U.S. patent application number 13/816074 was filed with the patent office on 2013-06-27 for method for processing solid and liquid wastes from the production of vegetable oil.
This patent application is currently assigned to LURGI GMBH. The applicant listed for this patent is Ingo Bauer, Rudolf Bonsch, Manfred Hoffmann, Helmut Saft, Wolfgang Schmidt, Eckhard Seidel. Invention is credited to Ingo Bauer, Rudolf Bonsch, Manfred Hoffmann, Helmut Saft, Wolfgang Schmidt, Eckhard Seidel.
Application Number | 20130160355 13/816074 |
Document ID | / |
Family ID | 44484962 |
Filed Date | 2013-06-27 |
United States Patent
Application |
20130160355 |
Kind Code |
A1 |
Bonsch; Rudolf ; et
al. |
June 27, 2013 |
Method for Processing Solid and Liquid Wastes from the Production
of Vegetable Oil
Abstract
A method for processing solid, organic wastes obtained in the
production of vegetable oil, for example the production of palm
oil, chiefly consisting of pressing residues of the oil plants
and/or oil seeds and oil-containing waste water by hydrothermal
carbonization (HTC), wherein the oil present in the waste water in
emulsified form is sorbed by the solids rich in carbon, which are
obtained from the solid wastes.
Inventors: |
Bonsch; Rudolf; (Frankfurt
am Main, DE) ; Seidel; Eckhard; (Frankfurt am Main,
DE) ; Schmidt; Wolfgang; (Frankfurt am Main, DE)
; Bauer; Ingo; (Frankfurt am Main, DE) ; Saft;
Helmut; (Niddatal, DE) ; Hoffmann; Manfred;
(Wehrheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bonsch; Rudolf
Seidel; Eckhard
Schmidt; Wolfgang
Bauer; Ingo
Saft; Helmut
Hoffmann; Manfred |
Frankfurt am Main
Frankfurt am Main
Frankfurt am Main
Frankfurt am Main
Niddatal
Wehrheim |
|
DE
DE
DE
DE
DE
DE |
|
|
Assignee: |
LURGI GMBH
Frankfurt am Main
DE
|
Family ID: |
44484962 |
Appl. No.: |
13/816074 |
Filed: |
April 29, 2011 |
PCT Filed: |
April 29, 2011 |
PCT NO: |
PCT/DE2011/000463 |
371 Date: |
March 11, 2013 |
Current U.S.
Class: |
44/589 |
Current CPC
Class: |
Y02W 10/37 20150501;
C05F 5/004 20130101; Y02E 50/30 20130101; Y02P 20/145 20151101;
Y02A 40/209 20180101; Y02A 40/21 20180101; C05F 5/002 20130101;
Y02A 40/20 20180101; C10L 9/086 20130101; Y02E 50/10 20130101 |
Class at
Publication: |
44/589 |
International
Class: |
C10L 5/44 20060101
C10L005/44 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 12, 2010 |
DE |
102010034135.5 |
Claims
1. A method for processing solid, organic wastes and waste water
obtained in the production of vegetable oil, wherein the solid
wastes comprise pressing residues of oil fruits or oil seeds and
the waste water contains vegetable oil residues beside other
organic impurities, which are present in the waste water in
emulsified form, wherein the solid, organic wastes are comminuted
and in a stirred, heated reactor mixed with the waste water to form
a suspension, the pH value of the suspension is adjusted in the
acidic range, the atmospheric oxygen is removed from the reactor by
flushing with inert gas, the reactor is closed gas-tight and the
suspension is heated to at least 170.degree. C. and kept at
elevated pressure for at least 0.5 hours, wherein the solid,
organic wastes chiefly are converted to a solid material rich in
carbon, and wherein the emulsion of waste water and vegetable oil
residues is broken and the oil is sorbed by the obtained solid
material rich in carbon, and wherein subsequently the suspension is
cooled, removed from the reactor and separated into a solids and a
waste water fraction.
2. The method according to claim 1, wherein the solid, organic
wastes are comminuted to a particle size of 2 to 5 cm.
3. The method according to claim 1 wherein the dry matter content
of the suspension before heating is adjusted to 10 to 40%.
4. The method according to claim 1 wherein the pH value of the
suspension, before heating, is adjusted to a value between 3.0 and
6.9.
5. The method according to claim 1 wherein inside the reactor,
before heating, an elevated pressure of 5 to 15 bar is generated by
introducing inert gas.
6. The method according to claim 1 wherein the suspension is heated
to and maintained at temperatures between 170 and 320.degree.
C.
7. The method according to claim 1 wherein the suspension is
maintained at over 170.degree. C. for a time between 0.5 and 16
hours.
8. The method according to claim 1 wherein the separation of the
suspension into a solids and a waste water fraction is effected by
means of mechanical separation methods.
9. (canceled)
10. (canceled)
11. The method according to claim 4 wherein the pH value of the
suspension, before heating, is adjusted to a value between 3.0 and
3.5.
12. The method according to claim 8 wherein the means of mechanical
separation is decantation, filtration or centrifugation.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a method for processing solid,
organic wastes obtained in the production of vegetable oil, chiefly
consisting of pressing residues of the oil fruits and/or oil seeds,
and of oil-containing waste water. This invention furthermore
relates to the advantageous use of products of the method according
to the invention in the cultivation of oil palms, and for energy
generation. In particular, the invention is suitable for use in the
production of palm oil.
PRIOR ART
[0002] To satisfy the demand for fuel from renewable raw materials,
such as biodiesel, large palm oil plantations have been established
in the last few years, especially in Malaysia and Indonesia. What
is problematic in this development, beside the loss of primeval
forest areas for establishing these plantations, is the large
amount of solid and liquid waste obtained in the palm oil
production.
[0003] When pressing out the palm oil in the oil mill, about 1.2 t
of pressing residues are left per ton of palm oil produced,
consisting of fruit fibers and palm seed husks, so-called Empty
Fruit Bunches (EFB).
[0004] Due to water washing of the palm oil pressed out in the oil
mill, about 3 to 4 m.sup.3 of waste water per ton of palm oil
produced are obtained at the same time, so-called Palm Oil Mill
Effluent (POME). The waste water obtained is loaded with organic
constituents, such as oil, fatty acids and carbohydrates. The
problem is that the organic constituents form a stable oil/water
emulsion with the water, which complicates the further treatment of
water.
[0005] The solid wastes usually are burnt for generating energy for
the oil mill, which involves strong smoke development and therefore
is a great burden for man and the environment.
[0006] The waste water from the oil production is collected in
waste water ponds. The organic substances in part are biodegraded
anaerobically, which beside a strong odor nuisance by sewer gases
leads to the formation of the gases carbon dioxide and methane,
which are harmful to the climate. To avoid these disadvantages, the
smoke development during the combustion of the solid wastes and the
environmental impact of the biological waste water clarification,
F. Schuchardt describes a method in which the treatment of the
waste water by anaerobic, biological reactions is carried out in a
fermentation reactor, so that the resulting gases carbon dioxide
and methane can be trapped and be utilized in a climate-friendly
manner. The waste water thus purified then is mixed with the
biological solid wastes in compost heaps and composted to
fertilizer. What is important for this method is the use of a
special high-performance fermenter or a fixed-bed reactor and for
the operation of the compost heaps the use of a special turning
machine for the intensive mixing of the compost; F. Schuchardt,
Bundesforschungsanstalt fur Landwirtschaft, Forschungs-Report
2/2007; Dr. F. Schuchardt, Bio-Solar Biogas-Fachtagung
"Regenerative Energie vom Bauernhof", May 2, 2003 in Heiden; M.
Bockisch, Fats and Oils Handbook, AOCS Press, 1993.
DESCRIPTION OF THE INVENTION
[0007] While by methods according to the prior art the wastes are
converted into compost and biogas, an alternative method should be
provided by the present invention, which converts the wastes into
water containing nutrients, which is suitable for watering the oil
plant plantation, and a carbonaceous solid fuel, which e.g mixed
with heating oil, is suitable for energy generation by
combustion.
[0008] The object is solved by a method according to the
characterizing part of claim 1 in cooperation with the features of
its generic part. Further advantageous aspects of the invention can
be taken from the sub-claims. In the method according to the
invention, the solid organic wastes are comminuted and in a
stirred, heated reactor mixed with the waste water to form a
suspension, the pH value of the suspension is adjusted in the acid
range, the atmospheric oxygen is removed from the reactor by
flushing with inert gas and the reactor is closed air- and
pressure-tight, and the suspension is heated to at least
170.degree. C. and kept at elevated pressure for at least 0.5
hours, wherein the solid, organic wastes chiefly are converted to a
solid material rich in carbon, and wherein the oil originally
contained in the waste water is sorbed by the obtained solid
material rich in carbon, and wherein subsequently the suspension is
cooled, removed from the reactor and separated into a coal and a
waste water fraction.
[0009] The conversion of biomass into solid products rich in
carbon, for example coal or coal precursors such as humus, peat and
lignite, is known under the term "Hydrothermal Carbonization" or
"HTC" and described in the specialist article "Zauberkohle aus dem
Dampfkochtopf", Max Planck Forschung 2/2006, pages 20-25 and in the
document WO 2008/113309. An advantage of this method consists in
that biomass is converted into coal or its precursors peat, humus,
lignite, without carbonaceous waste gases such as carbon dioxide or
methane being produced. As the only waste product water is
obtained, which possibly still contains dissolved by-products of
the HTC reaction.
[0010] In the present case of application, the processing of solid
and liquid waste substances of the production of vegetable oil, to
be observed by way of example in the production of palm oil, it is
however not obvious to use the hydrothermal carbonization, since
here water and biomass are not present as separate starting
substances, as described in the prior art of the HTC process, but
an extremely stable oil/water emulsion and the pressing residues of
the oil fruits and/or oil seeds are available as biomass to be
used.
[0011] As our own experiments have shown, the oil/water emulsion is
so stable that it cannot be broken by usual measures such as the
addition of surfactants, boiling, acidifying to a pH value of 2,
centrifuging or the addition of activated carbon. The reason for
the high stability of this emulsion probably are the free fatty
acids and glycerides likewise present in the waste water, among
them in particular the monoglycerides, which represent very
effective emulsifiers. Accordingly, it could not be expected that
the emulsion would be broken by the HTC process and hence the one
important problem of this waste processing, the treatment of the
waste water loaded by the oil/water emulsion, would be solved.
[0012] Contrary to this assumption, the experiments however have
led to the surprising result that by the HTC process the waste
water of the palm oil production, which is loaded with organic
impurities, is converted into an oil-free water advantageously
loaded with the salts and minerals originating from the plant
remains, which water is quite suitable for watering the palm oil
plantations. The oil originally contained in the loaded waste water
is sorbed by the solids rich in carbon obtained from the plant
remains. While carrying out the HTC process, the splitting of the
emulsion obviously is effected by the chemical and/or biological
processes during the conversion of the biomass into coal.
[0013] The fundamental and well-known chemical processes of the HTC
process consist in that hydrogen and oxygen atoms are extracted
from the compounds in which they are present in the biomass, e.g.
glucose, and combine to H.sub.2O. In order to not impair these
chemical processes, the process must must be carried out under
exclusion of air. Residue air must be removed from the reactor by
flushing with inert gas before heating the suspension. The energy
balance of these chemical processes on the whole is positive, but
the concrete height of the energy gain of course depends on the
kind of biomass used. Beside the energy balance of the chemical
processes, however, the energy balance of the technical processes
of the method must also be observed. For example, much heating
energy is required, because the HTC process only proceeds with
economic speed above 170.degree. C. In addition, because of the
high temperature level at which the HTC process takes place, a good
heat insulation of the reactors is required.
[0014] To operate the process uniformly and with a high conversion
rate of the biomass, energy also is required for constantly
intermixing the feedstocks. To economically operate the HTC
process, it is also important to use the energy produced by the
chemical processes for heating to the maximum possible extent.
Therefore, it is recommendable in principle to operate the process
with several reactors in parallel offset in time and with a common
heating system. The process in principle can be carried out both
intermittently and continuously or semicontinuously, wherein in the
two last-mentioned cases suitable measures must be taken for
supplying the educts and for discharging the products.
Preferred Aspects of the Invention
[0015] To create a sufficiently large surface of the solid
particles for the economic conversion of the solid wastes from the
production of vegetable oil, it is advantageous to comminute the
solid organic wastes to a suitable particle size, before mixing the
same into the waste water loaded with organic impurities. In the
case of the application of the method in the production of palm
oil, a particle size of 2 to 5 cm was found to be particularly
suitable.
[0016] To be able to provide sufficient thermal energy for
maintaining the process temperature of at least 170.degree. C., it
is advantageous to adjust the dry matter content of the suspension
before heating to 10 to 40%.
[0017] The chemical processes of the HTC process proceed at an
accelerated rate in an acidic environment. Therefore, the pH value
of the suspension before heating advantageously should be adjusted
to a value between 3.0 and 6.9, preferably to 3.0 to 3.5. However,
it is required to neutralize the oil-free water obtained by the
method, before using the same for watering the oil plants.
Preferably, KOH is used for this purpose.
[0018] To avoid too strong boiling of the suspension in the
reactor, which can lead to the soiling of the reactor cover and of
measuring and safety valve ports present in the cover, it is
advantageous when inside the reactor, prior to heating, an elevated
pressure, preferably of 5 to 15 bar, is generated by introducing
inert gas.
[0019] To allow the HTC process to proceed with economic speed, the
adjustment of an elevated operating temperature is required. Too
high temperatures on the other hand should be avoided, since they
put strain on the apparatuses and fittings used and lead to
unnecessary energy losses. Therefore, it is advantageous to carry
out the method at an operating temperature between 170 and
320.degree. C.
[0020] In dependence on the desired degree of conversion (so-called
degree of coalification) of the used solid, biological wastes to
peat, humus, lignite and/or hard coal, the residence time of the
suspension at operating temperature should be chosen. For the
present case of application, in which a fuel should be obtained as
product of the process, a maximum possible conversion of the
biomass into a solid material rich in carbon, such as coal, is
desired. Residence times between 0.5 and 16 hours were found to be
advantageous.
[0021] At the end of the HTC process, the separation of the
suspension into a solid and a waste water fraction is effected by
means of mechanical separation methods, preferably the decantation,
filtration or centrifugation, or combinations thereof.
[0022] A preferred development of the invention consists in the use
of the solid product rich in carbon as fuel, which can be used
alone or in admixture to other fuels, e.g. as suspension after
mixing into heating or heavy oil.
[0023] A further preferred development of the invention consists in
the use of the treated waste water for watering plants, preferably
oil plants, wherein the waste water first is neutralized,
preferably with KOH.
INDUSTRIAL APPLICABILITY
[0024] The invention provides a method for processing solid and
liquid wastes from the production of vegetable oil, which is
characterized by its technical simplicity and in which products are
obtained, which are unproblematic as regards their disposal or
which even can advantageously be reused at the site of the oil
plantation. Especially these advantages render the use of the
method according to the invention attractive for the palm oil
production in tropical countries.
* * * * *