DE102010064715B3 - Process and use of a tubular reactor for the treatment of solid-liquid mixtures - Google Patents

Abstract

A process for producing material or fuel, humus, Maillard or similar reaction products from a solid-liquid mixture of water and a carbonaceous component involves treating the solid-liquid mixture at a temperature in excess of 100°C and a pressure of more than 5 bar in a tubular reactor with largely vertical holding sections and direction-changing deflectors. The solid-liquid mixture flows through the holding sections more slowly than the remaining pipe sections because they have larger diameters.

Description

technical field

Hydrothermal carbonization (HTC), a chemical process for the simple and highly efficient production of hard coal and lignite as well as humus or peat, was first described in detail in 1913 by the German Nobel Prize winner Friedrich Bergius. Thus, the coalification process (i.e. the natural process of converting dead plant matter and biomass into humic acids and peat, then into lignite and finally into bituminous coal) can be technically mimicked within a few hours. Systematic investigations were carried out by E. Berl et al. (Ann. Chem. 493 (1932), pp. 97-123; Angew. Chemie 45 (1932), pp. 517-519) and by J.P. Schumacher et al. (Fuel, 39 (1960), pp. 223-234). In 2006, the HTC process, improved in laboratory terms, was presented to the public by Professor Markus Antonietti from the Max Planck Institute for Colloids and Interface Research in Potsdam near Berlin.

Biomass is heated to around 180°C together with water in a pressure vessel. After a few hours, a biochar suspension is present. The chronological sequence of the chemical reaction is divided into a warm-up phase, depolymerization phase, restructuring phase and stabilization phase. During the chemical conversion reaction, up to 34 percent of the energy contained in the starting material and in particular in saccharides is released as heat. After the reaction, the carbon suspension has advantageous properties compared to the starting materials due to molecular and structural chemical changes, which enable quick and easy dewatering, drying and, if necessary, subsequent comminution with minimal energy consumption.

The solid-liquid mixture is transformed into another substance with coal-like properties during treatment in the pressure vessel by hydrolysis, depolymerization, dehydration through complex chemical reactions (shown in Fig by Sevilla and Fuertes in Carbon 47 (2009), pp. 2281 - 2289 and in Chem. Eur. J. (2009) 15, pp. 4195 - 4203). The solids consist of small clusters of condensed benzene rings which in the core form compounds of stable groups with oxygen such as ethers, quinones, pyrones and the shell contains compounds with more reactive and hydrophilic oxygen functional groups including hydroxyl, carbonyl, carboxyl esters.

Biomass is the most important carbon converter with the greatest efficiency in sequestering CO ₂ from the atmosphere. Therefore, only biomass can provide the basis for building such truly carbon-reducing energy systems that are also capable of eliminating our emissions of the past. For the establishment of such a carbon outflow, the carbon must be sequestered by a process with a sufficiently high carbon efficiency. Carbon efficiency is the proportion of carbon that remains bound in the end product.

The limits of alternative biomass conversion processes, especially with regard to the limited choice of starting materials, have been known for a long time. With the dry thermal-chemical treatment at 200°C - 320°C (so-called torrefaction), only largely dry biomass and in particular wood can be processed economically. Biological conversion processes for the production of biogas, bioethanol or biodiesel have a preference for starting materials containing carbohydrates and are limited in their efficiency by the requirements and performance of the microorganisms, which, in addition to optimal metabolic conditions, require conversion times of several days and therefore high volumes. So far, technically complex processes with pressures over 50 bar or temperatures over 300°C including gasification or so-called biomass-to-liquid (BtL) processes have not yet been able to establish themselves on a large scale, although their application has been tried and tested for many years. Processes that run under operating conditions similar to those of the HTC have also not been able to establish themselves to date. One reason for this could be their relatively short treatment times of a few minutes, which only achieve a very incomplete chemical conversion, so that the advantageous product properties of the HTC described above, such as an easy-to-process biochar suspension and a fuel or material with a high carbon content and high calorific value.

The superiority of HTC compared to other biomass conversion processes is primarily due to the fact that both the highest carbon efficiency is achieved and the greatest flexibility with regard to the starting materials is given. In addition, the process is exothermic under certain conditions. For example, the carbon efficiency of HTC of up to 90% represents an increase of up to 80 percent compared to biogas production by fermentation (~50%). This leap in efficiency is considerable and is even clearer compared to wood gasification (~30%) and composting (~10%). Compared to these processes, the carbon efficiency of the HTC is approx. 3 times or 9 times higher. The very high carbon efficiency of HTC in connection with the use of HTC products as humus/biochar allows permanent binding of the carbon contained in the biomass. Other renewable energy sources are, at best, carbon neutral, which means that they can only reduce, but not offset, future CO ₂ emissions (Back to black: Hydrothermal Carbonization of Biomass to Clean Up CO ₂ Emissions From the Past; May 26 , 2007; http://news.mongabay.com/bioenergy/2007/05/scientists-describe-hydrothermal.html).

The possibility of using HTC to convert biomass into biochar, humus or biochar in an economically successful manner and on an industrial scale, thus improving the quality of the soil and thus the crop yields, was described as the "key innovation of the century" (Heiko Pieplow in "Valuable soil: the skin of the earth”, DIE ZEIT, May 7, 2009). A comparative analysis of different biomass conversion processes has shown that the HTC has the potential to significantly reduce the future global release of CO ₂ (Peter Brandt, J. Verbr. Lebensm. (2009), pp. 151 - 154): 11% of the biomass of our ecosystem grows on accessible farmland. Depending on the crop, up to 90% of agricultural biomass cannot be processed into food and is considered crop residues and biogenic waste. Extracting 8.5% of the produced biomass from the active ecosystem would compensate for the entire CO ₂ release from burning petroleum (Titirici et al., New J. Chem. (2007), pp. 787 - 789). With the HTC, a large amount of carbon could be permanently stored in biochar, HTC humus or biochar anywhere in the world. These products can also be used to improve soil (see http://de.wikipedia.org/wiki/Hydrothermale Carbonisierungs).

In addition to the minimal CO ₂ release and high environmental compatibility, flexibility with regard to the raw materials that can be used will be decisive for the economic efficiency and sustainability of a process for converting biomass in the future. The HTC is the only known biomass conversion process with high carbon efficiency in which all biogenic starting materials can be used. The starting materials include all plant components and especially harvest residues, wood, forest residues, roots, leaves, green waste, organic waste, biogenic fraction of residual waste or industrial waste, animal carcasses, slaughterhouse waste, leftover food, paper, textiles, excrement, sewage sludge, as well as other carbonaceous or Substances containing carbohydrates, cellulose, hemicellulose and lignin.

State of the art

In WO 2008/095589 A1 , DE 10 2007 012 112 B3 , WO 2008/113309 A1 , DE 10 2008 004 732 A1 , DE 10 2008 006 772 A1 , DE 10 2008 007 791 A1 have proposed reactors for the treatment of solid-liquid mixtures and in particular biomass suspensions, including a screw reactor or a simple tubular reactor. In practice, however, the superiority or functionality of the known reactors has not yet been demonstrated.

In chemical process engineering, reactions of solid-liquid mixtures and in particular of biomass with a reaction time of more than 20 minutes are unusual. Accordingly, no suitable reactors have yet been developed for this that would allow the reaction to be carried out continuously.

Presentation of the invention

It is the object of the invention to find a solution for the economical and continuous conversion of solid-liquid mixtures while preventing caking and blockages.

According to the invention, the object is achieved in that the diameter of a lower pipe part of the laminar flow reactor is smaller than that of a descending pipe section and at least the descending pipe sections are essentially vertical or at least inclined to the horizontal.

The reactor units of the laminar flow reactor can be connected directly to one another in such a way that they can largely do without the use of moving components including valves or mechanical stirring devices.

• • Der Durchmesser eines Umlenkers beträgt mindestens 5 - 500 oder 20 - 100 mm.
• • Der Durchmesser der Haltestrecken ist mindestens 1 %, 10% oder 100% größer als der des Umlenkers der gleichen Reaktoreinheit. Insbesondere ist der Durchmesser des Absteigers 25%, 50% oder 100% größer als der eines unteren Umlenkers der gleichen Reaktoreinheit. Der Durchmesser des Aufsteigers ist mindestens 1 %, 10% oder 100% größer als der des unteren Umlenkers der gleichen Reaktoreinheit. Die absteigenden und aufsteigenden Rohrteile stehen im Wesentlichen senkrecht.
• • Das Verhältnis der Durchmesser d_n1 / d_n2 beträgt mindestens 1,01 - 400 oder 4 bis 40. Das Verhältnis der Durchmesser d_n1 / d_n3 beträgt 1 - 400 oder 3 bis 30. Das Verhältnis der Durchmesser d_n3/d_n2 beträgt 1 - 400 oder 3 bis 30.

• • In Ausführungsformen sind mindestens zwei Reaktoreinheiten direkt miteinander verbunden.
• • Jede der Reaktoreinheiten bestehend aus mindestens einem Umlenker und einer Haltestrecke.
• • Die Gesamtlänge aller verbundenen Rohrstrecken beträgt mindestens 4, 16, 64 oder 256 Meter. Die absolute Gesamtlänge aller verbundenen Rohrstrecken beträgt 4 - 64.000 oder 250 - 4.000 Meter.
• • Die Mindestlänge von zusammenhängenden Rohrstrecken, die nicht zum Beispiel durch Sperrvorrichtungen voneinander ganz oder teilweise getrennt werden können, beträgt 1, 4, 16 oder 64 Meter. Die Zahl der über Rohrstrecken zusammenhängenden Rohrreaktoreinheiten, die nicht voneinander ganz oder teilweise getrennt werden können, beträgt 2 - 1000 oder 11 - 100.
• • Die Länge des Laminarstromreaktors umfasst die Rohrabschnitte, bei denen der Betriebsdruck mehr als 5 bar beträgt.
• • In Ausführungsformen sind eingangs und/oder ausgangs des Reaktors Wärmetauscher positioniert, in denen die Temperatur des Fest-Flüssig-Gemischs auf >160°C erhöht wird. In diesen Bereichen kann der Volumenstrom des Fest-Flüssig-Gemischs auf parallele Teilströme aufgeteilt sein.

A laminar flow reactor within the meaning of the present application is a tubular pressure vessel which, due to its design, allows a solid-liquid mixture to flow through for flow times of over 40, 60, 90 or 120 minutes and at the same time has as little turbulent flow as possible conditions guaranteed. In embodiments, it consists of at least two interconnected reactor units, each of which consists of several pipe sections, pipe parts, pipe sections or pipe sections, with at least one deflector or direction-changing pipe part having a smaller volume or at least a smaller cross-section than the holding sections (pipe parts without a change in direction). For certain embodiments:

• • The diameter of a deflector is at least 5 - 500 or 20 - 100 mm.
• • The diameter of the holding sections is at least 1%, 10% or 100% larger than that of the diverter of the same reactor unit. In particular, the diameter of the downcomer is 25%, 50% or 100% larger than that of a lower diverter of the same reactor unit. The diameter of the riser is at least 1%, 10% or 100% larger than that of the bottom diverter of the same reactor unit. The descending and ascending pipe sections are essentially vertical.
• • The ratio of the diameters d _n1 / d _n2 is at least 1.01 - 400 or 4 to 40. The ratio of the diameters d _n1 / d _n3 is 1 - 400 or 3 to 30. The ratio of the diameters is d _n3 /d _n2 1 - 400 or 3 to 30.

• • In embodiments, at least two reactor units are connected directly to one another.
• • Each of the reactor units consisting of at least one deflector and a holding section.
• • The total length of all connected pipe runs is at least 4, 16, 64 or 256 meters. The absolute total length of all connected pipe sections is 4 - 64,000 or 250 - 4,000 meters.
• • The minimum length of connected pipe sections that cannot be completely or partially separated from one another, for example by locking devices, is 1, 4, 16 or 64 metres. The number of tubular reactor units connected via tubular sections that cannot be separated from one another in whole or in part is 2-1000 or 11-100.
• • The length of the laminar flow reactor includes the pipe sections where the operating pressure is more than 5 bar.
• • In embodiments, heat exchangers are positioned at the inlet and/or outlet of the reactor, in which the temperature of the solid-liquid mixture is increased to >160°C. In these areas, the volume flow of the solid-liquid mixture can be divided into parallel partial flows.

Pipes, pipe sections, pipe parts, pipe sections or reactor units are connected to one another if, in the operating state, there is a continuous connection between the reaction chambers, which enables the pressure in the reaction chambers to be equalized with one another. In the case of a laminar flow reactor, such a connection exists at least over two reactor units or over a length of pipe of at least 4, 16, 64 or 256 meters.

Pipe sections, pipe parts or pieces of pipe are the elongated cavities through which the reaction mixture flows, regardless of their shape and geometry. Deflectors are defined as a change in mean flow direction of at least 90 degrees and up to 200 degrees. The cross-section is expediently round in shape since it is a pressurized process. Descenders, ascenders and deflectors can consist of several different shaped pipe or components.

In the operating state, the reaction spaces of at least two reactor units are connected to one another at pressures of more than 5 bar and are not separated by valves or other blocking or control devices.

The lower pipe, piece of pipe or pipe part is the lower direction-changing pipe part or the lower deflector with the diameter d _n,2 . Pipes, pipe sections or pipe parts are also referred to as pipe sections. The riser is the ascending tube, piece of tube or part of tube with diameter d _n.3 . The upper pipe or piece of pipe is the upper part of the pipe changing direction or the upper deflector with the diameter d _n.4 . The holding section is a descending (descending) or ascending (rising) pipe, piece of pipe or part of pipe with diameter d _n,1 .

Relegated and/or climbed are stopping distances. They have a higher volume than the deflectors. The mean direction of flow of the solid-liquid mixture in the holding section is inclined to the horizontal. It is advantageous if the stopping distance, which is particularly straight, is largely vertical. The stopping distance is generally positioned so that the angle of the pipe centerline to the horizontal plane is at least 2 or at least 60 degrees.

A deflector is arranged below a holding section. The lower deflector is a pipe section that deflects the mean flow direction of the solid-liquid mixture upwards. The upper and lower deflectors are designed in such a way that the change in the absolute value angle of the pipe axis is around 180 degrees, but at least 100 or 150 degrees.

The various pipe elements are connected to one another by flanged or welded joints. If pipe elements with different diameters are connected, a reducer is also inserted. A reducer or reducer, which also includes an inverted reducer, is a tapered piece of pipe within a pipeline and, as a fitting, represents the transition of two different nominal sizes. Reducers can be made of standard elements or metal components including dished, basket heads, cones and can be concentric or run eccentrically. In the case of concentric reducers, the wall of the reducer follows a straight circular cone, in the case of eccentric reducers, the wall of the reducer follows an inclined circular cone and one of the surface lines runs parallel to the pipe axis. Concentric reducers are more streamlined, while eccentric reducers can offer assembly advantages.

The mean flow rate of the solid-liquid mixture in the lower deflector is at least 50% greater than in the holding section immediately preceding it.

The diameters, in particular of the descenders, are expediently chosen such that the maximum segregation rate to be expected is less than the flow rate. Depending on their tendency to float, the velocity of the solid components in the descenders is lower than that of the liquid phase; and a dwell time in the descender in question, which is the inverse of the difference between the flow rate and the demixing rate. As a result, the residence time of the solid components is always (possibly even considerably) longer than the flow time of the liquid phase. A larger diameter of the descenders ultimately means that the residence time of the solid components is significantly longer than that of the liquid phase and thus reactor space is saved. It also means that there is an accumulation of the solid components in the downcomers, and when the flow rate drops too far and gets close to the segregation rate, the solid-in-liquid dispersion there becomes a liquid-in-solid -Mass can develop. An upper limit for the descent diameter also has a desired technical effect.

According to a preferred embodiment, the length of a stopping distance is 2-12 meters. The total length of the climbers and climbers is 320 - 1,920 meters. Further details can be found in the table below: reactor unit dn _,1 (mm) d _n.2 (mm) d _n.3 (mm) d _n.4 (mm) 1 -6 100 50 50 50 7-20 200 50 50 50 21 - 40 300 50 100 100 41 - 80 400 60 200 200 81 - 120 500 70 200 200 120 - 160 600 80 300 300

The diameters are in the relation d _n,1 ≥ d _n,3 and d _n,1 > 1.25 d _n,2 to each other. In particular, d _n,1 > d _n,3 ≥ d _n,4 ≥ d _n,2 contains six single relations between the diameters: d _n,1 > d _n,3, d _n,1 > d _n,4 , d _{n, 1} > d _n,2 , d _n,3 ≥,d _n,4 , d _n,3 ≥ d _n,2' d _n,4 ≥ d _n,2 which can be fulfilled independently of one another.

Unless otherwise mentioned or described, the definitions and explanations in the language and wording apply DE 10 2008 058 444.4 , which is incorporated by reference into the disclosure of the present application.

• • Unter „variable stoffliche Parameter“ sind die Parameter zu verstehen, die sich im Reaktionsverlauf ändern. Fast alle stofflichen Variablen aller Phasen (fest, flüssig und gasförmig) und insbesondere die der kohlenstoffhaltigen Komponente, die letztlich das Reaktionsprodukt definiert, verändern sich während der Reaktion, wie zum Beispiel (dynamische) Viskosität η (abnehmend) und Dichte p (steigend).
• • „Variable Prozessparameter“ lassen sich über eine Steuerung verändern wie zum Beispiel der Volumenstrom (Volumendurchfluss) V oder die Durchflussgeschwindigkeit v.
• • „Fixe Prozessparameter“ werden über die Hardware, das heißt die Auslegung und Spezifikationen der Anlage vorgegeben und können daher nicht oder nicht ohne weiteres innerhalb einer Anlage verändert werden, wie zum Beispiel der Radius r bzw. (hydraulische) Rohrdurchmesser d. Der hydraulische Rohrdurchmesser ist hier definiert als 4A/U mit A: Querschnittsfläche und U: Umfang. Für einen kreisrunden Querschnitt ist der hydraulische Durchmesser also gleich dem geometrischen.

The following parameters and physical variables play a role in the design of the laminar flow reactor and the process control:

• • “Variable material parameters” are understood to mean the parameters that change over the course of the reaction. Almost all material variables of all phases (solid, liquid and gaseous) and in particular those of the carbon-containing component, which ultimately defines the reaction product, change during the reaction, such as (dynamic) viscosity η (decreasing) and density p (increasing).
• • "Variable process parameters" can be changed via a controller, such as the volume flow (volume flow) V or the flow rate v.
• • "Fixed process parameters" are given by the hardware, ie the design and specifications of the system and can therefore not be changed within a system, or not easily, such as the radius r or (hydraulic) pipe diameter d. The hydraulic pipe diameter is defined here as 4A/U with A: cross-sectional area and U: circumference. For a circular cross-section, the hydraulic diameter is therefore equal to the geometric one.

A reactor unit of a laminar flow reactor consists of at least 2 or 4 different tube diameters, the diameter of a tube section with the sequence number nd _n,1 > d _n,3 ≥ d _n,4 ≥ d _n,2 (see above). The tube diameters in embodiments increase incrementally with increasing distance from the first reactor unit (increasing n).

The mean flow velocity can be determined using flow sensors. For example, the time that a defined volume of a colored liquid requires between entering and exiting the laminar flow reactor can be used to determine the volume flow per unit of time and thus also the flow velocities for the different given hydraulic diameters. Entry and exit of the colored liquid (e.g. a defined amount of water is colored with potassium permanganate) from the laminar flow reactor can be determined optically through sight glasses. In a system, the flow rate is determined, for example, with a Coriolis flow meter (e.g. Promass 83S25 from Endress+Hauser).

The ratios of the average flow velocities v _nm of the solid-liquid mixture flowing through pipe sections m of a reactor or a tubular reactor unit n are v _n,2 > v _n.1 , v _n,2 ≥ v _n,3 , v _n,2 ≥ V _n,4 or _vn,4 ≥ vn _,3 . The average flow speed in the lower deflector _Vn , ₂ is 1 - 5,000, 10 - 500 or 30 - 200 m/min.

The mean flow rate of the solid-liquid mixture is 0.01 - 20, 0.05 - 10 or 0.1 - 3 m/min in a descending holding section. In an ascending holding section, the mean flow velocity is at least 50% greater than in a descending holding section. In the lower deflector, the mean flow velocity v _n,2 is 1 - 1,000 times, 5 - 300 times or 20 - 100 times greater than that in an adjacent holding section.

The mean flow rate depends on the diameter, which increases incrementally as the distance from the conveyor with the tubular reactor units according to the formula v _n=1 ≥v _n=2 etc. increases. For the non-downflow pipe sections, the flow rate is increased by at least 10%, 20%, 50%, 100% or more. The flow velocity of the non-downflow pipe sections is increased at least 1.1 times, 2, 5, 9, 20, 100 times or more.

The reaction begins when the operating temperature of 100 - 250 or 140 - 180°C is reached. Depending on the desired reaction product, the conversion reaction lasts between 40 and 720 or 90 - 180 minutes, in individual cases even up to 2,160 minutes. The flow time through the laminar flow reactor is at least 40, 60, 90 or 120 minutes. For example, the carbon content of spent grains as a starting material is increased from 30% to 40% of the mass fraction of the dry matter within 120 minutes. The flow time of the solid-liquid mixture within all connected purities or reactors is at least 40, 60, 90 or 120 minutes and a total of 90 - 180, 180 - 720 or 720 - 2160 minutes.

• • nimmt die Viskosität des Reaktionsgemischs ab
• • nehmen die Dichteunterschiede ab
• • nimmt die Entmischungsgeschwindigkeit des Fest-Flüssig-Gemischs ab
• • können größere Durchmesser für die Rohrabschnitte gewählt werden (wachsende Durchmesser)

With increasing reaction time, ie with increasing distance (distance) to the first conveyor or the reactor entrance

• • the viscosity of the reaction mixture decreases
• • the density differences decrease
• • the rate of separation of the solid-liquid mixture decreases
• • larger diameters can be selected for the pipe sections (increasing diameters)

In order to maintain a flow that is as laminar as possible or to avoid strong turbulence with the need for pressure increases of more than 3, 5 or 10 bar above the pressure difference prevailing in normal operation, the viscosity is increased or the flow rate reduced by increasing the diameter, removing water or feeding it of starting materials or intermediate products with a solids content above that of the solid-liquid mixture at the feed point.

Holding section is a pipe section within the tubular reactor that follows the heat exchanger, i.e. a pipe section in which the reaction mixture has reached the target or reaction temperature.

The total volume of a laminar flow reactor is made up of the sum of the volumes of the individual reactor units n, where x is the number of reactor units. The reactor units n consist of the tube sections m. The density of the solid phase increases and the viscosity of the solid-liquid mixture decreases as a result of heating and the course of the chemical reaction. At the same time, the particle size decreases. This reduces the segregation speed. A decreasing segregation rate allows the volumes of the tube sections to be incrementally increased in the course of the reaction by choosing larger diameters.

l_nm Längen von Rohrabschnitten mit mittlerem Durchmesser d_nm, n Laufzahl der Rohrreaktoreinheit, m Laufzahl des Rohrabschnitts, x Anzahl der Reaktoreinheiten.The total volume of a laminar flow reactor, neglecting the cross-sectional transitions and curvatures, is calculated as follows: $$V=\pi {\displaystyle \sum _{n=1}^x{\displaystyle \sum _{m=1}^4{l}_{nm}\frac{{\mathrm{i.e}}_{nm}^2}{4}}}$$

l _nm lengths of pipe sections with average diameter d _nm n run number of the tubular reactor unit m run number of the pipe section x number of reactor units.

The volume of a holding section is expediently 0.1-100 or 0.5-10 m ³ . The total volume of a laminar flow reactor is expediently 10-10,000 or 100 to 1,000 m ³ . The volume of a climber is 1%, 10% or 100% or even 1.1 - 40 or 2 - 4 times larger than that of an immediately following climber.

The mean direction of flow of the solid-liquid mixture within a holding section is inclined to the horizontal in at least 5%, 20% or 80% of the volume of a reactor unit or at least 1%, 5% or 50% of the entire pipe section. It is advantageous if the mean direction of flow in the holding sections runs largely parallel to the force of gravity. The angle of the flow direction of the largely vertical current flow is at least 2 or at least 60 degrees to the horizontal.

• • das Verhältnis von flüssigen zu festen Bestandteilen im Fest-Flüssig-Gemisch
• • das Mischungsverhältnis verschiedener Ausgangsstoffe
• • das Abziehen oder Zuführen von Wasser oder Feststoff
• • chemische oder physikalische Veränderung wie zum Beispiel der Dichte, oder eine Zerkleinerung.

During the conversion reaction, the density increases by 5 - 60% or 20 - 40% over time due to the chemical conversion. To maintain the functionality of the laminar flow reactor, the flow resistance must be kept low. Turbulence leads to an increase in flow resistance. The flow loss of turbulent flows is therefore significantly larger and is many times that of a laminar flow. By increasing the viscosity, the critical Reynolds number also increases and the transition point, which characterizes the onset of turbulence, is shifted towards higher flow velocities. Viscosity is affected by before, during and after the reaction

• • the ratio of liquid to solid components in the solid-liquid mixture
• • the mixing ratio of different starting materials
• • the withdrawal or addition of water or solids
• • chemical or physical change such as density, or comminution.

Viscosity decreases significantly on heating. At the same time, there is an additional decrease in viscosity during the course of the reaction due to the chemical reaction.

• • das Abziehen von Wasser und/oder
• • das Zuführen von Feststoff.

Viscosity is inversely related to density, which increases after heating during the chemical conversion reaction. The viscosity therefore decreases as the reaction progresses and the flow resistance decreases. At the same time, however, the tendency to turbulence increases. In order to make better use of the reaction space and to stabilize the flow, especially in the lower deflectors, the viscosity is increased along the reactor section in some embodiments

• • draining of water and/or
• • the feeding of solids.

The supply of raw materials with a high solids content of more than 25%, 50% or 75% and a particle size of up to 2, 4 or 6 mm, in particular after the first heat exchanger sections or during the course of the process, e.g. B. in the middle third of the reactor section, by means of a feed to downstream reactor units, increases the viscosity. It can also counteract overheating. For example, corn silage with a solids content of 12-15% flowed through a heat exchanger with pipe diameters of 50 mm at a rate of 3-7 m ³ /hour. A pressure drop of 2 - 4 bar was measured over a distance of approx. 120 meters. The low pressure drop suggests laminar flow. If water flowed through the same section with the same throughput, the pressure dropped sharply by a multiple (>15 bar). This suggests that the transition point (Reynolds number) has been passed and the laminar flow has changed to turbulent flow.

character list

• 1 shows an example of a schematic representation of a tubular reactor unit n with the tube sections m.
• 2 shows an example of a schematic representation of a plant for the continuous production of materials or fuels from a solid-liquid mixture.

1 shows an example of a schematic representation of a tubular reactor unit n with the tube sections m (1-4) with the diameters d _nm of a laminar flow reactor. The solid-liquid mixture enters the pipe section 1 with the diameter d _n.1 via an inverted reducer. As the diameter of pipe section 1 increases compared to the preceding pipe section, the flow rate v _nl in pipe section 1 slows down (indicated by the single arrow). The solid-liquid mixture enters the pipe section 2 with the diameter d _n.2 via a reducer 5 from the pipe section 1 with the diameter d _n.1 . The solid-liquid mixture enters the pipe section 3 with the diameter d _n,3 from the pipe section 2 with the diameter d _n,2 via a further, inverted reducer 6 . Via a further reducer 7 the solid-liquid mixture passes from the pipe section 3 with the diameter d _n.3 into the pipe section 4 with the diameter d _n.4 . The solid-liquid mixture flows from pipe section 4 into the subsequent reactor unit n+1 (not shown). This sequence is repeated periodically. The flow velocities and lengths of the pipe sections (measured along their respective center lines) are indexed v _nm and l _nm , respectively. In addition, two (pipe section m=3) to four (pipe section m=2) arrows are drawn in for illustration purposes in areas with higher flow rates.

2 shows an example of a schematic representation of a plant for the continuous production of materials or fuels from a solid-liquid mixture of water and a carbon-containing component, the solid-liquid mixture being heated at a temperature of over 100°C and a pressure of over 5 is treated in cash. The system includes a double-strand loading device consisting of conveyor strands I and II. Line I is used to convey “dry” biomass from starting materials that are difficult or impossible to pump, for example with a high solids content of 15 to 99% by weight. For this purpose, the "dry" biomass is stored in a silo 11 and from there into a container 12, preferably a walking floor container. The starting materials are fed into a comminution device 13, e.g. designed as a wet or dry mill or as another suitable mechanical comminution unit, and from there into a mixing container 16 via a conveyor device, which can be a screw conveyor or a conveyor belt, for example. In the mixing tank 16, the dry biomass is mixed with water, which may contain process water or concentrated process water, from the reservoir 14 and a catalyst or a catalyst mixture from at least one container or dispenser 15 using an agitator. The mixture is fed to the incubation container 18 via the conveying device 17 . The incubation vessel 18 allows for a low pressure exposure time of the catalyst to the material. The containers 16 and 18 are double-walled and have a heating water connection to enable the material to be preheated to, for example, 20 - 99°C or 50 - 70°C. Via the conveying devices 19 and 20, which are designed, for example, as screw or trough chain conveyors or as conveyor belts, the incubated material of the "dry" starting materials is transported via a feeding device from the first conveyor line I into a tubular reactor unit n such as 29, 30, 31 , 32 or 33, 34 introduced under pressure above the vapor pressure of the reaction mixture. The introduction device consists of a pendulum flap sluice, a compulsory conveyor, which, for example, injector, twin screw extruder, a progressive cavity pump, a piston pump, a positive displacement scroll pump, each equipped with or without compressor screws, or a twin screw compressor. The insertion device can also be provided with a shut-off device. The introduction device ensures that the incubated material from line I is introduced into the respective reactor unit at a pressure level above the internal reactor pressure and prevents repercussions on the feed device. The pendulum flap sluice is filled, for example, via a cell wheel sluice.

"Moist" biomass consisting of pumpable starting materials or biomass pulp, which can also consist of various mixtures of starting materials, for example with a solids content of 1 to 50% by weight, is transported via conveyor line II from a storage container 22 by means of a conveyor device 23 into a mixing device 24 and mixed in the mixing device 24 with water or process water from the reservoir 14 and catalyst from at least one container or dosing device 25, incubated in an incubation container 26 and by means of a suitable conveying device 27, for example as a piston, displacement or eccentric screw pump may be designed, fed to the reactor 29-38. The material is heated to at least 160-180, 200-220 or 220-250° C. via at least one heat exchanger unit 28 . The "wet" raw materials from conveyor line II pretreated in this way are brought together with the "dry" raw materials from conveyor line I via the described or other suitable conveyor systems. The point of introduction of "dry" starting materials can be varied and can be in a reactor or tubular reactor unit n such as 29, 30, 31, 32 or 33, 34 but also in 35, 36 or 37, 38 etc. Conveniently "Dry" starting materials, in particular those with a maximum particle diameter of less than 6 mm, less than 4 mm or less than 2 mm, and a dry matter content of more than 30%, more than 40% or more than 50%, are fed into the middle third of the reactor section. For example, the feed can take place in the area of an upper deflector 4 or at the transition 8 between this and the subsequent descender 1 . The "wet" starting materials were previously introduced or initially introduced under pressure above the vapor pressure of the reaction mixture. The ratio of the mass throughput of conveyor line I to conveyor line II or of the starting materials supplied is, for example, 1:20, 1:5, 1:1 or 10:1 uniform mixing of the reaction mixture. The heating and the dissipation of the exotherm occurring during the reaction takes place via temperature control devices such as, for example, a heat exchanger device and/or a double wall of the reactor or a reactor unit. Temperature control devices can be designed, for example, as spiral, tube, bundle or spiral heat exchangers. The necessary flow or residence time is achieved by connecting reactor units in series. In order to allow a longer residence time, the reaction mixture is kept in motion in individual reactor units by means of a circulating pump. This avoids caking or blockages.

In addition, conveying means for accelerating liquids, including liquid jet mixers or nozzles, can be used.

Due to the removal of process water, smaller reactor volumes or smaller reaction spaces are required in the further course of the process. The pressure relief 40 after the flow is complete is controlled by a backward-facing relief pump, which is designed as a forced-feed pump, an eccentric screw pump, a spiral displacement pump, or a piston membrane pump. In a buffer and/or expansion tank 41, the reaction mixture is further cooled and buffered and from there or directly from the expansion pump it reaches drainage and/or drying 42. The reaction product is temporarily stored in a storage tank or silo 43 as slurry or dried bulk material before it is transported away 44 or fed into another process.

1. 1. Eine Vorrichtung zur Behandlung eines Fest-Flüssig-Gemischs aus Wasser und einer kohlenstoffhaltigen Komponente bei einer Temperatur von über 100°C und einem Druck von über 5 bar, mit wenigstens einer aus wenigstens zwei unterschiedlichen Rohrabschnitten bestehenden Reaktoreinheit, wobei
   1. a. an einen ersten, absteigend von dem Fest-Flüssig-Gemisch durchflossenen Rohrabschnitts unmittelbar ein zweiter, eine mittlere Flussrichtung des Fest-Flüssig-Gemischs nach aufwärts umlenkender Rohrabschnitt anschließt, wobei der erste Rohrabschnitt der wenigstens einen Reaktoreinheit zur Waagerechten geneigt oder senkrecht ist;
   2. b. der Querschnitt des ersten Rohrabschnitts um mindestens 50% größer als der des unmittelbar anschließenden zweiten Rohrabschnitts ist; und
   3. c. die Gesamtlänge der von dem Fest-Flüssig-Gemisch durchflossenen Rohrabschnitte innerhalb des mit dem Druck beaufschlagten Reaktorsystems mindestens 20 Meter beträgt.
2. 2. Die Vorrichtung nach Kombination 1, wobei die Gesamtlänge der von dem Fest-Flüssig-Gemischs durchflossenen Rohrabschnitte aller mit dem Druck beaufschlagten Rohrstrecken mindestens 60 oder mindestens 250 Meter beträgt.
3. 3. Die Vorrichtung nach Kombination 1 oder 2, ferner umfassend einen unmittelbar an den Aufwärts-Umlenker anschließenden dritten, aufwärts durchflossenen Rohrabschnitt sowie einen daran anschließenden vierten, das durchströmende Gemisch wieder nach abwärts umlenkenden Rohrabschnitt.
4. 4. Die Vorrichtung nach Kombination 3, wobei die hydraulischen Durchmesser der unmittelbar aufeinanderfolgend durchströmten ersten bis vierten Rohrabschnitte einer oder mehrerer der Bedingungen d_n1 > d_n3 ≥ d_n4 ≥d_n2 genügen, wobei n die Laufziffer der Reaktoreinheit ist und die Zahl der Indices die Laufziffer des Rohrabschnitts angibt.
5. 5. Die Vorrichtung nach Kombination 3 oder 4, umfassend mehrere aneinander anschließend angeordnete Reaktoreinheiten.
6. 6. Die Vorrichtung nach Kombination 5, wobei der hydraulische Durchmesser von Rohrabschnitten einer nachfolgenden Reaktoreinheit jeweils größer ist als der von entsprechenden Rohrabschnitten einer vorangehenden Reaktoreinheit.
7. 7. Die Vorrichtung nach einer der Kombinationen 1 bis 6, wobei mindestens ein Wärmetauscher eingangs und/oder mindestens ein Wärmetauscher ausgangs der Rohrreaktoreinheiten positioniert ist.
8. 8. Die Vorrichtung nach einer der Kombinationen 1 bis 7, wobei vor und/oder hinter den Reaktoreinheiten eine Pumpe bzw. Gegendruckpumpe positioniert ist, um den Druck im Reaktorinneren aufrechtzuerhalten.
9. 9. Die Vorrichtung nach einer der Kombinationen 1 bis 8, wobei das Verhältnis der Länge von geraden Rohrabschnitten zu der von gekrümmten Rohrabschnitten mindestens 10:1 beträgt.
10. 10. Die Vorrichtung nach einer der Kombinationen 1 bis 9, wobei das Verhältnis der Länge jedes der geraden Rohrabschnitte zu seinem hydraulischen Durchmesser 2:1 bis 800:1, 5:1 bis 400:1 oder 10:1 bis 160:1 ist.

The present disclosure also includes the following combinations of features:

1. 1. A device for the treatment of a solid-liquid mixture of water and a carbon-containing component at a temperature of over 100 ° C and a pressure of over 5 bar, with at least one consisting of at least two different pipe sections reactor unit, wherein
   1. a. A first pipe section through which the solid-liquid mixture flows in a descending direction is directly followed by a second pipe section that deflects a central flow direction of the solid-liquid mixture upwards, the first pipe section of the at least one reactor unit being inclined or perpendicular to the horizontal;
   2. b. the cross-section of the first pipe section is at least 50% larger than that of the immediately adjoining second pipe section; and
   3. c. the total length of the pipe sections through which the solid-liquid mixture flows within the pressurized reactor system is at least 20 meters.
2. 2. The device according to combination 1, wherein the total length of the pipe sections through which the solid-liquid mixture flows of all pipe sections subjected to pressure is at least 60 or at least 250 meters.
3. 3. The device according to combination 1 or 2, further comprising a third pipe section, through which flow occurs upwards, directly adjoining the upward deflector, and a fourth pipe section adjoining it, which again deflects the mixture flowing through downwards.
4. 4. The device according to combination 3, wherein the hydraulic diameters of the first to fourth pipe sections through which flow occurs in immediate succession satisfy one or more of the conditions d _n1 > d _n3 ≥ d _n4 ≥ d _n2 , where n is the serial number of the reactor unit and the number of indices indicates the serial number of the pipe section.
5. 5. The device according to combination 3 or 4, comprising a plurality of reactor units arranged one after the other.
6. 6. The apparatus of combination 5, wherein the hydraulic diameter of pipe sections of a subsequent reactor unit is greater than that of corresponding pipe sections of a preceding reactor unit.
7. 7. The device according to one of combinations 1 to 6, wherein at least one heat exchanger is positioned at the inlet and/or at least one heat exchanger at the outlet of the tubular reactor units.
8. 8. The device according to any one of combinations 1 to 7, wherein a pump or back pressure pump is positioned upstream and/or downstream of the reactor units in order to maintain the pressure inside the reactor.
9. 9. The apparatus of any one of combinations 1 to 8, wherein the ratio of the length of straight pipe sections to that of curved pipe sections is at least 10:1.
10. 10. The apparatus of any one of combinations 1 to 9, wherein the ratio of the length of each of the straight pipe sections to its hydraulic diameter is 2:1 to 800:1, 5:1 to 400:1, or 10:1 to 160:1.

Claims (18)

Process for the production of humus or fuels from a solid-liquid mixture of water and a carbon-containing component, the solid-liquid mixture being heated at a temperature of more than 100°C and a pressure of more than 5 bar in a tubular reactor with at least one holding section (1, 3) and at least one deflector (2), characterized in that the at least one deflector (2) is arranged below the at least one stopping section (1, 3), wherein a. the mean flow rate of the solid-liquid mixture in the lower deflector (2) is at least 50% greater than that in the holding section (1, 3), b. the mean direction of flow of the solid-liquid mixture in the holding section (1, 3) is inclined to the horizontal or is essentially vertical, and c. the flow time of the solid-liquid mixture through the tubular reactor is at least 40 minutes. procedure after claim 1 , whereby the average flow speed in the lower deflector (2) is 1 - 1,000, 10 - 500 or 30 - 200 m/min. procedure after claim 1 or 2 , whereby the average flow speed in the lower deflector (2) is 1.5 - 1000, 5 - 300 or 20 - 100 times greater than in the holding section (1, 3). Process according to one of the preceding claims, in which, after the lower deflector (2), the solid-liquid mixture flows through an upward holding section (3) and then through an upper deflector (4). procedure after claim 4 , whereby the average flow speed in the lower deflector (2) is 1.1 - 2, 2 - 5 or 4 - 40 times faster than in the upper deflector (4). procedure after claim 4 or 5 , the flow velocity in an ascender (3) immediately following the lower deflector (2) being 1.1 - 40 or 2 - 5 times faster than in the descender (1) immediately preceding the lower deflector (2). Procedure according to one of Claims 1 until 6 , the mean flow velocity in the descending holding section (1) being 0.01 - 20, 0.05 - 10 or 0.1 - 3 m/min. amounts to. Procedure according to one of Claims 1 until 7 , wherein the tubular reactor has a plurality of reactor units, each with a holding section (1, 3) and a deflector (2) arranged below it, and the reactor units are connected to deflectors (4) arranged above the holding sections (1, 3), and wherein a preceding one of the several Reactor units (29) is used to feed the carbonaceous component, the carbonaceous component having a solids content of 1 to 50%. procedure after claim 8 , wherein a downstream reactor unit (31, 33) of the tubular reactor is used to supply a further carbon-containing component with a dry substance content of at least 30%, containing particles with a maximum diameter of less than 6 mm. Use of a tubular reactor with at least one stopping section (1, 3) and at least one deflector (2) arranged underneath for the production of humus or fuels from a solid-liquid mixture of water and a carbon-containing component in the method according to claim 1 . use after claim 10 , whereby the average flow speed in the lower deflector (2) is 1 - 1,000, 10 - 500 or 30 - 200 m/min. amounts to. use after claim 10 or 11 , whereby the average flow speed in the lower deflector (2) is 1.5 - 1000, 5 - 300 or 20 - 100 times greater than in the holding section (1, 3). Use after one of Claims 10 until 12 After the lower deflector (2), the solid-liquid mixture flows through an upward holding section (3) and then through an upper deflector (4). use after Claim 13 , whereby the average flow speed in the lower deflector (2) is 1.1 - 2, 2 - 5 or 4 - 40 times faster than in the upper deflector (4). use after Claim 13 or 14 , the flow velocity in an ascender (3) immediately following the lower deflector (2) being 1.1 - 40 or 2 - 5 times faster than in the descender (1) immediately preceding the lower deflector (2). Use after one of Claims 10 until 15 , the mean flow velocity in the descending holding section (1) being 0.01 - 20, 0.05 - 10 or 0.1 - 3 m/min. amounts to. Use after one of Claims 10 until 16 , wherein the tubular reactor has a plurality of reactor units, each with a holding section (1, 3) and a deflector (2) arranged below it, and the reactor units are connected to deflectors (4) arranged above the holding sections (1, 3), and wherein a preceding one of the several Reactor units (29) is used to feed the carbonaceous component, the carbonaceous component having a solids content of 1 to 50%. use after Claim 17 , wherein a downstream reactor unit (31, 33) of the tubular reactor is used to supply a further carbon-containing component with a dry substance content of at least 30%, containing particles with a maximum diameter of less than 6 mm.

Images