decisive for the final definition of the limit values, however, are the technical requirements that the firing plant places on the biofuel as well as the limits for flue gases, ashes and fuel resulting from the emission permit. Alternatively, limit values can also be specified by standards, individual dealers or trading venue forms. Examples of limit values are shown in the following table. unit Trading place APEX Dried brown coal Lusatian territory Dried lignite Rheinisches Revier elemental composition chlorine Mass% TS ≤ 0.1 ≤ 0.2 ≤ 0.2 nitrogen Mass% TS ≤ 1.5 ≤ 0.7 ≤ 0.7 sulfur Mass% TS ≤ 0.4 ≤ 0.8 ≤ 0.4 trace elements arsenic mg / kg TS ≤ 6 cadmium mg / kg TS ≤ 10 chrome mg / kg TS ≤ 250 Ash melting behavior Ash melting temperature ° C ≥ 1,100 ≥ 1,200 ≥ 1,100 Ash flow temperature ° C ≥ 1,300 ≥ 1,250

Embodiment:

The inventive method is based on a first embodiment, which by and Table 1 is further described, described:
Feedstock is biomass from landscape conservation with a water content (WG) of 55% by mass based on the total mass and an organic dry matter content (OTS) of 90% by mass based on the dry matter (TS). The chlorine content of the feedstock is 0.4% by mass, the nitrogen content at 1.2% by mass based on the dry matter. The ash softening temperature is 1010 ° C. The required limit values for the biofuel to be produced by the process according to the invention for chlorine are <0.2% by mass for nitrogen at <1.0% by mass, based on the dry matter and for the ash softening temperature, greater than 1100 ° C.

10,000 kg / h of biomass ( 1 ) is introduced into the first process step, a hydrothermal carbonation. Furthermore, 6,093 kg / h of filtrate (press water; 7 ) from the second process stage for balancing the water balance of the first process stage introduced into this. The biomass ( 1 ) and the press water ( 7 ) are heated in the first stage of the process and pressurized and subjected together at a temperature of 215 ° C and a pressure of 22 bar absolute over a period of 4 hours of a hydrothermal carbonization. 660 kg / h of permanent gas ( 12 ) and discharged from the first process stage. 15,432 kg / h carbonation product ( 2 ) are discharged after recooling and relaxation with a water content of 75% from the first process stage and fed to the second process stage. In the second stage of the process, the carbonation product ( 2 ) together with 108 kg / h of recycled residue ( 9 ) from the fourth process stage mechanically dehydrated to a water content of 50%. The separated press water is partly recirculated and returned to the first process stage (7, 6,093 kg / h) and partly to the fourth process stage ( 5 ; 2863 kg / h). The press cake (obtained in the second process stage) 3 ; 6.585 kg / h) is fed to the third process stage where it is thermally dried to a water content of 10% and discharged therefrom and used as biofuel ( 4 ; 4,001 kg / h). The drying takes place in a steam atmosphere and the evaporated water ( 6 ; 2,584 kg / h) is discharged from the third process stage and entered in the fourth process stage. The press water entered in the fourth process stage ( 5 ; 2.863 kg / h) is decomposed there by evaporation into condensate and residue. The from the process water ( 5 ) is condensed together with the condensed vapor from the third process stage ( 6 ) discharged from the process via 11 as 5,231 kg / h wastewater and fed to a biological treatment. The from the process water ( 5 ) is deducted after deduction of the recirculated ( 9 ) discharged over 8 as 108 kg / h waste for recovery from the process.

After completion of the process, the chlorine content of the biofuel produced is 0.1% by mass, the nitrogen content is 0.8% by mass, based on the dry mass. The ash softening temperature is 1,190 ° C. The required limits are thus achieved. At the same time, the amount of residue ( 8th ), which is discharged from the process, halved by recycling of 50% of the residue produced in the fourth process stage in the third process stage to 108 kg / h. Furthermore, the COD content of the waste water / condensate ( 11 ) at 9,000 mg / l and the biodegradability thereof at 98% and thus significantly above the CSB content of the press water ( 5 ) at 50,000 mg / L with a biodegradability of 85%. The amount of ash discharged with the biofuel was reduced by 12% compared to the amount of ash entering the process with the biomass, whereby the ash content of the biofuel is slightly above that of the biomass used due to the mass reduction of the organic dry substance in the hydrothermal carbonization. No description total OTS ash water 1 biomass 10,000 4050 450 5500 2 carbonization 15433 3298 560 11574 3 press cake 6529 3192 399 2938 4 biofuel 3967 3173 397 397 5 press water 2811 34 51 2727 6 Evaporated water 2562 18 2 2541 7 Press water cycle 6092 73 110 5910 8th Waste / residue 212 15 49 148 9 Residue cycle 0 0 0 0 10 Condensate circulation 0 0 0 0 11 Waste water / condensate 5161 37 4 5120 12 permanent gas 660 yield 39.67% 78.35% 88.30% 7.21% Table 1: Processing of biomass from landscape management

The inventive method is further based on a second embodiment, which by and Table 2 is further described:
Feedstock is biomass from agriculture with a water content (WG) of 60% by mass based on the total mass and an organic dry matter content (OTS) of 90% by mass based on the dry matter (TS). The chlorine content of the feedstock is 0.8% by mass, the nitrogen content at 1.8% by mass based on the dry mass. The ash softening temperature is 800 ° C. The required limit values are, as in the first exemplary embodiment, for the biofuel for chlorine to be produced by the process according to the invention at <0.2% by mass for nitrogen at <1.0% by mass based on the dry mass and for the ash softening temperature at greater than 1100 ° C. ,

10,000 kg / h of biomass ( 1 ) is introduced into the first process step, a hydrothermal carbonation. Furthermore, 1,394 kg / h of condensate ( 10 ) from the fourth process stage and 2,637 kg / h press water ( 7 ) from the second process stage for balancing the water balance of the first process stage introduced into this. The biomass ( 1 ) and the press water ( 7 ) are heated in the first stage of the process and pressurized and subjected together at a temperature of 215 ° C and a pressure of 22 bar absolute over a period of 4 hours of a hydrothermal carbonization. 583 kg / h of permanent gas ( 12 ) and discharged from the first process stage. 13,448 kg / h of carbonation product ( 2 ) are discharged after recooling and relaxation with a water content of 75% from the first process stage and fed to the second process stage. In the second stage of the process, the carbonation product ( 2 ) is drained mechanically to a water content of 50%. The separated press water is partially recycled and returned to the first process stage ( 7 ; 2,637 kg / h) and partly the fourth process stage ( 5 ; 5122 kg / h). The press cake (obtained in the second process stage) 3 ; 5.689 kg / h) is fed to the third process stage where it is thermally dried to a water content of 10% and discharged therefrom and used as biofuel ( 4 ; 3,457 kg / h). The drying takes place in a steam atmosphere and the evaporated water ( 6 ; 2,232 kg / h) is discharged from the third process stage and entered in the fourth process stage. The press water entered in the fourth process stage ( 5 ; 5.122 kg / h) is decomposed there by evaporation into condensate and residue. The from the process water ( 5 ) is condensed together with the condensed vapor from the third process stage ( 6 ) discharged over 11 as 5 574 kg / h wastewater from the process and fed to a biological treatment. The from the process water ( 5 ) is discharged via 8 as 386 kg / h of waste for recovery from the process.

After completion of the process, the chlorine content of the biofuel produced is 0.2% by mass, the nitrogen content is 0.9% by mass based on the dry mass. The ash softening temperature is 1,150 ° C. The required limits are thus achieved. Furthermore, the COD content of the waste water / condensate ( 11 ) at 8,500 mg / l and the biodegradability of the same at 98% and thus significantly above the CSB content of the press water ( 5 ) at 50,000 mg / L with a biodegradability of 85%. The amount of ash discharged with the biofuel was reduced by 23% compared to the amount of ash entering the process with the biomass, whereby the ash content of the biofuel is only slightly below that of the biomass used due to the mass reduction of the organic dry substance in the hydrothermal carbonization. No description total OTS ash water 1 biomass 10,000 3600 400 6000 2 carbonization 13448 2913 449 10086 3 press cake 5689 2820 309 2560 4 biofuel 3457 2804 307 346 5 press water 5122 61 92 4968 6 Evaporated water 2232 16 2 2215 7 Press water circulation 2637 32 47 2558 8th Waste / residue 386 27 88 270 9 Residue cycle 0 0 0 0 10 Condensate circulation 1394 10 1 1382 11 Waste water / condensate 5574 40 4 5530 12 permanent gas 583 yield 34.57% 77.89% 76.79% 5.76% Table 2: Processing of biomass from agriculture

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• AT 86234 [0010]
• US 3552031 [0011]
• US 3992784 [0012]
• WO 2008081409 A2 [0013]
• EP 1970431 A1 [0014]
• WO 2008095589 A1 [0015]
• WO 2010/112230 [0016]
• EP 2206688 [0018]

Cited non-patent literature

• DIN EN 14961-1 [0004]

Claims (10)

Process for producing a homogeneous solid from biomass, characterized in that - in the second process stage (mechanical dewatering) recovered filtrate, which is not directly attributed to the first process stage (hydrothermal carbonization), in the fourth process stage (evaporation) by evaporation in a residue and a condensate is decomposed and - the proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), and the proportion of the condensate from the fourth process stage (evaporation) , which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), is selected so that - that discharged from the second process stage (mechanical dewatering) solid does not exceed at least one threshold or - that from the second Proz filtrate or the residue entered in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) does not exceed at least one limit value, - if exceeding one of the limit values, the proportion of residue from the fourth process stage (Evaporation), which is entered into the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is reduced and / or the proportion of condensate from the fourth process stage (evaporation) in the first process stage (hydrothermal carbonization) and / or second process stage (mechanical drainage) is entered is increased. A method according to claim 1, characterized in that - in the second process stage (mechanical dewatering) recovered filtrate, which is not directly attributed to the first process stage (hydrothermal carbonization), decomposed in the fourth process stage (evaporation) by evaporation in a residue and a condensate and - the proportion of the residue from the fourth process stage (evaporation), which is entered in the first process stage (hydrothermal carbonation) or second process stage (mechanical dewatering), and the portion of the condensate from the fourth process stage (evaporation), which enters the first process step (hydrothermal carbonation) or second process step (mechanical drainage) is selected, is selected so that - that discharged from the second process stage (mechanical dewatering) solid does not exceed at least one limit and - that from the second process stage (mechanical drainage) out carried filtrate or in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical drainage) registered residue does not exceed at least one threshold, - wherein when exceeding one of the limits, the proportion of residue from the fourth process stage (evaporation), the in the first process stage (hydrothermal carbonation) and / or second process stage (mechanical dewatering) is registered, is reduced and / or the proportion of condensate from the fourth process stage (evaporation) in the first process stage (hydrothermal carbonization) and / or second process stage (mechanical drainage) is increased. Method according to one or more of the preceding claims, characterized in that are used as the limit value for the solid, the mass fraction of ash, chlorine, sulfur, nitrogen, potassium of one or more heavy metals and / or one or more halogens in the total mass of the solid. Method according to one or more of the preceding claims, characterized in that the limit value for the filtrate or the residue, the conductivity or the dry matter content are used. Method according to one or more of the preceding claims, characterized in that the compliance of the limit or the limits is regularly checked, wherein - in excess of the limit or the proportion of residue from the fourth process stage (evaporation), in the first process stage (hydrothermal Carbonation) and / or second process stage (mechanical drainage) is registered, is reduced and / or the proportion of condensate from the fourth Process step (evaporation), which is entered in the first process step (hydrothermal carbonation) and / or second process step (mechanical drainage) is increased, and - in case of falling below the limits or the proportion of residue from the fourth process stage (evaporation), the in the first process step (hydrothermal carbonation) and / or second process step (mechanical dewatering) is entered, and / or the proportion of condensate from the fourth process step (evaporation) into the first process step (hydrothermal carbonization) and / or second process step ( mechanical drainage) is registered, is reduced. Method according to one or more of the preceding claims, characterized in that when exceeding the limit or limits, first the proportion of residue from the fourth process stage (evaporation) in the first process step (hydrothermal carbonization) and / or second process step (mechanical drainage) registered is reduced before the proportion of condensate from the fourth process stage (evaporation) is entered in the first process step (hydrothermal carbonation) and / or second process step (mechanical dewatering) is increased. Method according to one or more of the preceding claims, characterized in that at a fall below the limits or first the proportion of condensate from the fourth process stage (evaporation) in the first process step (hydrothermal carbonization) and / or second process step (mechanical drainage) entered is reduced before the proportion of residue from the fourth process stage (evaporation) in the first process step (hydrothermal carbonation) and / or second process step (mechanical dewatering) is entered, is increased. Method according to one or more of the preceding claims, characterized in that the inventive method includes a third process stage (thermal drying) and the residue from the fourth process stage (evaporation) in the third process stage (thermal drying) is introduced and exceeding the or Limits for the solid is determined at the earliest after leaving the third process stage (thermal drying). Method according to one or more of the preceding claims, characterized in that the inventive method includes a third process stage (thermal drying) and the process steam generated in the third process stage is introduced into the fourth process stage (evaporation) and condensed there, and the condensate thus produced as well the condensate from the actual evaporation is used. Method according to one of the preceding claims, characterized in that the biomass is mixed in a first process stage upstream laundry with washing water and freed from mineral, the mineral by gravity separation to an ash content of at least 80% by mass based on the dry matter and a TS Content of at least 40 mass% based on the total mass concentrated and discharged from the laundry and the remaining organic-mineral mixture with an ash content of not more than 20% by mass based on the dry matter and a water content of not more than 85% by mass based on the Total mass discharged from the laundry and the first process stage is supplied, the TS content of the wash water by mixing with filtrate from the second process stage or condensate from the fourth process stage to a value between 5% by mass based on the total mass and 20% by mass adjusted to the total mass, the excess e Wash water is discharged from the laundry and fed to the first process stage.

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