Patent ID: 12203042

DETAILED DESCRIPTION

FIG.1shows a system1for the hydrothermal carbonization of a flowable biomass, comprising a pump5, a heat exchanger10and a tubular reactor15. The pump5is connected to the heat exchanger10via a delivery conduit6for the flowable biomass. If the pump5is in the operating state, the pressure of the flowable biomass in the delivery conduit6leading to the heat exchanger10can be increased to a pressure of at least 10 bar. The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element. For the system, a tubular rector15can be used, which is insulated from the environment by means of an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

The flowable biomass can be stored in a storage container30if it is not supplied continuously by an upstream process.

FIG.2shows a system2for the hydrothermal carbonization of a flowable biomass according to a second embodiment. The same reference numerals as inFIG.1are used for elements that are the same or have the same effect. The system2comprises a pump5, a heat exchanger10, a tubular reactor15and a separation unit20. The pump5is connected to the heat exchanger10via a delivery conduit6for the flowable biomass. If the pump5is in the operating state, the pressure of the flowable biomass in the delivery conduit6leading to the heat exchanger10can be increased to a pressure of at least 10 bar. The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element. For the system, a tubular rector15can be used, which is insulated from the environment by means of an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

The separation unit20can be configured as a pressing device. The separation unit20is used to separate the solid components of the carbonaceous reaction product from the liquid components of the carbonaceous reaction product. The separation unit can be configured, for example, as a piston press or as a hose press. The solid components of the carbon-containing reaction product can be further processed in a downstream process or fed to an incinerator for energy generation. The liquid components of the reaction product containing carbon can be fed to a downstream cleaning process. Alternatively, at least some of the liquid components can be fed into the delivery conduit6in order to be fed back to the heat exchanger10and the tubular reactor15for conversion together with the flowable biomass.

According to this embodiment, the reaction products containing carbon, which are discharged from the tubular reactor15as a product stream, can be used as a heat transfer medium, for example for a preheater80which is arranged between the pump6and the heat exchanger10and is used to preheat the flowable biomass.

FIG.3shows a system3for the hydrothermal carbonization of a flowable biomass according to a third embodiment. The same reference numerals as inFIG.1orFIG.2are used for elements that are the same or have the same effect. The system3comprises a pump5, a heat exchanger10, a tubular reactor15and a separation unit20. The pump5is connected to the heat exchanger10via a delivery conduit6for the flowable biomass. If the pump5is in the operating state, the pressure of the flowable biomass in the delivery conduit6leading to the heat exchanger10can be increased to a pressure of at least 10 bar. The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element. For the system, a tubular rector15can be used, which is insulated from the environment by means of an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

The separation unit20can be configured as a pressing device. The separation unit20is used to separate the solid components of the carbonaceous reaction product from the liquid components of the carbonaceous reaction product. The separation unit can be configured, for example, as a piston press or as a hose press. The solid components of the carbon-containing reaction product are fed to a dryer40according to this embodiment.

The portion of liquid components of the reaction product containing carbon in the solid can be lowered to less than 15%. The solid can be comminuted in a subsequent method step, for example formed into pellets or briquettes. The solid can also be further processed into a free-flowing bulk material. The solid can be used as a fuel, for example. Depending on the composition, the solid can also be used as a fertilizer. Additional components can be added to the solid in subsequent method steps depending on the application. If drying is provided for the solid components of the carbonaceous reaction product, the solid can be transported more cheaply and can be stored for a prolonged time. Of course, the solid can also be used as fuel in an incinerator to generate energy.

The liquid components of the reaction product containing carbon can be fed to a downstream cleaning process. Alternatively, at least some of the liquid components can be fed into the delivery conduit6in order to be fed back to the heat exchanger10and the tubular reactor15for conversion together with the flowable biomass.

FIG.4shows a system4for the hydrothermal carbonization of a flowable biomass according to a fourth embodiment. The same reference numerals as in the previous embodiments are used for elements that are the same or have the same effect. The system4comprises a pump5, a heat exchanger10, a tubular reactor15and a separation unit20. The pump5is connected to the heat exchanger10via a delivery conduit6for the flowable biomass. If the pump5is in the operating state, the pressure of the flowable biomass in the delivery conduit6leading to the heat exchanger10can be increased to a pressure of at least 10 bar. The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element. For the system, a tubular rector15can be used, which is insulated from the environment by means of an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

The separation unit20can comprise a pressing device25. The separation unit20is used to separate the solid components of the carbonaceous reaction product from the liquid components of the carbonaceous reaction product. A plurality of similar or different separation units can be provided for this purpose. According to this embodiment, a first separation unit20is provided, which is configured as the pressing device25. The separation unit can be configured, for example, as a piston press or as a hose press. According to the present embodiment, a second separation unit20is provided, which is configured as a dryer40. According to this embodiment, the solid components of the reaction product containing carbon are fed to the dryer40.

The portion of liquid components of the carbonaceous reaction product in the solid can be lowered to less than 15%. The solid can be comminuted in a subsequent method step, for example formed into pellets or briquettes. The solid can also be further processed into a free-flowing bulk material. The solid can be used as a fuel, for example. Depending on the composition, the solid can also be used as a fertilizer. Additional components can be added to the solid in subsequent method steps depending on the application. If drying is provided for the solid components of the carbonaceous reaction product, the solid can be transported more cheaply and can be stored for prolonged time. Of course, the solid can also be used as fuel in an incinerator to generate energy.

The liquid components of the carbonaceous reaction product are fed to a downstream third separation unit. According to the present embodiment, the third separation unit comprises an evaporator50. By means of the evaporator50, at least some of the volatile components of the liquid components of the reaction product containing carbon are vaporized. The evaporator50can be operated as a vacuum evaporator to reduce the thermal energy required for evaporation. The liquid components of the carbonaceous reaction product contain more than 50% (w/w) water. The water is at least partially evaporated in the evaporator and, in a subsequent cooling step, cooled by a cooler and/or condensed by a condenser60, if required. The cooler can also contain a preheater (not shown), which is used to preheat the flowable biomass before it enters the heat exchanger10. The condensate can, for example, be fed to a wastewater treatment plant and returned to the water cycle.

The concentrate of the evaporator50can be at least partially fed into the delivery conduit6in order to be fed back to the heat exchanger10and the tubular reactor15together with the flowable biomass for carbonization.

Alternatively, the concentrate can be fed to a cooler70before it can be fed into the delivery conduit6or, alternatively, into the storage container30. The cooler70can be coupled to a preheater85when the concentrate or the liquid components of the carbonaceous reaction products are fed from the pressing device25or the dryer40into the delivery conduit6for the flowable biomass.

According to each of the embodiments, the pressure of the stream of carbon-containing reaction products exiting from the tubular reactor15can be reduced to ambient pressure by a pressure-reducing element17. Depending on the design of the downstream separation unit20, unpressurized operation of the same can be more cost-effective, since the separation unit20and other system components possibly present downstream of the tubular reactor15do not need to be designed as pressure vessels in accordance with the required regulations.

The pressure-reducing element17can be configured as a throttle element, for example.

FIG.5ashows a detail of a heat exchanger10according to a first variant, which can be used for any of the systems1,2,3,4previously described.

The heat exchanger10for heating the flowable biomass comprises a duct100for the flowable biomass, wherein the duct100comprises an inlet opening101and an outlet opening102, wherein the duct is surrounded by a heatable duct casing110.

In particular, the insert element12is not connected to an inner wall of the heatable duct casing110, so that the heatable duct casing110and the insert element12are arranged in the duct100such that they can be moved relative to one another.

According to an embodiment, the insert element12is configured as a spiral-shaped insert element. In particular, the length of the spiral-shaped insert element can essentially correspond to the length of the duct. The insert element12can have an outer diameter that is up to 10 mm smaller than the inner diameter of the heatable duct casing110. In particular, the outer diameter of the insert element12can be up to 5 mm smaller than the inner diameter of the heatable duct casing110. In the case of outer diameters of a maximum of 60 mm, the outer diameter of the insert element12can be smaller than the inner diameter of the heatable duct casing110by up to 2.5 mm. According to an advantageous variant, the insert element12has an inner diameter that is greater than 0 and at most 5 mm smaller than the outer diameter of the insert element12.

According to an embodiment, the outer diameter can be 30% up to and including 50% larger than the inner diameter of the insert element12. According to an embodiment, the inner diameter of the insert element12is 28 mm and the outer diameter is 52 mm. According to an embodiment, the spiral-shaped insert element is configured as a spiral with a pitch of at least 20 mm and at most 50 mm. According to an embodiment, the pitch of the spiral amounts to 38 mm.

In particular, the spiral-shaped insert element has a wall thickness of 2 up to and including 10 mm. According to an embodiment, the wall thickness is in a range from 4 up to and including 4.2 mm. For example, the spiral-shaped insert element can contain a metallic material. In particular, the spiral-shaped insert element can contain stainless steel or spring steel.

According to an embodiment, the heatable duct casing110contains a duct casing channel113for a heat transfer fluid, wherein the duct casing channel113extends from a duct casing channel inlet opening111for the entry of the heat transfer fluid into the duct casing channel113to a duct casing channel outlet opening112for the discharge of the heat transfer fluid from the duct casing channel113.

FIG.5bshows a radial section through the heat exchanger according toFIG.5a. The insert element12is configured without a core. In other words, the flowable biomass can flow unhindered through a core portion of the heat exchanger10. A cavity13is formed by the insert element12. This cavity13surrounds the longitudinal axis14of the heat exchanger10, the cavity thus extends along a central portion of the heat exchanger10, which can also be referred to as the core portion.

The core portion of the heat exchanger extends along the longitudinal axis14of the heat exchanger10. The core portion of the heat exchanger includes, in particular, a portion of the volume of the interior space of the heat exchanger. The core portion is configured in particular as a cylindrical cavity13. The cavity13surrounds the longitudinal axis14of the heat exchanger, which for the embodiment of a cylindrical cavity coincides with the longitudinal axis of the cylindrical cavity. In particular, the diameter of the cavity13of the core portion DK corresponds to at least 25% of the diameter D of the interior space of the heat exchanger. According to an embodiment, the diameter of the cavity of the core portion DK corresponds to at least 30% of the diameter D of the interior space of the heat exchanger. According to the present embodiment, the interior space of the heat exchanger10is cylindrical.

FIG.6shows a detail of a heat exchanger10according to a second variant, which can be used for any of the systems1,2,3,4previously described.FIG.6differs from the variant according toFIG.5in that the heat transfer fluid flows in countercurrent flow with respect to the flowable biomass flowing through the duct100.

FIG.7shows a detail of a heat exchanger10according to a third variant, which can be used for any of the systems1,2,3,4previously described.FIG.7differs from the variant according toFIG.5in that the insert element12can be made to rotate by means of a drive element115. When the insert element12performs a rotational movement, deposits on the inner wall of the heatable duct casing110forming the duct100can be removed particularly efficiently from the inner wall.FIG.7also shows part of the delivery conduit6leading to the inlet opening101and part of the connecting conduit11leading away from the outlet opening102. According to the illustration inFIG.7, the drive element extends into the delivery conduit6. Alternatively, the drive element115could be provided in the connecting conduit11. The spiral-shaped insert element has no conveying effect, therefore, the drive element115can be arranged at any location.

FIG.8shows a system120for the hydrothermal carbonization of a flowable biomass according to a fifth embodiment. The same reference numerals as in the previous embodiments are used for elements that are the same or have the same effect. The system120comprises a pump5, a heat exchanger10, a tubular reactor15and a separation unit20. The pump5is connected to the heat exchanger10via a delivery conduit6for the flowable biomass. If the pump5is in the operating state, the pressure of the flowable biomass in the delivery conduit6leading to the heat exchanger10can be increased to a pressure of at least 10 bar. The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element. For the system, a tubular rector15can be used, which is insulated from the environment by means of an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

According to the present embodiment, a pressure of 18 bar was measured in the delivery conduit. The pressure in the delivery conduit6and in the heat exchanger10and the tubular reactor15can be in the range from 10 bar up to and including 40 bar. The pump5can in particular be configured as an eccentric screw pump. The pump5is connected to a storage container30via a supply line. The storage container30can contain a stirring element for the homogenization of the flowable biomass. According to an embodiment, a flowable biomass with a dry matter content of 9.5% (w/w) has been used.

According to this embodiment, the reaction products containing carbon, which leave the tubular reactor15as a product stream, can be used as a heat transfer medium, for example for a preheater80which is arranged between the pump6and the heat exchanger10and is used to preheat the flowable biomass. In the present embodiment, the flowable biomass has been heated to a temperature of 120 degrees Celsius, that means that the temperature of the flowable biomass amounts to 120 degrees Celsius when it enters the heat exchanger10.

The heat exchanger10is connected to the tubular reactor15via a connecting conduit11. In the operating state, there is thus a heated biomass in the connecting conduit11, which can be fed to the tubular reactor15for converting the heated biomass into a carbonaceous reaction product. The heat exchanger10contains an insert element12and the tubular reactor15does not contain an insert element.

The heat exchanger10for heating the flowable biomass comprises a duct100for the flowable biomass, the duct100comprising an inlet opening101and an outlet opening102, wherein the duct is surrounded by a heatable duct casing110. In particular, the insert element12is not connected to an inner wall of the heatable duct casing110, so that the heatable duct casing110and the insert element12are arranged in the duct100such that they can be moved relative to one another. According to this embodiment, the insert element12is configured as a spiral-shaped insert element. In particular, the length of the spiral-shaped insert element can essentially correspond to the length of the duct.

According to this embodiment, the heatable duct casing110contains a duct casing channel113for a heat transfer fluid, the duct casing channel113extending from a duct casing channel inlet opening111for the heat transfer fluid to enter the duct casing channel113to a duct casing channel outlet opening112for the heat transfer fluid to leave the duct casing channel113. The heat transfer fluid can include an oil that is heated by means of a thermal oil burner. According to an embodiment, the temperature of the heated, flowable biomass at the feed into the tubular reactor15is 205 degrees Celsius. The temperature of the heated flowable biomass at the feed to the tubular reactor15can be in a range from 150 degrees Celsius to 220 degrees Celsius. According to an embodiment, the temperature of the oil is 270 degrees Celsius. The temperature of the oil can be in a range from 250 degrees Celsius up to and including 300 degrees Celsius.

A tubular rector15can be used for the system, which is insulated from the environment with an insulating jacket. In particular, the tubular reactor15does not contain a heat exchanger.

The separation unit20can include a pressing device25. The separation unit20is used to separate the solid components of the carbonaceous reaction product from the liquid components of the carbonaceous reaction product. A plurality of similar or different separating units can be provided for this purpose. According to this embodiment, a first separation unit20is provided, which is configured as the pressing device25. The pressing device25can be configured, for example, as a piston press or as a hose press. According to this embodiment, the material to be pressed has a dry matter content of 68.5%. Depending on the composition of the biomass, the dry matter content can range from 50% up to and including 80%.

According to the present embodiment, a second separation unit20is provided, which is designed as a dryer40. According to this embodiment, the solid components of the reaction product containing carbon are fed to the dryer40.

The portion of liquid components of the carbon-containing reaction product in the solid can be lowered to less than 20%, in particular less than 15%, in particular when using a multi-stage dryer to less than 2.2%. After drying, the dried solid can have a dry matter content of 90%. The dryer can be configured in particular as a fluidized bed dryer. The dried solid can be comminuted in a subsequent method step, for example formed into pellets or briquettes. The solid can be used as a fuel, for example. Depending on the composition, the solid can also be used as a fertilizer. Depending on the application, additional components can be added to the solid in subsequent method steps. If drying is provided for the solid components of the carbonaceous reaction product, the solid can be transported more cheaply and can be stored for a prolonged time. Of course, the solid can also be used as fuel in an incinerator to generate energy.

The liquid components of the carbonaceous reaction product are fed to a downstream third separation unit. According to the present embodiment, the third separation unit comprises an evaporator50. By means of the evaporator50, at least some of the volatile components of the liquid components of the reaction product containing carbon are vaporized. The evaporator50can be operated as a vacuum evaporator to reduce the thermal energy required for evaporation. The liquid components of the carbonaceous reaction product from the first separation unit contain more than 50% by weight water. The water is at least partially evaporated in the evaporator and, in a subsequent cooling step, cooled by a cooler and/or condensed by a condenser60, if required. The condensate can, for example, be fed to a wastewater treatment plant and returned to the water cycle.

At least part of the concentrate obtained in the evaporator50can be fed into the product stream of the tubular reactor15in order to be used as a heat transfer fluid for the preheater80.

According to this embodiment, the pressure of the stream of carbon-containing reaction products leaving the tubular reactor15is reduced to ambient pressure by a pressure-reducing element17. Depending on the configuration of the downstream separating unit20, unpressurized operation of the same can be more cost-effective, since the separating unit20and other system components possibly downstream of the tubular reactor15do not need to be designed as pressure vessels in accordance with the required regulations.

The pressure-reducing element17can be configured as a throttle element, for example. In particular, the pressure-reducing element can include a pressure-reducing valve.

FIG.9ashows a detail of a heat exchanger10according to a fourth variant, which can be used for any of the systems previously described. According to the present embodiment, the insert element12is configured as a twisted tubular element. The twisted tubular element contains a spiral flight. A spiral flight can consist of an element of the group consisting of a protrusion, a groove or an indentation on the twisted tubular element surface that runs spirally. InFIG.9a, a spiral flight is shown as an example, which is attached as a protrusion on the outside of a tubular element16, which is part of the twisted tubular element. The arrows shown in the drawing show the flow of the flowable biomass, which flows through the tubular element16and flows around the tubular element16.

As in the variant according toFIG.7, if the insert element12performs a rotational movement, deposits on the inner wall of the heatable duct casing110forming the duct100can be removed particularly efficiently from the inner wall.FIG.9aalso shows a portion of the delivery conduit6leading to the inlet opening101and a portion of the connecting conduit11leading away from the outlet opening102. According to the illustration inFIG.9a, the drive element115extends into the delivery conduit6. The drive element115could instead also be attached in the connecting conduit11.

The tubular element16of the insert element12is shown partially cut open so that it can be seen that the insert element12according toFIG.9ais also configured without a core.

According to an embodiment that is not shown in the drawings, the tubular element16can contain openings in the tubular element casing, so that an exchange can take place between the flowable biomass flowing inside the tubular element and the flowable biomass flowing around the tubular element for further improving the heat transfer.

FIG.9bshows a radial section through the heat exchanger according toFIG.9a. The insert element12is configured without a core. In other words, the flowable biomass can flow unhindered through a core portion of the heat exchanger10. A cavity13is formed by the insert element12and is located in the interior space of the tubular element16according to this embodiment. This cavity13surrounds the longitudinal axis14of the heat exchanger10, the cavity13thus extends in a central portion of the heat exchanger10, which can also be referred to as the core portion.

The core portion of the heat exchanger extends along the longitudinal axis14of the heat exchanger10. The core portion of the heat exchanger includes, in particular, a portion of the volume of the interior space of the heat exchanger. The core area is configured in particular as a cylindrical cavity13. The cavity13surrounds the longitudinal axis14of the heat exchanger, which for the embodiment of a cylindrical cavity coincides with the longitudinal axis of the cylindrical cavity. In particular, the diameter of the cavity13of the core portion DK corresponds to at least 25% of the diameter D of the interior of the heat exchanger. According to an embodiment, the diameter of the cavity of the core portion DK corresponds to at least 30% of the diameter D of the interior space of the heat exchanger. According to the present embodiment, the interior space of the heat exchanger10is cylindrical.

FIG.10shows a detail of a heat exchanger10according to a fifth variant, which can be used for any of the systems previously described.FIG.10differs from the previous embodiment according toFIG.9aby the use of an insert element which is configured as a twisted tubular element which contains two counter-rotating spiral flights.

It is obvious to a person skilled in the art that many other variants are possible in addition to the systems or method variants described, without departing from the inventive concept. The subject of the invention is thus not limited by the foregoing description and is to be determined by the scope of protection defined by the claims. For the interpretation of the claims or the description, the broadest possible reading of the claims is decisive. In particular, the terms “include” or “include” should be construed as referring to elements, components or steps in a non-exclusive sense, thereby indicating that the elements, components or steps may be present or used that they can be combined with other elements, components or steps that are not explicitly mentioned. When the claims relate to an element or component from a group that may consist of A, B, C to N elements or components, this language should be interpreted as requiring only a single element of that group, and not one Combination of A and N, B and N or any other combination of two or more elements or components of this group.