EP2473585A1

EP2473585A1 - Method and system for producing pellets from biomass in a pellet press for use as fuel in fireplaces

Info

Publication number: EP2473585A1
Application number: EP10757155A
Authority: EP
Inventors: Gernot Von Haas
Original assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Current assignee: Dieffenbacher GmbH Maschinen und Anlagenbau
Priority date: 2009-09-04
Filing date: 2010-09-04
Publication date: 2012-07-11
Also published as: US20120233913A1; CA2771647A1; RU2012112946A; KR20120061945A; DE102009040172A1; CN102625826A; WO2011026642A1

Abstract

The invention relates to a system and to a method for producing pellets (9) from biomass (1) in a pellet press (8) for use as fuel in fireplaces. The aim of the invention is to produce pellets in an energy-saving and more energetically cost-effective manner as compared to the prior art. In the method according to the invention, the biomass (1), which consists of cellulosic and/or lignocellulosic fibers, chips or shreds and is heated and dried in the course of the production process in a dryer (2), separated from the dryer air, and the biomass (1) is supplied to a pellet press (8), wherein the temperature of the biomass (1) is heated or substantially maintained by hot air in a treatment region (23) between the dryer (2) and the pellet press (8), and the treatment region (23) comprises at least parts of the transport path and/or at least one additional device for carrying out at least one additional method stop, and wherein the temperature of the hot air exceeds at least 65° Celsius.

Description

Method and plant for producing pellets from biomass in a pelleting press for use as fuel in fuel stations

The invention relates to a process for the production of pellets in a pelleting press for use as fuel in fireplaces according to the preamble of claim 1.

Furthermore, the invention relates to a plant for the production of pellets from biomass in a pelleting press for use as fuel in fireplaces according to the preamble of claim 17.

The production of pellets, also called pellets or granules, from fines or compacted and / or molten material has been known for a long time. Briquetting presses have compressed material between two rolls, either one or both of which have been worked out as a die, and formed into briquettes for price increase. In the plastics industry or the

Animal feed processing industry pelleting by means of extruders and perforated discs, possibly with subsequent cutting devices, also well known. The production of pellets for use as

Fuel in fireplaces of preferably comminuted biomass, such as wood, its sawdust, dust or the like is also already well known and in the field of renewable energies as a forward-looking technology for climate protection, especially in Europe, propagated. The manufacturing process is subject to certain standards, so the pellets produced must have a certain abrasion resistance (for pneumatic transport) and must not be used in the course of

Incinerate toxic or environmentally harmful substances. Inferior pellets often contain foreign substances (lubricants, dyes, ...).

In the plant design for the production of pellets for use in fireplaces, especially in large industrial plants, in particular the cost factor by the energy to be expended is a problem.

It makes sense that the production of pellets should consume very little energy, since these are generally not from renewable sources (oil / gas combustion, power plants). It is also problematic to build a large-scale system consisting of several purchased component systems, in particular of niche manufacturers, since each individual component system

(Heavy material separator, drying device, grinding device, cyclone or pelleting press) can rarely be economically and optimally integrated in an overall system. In previous systems, the chips are dried very intensively, so that the chips can be warmed up with steam before pelleting. The reason for this is that the chips during transport from the dryer to pelleting, or in other devices for the treatment of chips, but also

especially during storage in a silo, lose much of its temperature obtained by the drying process. For a quick Therefore, the manufacturing process uses steam to preheat the chips before the pelleting press, since the condensing vapor is not just one

Humidification of the chips, but also promises a rapid increase in temperature of the chips. However, known dampness of the chips before pelleting, usually 12 percent by weight of moisture, should not be exceeded, so that with a 2 to 4 percent increase in the chip moisture by the sputtering the chips must be dried to 8 to 10 weight percent. The excessive drying of the chips and the production of the steam require a lot of energy.

The object of the invention is that a method and a plant is to be created in which / compared to the prior art energy-saving biomass, preferably wood pulp in the form of chips, and energetically inexpensive to pellets can be pressed.

The solution of the problem for a method is that the method heats biomass during the production in a dryer and

dried, the dried and heated biomass from the

Dryer air is separated and the biomass is fed to a pelleting press,

wherein the temperature of the biomass is heated in a treatment area between the dryer and the pelleting press with hot air or in Essentially, the treatment area comprises at least parts of the transport path and / or at least one further device for carrying out at least one additional method step, and wherein the temperature of the hot air exceeds at least 65 ° Celsius.

The solution of the task for a plant is that in the plant for drying and heating the biomass, a dryer with a

Sluice for separating the dryer air in the production direction is arranged in front of the pelleting press,

wherein in the system at least one treatment area between the lock and the pelleting press is arranged and this

Treatment area is arranged at least one transport means for transporting the biomass between the dryer and the pelleting press and / or at least one device for performing at least one further process step, the treatment area associated at least one heating device for heating and / or providing hot air of substantially above 65 ° C. Celsius is arranged, wherein the heating device is operatively connected at least once with the means of transport and / or with a device for performing further process steps for supplying the hot air.

Advantageously, the method according to the invention achieves high potential savings in energy consumption in the case of large-scale industrial plants, because the entire manufacturing process is carried out energetically optimized and energetically expensive temperature increases to

be avoided biomass or unnecessarily high-energy process measures, such as humidification of the biomass with steam to increase the temperature, simultaneous increase in biomass moisture by several percent and subsequent drying of the biomass for

Production of the necessary degree of drying of the biomass for pelleting. For this purpose, the biomass is advantageously heated by the dryer along its transport path and / or in other devices for carrying out further process steps by means of hot air. The other devices are hereinafter referred to as treatment area (between

Dryer and pelleting press). Advantageously, the corresponding transport routes and / or the devices should be sufficiently isolated from the environment or the lower temperature.

For the basic drying method is preferably a

Hot steam dryer, or a power dryer used. Particularly preferred, because of the high outlet temperature and / or the high

Throughput is but a drum dryer. A drum dryer, or current dryer or a hot steam dryer can usually be a 10 ° higher temperature of the biomass over the conventional

Have belt dryers. Preferably, a treatment area is established in an advantageous manner between the dryer and the pelleting press, in which the dried biomass is processed for the pelleting press. Necessary or useful preparations, for example, the passage through a

Heavy material separator, a grinding device, a classifier, a water spray device, a metering device for the pelleting press, transport devices or the like more. In all of these

Devices are usually, but especially in the startup operation of the plant, the temperature of the biomass significantly reduced. Conventional plants have for this purpose a steamer before the pelleting press, the energy costly biomass back to a

increased pellet temperature. However, the steaming generally also increases the moisture content of the biomass, so that in anticipation a dryer must dry the biomass more intensively by this increased moisture content. Particularly advantageous in the present invention, the property that this special energy consumption, especially by a special design of the treatment area between dryer and pelleting press no longer needs to be done twice. It is sufficient to facilitate the pelleting in the pelleting press, to apply water to the biomass before the pelleting press, preferably to spray. The water should of course be preheated in this context and preferably have a temperature of about 60 °. The biomass will preferably transported with hot air and / or introduced into the treatment devices or passed through as required. In addition to the optimum temperature control of the machine elements that come into contact with the biomass, the temperature maintenance or the temperature increase of the biomass is possible. In the system are preferably a variety of measuring and control devices to adjust the temperature and the control or regulation of the hot air supply or the temperature of the hot air energetically optimal. The aim is to transport the biomass at a temperature of substantially above 65 ° C into the pelleting press, without the essential temperature level of the biomass after the dryer whose exit temperature is preferably above 60 ° C, down towards a common ambient temperature change. This measure is to be supported in particular by isolating the corresponding devices in the treatment area and / or heating devices of the devices themselves.

In a particularly preferred embodiment is as

Treatment area a hot air circulation created, the at least one device for effecting a process step (eg., Grind, sort, classify, heat), a hot air heater and a cyclone for separating the hot air from the biomass.

Known plant technical needs, such as tax and

Regulating devices, fresh air supply, hot air cleaning, or the like is by a specialist according to the technical equipment

Necessities or specifications added where necessary or useful. Especially in the course of a total energy efficiency.

In the course of an energetic optimization, it may be useful or even necessary to use instead of hot air, a hot air-steam mixture, which allows a better heat transfer, especially when heating the biomass. In this case, of course, can be dispensed with a Wasserbeaufschlagung before spraying or before the pelleting press or this is throttled accordingly.

Incidentally, the water is heated to a temperature of above 65 ° C., preferably to above 80 ° C., particularly preferably to 90 ° C., before or during the feed to the biomass. In a preferred embodiment, alternatively or supportively, the applied water can be heated on the biomass by means of radiation energy. Preferably microwave ovens are arranged for this, which heat the water or the biomass during transport between the Wasserbesprühung and the pelleting press. Particularly preferably, the temperature of the hot air is adjusted with a heating device, wherein the heater uses fresh air as supply air and / or preheated air from at least one hot air return and / or preheated air from a heat exchanger or directly from the waste heat of a pellet cooler after the pelleting press. In the treatment area between the dryer, preferably a drum dryer with a lock device for separating the Drying air from the biomass, and the pelleting press several process steps may be necessary to prepare or prepare the biomass for pelleting. Also safety aspects for the pelleting press even before metals, stones or the like should be considered. This would require, for example, a heavy material separator for separating heavy material and / or a grinding device for comminuting the biomass and / or a cyclone for separating the hot air from the biomass in front of the pelleting press. The separation of the hot air from the biomass may be necessary to increase the overall energy balance of the plant. This is particularly advantageous if in the treatment area the hot air is to be conducted via the heating device in a substantially closed circuit. This cycle essentially offers

Advantages in terms of control and regulation. Of course, the circulation can also be extended via an optional silo and / or the pelleting press itself, so that after the pelleting press, preferably in the

Pellet dryer the still warm hot air, preferably then via a heat exchanger via a hot air return respectively

Heat recovery is returned to the heater. The hot air in the circulation of the treatment area should be regularly replaced and / or filtered, at least in parts, the corresponding exhaust air, in accordance with environmental regulations, if necessary via a

Exhaust air purification device, such as a wet-electrostatic Separator (WESP) and / or a regenerative thermal oxidation (RTO) should be performed.

The teaching of the invention states in principle that the cooling of the biomass between the drying in the dryer and the pelletizing should be reduced or even prevented as possible. Depending on the type of plant or type of process, even a warming of the biomass

be provided, in particular, if the biomass must still be stored in a silo before the pelleting press to order a proper distribution or bed of biomass in one or more

To ensure pelleting presses. Depending on the definition, storage and discharge from the silo can also be considered as a process step associated with the treatment area. The biomass should preferably reach the pelleting press at a temperature above 65 ° C, and accordingly the hot air should be adjusted in the treatment area. Further information on the design or regulation of the temperature of the biomass is, of course, dependent on the devices used for carrying out the method steps in the treatment area and the biomass used itself. The possibility of isolating the respective devices or transport routes is also in parts

Design matter of the designer of the system and therefore can not be presented in individual cases for the expert. Preferably, however, the biomass is also surrounded during transport at least with hot air or transported pneumatically accordingly.

To support the requirement that the biomass reach the pelleting press at 65 ° C, it may be necessary for the biomass to release the pelletizer

Drum dryer leaves at least with a temperature Ti of substantially above 65 ° C. Subsequently, the biomass should in a further process step by means of hot air through at least one

Heavy goods transported and / or passed through a grinding device and crushed. For any necessary

Heating the biomass, it may be necessary to increase the temperature of the hot air, in particular with hot air at a temperature of 70 ° to 80 ° C, and to transport the biomass through at least one heavy material separator and at the same time to heat and / or by a

Through grinding mill to lead, crush and heat there. It would also be advantageous, alternatively or in combination with the previous method steps, to charge the biomass with hot air, in particular with hot air at a temperature above 65 ° C., in at least one silo and / or in a discharge device associated with the silo. to

Energy savings may be needed further

the biomass is separated in a further process step after the grinding device and / or a heavy material separator in a cyclone from the hot air, with insufficiently comminuted parts of the biomass of the grinding device recycled and / or the separated hot air are fed via a hot air return of the heater. It is energetic depending on the starting temperature of the dryer, the hot air for the means of transport, the heavy material separator, the grinding device, the silo and / or the cyclone is heated at least to the temperature of the biomass.

Further advantageous measures and embodiments of the subject matter of the invention will become apparent from the subclaims and the following

Description with the drawing out.

The biomass 1 used and produced consists partly of

Sawmills and other types of fabrication as waste product resulting chips or chips, which are delivered on trucks. In large-scale pellet production, it is necessary to hit

Tree stock, which by means of so-called

Cutting machines to chips or chips is crushed. These are introduced into a dryer 2 after a first preparation, possibly even a mechanical drainage. Preferably, drum dryer are provided in the large-scale industrial pellet production, which are characterized by large flow rates and uniform outlet temperature Ti of the biomass 1. A dryer 2 in drum design is supplied with a dryer supply 11, which is preferably circulated and this is separated after the dryer 2 by a dryer cyclone 10 of the biomass 1. The dryer air is usually strong

Dust-loaded and even loaded with pollutants due to drying and is replaced either completely or in a circulation application of the dryer supply 11 (dashed line) in parts regularly. The moist and dust-enriched dryer air is usually pre-cleaned in an exhaust air purification system 12 before it can be discharged as exhaust air 25 to the environment.

The biomass 1 passes from the dryer cyclone 10 via a lock 13, usually a rotary feeder, with a temperature Ti in the

Treatment area 23 and has after the treatment area 23 a temperature Τ ₄ / Τ ₄ · on.

In the treatment area 23 there is at least one device for carrying out a method step, which may include sorting, classification, grinding, separation of heavy substances and much more. Also, the transport of the biomass 1 between the dryer 2 and the pelleting press 8 is evaluated in this context as a process step, as well as the storage in a silo 6, although the latter is not shown in the overview drawing. The overview drawing primarily represents a simplified system with a process stage between the dryer 2 and the pelleting press 8. The course of the process is read on the basis of the continuous process arrows as follows. After the lock 13, the biomass 1 is transported at a temperature T1 in a grinding device 4, in the grinding device 4, this is a hot air with a

Temperature T2 from the Heizvorichtung 15 applied, the biomass 1 then has a temperature T3, preferably at least the temperature T1 is equal to or even higher and is transferred with the hot air in the cyclone 5. The cyclone 5 separates the hot air one

Temperature T6 from the biomass 1 and transfers the hot air back into the heater 15 for reheating to the temperature T2, if necessary. The biomass 1 is discharged after cyclone 5 via a lock 13, preferably a rotary valve, from the treatment area 23 and at a temperature T4, which is above 60 ° Celsius, preferably above 65 ° C, is fed to a pelleting press 8. After pelleting the biomass 1 into pellets 9, these are stored in a pellet cooler 17 or passed through and cooled. The waste heat 18 with a temperature T7 can be fed back to the heater 15 via an optional heat exchanger 19 with a temperature T8 to maintain the temperature T1 of the biomass 1 after the dryer 2 or even to heat. The latter possibility is an extension of the hot air circulation of the treatment area 23, which may be used alternatively or in combination. The cycle has a correspondingly necessary

Fresh air intake on and regularly in parts or completely becomes the

Hot air in the circulation, preferably before or in the area of the heating device 15, in an exhaust air purification device (not shown) cleaned and discharged as exhaust air 25 to the environment.

In an alternative embodiment, in the use of a silo 6 for storage of the biomass 1 with an associated Discharge device 7 may or even should be elevated in temperature T4 'so that heat losses of biomass 1 during storage and discharge from silo 6 can be compensated and temperature T5 of the biomass before pelleting press 8, in conjunction with optional water entry through a spray device 22, the specifications and preferably above 60 ° C, preferably above 65 ° C, is.

In a further alternative embodiment, in

Treatment area 23 or as shown in the drawing, the biomass through a sieve 24, preferably configured as a flat screen. Again, it is advantageous if the entrained air is heated as hot air and at least the temperature of the biomass has 1 or even higher. The screen 24 is preferably used to screen off sand or particulate matter. Analogous to the use of a silo 6, a temperature T4 "and subsequently the biomass may also have a temperature T5 'in advance, the temperature T5' preferably being above 60 ° C., particularly preferably above 65 ° C.

In an optional embodiment of the double-dot dashed

Treatment area 23, the hot air already after the

Extraction of the biomass 1 after the lock 13 of the dryer cyclone 10 of the biomass as transport air or as ambient air with a

Temperature T2 of the biomass 1 on the way to the grinding device 4 are supplied. The dashed alternatives include other possible ones Additional applications of hot air, also in combination with several process steps. One of these steps is the additional arrangement of a heavy material separator 3 between the dryer 2 and the grinding device 4. The biomass is accordingly first a

Heavy separator fed to stones or too large chunks of

Biomass 1, preferably with harmful properties for the subsequent devices to excrete. However, a heavy material separator requires a large amount of air for turbulence of the biomass and cools the biomass accordingly in non-preheated hot air. Here, the teaching of the invention is particularly advantageous and leads the biomass 1 already acted upon with a hot air ambient air

Heavy material separator and / or causes the air turbulence in

The heater 15 is fresh air as supply air 14 and / or regenerated heat / air at a temperature T8 from the pellet cooler 17 and / or a hot air return 21 hot air from the cyclone 5 for heating and setting the Hot air supplied to the temperature T2. Also in the

Hot air used in the treatment area should and can be regularly exchanged for fresh air or can be filtered by means of a round filter 16 in parts or regularly. LIST OF REFERENCE NUMBERS

1. Biomass 14. Supply air

2nd dryer 15. Heating device

3. Heavy material separator 16. Round filter

4. Grinding device 17. Pellet cooler

5. Cyclone 20 18. Waste heat

6. Silo 19. Heat exchanger

7. Discharge device 20. fresh air

8. Pelleting press 21. Hot air return

9. Pellets 22. Water sprayer

10. Dryer cyclone 25 23. Treatment area

11. Dryer supply 24. Sieve

12. exhaust air purification device 25. exhaust air

13th lock

T _\ temperature biomass dryer after (before treatment area)

T ₂ temperature hot air for biomass

T ₃ temperature hot air / biomass

T ₄ temperature biomass after treatment area

T ₅ temperature biomass after storage in silo

T ₆ Hot air temperature after cyclone 16

T ₇ Temperature Air Waste heat (air) from pellet cooler

T ₈ temperature air after heat exchanger 19

Claims

claims

Process for the production of pellets (9) from biomass (1) in a pelleting press (8) for use as fuel in

Fireplaces, where the biomass (1) consists of cellulose and / or lignocellulosic fibers, shavings or chips, the biomass (1) is heated and dried during production in a dryer (2) which has been dried and heated

Biomass (1) is separated from the dryer air and the

Biomass (1) is fed to a pelleting press (8),

wherein the temperature of the biomass (1) in one

Treatment area (23) between the dryer (2) and the pelleting press (8) is heated or substantially obtained with hot air and the treatment area (23) at least parts of the transport path and / or at least one further apparatus for performing at least one additional method step comprises and the temperature of the hot air exceeds at least 65 ° Celsius.

Method according to claim 1, wherein the temperature of the hot air is set with a heating device, wherein the heating device (15) fresh air as supply air (14) and / or preheated air from at least one

Hot air return (21) and / or preheated air from one Heat exchanger (19) of the waste heat (18) of a pellet cooler (17) after the pelleting press (8) used.

A method according to claim 1 or 2, characterized in that in the treatment area (23) the at least one device for carrying out at least one further

Process step, a heavy material separator (3) for the separation of heavy material and / or a grinding device (4) for comminuting the biomass (1) and / or a cyclone (5) for separating the hot air from the biomass (1).

Method according to one or more of the preceding

Claims, characterized in that at least one device for carrying out at least one further

Process step and the heater (15), the hot air in the treatment area (23) lead in a substantially closed circuit.

5. The method according to claim 4, characterized in that the hot air is exchanged in the circulation of the treatment area (23) at least in parts regularly and / or filtered. Method according to one or more of the preceding claims, characterized in that the temperature of the hot air is adjusted such that the biomass (1) reaches the pelleting press at a temperature (T4 / T5) of above 65 ° C.

Method according to one or more of the preceding claims, characterized in that the biomass (1) leaves the drum dryer at a temperature (T-i) substantially above 65 ° C.

Method according to one or more of the preceding claims, characterized in that the biomass (1) is transported in a further process step by means of hot air through at least one heavy material separator (3) and / or passed through a grinding device (4) and crushed.

9. The method according to one or more of the preceding

Claims, characterized in that biomass

(1) in a further process step by means of hot air,

in particular with hot air at a temperature of 70 ° to 80 ° C, transported by at least one heavy material separator (3) and heated and / or passed through a grinding device (4), crushed and heated.

Method according to one or more of the preceding

Claims, characterized in that biomass (1) in a further process step with hot air, in particular with hot air at a temperature above 65 ° C, in at least one silo

(6) and / or in a silo (6) associated discharge device

(7).

Method according to one or more of the preceding

Claims, characterized in that

the biomass (1) is separated from the hot air in a further process step after the grinding device (4) and / or a heavy material separator (3) in a cyclone (5), whereby insufficiently comminuted parts of the biomass (1) are returned to the grinding device (4) and / or the separated hot air over a

Hot air return (21) of the heater (15) are supplied. 12. The method according to one or more of the preceding

Claims, characterized in that the biomass (1) at least partially during transport and / or storage between the individual processing stages by means of hot air and / or sufficient insulation against the

Ambient temperature approximately at the same

Temperature level is maintained or heated.

Method according to one or more of the preceding

Claims, characterized in that the hot air for the transport, the heavy material separator (3), the grinding device (4), the silo (6) and / or the cyclone (5) at least on the

Temperature of the biomass (1) is heated.

Method according to one or more of the preceding

Claims, characterized in that the

Biomass (1) substantially shortly before the pelleting press (8) supplied water, in particular sprayed.

Method according to one or more of the preceding

Claims, characterized in that the water before or during the supply to the biomass (1) to a

Temperature of above 65 ° C, preferably to above 80 °, especially preferably to 90 ° C, is warmed up.

16. The method according to one or more of the preceding

Claims, characterized in that the water with the biomass (1) after application to the biomass (1) is heated by radiant energy.

Plant for the production of pellets (9) from biomass (1) in a pelleting press (8) for use as fuel in

Fire stations, wherein the biomass (1) consists of cellulose and / or lignocellulosic fibers, shavings or chips, for drying and heating the biomass (1) a dryer (2) with a lock (13) for separating the dryer air in

Production direction in front of the pelleting press (9) is arranged, wherein in the system at least one treatment area (23) between the lock (13) and the pelleting press (9) is arranged and this treatment area (23) at least one

Transport means for transporting the biomass (1) between the dryer (2) and the pelleting press (9) and / or at least one device for carrying out at least one further

Process step is arranged, the treatment area (23) associated at least one heating device (15) for heating and / or provision of hot air of substantially above 65 ° C is arranged, wherein the heating device (15) at least once with the transport and / or with a device for performing further process steps for supplying the hot air is operatively connected. Plant according to claim 17, characterized in that in the system at least in parts to the

Transport devices and / or on at least one silo and / or on at least one device for the method steps to the ambient temperature insulation are arranged.

Plant according to claim 17 or 18, characterized

characterized in that in the Behanldungsbereich (23) as devices for carrying out at least one further

Method step, a heavy material separator (3) for separating heavy material and / or a grinding device (4) for comminuting the biomass (1) and / or a silo (6) and / or a sieve (24) and / or a cyclone (5) Deposition of the hot air from the biomass (1) are arranged.

Installation according to one or more of claims 17 to 19, characterized in that for storage of the biomass (1) a silo (6) with an associated discharge device (7) is arranged.

21. Plant according to one or more of claims 17 to 20,

characterized in that for establishing a closed circuit of the hot air in the treatment area (23) a hot air return (21) is arranged.

Installation according to one or more of Claims 17 to 21, characterized in that a pellet cooler (17) is used for storage and cooling of the pellets (9) produced.

is arranged, which is arranged with the heating device (15) and / or a heat exchanger (19) for reuse of the waste heat (18).

Installation according to one or more of claims 17 to 22, characterized by

the implementation of the method according to claim 1.