U.S. patent application number 10/076217 was filed with the patent office on 2003-02-06 for method and device for reducing the acidic pollutant emissions of industrial installations.
Invention is credited to Huber, Karheinz, Mueller, Martin.
Application Number | 20030027089 10/076217 |
Document ID | / |
Family ID | 26316695 |
Filed Date | 2003-02-06 |
United States Patent
Application |
20030027089 |
Kind Code |
A1 |
Mueller, Martin ; et
al. |
February 6, 2003 |
Method and device for reducing the acidic pollutant emissions of
industrial installations
Abstract
The invention relates to a method for reducing the acidic
pollutant emissions, in particular the sulfur trioxide emission, of
industrial installations with at least one burner for the
combustion of liquid fossil fuels. In particular, the invention
relates to flue gas neutralization in the combustion of heavy oils.
According to the invention, it is proposed that, before the
combustion, an emulsion of the fuel with a solution of a
magnesium-containing active ingredient or a magnesium compound is
formed, and led into the burner.
Inventors: |
Mueller, Martin;
(Halstenbek, DE) ; Huber, Karheinz; (Norderstedt,
DE) |
Correspondence
Address: |
William Bak
Howson And Howson
P.O. Box 457
Spring House
PA
19477
US
|
Family ID: |
26316695 |
Appl. No.: |
10/076217 |
Filed: |
February 14, 2002 |
Current U.S.
Class: |
431/4 ;
431/174 |
Current CPC
Class: |
F23K 5/10 20130101; F23K
5/12 20130101; C10L 1/328 20130101; F23K 2300/20 20200501 |
Class at
Publication: |
431/4 ;
431/174 |
International
Class: |
F23J 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 19, 2001 |
GR |
20010100091 |
Feb 19, 2001 |
GR |
20010100092 |
Claims
1. Method for reducing the acidic pollutant emissions, particularly
the sulfur trioxide emission, of industrial installations with at
least one burner for burning liquid fossil fuels, characterized in
that, before the combustion, an emulsion of the fuel is formed with
a solution of a magnesium-containing active ingredient or a
magnesium compound, and led into the burner.
2. Method for reducing the acidic pollutant emissions, in
particular the sulfur trioxide emission, of industrial
installations with at least one burner for burning liquid fossil
fuels, characterized in that, before the combustion, an aqueous
solution of a water soluble magnesium-containing active ingredient
or a magnesium compound is introduced into the fuel.
3. Method according to claim 1, characterized in that the solution
is introduced into the fuel at high pressure.
4. Method for reducing the acidic pollutant emissions, in
particular the sulfur trioxide emission, of industrial
installations with at least one burner for burning liquid fossil
fuels, characterized in that, an aerosol of an aqueous solution of
a water soluble magnesium compound is introduced into the
combustion gases.
5. Method according to claim 4, characterized in that the aerosol
is introduced into the combustion gases at several places along the
circumference of the combustion pipe, with the formation of an
umbrella of the aerosol, which covers the cross section at least
approximately completely.
6. Method according to one of claims 1-5, characterized in that the
magnesium-containing active ingredient or the magnesium compound
is, or contains, a salt of an organic or inorganic acid.
7. Method according to one of claims 1-6, characterized in that the
magnesium containing active ingredient or the magnesium compound
contains magnesium nitrate and/or magnesium acetate.
8. Device for reducing the acidic pollutant emissions, particularly
the sulfur trioxide emission, of industrial installations, with one
or a multitude of burners for burning liquid fossil fuels,
characterized in that at least one, and preferably each, burner is
associated with a metering device (10) and a feed device (8), which
opens into the fuel line (9) and which leads, into the liquid fuel,
a solution of a magnesium compound from a central supply container
(5) with formation of an emulsion with the fuel.
9. Device according to claim 8, characterized in that the
introduction device opens into the fuel line in the flow direction
of the fuel downstream from the fuel reconduction.
10. Device according to one of claims 8 or 9, characterized in that
the feed device opens into the fuel line in the flow direction of
the fuel a short distance upstream from the burner nozzle.
11. Device according to one of claims 8-10, characterized in that
the solution is led under pressure into each burner, and in that
each metering device comprises an adjustment valve (10).
12. Device for the reduction of the acidic pollutant emissions, in
particular the sulfur trioxide emission, of industrial
installations, with one or a multitude of burners for burning
liquid fossil fuels, characterized in that in at least one, and
preferably in each combustion pipe and/or flue gas duct and/or
boiler passage, at least one nozzle (11) with pressurized air inlet
(12) is arranged, which nozzles are supplied from a central
delivery container (5) with a solution of a magnesium compound,
which solution is introduced into the combustion gases through a
nozzle with pressurized air and with the formation of an aerosol.
Description
DESCRIPTION
[0001] The invention relates to a method for reducing the acidic
pollutant emissions, particularly the sulfur trioxide emissions, of
industrial installations with at least one burner for burning
liquid fossil fuels. In particular, the invention relates to flue
gas neutralization in the burning of heavy oils.
[0002] Flue gas neutralization in the burning of fossil fuels has
been carried out for a long time to reduce the SO.sub.3 content in
the flue gas. A minimization of the SO.sub.3 content decreases the
tendency to soiling and the corrosion in the high and low
temperature region of the boiler. In addition, the emission of rust
flakes is avoided, and the surfaces of the boiler, which remain
clear and which are clean, allow a more effective heat
transfer.
[0003] It is known to add a neutralizing additive in the form of
magnesium oxide powder to the fuel. Here the reactivity of the
magnesium oxide depends essentially on the particle size of the
added powder. However, there are limits to the SO.sub.3 reduction
in this process. The limits have a value of approximately 30%.
[0004] From EP 0 426 978 A1 it is known to add magnesium containing
active ingredients in the form of a solution which is miscible with
the liquid fuel. It is also known to add metallic soaps to the
fuel. By these measures, the SO.sub.3 reduction can be clearly
improved to approximately 60%.
[0005] Furthermore, in principle, it is known to reduce the
pollutant emissions not only by additives, which are added to the
liquid fuel, but also by additives which are added to the flue gas.
In the above mentioned patent, EP 0 426 976 A1, a method is
disclosed in which a urea-containing and ammonia releasing
reduction agent is led into the flue gases for reducing the content
of oxides of nitrogen. From DE 44 17 874 C2 it is known to
introduce, through a nozzle, an aqueous solution of a magnesium
compound together with a NO.sub.x reduction agent into the furnace.
The purpose of this approach is to prevent the formation of
ammonium hydrogen sulfates.
[0006] Using oil soluble additives has the drawback that they
usually are combustible fluids. The fact that these additives are
in part toxic substances represents a drawback. However, in
particular, a drawback consists in that the entire magnesium
containing compound introduced cannot be reacted because a part of
the magnesium reacts with the fuel ash to form mixed oxides.
[0007] The invention is based on the problem of designing a method
and a device of the type described above in such a manner that, for
one thing, the handling of the additives used can be simplified.
For another thing, an improved reaction is to be achieved with a
view to recycling the introduced active ingredient.
[0008] According to the invention, the problem is solved by
forming, prior to the combustion, an emulsion of the fuel with a
solution of a magnesium-containing active ingredient or a magnesium
compound, which is then introduced into the burner. This emulsion
with the fuel can be formed, for example, with an aqueous solution
of a water soluble magnesium containing active ingredient or a
magnesium compound. As a result of this measure, the active
ingredient, namely the magnesium compound, is finely distributed in
its own liquid phase. The emulsion is finely divided in the fuel
nozzle with a result that almost the entire quantity of
magnesium-containing compound introduced can be reacted. No
reaction with fuel ash occurs.
[0009] An additional advantage in using such a solution, and in
particular, an aqueous solution of a water soluble magnesium
containing active ingredient, consists in that the latter is not
combustible. Therefore, the possibility exists of conveying the
solution, which is added to the fuel, over relatively large
distances within the industrial installation. Moreover, these
solutions usually are not toxic so that there is no risk of
environmental problems should a leak occur.
[0010] It is advantageous to introduce the solution into the fuel
at high pressure. The use of high pressure promotes the formation
of the emulsion in the fuel.
[0011] According to another embodiment variant of the invention,
this solution of a magnesium-containing active ingredient or a
magnesium compound is led into the combustion gases in the form of
an aerosol. Here too, the solution can be an aqueous solution of
water soluble magnesium compound. It is preferred to generate the
aerosol with pressurized air, which is led into the solution to be
introduced before the passage through a nozzle.
[0012] In the case of an aerosol as well, the magnesium-containing
active ingredient or the magnesium compound is in its own liquid
phase. Here too, a fine distribution of the liquid phase is
effected so that almost all the magnesium-containing compound, for
example MgSO.sub.4, can react.
[0013] It is advantageous if the aerosol is introduced into the
combustion gases at several places along the circumference of the
combustion pipe, the flue gas pipe or the boiler passage with the
formation of an umbrella of aerosol, which covers at least nearly
completely the entire cross section. This has the advantage that
the entire flue gas cross section is reached by the active
ingredient. The leakage of unneutralized flue gases can thus be
prevented or at least considerably reduced.
[0014] The magnesium-containing active ingredient, or the magnesium
compound, can be, or contain, the salt of an organic or inorganic
acid. One can also provide for the magnesium-containing active
ingredient or the magnesium compound to contain magnesium nitrate
and/or magnesium acetate.
[0015] Based on the preferred use of an aqueous solution of the
water soluble magnesium compound, this additive which is added by
metering can be conveyed without problem over longer distances
within industrial installations. Here the advantage of the
invention becomes particularly clear. One can use, in industrial
installations which comprise a multitude of burners for burning
liquid fossil fuels, a metering device and an introduction device
which are associated with each burner, where the introduction
device opens into the fuel line and, from a central delivery
container, it leads this solution of the magnesium compound into
the liquid with the formation of an emulsion with the fuel. The use
of a central delivery container has the advantage that the handling
and the use, as well as the refilling, of the solution by personnel
can be considerably facilitated. One need only ensure that the
central delivery container is always sufficiently filled with the
solution in question.
[0016] It is advantageous if the introduction device opens into the
fuel line in the flow direction of the fuel downstream from the
fuel reconduction of each burner. This has the advantage that an
undesired increase in the concentration of the solution in the fuel
is prevented.
[0017] Furthermore, one can provide for the feed device to open
into the fuel line in the flow direction of the fuel a small
distance upstream from the burner nozzle. As a result, it is
possible to prevent the re-agglomeration of the liquid phase of the
active ingredient which is present in the emulsion, to form larger
liquid drops. In principle, the added solution can also contain
emulsifiers. Fine distribution in the atomization of the emulsion
in the burner nozzle and a clean flame pattern are thus
maintained.
[0018] It is advantageous to lead the solution under pressure to
the individual burners, where each metering device comprises an
adjustment valve.
[0019] This too considerably facilitates the handling, because only
one pump is needed, which generates the required introduction
pressure. Adjustment values can be regulated in a simple manner and
controlled so that the required quantity of solution can be led to
each burner depending on its individual consumption.
[0020] The invention is explained in greater detail below with
reference to the diagrammatic drawings:
[0021] FIG. 1 shows a diagram of central additive feed in an
industrial installation with several burners;
[0022] FIG. 2 shows the diagram of an additive introduction in an
industrial installation with several combustion pipes into which
the additive is fed; and
[0023] FIG. 3 shows a cross section through a combustion pipe with
a multitude of nozzles for the introduction of the aerosol.
[0024] FIG. 1 shows a system for the introduction, into the fuel,
of an additive for reducing the acid pollutant emission of
industrial installations. There is a first delivery container 1
with a concentrate of the magnesium containing active ingredient or
the magnesium compound. This magnesium-containing active ingredient
can be, for example, a 20-60% magnesium acetate or magnesium
nitrate solution. It is considered to be advantageous to use a
dilution with water from 1:2 to 1:50, and in particular from 1:5 to
1:15. A second delivery container 2 is provided, which contains the
carrier water for the formation of an aqueous solution in the
desired final concentration of the solution to be introduced. In
principle, this second delivery container 2 can be replaced by a
central water supply.
[0025] The desired quantity of the concentrate from the delivery
container 1 and the desired quantity of the carrier water from the
delivery container 2 are led through a measurement device 3 and
pumps 4 into a delivery container 5. The delivery container 5 thus
contains the solution in the desired concentration, which is then
led to the burners. The delivery container 5 is connected with a
main distribution 6, which in turn is connected to a multitude of
sub-distributions 7. Each sub-distribution 7 is connected with one
or more feed devices 8, which open(s) into the fuel line 9 of a
burner which is not shown. The details of the arrangement are such
that the feed device 8 opens in the flow direction of the fuel,
upstream from the fuel nozzle and downstream from the fuel
reconduction into the fuel line 9. The feed device 8 also comprises
an adjustment valve 10, by means of which the desired quantity of
the aqueous solution is led into the fuel with the formation of an
emulsion.
[0026] Because the use of an aqueous solution of a water soluble
magnesium-containing active ingredient or a water soluble magnesium
compound makes it possible to convey within the industrial
installation over longer distances without problems, the addition
of the given quantity at the desired concentration can be carried
out by means of a simple valve control before each burner. In
particular, it is not necessary to provide each burner with its own
additive preparation installation with separate pump and separate
metering device. Rather, the solution which is led into the fuel
can be generated centrally, and mixed, and then it can be led
through a corresponding distribution device 6, 7 and corresponding
feed devices with metering devices 8, 10 into the fuel. As a
result, the control of the introduced additive and the operation of
the entire industrial installation are considerably simplified with
the use of neutralizing additives.
[0027] FIG. 2 represents the feed of additive into the flue gas in
an industrial installation with a multitude of combustion
installations to be supplied. As far as the principle of the design
is concerned, this additive feeding corresponds to the additive
feeding into the fuel, and the same components, or components
having the same effect, are denoted with the same reference
numerals.
[0028] From the supply container 5, the ready-mixed additive
reaches a main distribution 6, which is connected with a multitude
of sub-distributions 7. A sub-distribution 7 is connected with a
multitude of nozzles 11, through which the additive reaches the
combustion gas. The nozzles can be present in the combustion pipe
and/or in the flue gas duct and/or in the boiler pass of the
combustion installation. For example, one can provide for each
sub-distribution 7 to be allocated to a number of nozzles 11 which
are arranged in a combustion pipe. However, it is also possible for
one sub-distribution 7 to supply additive to nozzles in several
combustion pipes.
[0029] The additive is led in the form of an aerosol into the
combustion gases in the combustion pipe. For this purpose, the
nozzles 11 are provided with a pressurized air inlet 12 to generate
the aerosol. The pressurized air can be added to the additive at a
pressure of 3.0-10.0 and, in particular, 5.0-7.0 bar. As a result,
the aerosol can successively be injected over some distance through
a nozzle into the combustion pipe.
[0030] FIG. 3 shows a possible arrangement of the nozzles for the
introduction of the aerosol into the combustion pipe. The nozzles
11 are distributed essentially uniformly along the circumference
and they are directed toward the middle of the combustion pipe. In
principle, any other orientation of the nozzle is advantageous,
provided that an essentially complete umbrella of aerosol covers
the cross section. Overall, it is thus possible to achieve an
effective neutralization of the combustion gases.
[0031] FIG. 1 shows the introduction of an additive into the fuel.
FIGS. 2 and 3 show the introduction of an additive into the flue
gas. Both additives have the same active ingredient, mainly a
magnesium containing compound, which is preferably led in the form
of an aqueous solution into the fuel or into the combustion gases.
With reference to the quantity of fuel, one can carry out an
addition of, for example, 5-500 mg MgO per 1 kg fuel. The
introduced quantity, in both methods, is calculated depending on
the specific properties of the fuel and the sulfur trioxide content
in the waste gas. Here too, the formation of an emulsion on the one
hand, and of an aerosol on the other, result in the active
ingredient being present in its own liquid phase, which has an
advantageous effect on the reactivity of the active ingredient and
its complete reaction.
[0032] Naturally, it is also possible to use both methods in
combination. For this purpose, one can provide, for example,
downstream form the main distribution 6, a sub-distribution 7 for
feeding aerosol nozzles 11, while another sub-distribution 7
supplies the feed device 10 for metering into the fuel. Even if the
individual introduction devices or nozzles operate at a different
pressure, said pressure can be generated by a corresponding number
and a corresponding arrangement of throttle valves, or by
additional pumps.
* * * * *