U.S. patent application number 13/877730 was filed with the patent office on 2013-08-29 for method for processing biomass.
The applicant listed for this patent is Hans-Joachim Boltersdorf. Invention is credited to Hans-Joachim Boltersdorf.
Application Number | 20130221140 13/877730 |
Document ID | / |
Family ID | 45832626 |
Filed Date | 2013-08-29 |
United States Patent
Application |
20130221140 |
Kind Code |
A1 |
Boltersdorf; Hans-Joachim |
August 29, 2013 |
METHOD FOR PROCESSING BIOMASS
Abstract
The invention relates to a method for processing biomass, such
as in particular green waste containing wood, and a high density
pulper having a spiral, wherein the green waste is treated in a
continuously operated, bladed pulper and then the separated fibers
are ground in a pulper ball mill.
Inventors: |
Boltersdorf; Hans-Joachim;
(Brohl-Luetzing, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boltersdorf; Hans-Joachim |
Brohl-Luetzing |
|
DE |
|
|
Family ID: |
45832626 |
Appl. No.: |
13/877730 |
Filed: |
September 21, 2011 |
PCT Filed: |
September 21, 2011 |
PCT NO: |
PCT/DE2011/001754 |
371 Date: |
April 22, 2013 |
Current U.S.
Class: |
241/23 ;
241/24.29; 241/28; 241/282.1 |
Current CPC
Class: |
D21B 1/14 20130101; D21B
1/04 20130101; D21B 1/345 20130101; D21B 1/12 20130101 |
Class at
Publication: |
241/23 ; 241/28;
241/24.29; 241/282.1 |
International
Class: |
D21B 1/12 20060101
D21B001/12; D21B 1/34 20060101 D21B001/34; D21B 1/14 20060101
D21B001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 5, 2010 |
DE |
10 2010 047 363.4 |
Feb 23, 2011 |
DE |
10 2011 012 191.9 |
Claims
1. A method for preparing biomass, such as in particular
wood-containing green waste, in which the biomass is treated in a
continuously operated, bladed pulper and then the separated fibres
are milled in a pulper ball mill.
2. The method according to claim 1, wherein the consistency in the
bladed pulper is from 10 to 20% dry content.
3. The method according to claim 1, wherein the speed of the blade
relative to the biomass in the bladed pulper is above 10 m/s.
4. The method according to claim 1, wherein the separated fibres
have a length between 1 mm and 5 mm.
5. The method according to claim 1, wherein the biomass is
processed dry before treatment in the continuously operated bladed
pulper.
6. The method according to claim 1, wherein the biomass is heated
before treatment in the continuously operated bladed pulper.
7. The method according to claim 6, wherein the biomass is heated
under pressure.
8. The method according to claim 6, wherein the biomass is kept hot
for several hours.
9. The method according to claim 1, wherein the separated fibres
are concentrated on a screening machine and freed from fine
material which impedes the milling process after it has been
treated in the continuously operated bladed pulper.
10. The method according to claim 1, wherein the separated fibres
are milled in a fibrillating manner in the pulper ball mill.
11. The method according to claim 1, wherein the separated fibres
are milled in the pulper ball mill with lightweight balls which
have approximately the density of plastic.
12. The method according to claim 1, wherein the oversize material
of the continuously operated bladed pulper is milled in a second
pulper ball mill with heavy balls which have approximately the
density of steel, stone or ceramic.
13. The method according to claim 1, wherein a post-sorting process
takes place after the fibrillating milling.
14. A high-consistency pulper having a spiral, wherein the spiral
has blades with a cutting edge having a radius of less than 1 mm.
Description
[0001] The invention relates to a method for preparing biomass,
such as in particular wood-containing green waste, and a
high-consistency pulper having a spiral.
[0002] A specific method is required in particular for processing
biomass in pulpers for producing cellulose and wood pulp fibres for
paper production, as the biomass must be processed thoroughly in
order to release the cellulose fibres and the process must be
conducted in such a manner that cellulose fibre lengths which are
suitable for paper production are obtained.
[0003] The invention is therefore based on the object of providing
a method for preparing biomass, with which fibres of specific
length and properties, in particular for paper production, can be
obtained.
[0004] This object is achieved with a method for preparing biomass,
such as in particular wood-containing green waste, in which the
biomass is treated in a continuously operated, bladed pulper and
then the separated fibres are milled in a pulper ball mill.
[0005] The specific combination of bladed pulper with the treatment
in a pulper ball mill surprisingly led to a method with which
biomass can be treated in a particularly simple manner to provide
fibres. Fibres can therefore be provided for a variety of uses
depending on the treatment step and configuration of the bladed
pulper and of the balls for the ball mill.
[0006] It is advantageous if the bladed pulper is operated as a
high-consistency pulper. An advantageous consistency in the bladed
pulper is therefore from 10 to 20% dry content.
[0007] The speed of the blade relative to the biomass is of great
relevance. Particularly good results have been achieved with blade
speeds of over 10 m/sec relative to the biomass.
[0008] It is ideal for use of the fibres in the paper industry if
the separated fibres have a length between 1 mm and 5 mm.
[0009] It is advantageous, in particular if the biomass has a high
content of woody constituents, if the biomass is processed dry
before treatment in the continuously operated bladed pulper. To
this end, a rapidly rotating blade, such as in a lawnmower, can be
used with subsequent dry screening in addition to feedback of the
oversize material. This means that a classical mill/classifier
system is used and, for example, the biomass produced is separated
in the form of for example wood chips and for example fed to a
biomass combined heat and power plant.
[0010] It is advantageous, in particular if the biomass has wood
constituents, if the biomass is heated before treatment in the
continuously operated bladed pulper. This also makes it possible to
treat wood waste, green waste with wood-containing parts and even
comminuted wood and wood chips.
[0011] To ensure that water penetrates into the wood or
wood-containing constituents, it is proposed that the biomass be
heated under pressure. An autoclave can be used for this.
Continuous heaters can however also be used. In the process, water
can be supplied and steam can be let out in order to influence the
processes during heating.
[0012] It is advantageous if the biomass is kept hot for several
hours. If no steam is let out, it is sufficient to bring the
biomass preferably under pressure to a temperature of for example
between 100.degree. C. and 200.degree. C., so that the biomass
becomes soft and thereby easier to handle.
[0013] It is proposed in particular for the wood pulp milling that
the separated cellulose fibres be concentrated on a screening
machine and freed from fine material which impedes the milling
process after it has been treated in the continuously operated
bladed pulper.
[0014] Particularly good results are achieved by milling the
separated fibres in the pulper ball mill in a fibrillating
manner.
[0015] To treat the separated fibres it is proposed that these
fibres be milled in the pulper ball mill with lightweight balls
which have approximately the density of plastic. The separated
fibres are thus subjected to careful treatment in a pulper ball
mill as undersize material.
[0016] It is furthermore advantageous if the oversize material of
the continuously operated bladed pulper is milled in a pulper ball
mill with heavy balls which have approximately the density of
steel, stone or ceramic.
[0017] Depending on the result, it can be advantageous if
post-sorting takes place after the fibrillating milling.
[0018] Known blades in pulpers have edges of a few millimetres
radius. These blades act as impact discs. They move the biomass
inside the pulper as pulper drivers. There is no or only an
insignificant amount of cutting. In contrast to this, for the
method according to the invention, a high-consistency pulper with a
spiral is proposed, in which the spiral has blades with an edges
having a radius of less than 1 mm.
[0019] The present invention is based on the finding that it is
expedient to use blades having a particularly sharp cutting edge in
a high-consistency pulper. Sharp blades such as trimming knives or
other sharp blades can be used as the cutting edges.
[0020] Two method schemata for preparing biomass are shown in the
drawing and are described in more detail below.
[0021] FIG. 1 schematically shows a method with a bladed pulper and
a pulper ball mill and
[0022] FIG. 2 schematically shows a method with a bladed pulper and
two pulper ball mills.
[0023] The method shown in FIG. 1 is particularly suitable for
green waste such as grass. This method is very advantageous, as the
majority of the cellulose fibres which can be used for paper
production can be exposed with it.
[0024] In the method schema T shown in FIG. 1, the first method
step 2 is a dry preparation step. To this end, a rapidly rotating
blade 3 is provided, which comminutes the green waste conveyed on
the belt 4 like a lawnmower.
[0025] This is followed by a dry screening step 5, to which the
oversize material 6 is fed back. Periodically occurring biomass in
the form of wood chips 7 is disposed of by means of the trolley 8
and for example fed to a combined heat and power plant.
[0026] The undersize material 9 is fed to the high-consistency
pulper 10 and treated there according to the kappa effect. The
supplied undersize material 9 is cut using a bladed spiral 11 and
the cut undersize material 12 is removed underneath a screen plate
13.
[0027] The bladed spiral 11 of the pulper 10 acting as the reactor
is driven at high rotation speeds in order to achieve high cutting
speeds.
[0028] A perforated plate with hole diameters of approx. 1 to 4 mm,
for example 1.5 mm, is provided as the screen plate 13. The fibrous
material is thereby extracted as cut undersize material 12. The
pulper 10 is operated as a reactor in such a manner that the
relatively long green waste are shortened to a length of approx. 5
to 6 mm which is expedient for paper production.
[0029] While the first main method step relates to cutting the
fibres in the bladed reactor 10, the second main method step is
fibrillating milling of the fibres in a continuously operated
pulper ball mill 14. This pulper ball mill 14 has hole diameters of
approximately 2 mm in the perforated plate 15, a spiral 16 and
balls 17 which have approximately the density of plastic. During
this fibrillating milling, the fibres are roughened in such a
manner that they have a good connection to each other during later
paper production.
[0030] This second process step in the pulper ball mill 14 is
preferably operated in a two-stage manner. The fibrous material to
be milled is milled with the addition or through-flow of relatively
little water until the desired increase in strength is achieved. In
a second step, the fibres are washed out of the ball fibre mixture
using a relatively large amount of water.
[0031] In case there are particles in the washed-out fibrous
material 18 which have an unsuitable size for paper production,
post-sorting (classification) is carried out in a slotted sorter
19, which has slots of <0.3 mm in the sorting plate 20. The
cleaned fibrous material 21 is then removed from the classifier 19,
while the larger particles 22 are removed by means of the trolley
23.
[0032] The method shown in FIG. 1 with the two main method steps in
the bladed pulper 10 and ball mill 14 can also be replaced by a
three-stage method. This method step is shown in FIG. 2 without the
pre- and post-treatment shown in FIG. 1.
[0033] In the method schema 30 shown in FIG. 2, a screening machine
34 is provided between the reactor 31 with the bladed spiral 32 and
the pulper ball mill 33 in order to concentrate the fibrous portion
35 removed as undersize material from the reactor 31 and to free it
from fine material 36 which would impede the milling process. The
oversize material 37 of the concentrator 34 is fed to the pulper
ball mill 33, which has lightweight balls such as plastic balls 38,
as explained in the example of FIG. 1.
[0034] After fibrillating milling in the pulper ball mill 33, the
milled fibrous material 8 exits the system for further use, in
particular for paper production.
[0035] The oversize material 39 in the pulper 31 with the bladed
spiral 32 is fed to a second pulper ball mill 40, which has heavier
milling bodies 41, a spiral 42 and a screen plate 43. The oversize
material 39 is subjected to a fibrillating milling process which
shortens the fibres and at the same time opens up the woody
constituents. The fibrous portion 44 then leaves the system.
[0036] A concentrator between the bladed pulper 10, 31 and the
pulper ball mill 14, 33, 40 can be arranged at any point between
these units. Owing to its washing properties, such a concentrator
removes the constituents which are unsuitable for paper, such as
ash, proteins, floury fine material, colloids etc. in order to
separate them from the fibrous material in an early method step and
feed them to another use. This includes the preparation of animal
feed or else fermentation to produce biogas. When the balls in the
pulper ball mills are selected, the diameters of the balls are 4 mm
and above. If smaller balls of around 2 mm are used, too much fine
material is produced, which impedes the process.
[0037] For the preparation of wood waste, wood-containing green
waste or wood chips, the biomass is first pretreated in an
autoclave. In this case the biomass is kept under pressure at
approx. 120.degree. C. in the autoclave for several hours, where
necessary with the addition of water. In the process the wood
becomes so soft that further treatment such as for green waste or
together with green waste can be carried out.
* * * * *