U.S. patent application number 11/623330 was filed with the patent office on 2008-09-18 for system and method for zero emissions, hydrogen fueled steam generator.
Invention is credited to George Doland.
Application Number | 20080223315 11/623330 |
Document ID | / |
Family ID | 39761381 |
Filed Date | 2008-09-18 |
United States Patent
Application |
20080223315 |
Kind Code |
A1 |
Doland; George |
September 18, 2008 |
System and Method for Zero Emissions, Hydrogen Fueled Steam
Generator
Abstract
As we move towards a hydrogen economy or use hydrogen as an
energy carrier, the need to get heat energy and steam out of the
hydrogen is arising more frequently. This invention addresses that
need without the atmospheric pollutants which would result from
burning carbon based fuels or hydrogen freely in the air. Presented
is an invention which has very high overall efficiency and
generates no oxides of carbon and nearly zero nitrogen oxide
compounds. The generated steam can be used for comfort heating,
process heating, electric generation and other common applications
requiring steam. The invention can also be used for generation of
hot water. The process of steam generation is accomplished by
precisely metering the mixing and oxidation of hydrogen and oxygen
under controlled conditions. The result of this oxidation reaction
is simply only water and heat, which are used to generate
steam.
Inventors: |
Doland; George; (Houston,
TX) |
Correspondence
Address: |
GEORGE J. DOLAND
7026 FAUNA STREET
HOUSTON
TX
77061-3918
US
|
Family ID: |
39761381 |
Appl. No.: |
11/623330 |
Filed: |
March 15, 2007 |
Current U.S.
Class: |
122/1C |
Current CPC
Class: |
F22B 13/04 20130101;
F22B 37/06 20130101; F22G 3/006 20130101; F22G 1/02 20130101; F22B
37/025 20130101 |
Class at
Publication: |
122/1.C |
International
Class: |
F22D 1/00 20060101
F22D001/00 |
Claims
1. A system and method for generation of steam comprising: (a) a
hydrogen fuel source (b) a pressure chamber or heat exchanger for
converting water to steam by the addition of heat energy, (c) a
means for metering hydrogen and oxygen into a reaction chamber to
generate heat energy, (d) a means of using a plurality of high
temperature tubes for transferring said heat energy from the
reaction chamber to the water so as to generate steam, (e) said
reaction system and steam generation system are isolated from each
other, and from the outside atmosphere and do not necessarily
operate at the same pressure, (f) a control system for said steam
generator system.
2. The steam generator of claim 1, wherein the hydrogen fuel and
isolated systems result in a zero emission, closed system.
3. The steam generator of claim 1, wherein a gas or liquid is added
to the reaction chamber for the purpose to control one or more of
the following: temperature, erosion, corrosion, embrittlement, or
reaction characteristics.
4. The steam generator of claim 1, wherein the tubes are coated
with a protective material such as chromium, titanium dioxide,
ceramic or similar material.
5. The steam generator of claim 1, wherein the pressure chamber or
exchanger is connected via a conduit to a superheater. Said
superheater is provided the necessary heat energy from a hydrogen
and oxygen reaction.
6. The steam generator of claim 1, wherein a condenser is use to
recover energy from the reaction products and additives supplied in
the reaction chamber.
7. The steam generator of claim 6, wherein the water from said
condenser is fed into the pressure chamber as feedwater.
8. A system and method for generation of steam comprising: (a) a
hydrogen fuel source (b) a pressure chamber or heat exchanger for
converting water to steam by the addition of heat energy, (c) a
means for metering hydrogen and oxygen into a reaction chamber to
generate heat energy, (d) a means of using a plurality of high
temperature tubes for transferring said heat energy from the
reaction chamber to the water so as to generate steam, (e) said
reaction system and steam generation system are connected together,
and are isolate from the outside atmosphere and operate at
substantially the same pressure. (f) a control system for said
steam generator system.
9. The steam generator of claim 8, wherein the hydrogen fuel and
isolated systems result in a zero emission, closed system.
10. The steam generator of claim 8, wherein a gas or liquid is
added to the reaction chamber for the purpose to control one or
more of the following: temperature, erosion, corrosion,
embrittlement, or reaction characteristics.
11. The steam generator of claim 8, wherein the tubes are coated
with a protective material such as chromium, titanium dioxide,
ceramic or similar material.
12. The steam generator of claim 8, wherein the pressure chamber or
exchanger is connected via a conduit to a superheater. Said
superheater is provided the necessary heat energy from a hydrogen
and oxygen reaction.
13. The steam generator of claim 8, wherein a condenser is used to
recover energy from the reaction products and additives supplied in
the reaction chamber.
14. The steam generator of claim 8, wherein the water from said
condenser is fed into the pressure chamber as feedwater.
15. A system and method for generation of steam comprising: (a) a
hydrogen fuel source (b) a pressure chamber or heat exchanger for
converting water to steam by the addition of heat energy, (c) a
means for metering hydrogen and oxygen into a reaction chamber to
generate heat energy, (d) a means of using a plurality of high
temperature tubes for transferring said heat energy from the
reaction chamber to the water so as to generate steam, (e) said
reaction system and steam generation system are isolated from each
other, and do not necessarily operate at the same pressure, (f) a
control system for said steam generator system.
16. The steam generator of claim 15, wherein a gas or liquid is
added to the reaction chamber for the purpose to control one or
more of the following: temperature, erosion, corrosion,
embrittlement, or reaction characteristics.
17. The steam generator of claim 15, wherein the tubes are coated
with a protective material such as chromium, titanium dioxide,
ceramic or similar material.
18. The steam generator of claim 15, wherein the reaction products
are released out a stack to the atmosphere.
19. The steam generator of claim 18, wherein the oxygen is supplied
from outside air.
20. A steam generator of claim 18, wherein the exhaust passes
through a nitrogen compound scrubber or selective catalytic reactor
(SCR) to further reduce the nitrogen pollution released to the
atmosphere.
21. The steam generator of claim 15, wherein the pressure chamber
or exchanger is connected via a conduit to a superheater.
22. The steam generator of claim 15, wherein a condenser is used to
recover energy from the reaction products and additives supplied in
the reaction chamber.
23. The steam generator of claim 15, wherein the water from said
condenser is fed into the pressure chamber as feedwater.
24. The steam generator of claim 15, wherein said reaction chamber
contains a catalyst material which promotes the hydrogen-oxygen
reaction
25. A system and method for generation of steam comprising: (a) a
hydrogen fuel source (b) a pressure chamber or heat exchanger for
converting water to steam by the addition of heat energy, (c) a
means for metering hydrogen and oxygen into a reaction chamber to
generate heat energy, (d) a means of using a plurality heat
transfer plates or fins for transferring said heat energy from the
reaction chamber to the water so as to generate steam, (e) a
control system for said steam generator system.
26. A system and method for generation of steam comprising: (a) a
hydrogen fuel source (b) a pressure chamber or heat exchanger for
converting water to steam by the addition of heat energy, (c) a
means for metering hydrogen and oxygen into a reaction chamber to
generate heat energy, (d) a reaction chamber which directly
transfers heat energy to generate steam, (e) a control system for
said steam generator system.
Description
FIELD OF INVENTION
[0001] The present invention relates generally to generation of
steam. More particularly, the present invention relates to a system
and method of generating steam using hydrogen as the fuel source.
The present invention generates no air emissions in most cases, and
no carbon pollution in all cases.
BACKGROUND
[0002] The use of a boiler to generate steam dates back centuries.
In the 1.sup.st century A.D., Hero of Alexandria used a combination
of a steam engine and boiler to turn boiling water into mechanical
energy. His invention, called an aeolipile, used a kettle connected
via tubes to a round copper sphere. The kettle or boiler was filled
with water and as it was heated it vented steam through the copper
tubes then out small tubes around the radius of the sphere to
created jets to propel his engine.
[0003] Early steam generators used wood or lamp oil as a fuel.
Later, natural gas and coal were introduced as fuels. The use of
coal, natural gas and oil have been around for hundreds of years,
and are the predominate fuels used in boilers today. All of these
fuels contain carbon, and produce the undesirable green house gas
called carbon dioxide when they are burned. Most recently, nuclear
energy has been used to generate steam for steam turbine
generators.
[0004] A steam boiler in its basic form resembles a kettle of water
boiling on the stove. Early steam ships and locomotives placed the
fire in the middle of the water. The boiler consisted of an inner
tube open at one end and an outer tube sealed at both ends. The
area between the inner and outer tubes was filled with water which
boiled when heated. A fire tender would add fresh wood or coal to
the fire as it burned down. Much of the heat was lost out the steam
ship's or locomotive's stacks. Most people will remember seeing
pictures with smoke pouring out the stack of a train or steam ship.
This smoke was predominately wasted heat and practically unburned
fuel. Early steam ships and locomotives were prone to disastrous
explosions due to poor pressure controls.
[0005] Boiler efficiencies have improved over the recent years.
Modern boilers use more precise controls which reduce the smoke
produced out the stacks and improve efficiencies. Modern stationary
boilers put the steam in high pressure tubes outside the fire which
increases the boiler pressure rating and reduces the chance of
explosions. They also place economizing heat exchangers on the
smoke stacks which, reduces the heat lost out the stack. They also
use motor driven fans to force air into the firebox to promote more
complete combustion.
[0006] Even though the smoke stacks no longer produce smoke, they
still pour out air pollution. The burning of carbon based fuels
produces carbon monoxide and carbon dioxide. The hotter flames
which result in better combustion also produce oxides of nitrogen.
New low NOx burners which reduce the flame temperature have been
able to reduce nitrogen pollution, but have not eliminated it.
[0007] There are two basic types of package boilers or steam
generators. The first is the fire tube boiler. The fire tube boiler
is used in the traditional steam locomotive and steam ships
referenced earlier. The fire tender or engineer would place wood or
coal into the firebox where it burned. The hot gases would flow
through tubes and then out the stack. Water would be located in a
chamber outside the tubes and would boil into steam. In the
alternate water tube case, water would be in the tubes and would
flow up from the mud drum on the bottom then up through the tubes
and out the steam drum on top. The fire and combustion is be placed
in the middle of the bundle of tubes, and is located above the mud
drum and below the steam drum.
SUMMARY OF THE INVENTION
[0008] An objective of this invention is the generation of steam
without generating air pollution. In the prior art, carbon based
fuels are combusted in air and the resulting heat is used to
generate steam. Hydrogen fuel contains no carbon atoms. Therefore,
it cannot create carbon monoxide or carbon dioxide like previous
fuels such as natural gas, methane (from Biomass and other
sources), coal and coal based syngas, oil, wood, petroleum products
and byproducts, cellulose based fuels and cellulose byproducts,
slag, etc. Burning of these carbon based fuels is the number one
method of generating steam. The second and third most popular
methods are electric heating and nuclear reactors. This invention
introduces a new, novel method of generating steam without
generating pollution.
[0009] The invention presented here takes advantage of several
features of the hydrogen oxidation reaction. First, this reaction
is one of the most energetic binary reactions of two basic
elements. It produces tremendous energy yet it takes very little to
get the reaction started and it occurs spontaneously at relatively
low temperatures. In the presence of a catalyst, such as platinum,
spontaneous oxidation will occur at an even lower temperature.
Therefore, in one embodiment of this invention, a catalyst is used
to lower the combustion temperature to the point where very little
nitrous oxide is created, even when air is used to provide the
oxygen. Unlike complex hydrocarbon oxidation reactions, the
hydrogen-oxygen reaction easily goes to completion, so the hydrogen
fuel is efficiently converted to heat which is used to boil the
water. The result of the combustion reaction is essentially water,
with virtually no nitrogen compounds, and absolutely no carbon
compounds. The resulting exhaust can be condensed to recover the
water which enables the process to use the high heating value (HHV)
for the hydrogen fuel.
[0010] In another embodiment of the invention, the hydrogen-oxygen
reaction occurs without a catalyst in a pure hydrogen/oxygen
environment. It is easy to see that these two processes can be
combined to result in other embodiments of the invention. However,
in the pure oxygen environment, only water can be produced as a
result of the reaction. Therefore, it produces no nitrogen or
carbon pollution. In this process, the water is condensed and fed
back into an outside process where the hydrogen and oxygen were
originally split. This produces a closed loop system where water is
the working fluid. The heat from the reaction is used to boil water
to create steam. The resulting steam can be used just as any other
steam boiler system. In most boiler systems, the steam is condensed
back into condensate which is usually returned to the system. In
this embodiment, energy is provided to the system by splitting
water into hydrogen and oxygen. The energy is stored in the gasses
until it is needed. Then the hydrogen and oxygen gasses are
combined in the boiler to make steam, which is a very good media
for moving heat energy throughout a plant or facility.
[0011] In yet another embodiment of this invention, water is
injected with the hydrogen and oxygen. The result is lowering the
temperature of the reaction chamber. This reduces the stresses on
the mechanical components, and lengthens the life of the steam
generator. The steam generated in the reaction chamber by the
vaporizing of the injected water is recovered to maintain the
overall efficiency of the generator.
[0012] In yet another embodiment of this invention, the tubes are
coated with material to reduce the effects on them when operated in
an environment of hydrogen, oxygen, high temperature and water
vapor. Coatings like titanium dioxide form a barrier which prevents
hydrogen atoms from migrating through a metal surface and resulting
in hydrogen embrittlement. Similarly, chromium surface coatings
have been used as a barrier for water and steam related erosion.
Also, ceramic and carbon coatings have been used as barriers
against the effects of very high temperatures.
[0013] In yet another embodiment of this invention, the process
uses closed loop systems and condensate recovery to limit water
consumption. This embodiment not only conserves the valuable water
resources, but it also conserves energy by recovering the heat
contained in water vapors. This embodiment also saves on water
treatment chemicals as the closed loops with pure deionized water
will require little or no treatment. The reaction chamber system in
this embodiment consists of the chamber to which a multiplicity of
tubes is connected at one end. At the other end of the tubes is
connected a condenser. In operation, the hydrogen and oxygen are
started to react in the chamber. As the gasses react and travel
down the tubes, they transfer the heat outside the tubes and the
gasses are cooled. At the same time, as the gasses travel down the
tubes, the reacting gasses are forming water vapor (the result of
hydrogen and oxygen reacting). By the specification of this
invention, the tubes are designed sufficiently long for all of the
gasses to be converted to water, and most of the heat generated to
be transferred out through the side of the tubes. The remaining
heat is removed by the condenser leaving liquid water. Any water
that was added in with the fuel would also be condensed. The liquid
water can then be split back into hydrogen and oxygen by some other
process such as electrolysis. This would complete the cycle for the
reaction loop.
[0014] In the steam loop, liquid water would be fed under pressure
into the steam side of the tubes. Heat from the reaction process is
transferred through the walls of the tubes to heat the water. Steam
is generated and rises to the top, where it leaves the steam
generator. The steam is used by another process and the heat energy
is removed. When sufficient energy is removed, the steam condenses
back into liquid water. For example, the steam from the steam
generator could be used to power a simple cycle, condensing steam
turbine generator (STG). In this case, the steam would power the
turbine, and as it moves through the turbine the pressure and
temperature would decrease. At the discharge of the turbine, a
condenser would create a partial vacuum as it takes the last bit of
heat out of the steam and condenses it back to liquid water. This
liquid water would then be send back to the feed water pumps to
complete the cycle.
[0015] In this embodiment, the two closed loops can operate at the
same, or at different pressures. For example, again using the STG
scenario, the steam loop would operate at super critical conditions
to supply the STG, while the reaction loop would operate at a much
lower pressure in the range of 100 to 200 PSI. Water condensed in
the reaction could be used as feed water for the steam loop,
provided a high pressure pump was employed to inject the water into
the boiler tubes.
[0016] In yet another embodiment of this invention, a closed loop
steam loop would be used with an open loop reaction system. This
arrangement is similar to most package boilers produced today.
Whether it is a fire tube or a water tube boiler, the reaction side
is open with the flue gas venting to the atmosphere and the steam
loop is a closed loop with condensate returned to the system
elsewhere in the process. The difference between the prior art and
this invention is the hydrogen fuel, the resulting lack of air
pollution, and the addressing of the extremely harsh environment
resulting from the fuel/oxidizer combination.
[0017] This difference is the result of many subtle, but important
differences from modern steam boilers. Even at normal hydrocarbon
boiler conditions and combustion temperatures, hydrogen
embrittlement is a significant problem resulting in boiler tube
failures. The boiler of this invention uses a hydrogen rich
atmosphere at elevated temperature, compounding the problem. An
oxygen rich atmosphere has a similar problem, but a different
failure mode. A high temperature oxygen rich atmosphere results in
oxidation or burning of the boiler metal much like an oxy-acetylene
torch. Still another problem addressed is the fact that high
temperatures alone present a problem. This problem is similar to
the tube failures which result from a lack of sufficient water in a
boiler super heater. On top of all of these, the presence of
vaporizing water is very erosive to the components. This invention
addresses each of these problems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The drawings depict various arrangements of the invention,
not to limit, but rather to illustrate some of the possible
arrangements which include:
[0019] FIG. 1 illustrates a basic arrangement of the invention
using a shell and tube style of the fire tube embodiment,
[0020] FIG. 2 illustrates the present invention in its water tube
embodiment with air supplying the oxygen, a catalyst promoting the
reaction and the combustion gasses vented out a stack,
[0021] FIG. 3 illustrates the fire tube embodiment with an integral
superheater and various additional components.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] FIG. 1 illustrates one preferred embodiment of this
invention wherein the steam generator is operates within a shell 20
with one head 24 fixed on the left end and the other head 25 fixed
on the right end. The heads 24 and 25 are shown separated from the
shell 20 for illustration purposes, so the path of the gasses and
the divider plate within the heads can be more clearly understood.
In operation the heads are affixed to the shell. The boiler tubes
23 are fixed at each end to the tube sheets 22.
[0023] In operation, water 10 enters the shell through the nozzle
at the bottom of the shell. The controller maintains a fixed water
level within the shell 20. Hydrogen 12 and oxygen 13 enter through
conduits penetrating the left head 24. The hydrogen 12 and oxygen
13 react together in the reaction chamber 16. As these reaction
gasses 14 combine together they move down the path shown by the
arrows. The heat generated by the reaction, passes through the tube
walls causing the water 10 to boil and generate steam. The steam 11
which is lighter than the water 10 rises to the top of the steam
chamber 17 and exits out the nozzle at the top of the shell.
[0024] As the hydrogen 12 and oxygen 13 react in the reaction
chamber 16, they form water vapor. The zig-zag path through the
tubes 23 is sufficiently long enough for all of the hydrogen 12 and
oxygen 13 to fully react. The resulting water vapor continues down
the zig-zag path cooling while it transfers the generated heat
through the boiler tubes 23. The cooler water vapor exits the steam
generator through the upper nozzle in the right hand head 25. The
exhaust vapor 15 does not contain any contain any carbon or
nitrogen compounds.
[0025] FIG. 2 illustrates another preferred embodiment of this
invention wherein outside air is used to provided the oxygen and
the exhaust is vented out the stack. The oxygen level is controlled
via a blower fitted with a damper or a variable speed blower 18.
Hydrogen 12 is fed through a control valve 19 to meter the hydrogen
level. The reaction gasses 14 combine and flow through catalyst 26.
The combination of mixing nozzle 21 and catalyst 26 work together
to reduce the generation of nitrogen compound pollution. The volume
of the reaction chamber 16 and the catalyst 26 provide enough
resonance time for complete reaction of the hydrogen and oxygen.
The resulting exhaust gas 15 exits through the stack 27.
[0026] In FIG. 2, the feedwater 10 is pumped via feedwater pump 28
into the mud drum 30. The water level in the system is controlled
by the feedwater control valve 29. Heat generated in the reaction
chamber 16 is passed through the wall of the tubes 23 to heat the
water and make steam. As the water passes through the mud drum 30
then through the tubes 23 it is converted to steam 11 in the steam
drum 31. The control system (not shown) controls all the steam
generator operations including hydrogen feed, oxygen feed, blower
feed, water level, steam pressure, production rate, etc.
[0027] FIG. 3 illustrates another preferred embodiment of this
invention wherein a superheater 32 is integrated with the steam
generator, and a condenser 36 is used to recover the water vapor
which results from combining hydrogen 12 and oxygen 13. Hydrogen
and oxygen sensors in the reaction gas path 14 would provide
feedback to insure there is not a buildup of one more than the
other. In this embodiment hydrogen 12 is precisely metered with
oxygen 13 to create nothing but water. This is one of the ideal
arrangements for a completely closed system. This arrangement can
be used for dispatchable electrical power with the addition of
storage, a steam turbine generator and some form of electrolyzer
system.
[0028] The steam generator operates within a shell 20, with one
head 24 fixed on the left end and the other head 25 fixed on the
right end. Likewise, the superheater 32 has heads 34 fixed to each
end. The heads 24, 25 and 34 are shown separated from the shells 20
and 32 for illustration purposes so the path of the gasses and the
divider plate within the heads can be more clearly understood. In
operation, the heads are affixed to the shell. The boiler tubes 23
are fixed at each end to the tube sheets 22. In a similar manner,
the tubes of the superheater are fixed to tube sheets at either
end.
[0029] In the embodiment of FIG. 3, the hydrogen 12 and oxygen 13
combine in the reaction chamber 16. The hot reaction gasses 14
travel through the nozzle in the right hand head of the steam
generator 25 and up to the head of the superheater 34. These
reaction gasses, now between 900 deg. F. and 3000 deg. F., travel
first from right to left through the tubes of the superheater. Then
they switch direction in the left hand head of the superheater and
travel left to right. At the right head they reverse again and
travel right to left. During this traversing through the
superheater, heat energy from the reacting gasses is transferred
perpendicular to the direction of the flow and out the side of the
tubes to heat steam 11 entering the bottom and into superheated
steam 33 exiting the top.
[0030] The hot reaction gasses leaving the left hand superheater
head 34 enter the top nozzle on the left hand head 24 of the steam
generator. The hot gasses 14 are now below 1000 deg. F. and all of
the hydrogen and oxygen have combined to form water. The hot gasses
continue to loose their heat through the sides of the tubes heating
the water in the steam side of the tubes while the water begins to
condense on the reaction side of the tubes. The exact pressure,
temperature and quality of the steam are dependent on the operating
conditions and the application the steam generators is being used
in. The reaction vapors make one final turn at head 25, then the
cooled vapors 35 exit out of the steam generator head 24. The final
bit of heat is removed in condenser 36 turning the vapors back to
hot liquid water, which goes into tank 37.
[0031] Refer to FIG. 3 as the steam side of the system is traced.
Feedwater 10 is drawn out of water tank 37 by feedwater pump 28.
The water level in the steam generator shell 20 is controlled by
the control valve 29. The water 10 enters the shell and is heated
by the reaction gas heat which passes through the walls of the
tubes 23. This generates steam 11 which fills the top of the steam
chamber 17 and exits through the top nozzle on the shell 20 near
the head 25. The steam 11 then flows around the tubes in the
superheater gaining more heat. As the steam 11 passes through the
superheater 32 it becomes superheated and exits as superheated
steam 33. The superheated steam 33 is then used by the heat load
and returned to the system into hot feedwater water tank 37. The
heat load is outside the scope of this invention and is not shown
in FIG. 3.
* * * * *