WO2007133174A1 - Hydrogen generator - Google Patents

Abstract

A generator produces variable output of hydrogen and oxygen from electrolysis of water as a fuel supplement for combustion of hydrocarbon fuel. The generator includes an electrolytic reactor having a sealed cathode chamber partially filled with an electrolyte solution, and an anode immersed within the solution and electrically isolated from the chamber. A level sensor and reservoir maintain solution levels in one or more reactors configured in electrolyte communication. A source of electrical power energizes reactors responsive to changing combustion demand. A cooling system cools the reactors to allow the generator to operate at high amperage. An optional controller shifts reactor duty cycles to equalize reactor service over time. Gases produced in reactor air space above solution level are drawn or pumped to a combustion chamber to combine with hydrocarbon fuel and air. The combination results in greater combustion efficiency and reduces harmful emissions.

Description

HYDROGEN GENERATOR

BACKGROUND OF THE INVENTION

1. Field of the Invention.

[0001]

The present invention relates to hydrogen generators for improving the

efficiency of hydrocarbon fuel combustion. More specifically, the invention

relates to hydrogen generators used with internal combustion engines to reduce

harmful emissions from the internal combustion engines.

2. Description of Related Art.

[0002]

An internal combustion engine produces power by burning a fuel within

the combustion chambers of the engine. The fuel is mixed with air (which

contains about twenty percent oxygen) and fed into the combustion

chambers. The burning produces explosion and gases that move one or more

pistons or rotors. The moving pistons or rotors are connected to an output

shaft. Internal combustion engines are used to power automobiles, trucks, boats,

tools, generators, and many other devices. The three main types of internal

combustion engines are the conventional piston engine, the rotary engine, and

the diesel engine. [0003]

Most internal combustion engines burn a fuel that is refined from

petroleum. These fuels include gasoline, diesel fuel, and aviation

fuel. Petroleum is a non-renewable resource. Most countries have to import

petroleum and/or its refined products to meet their needs. The costs and the

political consequences are enormous. Many steps have been taken to improve

the efficiency of internal combustion engines and to supplement hydrocarbon

fuels with renewable fuels such as ethanol and vegetable oils. However, the

cost of hydrocarbon fuels continues to rise and the dependence on imported

petroleum continues to increase for most industrialized countries.

[0004]

Petroleum-based fuels contain a variety of hydrocarbons that, when

burned in an engine, produce water and carbon dioxide and lesser amounts of

carbon monoxide and unburned hydrocarbons. The hydrocarbon fuels generally

contain small quantities of nitrogen and sulfur compounds which result in the

formation of nitrogen oxides and sulfur oxides. Carbon monoxide, unburned

hydrocarbons, nitrogen oxides, and sulfur oxides are all harmful to the

environment. A variety of steps have been taken to reduce the air pollution

caused by emissions from internal combustion engines. Clean-air legislation is

one such step. However, when engine emissions fail to meet an environmental

standard, the consequences can be economically troublesome to a business, especially those that rely on large-scale engine operations. Management may

have no alternative but to shut down essential plant equipment until it can be

repaired or replaced.

[0005]

Accordingly, there has been a great incentive to reduce harmful

emissions from internal combustion engines and to supplement the hydrocarbon

fuels that are burned in them. It is widely believed that the fuel of the future is

hydrogen. Hydrogen burns cleanly and produces water as a by-product.

Hydrogen can be produced by electrolysis of water. Water is, of course, an

abundant resource. However, modifications to the internal combustion engine

must be made to burn solely hydrogen and an entire manufacturing and

distributing network for hydrogen must be created. Many experts believe it will

be many decades before hydrogen replaces petroleum-derived hydrocarbon

fuels.

[0006]

In the meantime, it is known that hydrogen produced by the electrolysis

of water can be used to supplement hydrocarbon fuels in existing internal

combustion engines. From the standpoint of thermodynamics, the energy

required to generate hydrogen and oxygen from water by electrolysis is greater

than the energy produced when the hydrogen and oxygen burn to regenerate

water. However, it has been discovered that adding supplemental hydrogen and oxygen to an internal combustion engine enables the engine to burn the

hydrocarbon fuel more efficiently, resulting in a net increase in efficiency and a

reduction in emissions.

[0007]

For example, U.S. Pat. No. 4,271,793 issued to Valdespino on June 9,

1981 (incorporated herein by reference) discloses a hydrogen generator for an

internal combustion engine. The generator comprises an electrolytic reactor that

creates hydrogen and oxygen from water. The hydrogen and oxygen are fed to

the intake of the engine. Another example, is U.S. Patent No. 5,231,954 issued

to Stowe on August 3, 1993 (incorporated herein by reference), which also

discloses a hydrogen generator for an internal combustion engine. The

electrolytic reactor contains a pop-off lid to reduce the danger of explosions and

the hydrogen and oxygen are fed into the positive crankcase ventilation system

rather than directly into the intake manifold. A third example is U.S. Pat. No.

6,817,320 issued to Balan et al. on November 16, 2004 (incorporated herein by

reference). Balan et al. discloses a plurality of electrolysis cells for providing

hydrogen to an internal combustion engine, and a control system for cell

operation and safety assurance.

[0008]

The electrolytic hydrogen generators of Valdespino, Stowe, and Balan et

al., as well as many other such generators that have been discussed or built, suffer from a variety of problems that have prevented them from achieving

widespread use. One problem is the risk of explosion inherent in any system

that accumulates a volume of pressurized hydrogen gas. Another problem is

controlling the generator of hydrogen gas in response to engine

demand. Another problem is maintaining electrolyte level and temperature

within desired limits during long term engine operation. Another problem is

developing a cost-effective system with uncomplicated controls. Accordingly, a

demand still exists for a safe and practical electrolytic hydrogen generator for an

internal combustion engine.

SUMMARY OF THE INVENTION

[0009]

The present invention provides a safe and practical hydrogen generator

for supplementing hydrocarbon fuel burned in a combustion chamber. The

invention improves combustion efficiency and reduces harmful emissions by

generating hydrogen according to combustion demand.

[0010]

In one embodiment, a hydrogen generator according to the present

invention comprises a reactor having a sealed cathode chamber partially filled

with an electrolyte solution, and an anode partially immersed in the solution and

electrically isolated from the cathode chamber. The system includes a reservoir and level sensor form maintaining a desired level of reactor solution. An

electric power source is configured to energize the reactor across its anode and

cathode terminals to liberate hydrogen and oxygen gas from the solution by

electrolysis. The power source may comprise an independent power supply or

an engine electrical system. A cooling system, such as a heat sink, transfers

heat from the reactor to counteract electrolyte heating and allows the reactor to

operate at higher amperage. In the reactor, the gases rise to an air space above

solution level and from there are drawn or pumped through conduit to combine

in the combustion chamber with hydrocarbon fuel and air. The generator may

include a plurality of electrolytic reactors maintained in electrolyte

communication.

[0011]

In one aspect of the invention, the components of the hydrogen generator

are mounted on a portable skid to facilitate connection as an auxiliary system to

stationary engines such as those used to power gantry cranes, mining drills,

diesel generators, and other large horsepower industrial machines and

equipment. In another aspect of the invention, the components of the hydrogen

generator are permanently installed as an auxiliary system for an internal

combustion engine mounted on a stationary apparatus or on a vehicle. [0012]

In another aspect of the invention, the electric power source is configured

to energize a single reactor or any combination of reactors to effect production

of hydrogen and oxygen responsive to engine demand. An engine demand

signal derived from an RPM sensor or throttle position sensor causes the source

to energize one or more reactors commensurate with the demand. In this aspect

the source may be configured with a programmable logic controller and power

relays to switch reactors between energized and non-energized states. In

another aspect, the logic controller is programmed to shift reactor duty cycles

with each engine start, such that reactor service times are substantially equalized

over time. Shifting duty cycles in this manner advantageously maximizes

system service time before maintenance. The logic controller may also be

programmed to energize initially a plurality of reactors for boosting hydrogen

and oxygen supplementation during cold-start conditions, and to de-energize

one or more reactors when the engine achieves steady state operation.

[0013]

In another embodiment, the invention provides a level control subsystem

comprising a sensor for sensing electrolyte solution level in one of the

reactors. Responsive to sensing a low level of solution in one reactor, the

subsystem actuates a pump to draw solution from the reservoir for refilling the

reactor. Responsive to sensing a high level of solution, the subsystem actuates a drain valve located between one of the reactors and the reservoir. Thus

configured, the reservoir may receive excess solution from reactors in case of

overflow, and also provide a source of make-up solution to rectify low

electrolyte levels. Maintaining the reactors in electrolyte communication

according to the invention advantageously allows the entire system to operate

with level sensing and reservoir connections limited to a single reactor.

[0014]

In another embodiment of the invention, the electrolyte solution

comprises about two to four percent dissolved electrolyte, about ten to twenty

percent alcohol, and a balance of deionized water. In one aspect, the electrolyte

comprises sodium hydroxide and the alcohol comprises methanol. The

methanol advantageously lowers the freezing point of the solution, and reacts in

water with free sodium ions to produce hydrogen.

[0015]

The present invention provides an environmental advantage by reducing

harmful emissions from the exhaust of internal combustion

engines. Experimental tests on engines equipped with a prototype of the

invention show a significant reduction in pollutants such as carbon monoxide,

unburned hydrocarbon, and nitrous oxide. The invention also provides a means

for cleaning engine internals, by removing or reducing carbon build-up. [0016]

Another notable advantage of the invention is that it minimizes the risk of

explosion. It does this by limiting hydrogen and oxygen production according

to engine demand, and also by preventing these gases from accumulating under

pressure. Another advantage is the extended service life realized by shifting

reactor duty cycles. Another advantage is the simplicity of the design. Thus,

hydrogen generation according to this invention is practical, safe, and requires

little maintenance.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]

Other systems, methods, features and advantages of the invention will be

or will become apparent to one with skill in the art upon examination of the

following figures and detailed description. It is intended that all such additional

systems, methods, features and advantages be included within this description,

be within the scope of the invention, and be protected by the accompanying

claims. The invention will better understood upon consideration of the

specification and the accompanying drawings, in which like reference numerals

designate like parts throughout the figures, and wherein: [0019]

FIG. 1 is a schematic illustration of a preferred embodiment of the

invention showing a single reactor and associated components.

[0020]

FIG. 2 is a schematic illustration of another embodiment of the invention.

[0021]

FIG. 3 is a schematic illustration of a preferred embodiment of a reactor

level control system according to the invention.

[0022]

FIG. 4 is a perspective illustration of the invention, showing two reactors

in electrolyte communication.

[0023]

FIG. 5 is a perspective illustration of a preferred embodiment comprising

two reactors encased within an insulated enclosure.

[0024]

FIG. 6 is a schematic illustration of a controller according to the

invention for energizing one or more reactors according to engine demand.

[0025]

FIG. 7 is an electrical schematic of a starting circuit for a hydrogen

generator in a preferred embodiment of the invention. [0026]

FIG. 8 is a block diagram of a control circuit for a hydrogen generator in

a preferred embodiment of the invention.

[0027]

FIG. 9 is an electrical schematic of a typical relay connected across

reactor starting and control circuits in a preferred embodiment of the invention.

[0028]

FIG. 10 is a flow chart illustrating a method according to the invention

for reducing harmful emissions in an internal combustion engine.

[0029]

FIG. 11 is a flow chart illustrating an alternate method according to the

invention for reducing harmful emissions in an internal combustion engine.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031]

FIG. 1 illustrates a system 100 according to the present invention. In this

embodiment, the system comprises an electrolytic reactor 11, a refillable

reservoir 12, a pump 13, a heat exchanger 14, and conduit 15 connecting the

foregoing components as shown. System 100 produces hydrogen and oxygen

by electrolysis of water within reactor 11. The hydrogen and oxygen are produced to supplement hydrocarbon fuel burned in a combustion chamber,

such as a wood or oil burning stove, a coal furnace, or cylinders of an internal

combustion engine. Electrical power for energizing reactor 11 may originate

from an independent source, or it may be derived from the electrical system of

an engine. To simplify the disclosure, no combustion chambers or engines are

shown in any of the figures.

[0032]

Refillable reservoir 12 is configured to hold up to about two gallons of

ionized water, although this volume may vary according to the particular

application. Reservoir 12 may be constructed of a lightweight material such as

plastic, but any other non-reactive material such as stainless steel is also

suitable. Reservoir 12 holds an electrolyte solution 16 that contains a sufficient

concentration of ions to conduct electricity and to carry out electrolysis in

electrolytic reactor 11. The electrolyte in solution 16 may comprise any acid,

base or salt that disassociates in water into cations and anions, provided that the

disassociated cation has less standard electrode potential than a hydrogen ion to

ensure production of hydrogen gas during electrolysis.

[0033]

In one embodiment, electrolyte solution 16 comprises salt water. The salt

water may be formulated, or it may be taken directly from a large body of

naturally occurring salt water. In the latter case, an ocean or saltwater lake may function as reservoir 16. This configuration may be applied in gasoline or

diesel engines located on offshore platforms or on boats or other seagoing

vessels.

[0034]

In another embodiment, solution 16 comprises an electrolyte such as lye

dissolved in pure (deionized) water. Sodium hydroxide or potassium hydroxide

may be used as the electrolyte.

[0035]

Reservoir 12 is further configured with a port 17 for adding additional

solution, and an outlet 18 that communicates, directly or indirectly, with

electrolytic reactor 11. In one embodiment, outlet 18 connects via conduit 15

directly to reactor 11. In another embodiment, outlet 18 connects via conduit 15

indirectly to reactor 11 through pump 13 and heat exchanger 14. Either way,

reservoir 12 is maintained in electrolyte communication with reactor 11.

[0036]

Electrolytic reactor 11 comprises a cathode 19 and an anode 20. Cathode

19 is a sealed chamber adapted to hold a smaller quantity of solution 16 relative

to the volume of reservoir 12. In one embodiment, the volume of the chamber

of cathode 19 is about one quarter gallon. During system operation, the amount

of solution 16 contained in reactor 11 fills about 50 to 75 percent of the chamber

such that an air space 24 exists above the level of solution for receiving gaseous reaction products. The chamber is made of an electrically conductive material,

preferably stainless steel, chosen for its corrosion-resistant properties. A

sufficiently heavy gauge of stainless steel is used so that the chamber can

withstand any explosion that might occur. Anode 20 comprises an electrically

conductive rod or tube disposed within the chamber and electrically isolated

from the chamber by means of a dielectric plug 25. In one embodiment, plug 25

comprises a synthetic rubber plug with a porcelain insert. Plug 25 insulates

anode 20 from cathode 19 and also provides an environmental seal to prevent

leakage. Anode 20 may be made from a graphite, aluminum, or copper rod

enclosed in a stainless steel tube, or it may be a solid steel electrode. In a

preferred embodiment, cathode 19 and anode 20 are made from 316L stainless

steel. Alternatively, both cathode 19 and anode 20 may be made of nickel-

plated steel.

[0037]

Reactor 11 contains an inlet 21 and outlet 22 that communicate with

reservoir 12. Inlet 21 and outlet 22 allow solution 16 to be circulated through

reactor 11 in a cooling loop to counteract the effects of electrical

heating. Heated fluid is drawn from reactor 11 through outlet 22 to the inlet of

pump 13. The fluid is then pumped through heat exchanger 14 where it is

cooled before returning to reactor 11 via inlet 21. Various sections of conduit

15 provide flow paths to complete the cooling loop. Conduit 15 may consist of any material suitable for the purpose, such as 3/8 inch braided hose or stainless

steel tubing.

[0038]

Heat exchanger 14 is preferably a finned water-to-air heat exchanger

similar to a conventional radiator. Heat exchanger 14 may include a fan to

increase the air flow across the fins. Heat generated within reactor 11 by

electrolysis can cause solution 16 to expand and boil. As the solution heats

excessively, it begins to lose its ability to conduct electric current, thereby

limiting the production of hydrogen and oxygen by electrolysis. Thus, heat

exchanger 14 enables higher electrical currents to be used which, in turn, create

greater quantities of hydrogen and oxygen. In one embodiment, system 100 is

configured to operate for extended periods at 60 to 80 amperes.

[0039]

In another embodiment, heat exchanger 14 is eliminated from the flow

path, and reactor cooling is accomplished by using a heat sink. The heat sink is

positioned in direct thermal contact with the reactor, and is configured to

maximize heat transfer from cathode chamber 19. The heat sink may be made

from any metal suitable for the purpose, such as copper or aluminum, and may

be configured with fins or other protrusions to increase surface area exposure to

ambient air. [0040]

Reactor 11 preferably contains a level control mechanism for maintaining

the level of solution 16 in reactor 12 at a desired level. In one embodiment, the

level control mechanism includes a water level detector 23 (such as a float

switch) located within the reactor, and a solenoid valve (not shown) located at

reservoir outlet 18. Level detector 23 is configured to close an electrical contact

upon detecting a low level of solution 16. Closure of the electrical contact

energizes the solenoid valve, allowing pump 13 to draw additional solution 16

into the circuit, thereby increasing the solution in reactor 11. When solution 16

achieves a desired level, detector 23 opens the electrical contact, de-energizing

the solenoid valve to isolate reservoir 12 and maintain the desired level. Many

other level control methods may be used without departing from the spirit of the

present invention.

[0041]

The level control system will allow the level of solution 16 to fluctuate

between high and low setpoints. In one embodiment, the low setpoint

corresponds to about 50% of chamber capacity, and the high setpoint

corresponds to about 75% of chamber capacity. Thus, the volume of air space

24 within chamber 19 fluctuates with changes in the solution level while

maintaining adequate space for the accumulation of hydrogen gas, oxygen gas,

and water vapors. A gas outlet 26 of cathode chamber 19 connects to an appropriate location of the engine intake system 44 to direct the gas products to

the cylinders of the engine. For example, the hydrogen and oxygen gases can

be directed to the intake manifold, to the turbo charger (if the engine contains

one), or to a line that communicates with the intake manifold.

[0042]

Electrical power may be provided to the reactor from the electrical

system of the engine (not shown). However, external power may also be

used. In one embodiment, the terminals of the engine battery are connected

across cathode 19 and anode 20. A starting circuit may be added with

appropriate interlocks to ensure that reactor 11 operates only when the engine is

running. For example, interlocks (not shown) may be linked to the ignition

switch and to an engine output to prevent energization of reactor 11 unless the

ignition switch is on and the engine is running. A suitable engine output

indicative of a running engine is oil pressure, which may be detected by means

of an oil sending unit.

[0043]

Before operation of the system can begin, reservoir 12 is completely

filled with electrolyte solution 16 and reactor 11 is filled to a desired level

between high and low setpoints. Then, the engine is turned on and the ignition

switch is placed in the on position. The oil pressure sending unit closes a relay

contact to connect the positive terminal of the engine battery to anode 20. Another relay set starts pump 13 and a fan (if any) in heat exchanger 14 to

cool and circulate solution 16 through reactor 11. The electric potential

between the cathode and the anode causes electrons to flow through the

electrolyte solution. As the electrons flow, electrolysis occurs and water

molecules disassociate according to the well-known equation:

2H₂O_(aq) → 2H₂(_g) + O_2(g)

with hydrogen gas collecting at the walls of the cathode and oxygen gas

collecting along the surface of the anode. The hydrogen and oxygen gases form

bubbles that rise through the surface of solution 16 to accumulate in air space

24. These gases are drawn through outlet 26 by vacuum pressure to the intake

system of the engine. There, the hydrogen and oxygen are combined with a

mixture of hydrocarbon fuel and air, and burn during the combustion cycle in

the engine cylinders. The hydrogen and the oxygen improve the speed of

combustion and/or combustion efficiency in the engine. As a result, the

emissions of carbon monoxide, unburned hydrocarbons, nitrogen oxides, and

sulfur oxides are reduced. Another result is the mileage of the vehicle (the

energy produced per unit of hydrocarbon fuel) increases. This is achieved while

minimizing the risk of accidental explosion because the gaseous reaction

products are not allowed to accumulate under pressure. [0044]

In certain applications, an engine may present a positive pressure to

reactor outlet 26. This may occur, for example, in engines equipped with turbo

chargers. In that case, a positive displacement pump (not shown) such as a

diaphragm pump may be installed between outlet 26 and the engine intake

manifold to force reaction products into the engine cylinders.

[0045]

In a single reactor, the rate of hydrogen and oxygen production may be

increased by increasing the electrolyzing current. In practice, this current will

be limited by a variety of factors, including the concentration of ions in solution,

the output rating of the power supply, electrical cable gauge, and the ability of

the cooling system or heat sink to prevent the solution from boiling within the

reactor.

[0046]

In one embodiment of the invention, an alcohol such as methanol or

ethanol is added to the electrolyte solution to enhance hydrogen production. For

example, methanol or ethanol can be added to a solution of lye or sodium

hydroxide dissolved in deionized water. During electrolysis, methanol reacts

with water to liberate hydrogen according to the following equation: CH₃OH + H₂O → CO₂ + 3H_2(g)

In a preferred embodiment, a system according to the invention is operated

using a solution 16 comprising about 2 to 4 percent sodium hydroxide, about 10

to 20 percent alcohol, and a balance of deionized water.

[0047]

FIG. 2 illustrates an alternate embodiment of a system 200 according to

the invention. The principles of reactor operation are the same as described in

the previous embodiment. However, system 200 demonstrates that alternative

configurations of mechanical components are possible without departing from

the scope of the invention. System 200 includes a reactor 11 comprising

cathode chamber 19 and an anode 20 maintained in electrolyte communication

with circulating pump 13 and heat exchanger 14 through conduits 15. In this

embodiment, reservoir 12 is located at a higher elevation than reactor 11. A gas

line 30 connects air space 24 of reactor 11 to an air space 31 maintained within

reservoir 12 above the level of solution 16. A refill pump 27 is provided to

supply make-up solution to reactor 11 from reservoir 12 through refill line 32,

which is configured to draw solution from the bottom portion of reservoir

12. Reservoir 12 also includes an outlet 26 which passes gaseous reaction

product to the engine intake system. System 200 is further configured with a

level controller comprising a level switch 23 and vertical tube 28. [0048]

System 200 also depicts a finned anode 20. In a finned anode, a portion

of the anode rod includes fins that extend radially outward from the axis of the

rod to increase the surface area of the anode that is exposed to solution 16. One

advantage of this variation is that it provides a means for adjusting the

resistivity of the reactor. Fins may be added or subtracted, or the diameter of

the fins may be selected to achieve higher or lower currents or current densities.

[0049]

FIG. 3 shows the level controller in greater detail. In this embodiment

the controller is located external to reactor 11 in a lower temperature area that

facilitates electrical connections and calibration. Tube 28 is connected to

cathode chamber 19 such that hydrostatic pressure causes an amount of solution

16 to rise within tube 28 to a level analogous to the level of solution 16 within

cathode chamber 19. A plastic float 33 connected to a threaded shaft 34 is

suspended from the top of tube 28, as shown. A contact nut 35 is fixed or

welded to shaft 34. Level switch 23 is positioned such that vertical movement

of nut 35 in response to action of float 33 will open a contact on switch 23 when

the level of solution 16 within tube 28 reaches a high setpoint. Opening the

contact de-energizes refill pump 27 to shut off the flow of make-up solution to

reactor 11. Those skilled in the relevant art will recognize that other

configurations of a level control circuit are possible. For example, switch 23 may be configured as a magnetic reed switch with multiple contacts

corresponding to high and low setpoints for turning pump 27 off or on, thereby

maintaining reactor solution level within desired limits.

[0050]

Referring again to FIG. 2, system 200 provides a further advantage by

locating reservoir 12 in an elevated location relative to reactor 11. The top

portion of reservoir 12 may be configured in the shape of a cone, as shown, to

form a first water trap. This configuration causes some amount of water vapor

rising from reactor 11 to condense and collect on the inner walls of the cone,

and eventually return by gravity to the body of solution 16 maintained within

the reservoir. An optional second water trap 29 may be provided to capture any

water vapor that passes through outlet 26 toward the engine intake.

[0051]

In an embodiment of the invention that uses seawater as the electrolyte

solution, the body of seawater serves as a reservoir for the hydrogen generator.

Seawater may be received into the reactor vessel through an inlet 21 having an

open end immersed in the sea, and discharged from the reactor back into the sea

through an outlet 22. The reactor includes a cathodic vessel configured to

maintain a minimum level of seawater to allow an anode to remain at least

partially submerged in the seawater during electrolysis. As in previous

embodiments, when a power source energizes the reactor, gaseous products accumulate in an air space above the water level, to be drawn from the reactor

through conduit to an intake manifold.

[0052]

In this embodiment, a pump 13 can be used to circulate the seawater

through the reactor. Or, in a hydrogen generator installed on a boat, seawater

can be directed through the inlet by force of the boat in motion on the water

without the need of a pump. Furthermore, because the saltwater circulation

loop is open to the sea, cooling system components such as the fan and heat

exchanger may be also eliminated from the system. In one aspect, the generator

provides fuel supplements to an engine that provides the motive force for

circulating seawater through the reactor.

[0053]

In another embodiment using seawater as electrolyte, the system may

include a means for adding alcohol into the cathode chamber to mix with

seawater. The alcohol may be stored in a tank or reservoir, and transferred at a

controlled rate into the chamber through conduit connections. A flow control

valve, such as a globe valve, may be placed in the flow path to regulate the

transfer rate of alcohol. The flow control valve may be configured to regulate

flow in response to engine demand. For example, the position of the globe

valve may be function of engine rpm or throttle position. [0054]

FIG. 4 shows a working prototype of the present invention, which

comprises a preferred configuration of multiple reactors maintained in

electrolyte communication. In this embodiment, cathode chambers of two

reactors HA and HB are linked by an inverted T-shaped conduit

15. Horizontal legs of conduit 15 connect to either chamber at a position below

a desired level of electrolyte solution. Electrolyte solution circulates out of the

chambers through the vertical leg of conduit 15, through a heat exchanger 14,

and back to the chambers through conduit 60. A second T-shaped conduit 61

directs solution from conduit 60 into the chambers through the base of

each reactor, as shown. A reservoir 12 is configured to supply make-up solution

to the reactors through conduit 62. Conduit 62 connects through isolation valve

63 to conduit 60. Outlet ports 26 extend from the top of each reactor 1 IA and

11B and are linked by T-shaped connector 36. From there, hydrogen and

oxygen products are directed to the engine intake system through conduit 37.

Each cathode chamber is electrically grounded, and positive DC voltage is

applied to each anode terminal 20. A pump (not shown) circulates the solution.

In operation, the dual-reactor prototype typically draws between 60 and 80

amps. [0055]

Experimental tests were run using the prototype generator of FIG. 4. In

the tests, the electrolyte solution consisted of about 3 % sodium hydroxide and

about 10 % methanol in deionized water. Emission levels were measured on

three separate diesel engines. These particular engines were in service as prime

movers on gantry cranes.

[0056]

First, emission levels were measured on a two-cycle engine running

without the prototype installed. The two-cycle engine had been in service for

some time. Second, emissions levels were measured on a new four-cycle

engine without the prototype installed, using the same test equipment and fuel

as in the first test. The new four-cycle engine was equipped with factory

installed twin catalytic converters. Third, emission levels were measured on

another two-cycle engine of similar design as the engine used in the first test.

The third engine had also seen significant service, and was tested under the

same conditions as in the first two tests, but with the prototype installed. With

the engine running, electrical current in the generator set was maintained

between 60 and 80 amps. The following table shows the test results:

2-cycle engine 4-cycle engine 2-cycle engine w/o Η.7 generator w/o ϊh generator w/H? generator

CO: 0.022 0.014 0.003

HC: 7 5 2

CO₂: 2.90 2.39 1.43 O₂: 16.86 17.48 18.73 NOx: 490 84 55

[0057]

A comparison of the tabulated results reveals that levels of harmful

emissions were significantly lowest with the prototype generator installed. In

particular, nitrous oxide emissions from the two-cycle engines dropped from

490 ppm to 55 ppm. In many jurisdictions, a reading of 490 ppm NOx would

clearly fail an emissions test, while a reading of 84 ppm NOx would clearly pass.

Note also that the used engine equipped with the prototype generator

outperformed the new four-cycle engine in all categories.

[0058]

In another experiment, opacity tests were performed on a four-cycle, six-

cylinder diesel engine equipped with twin catalytic converters. This engine was

also in service on a gantry crane. The first test was run without the prototype

installed. Opacity levels were measures from cold start over the first hour of

running time. Opacity is the degree, expressed in a percentage, to which

emissions reduce the transmission of light and obscure the view of the

background. In the second test, the prototype hydrogen generator was installed

on the same engine and opacity was again measured from cold start over the

first hour of running time. In the third test with the prototype still installed, the

same engine was allowed to continue running for three days, and opacity measurements were taken over the final hour of running time. The results of

these three tests are tabulated below:

4-cyc. 6-cyl., 4-cyc. 6-cyl., 4-cyc. 6-cyl., first hour first hour after 3 days w/o H? generator w/Hb generator w/H? generator

% opacity: 4.5 2.4 1.3

These results indicate that the prototype hydrogen generator significantly

reduced overall emissions from the diesel engine.

[0059]

Many advantages arise from configuring multiple reactors in electrolyte

communication. First, the size of each reactor is restricted to limit the volume

of volatile gases that can accumulate within reactor air space. This minimizes

the risk of explosion, and also minimizes the reactor vessel thickness required to

ensure explosion-proof properties of the reactor vessel. Second, by combining

multiple relatively small reactors, the size of the system may be scaled to meet

the demands of any size engine without the need to customize reactor

components. Manufacturing costs are minimized because standardized

components reduce overall tooling requirements. A further advantage of

multiple smaller-sized reactors is that high current densities can be achieved in

each reactor while maintaining electrolyzing currents at manageable

levels. Another advantage is the ability to vary system output according to

changing engine demand by selectively energizing and de-energizing one or more of the reactors in response to engine demand. By maintaining the reactors

in electrolyte communication, only a single reactor is required for monitoring

electrolyte levels in order to maintain solution levels in all reactors. In another

embodiment where the heat exchanger comprises a passive heat sink (i.e. a

radiator without fan or cooling pump), multiple reactors advantageously expose

greater total surface area for better heat transfer.

[0060]

FIG. 5 illustrates another embodiment of a system according to the

invention comprising dual reactors enclosed within an insulated housing

38. Housing 38 is preferably manufactured from a thermoplastic such as cross-

linked polyethylene. Housing 38 encloses a first reactor within a first portion

39, and a second reactor within a second portion 40, as shown. A bottom

portion 41 encloses conduit for maintaining the reactors in electrolyte

communication and for refilling the reactors, and electrical cable and other

components required for operating the reactors. The cable and conduit connect

to sources outside enclosure 38 through various ports (not shown).

[0061]

A connecting portion 42 encloses reactor outlet conduits to a common

port 37 configured for connection to an engine intake system. Port 37 may also

connect to the outlet port of a similar set of dual reactors in a three-way

connection that combines the output of four reactors for delivery to the engine. An unlimited number of reactor sets can be combined in similar

fashion. Connecting portion 42 may also be configured as shown to form a

convenient handle for carrying the system by hand. This facilitates set-up in

remote locations, such as mining operations, where engine access may be

difficult, and where multiple reactor sets are required to meet engine

demand. Enclosure 38 has a depth of about 6 inches, a width of about 2 to 3

feet, and a height of about 1.5 to 2.5 feet. The thickness of enclosure 38 is

about 1/16 to 1/8 inches.

[0062]

FIGS. 6 through 9 illustrate a control system according to the invention

for energizing one or more reactors according to engine demand. As shown in

FIG. 6, a system of four reactors HA, HB, HC and HD are configured to

deliver hydrogen and oxygen product to a single engine intake manifold

44. Reactors HA, HB, IIC and 11D are all maintained in electrolyte

communication through conduits 15 that connect below the electrolyte solution

level in each reactor. The conduits combine to connect to a reservoir 12 through

solenoid valve 18. Reactor 11A is configured with a level sensor 23. In

response to sensor 23 sensing a low level condition, a pump 13 pumps

electrolyte solution from reservoir 12 into reactors 11A, HB, IIC and HD

through a single inlet provided in reactor HA. Because the reactors are

maintained in electrolyte communication, hydrostatic pressure acts to equalize the solution levels in all four reactors. In response to sensor 23 sensing a high

level condition, solenoid valve 18 opens to drain electrolyte from the reactors

into reservoir 12.

[0063]

The cathode chamber of each reactor HA, HB, HC and HD is

electrically grounded, or electrically connected to the negative terminal of an

electrical DC power source 48. Each reactor HA, 11B, HC and HD is

configured with an anode 2OA, 2OB, 2OC and 2OD, respectively, as in

previously described embodiments. Each anode is connected to the positive

terminal of power source 48 through a relay contact 46A, 46B, 46C, or 46D, as

shown. The electrical circuit for the relay contacts is shown in FIG. 7.

[0064]

In one embodiment shown in FIG. 8, the control system comprises a

programmable logic controller 49 coupled to, or having an integral memory

50. In this embodiment, the control system components are considered an

integral part of the electrical power source that supplies power to the

reactors. These components may be physically located within the vehicle that

house the engine, or they may be located within a control module external to the

vehicle, for example, within a module mounted on a portable skid that includes

the reactor and its components. [0065]

Controller 49 may be any microprocessor known in the art and suitable

for accepting digital input signals and outputting digital control signals in

response to the input signals according to one or more control algorithms

maintained in memory 50. In the present example, controller 49 is coupled to

relays 51A, 51B, 51C and 51D, each operatively connected to actuate (or close)

its corresponding contact 46A, 46B, 46C or 46D in response to receiving an

actuation signal from controller 49.

[0066]

A schematic for a relay 51 is shown in FIG. 9. An actuation signal

presented across input terminals 54 closes contact 46. Contact 46 is electrically

isolated from the actuating circuit. In the schematic, terminals 54 may be the

terminals of a magnetic coil, or they may be the input gate of a transistor. Thus,

relay 51 may comprise a magnetic relay, a solid state relay, or any suitable

equivalent.

[0067]

One example of a starting sequence for the system will now be

described. Initially, the engine is off, contacts 46A, 46B, 46C and 46D are open,

and none of the reactors are energized. When the engine ignition switch is

turned on, an ignition sensor 52 sends a signal, such as a logical one, to

controller 49 indicating that the ignition switch is on. Controller 49 inputs this signal and awaits a second input signal indicating that the engine is

running. The second signal may be derived from a number of engine sensors,

such as an oil pressure sensor or an RPM sensor 53. When the engine achieves

a desired RPM, sensor 53 sends an engine-running signal to controller

49. Upon receipt of the second (engine-running) signal, controller 49 executes a

starting algorithm stored in memory 50, which directs controller 49 to actuate

one or more relays 5 IA, 5 IB, 51C and 5 ID. As each relay closes, its

corresponding reactor is energized to produce hydrogen and oxygen gas by

electrolysis.

[0068]

The number of reactors energized by controller 49 may vary according to

the RPM value, or according to a particular algorithm. For example, during an

engine cold-start condition, engine pollutants can be particularly high because

the cold temperature inhibits combustion of hydrocarbons. To address this

condition, a starting algorithm can be programmed to initially energize a

plurality of reactors in order to produce an abundance of hydrogen and oxygen

to assist with combustion. After the engine warms up to a steady-state

condition, the algorithm may cause one or more of the reactors to de-energize,

as necessary. An engine steady-state indicator 55 may be provided for this

purpose, i.e. to transmit a steady-state status indication to controller 49. Various

parameters may be monitored to provide a source for the steady-state indication. For example, engine running time, engine oil pressure, engine oil

temperature, engine coolant temperature, reactor solution temperature, or engine

exhaust chemistry may be used to provide this indication.

[0069]

In another embodiment, an algorithm may be provided to allow the

controller to energize one or more of the reactors in response to engine

demand. Engine demand may be represented by a signal such as engine RPM,

and transmitted to controller 49 by RPM sensor 53. For example, a single

reactor may be energized for a low range of RPM (0 to 1000), a second reactor

may be energized for a higher ranger of RPM (1000 to 1500), a third reactor

may be energized for the next range (1500 to 2000), and so on. Reactors may

then be de-energized as RPM decreases. In another aspect, engine demand may

be represented by a signal transmitted from a throttle position sensor.

[0070]

In another embodiment, controller 49 and/or memory 50 may be

configured with one or more counters that keep track of the service time for

each reactor to enable the controller to shift reactor duty cycles. For example, a

count maintained in a counter may represent the total time (in minutes or hours)

that a reactor has been energized. Algorithms may then instruct controller 49 to

energize reactors according to a priority such that reactor service times are

equalized over time. If, at a particular engine start, reactor HD has the lowest count among all reactors in a system, it is assigned a highest priority to ensure

that it sees additional service time even when fewer than all reactors need to be

energized to satisfy engine demand. In that instance, reactors with the highest

counts (and lower priorities) may remain temporarily de-energized. At a

subsequent engine start, if the service time of reactor HD has since exceeded

the service time of another reactor, controller 49 may shift the duty from reactor

1 ID to a reactor with higher priority.

[0071]

In another embodiment, the electrical power source and its associated

control system may be configured to energize initially a first set of one or more

reactors when the engine starts, and upon a subsequent start, to energize initially

a second set of one or more reactors. The second set of reactors may have some

reactors in common with the first set of reactors, provided that there is at least

one reactor in the second set that is absent from the first set. This provides

another means for the control system to shift duty cycles among the reactors,

since at least one reactor will remain idle. Over time, each reactor will see a

substantially equal amount of service time. This advantageously maximizes the

service time of the system between maintenance intervals.

[0072]

In another embodiment of the invention, the outlet conduit of each reactor

HA, HB, I IC and HD may be configured with an isolation valve 56A, 56B, 56C or 56D, respectively. These may be manual valves, or they may be valves

that can be closed automatically by the control system. In cases where engine

demand requires one or more reactors to remain idle, it may be advantageous to

isolate the air space of the idle reactors to reduce the load on the vacuum drawn

by the intake manifold. Each solenoid valve may be energized and de-energized

by a controller 49 and relay 51 in the same manner that the reactors are

energized and de-energized. This provision for isolating a reactor also allows

an inoperable, redundant reactor to be temporarily valved out of service.

[0073]

In accordance with the foregoing disclosure, methods of the present

invention will now be described. FIG. 10 illustrates one embodiment of a

method 1000 for generating hydrogen and oxygen by electrolysis of water

according to engine demand. The method begins at step 1002, which comprises

maintaining a plurality of electrolytic reactors in electrolyte

communication. Electrolytic communication is achieved by connecting each

reactor chamber to at least one other reactor chamber from among the plurality

of reactors, such that all connections are made to allow electrolyte solution to

flow from one reactor to another. The next step is step 1004, which comprises

providing a reservoir in electrolyte communication with at least one of the

reactors. [0074]

Next, step 1006 comprises sensing the level of electrolyte solution in the

reactors. Provided that the reactors are maintained in electrolyte

communication, it is only necessary to sense the solution level in any one of the

reactors, as its level will be substantially equal to the level in all others. The

next step is step 1008. This step comprises controlling the solution level in the

reactors responsive to the level sensed in the previous step. As discussed in

previous embodiments, a control circuit comprising the sensor, the reservoir,

one or more pumps, one or more valves, and a power source may be used to

effect this step. Next, in step 1010, one or more of the reactors are electrically

energized responsive to engine demand. Energization of the reactors begins the

electrolysis process that produces hydrogen and oxygen gas. To counteract the

resulting temperature rise within the reactors, step 1012 is performed. Step

1012 comprises cooling the reactors during energization, which may be

accomplished by circulating the electrolyte solution though a heat exchanger, or

by providing a passive heat sink for transferring heat from the reactor

vessels. The final step is step 1014, wherein hydrogen and oxygen reaction

products are directed from the reactors to the intake system of the internal

combustion engine. [0075]

Another method according to the invention is illustrated in FIG. 11. This

method begins at step 1102. Steps 1102 and 1104 are identical to steps 1002

and 1004 of the previous embodiment. In the next step 1106, an electrolyte

solution is circulated through the reactors. This particular solution consists of 2

to 4 % sodium hydroxide, 10 to 20 % alcohol, and a balance of deionized

water. In one example, the alcohol is methanol. In step 1108 a reactor solution

level is sensed, and in step 1110 reactor solution levels are controlled responsive

to the sensed level. The next step is 1112, wherein, responsive to engine

demand, one or more of the reactors are energized with an energizing current of

between about 60 and about 80 amps. In the final step 1114, the gaseous

hydrogen and oxygen reaction products are directed from the reactors to the

engine intake system.

[0076]

The invention has been presented in an illustrative style. The

terminology employed throughout should be read in an exemplary rather than a

limiting manner. While various exemplary embodiments have been shown and

described, it should be apparent to one of ordinary skill in the art that there are

many more embodiments that are within the scope of the subject

invention. Accordingly, the invention is not to be restricted, except in light of

the appended claims and their equivalents.

Claims

CLAIMSWhat Is Claimed Is:

1. A system for generating hydrogen and oxygen by electrolysis of

water for supplementing a hydrocarbon fuel burned in a combustion chamber,

the system comprising:

an electrolytic reactor comprising:

(i) a sealed cathode chamber partially filled with an

electrolyte solution; and

(ii) an anode at least partially immersed in the solution and

electrically isolated from the chamber;

a reservoir in electrolyte communication with the reactor;

a level controller for maintaining reactor solution level;

a cooling system for cooling the reactor;

conduit for directing hydrogen and oxygen product from the

reactor to the combustion chamber; and

a power source for energizing the reactor.

2. The system of claim 24 wherein the power source is configured

to energize the reactor with a variable electrolyzing current in response to

changing engine demand.

3. The system of claim 24 wherein the electrolyte solution

comprises water, alcohol, and dissolved lye.

4. The system of claim 24 wherein the cooling system comprises a

heat sink in direct thermal contact with the reactor.

5. A system for generating variable output of hydrogen and oxygen

by electrolysis of water for supplementing a hydrocarbon fuel in an internal

combustion engine, the system comprising:

a plurality of electrolytic reactors in electrolyte communication,

each reactor comprising:

(i) a sealed cathode chamber partially filled with an

electrolyte solution; and

(ii) an anode at least partially immersed in the solution and

electrically isolated from the chamber;

a reservoir in electrolyte communication with at least one of the

reactors;

level control means for maintaining solution level in the reactors;

a cooling system for transferring heat from the reactors;

conduit for directing hydrogen and oxygen product from the

reactors to the engine; and

a source of electric potential for energizing one or more of the

reactors in response to engine demand.

6. The system of claim 1 wherein the solution is an aqueous

solution comprising about 2 to 4 percent sodium hydroxide and about 10 to

20 percent alcohol.

7. The system of claim 1 wherein the level control means

comprises a level sensor coupled to a valve located between the reservoir and

the at least one reactor, whereby, responsive to the sensor sensing a high level

of solution, the valve opens to sink solution from the reactors to the reservoir.

8. The system of claim 1 wherein the level control means

comprises a level sensor coupled to a pump located between the reservoir and

one of the reactors, whereby, responsive to the sensor sensing a low level of

solution, the pump turns on to supply solution from the reservoir to the

reactors.

9. The system of claim 1 wherein the source further comprises a

means for sensing changing engine demand and a means for coupling the

source to one or more of the reactors responsive to changing engine demand

to produce hydrogen and oxygen output that varies according to changing

engine demand.

10. The system of claim 5 wherein the means for sensing changing

engine demand comprises a throttle position sensor.

11. The system of claim 5 wherein the means for sensing changing

engine demand comprises an RPM sensor.

12. The system of claim 1 wherein the source is configured to shift

reactor duty cycles such that reactor service times are substantially equalized

over time.

13. The system of claim 8 wherein the source is configured to

energize initially a first set of one or more reactors when the engine starts,

and upon a subsequent start, to energize initially a second set of one or more

reactors, the second set comprising at least one reactor absent from the first

set.

14. The system of claim 1 wherein the source is configured to

energize initially a plurality of reactors, and responsive to sensing a steady-

state operating condition, to de-energize one or more reactors.

15. The system of claim 10 wherein the steady-state operating

condition is selected from the group consisting of engine running time, engine

oil pressure, engine oil temperature, engine coolant temperature, reactor

solution temperature, and engine exhaust chemistry.

16. A system for generating hydrogen and oxygen by electrolysis of

water for supplementing a hydrocarbon fuel burned in a combustion chamber,

the system comprising:

an electrolytic reactor comprising:

(i) a cathode chamber having an inlet for receiving saltwater

flow and an outlet for discharging the flow; and (ii) an anode at least partially immersed in the flow and

electrically isolated from the chamber;

conduit for directing hydrogen and oxygen product from the

reactor to the combustion chamber; and

a power source for energizing the reactor.

17. The system of claim 16 wherein an engine comprises the

combustion chamber.

18. The system of claim 17 wherein the engine causes the saltwater

flow.

19. The system of claim 16 further comprising a means for adding

alcohol into the cathode chamber.

20. A method of generating variable output of hydrogen and oxygen

for supplementing a hydrocarbon fuel in an internal combustion engine intake

system by electrolyzing an electrolyte solution in a plurality of reactors, each

reactor electrically coupled to an electrical power source and comprising a

sealed cathode chamber partially filled with the solution and having an anode

immersed therein, the method comprising:

maintaining the reactors in electrolyte communication;

providing a reservoir in electrolyte communication with at least

one of the reactors;

sensing solution level in the reactors; controlling solution level responsive to the sensed level;

energizing one or more of the reactors by means of the electrical

power source responsive to engine demand;

cooling the reactors during energization; and

directing hydrogen and oxygen product from the reactors to the

engine intake system.

21. The method of claim 20 wherein the electrolyte solution is an

aqueous solution comprising about 2 to 4 percent sodium hydroxide and

about 10 to 20 percent alcohol.

22. The method of claim 20 wherein the controlling step further

comprises sinking solution from the reactors to the reservoir responsive to

sensing a high level of solution.

23. The method of claim 20 wherein the controlling step comprises

pumping solution from the reservoir to one of the reactors responsive to

sensing a low level of solution.

24. The method of claim 20 wherein the energizing step further

comprises sensing changing engine demand and responsive to changing

engine demand, coupling the source to one or more of the reactors to produce

hydrogen and oxygen output that varies according to changing engine

demand.

25. The method of claim 24 wherein sensing changing engine

demand further comprises sensing engine throttle position.

26. The method of claim 24 wherein sensing changing engine

demand further comprises sensing engine RPM.

27. The method of claim 20 wherein the energizing step further

comprises shifting reactor duty cycles such that reactor service times are

substantially equalized over time.

28. The method of claim 27 further comprising energizing initially a

first set of one or more reactors when the engine starts, and upon a subsequent

start, energizing initially a second set of one or more reactors, the second set

comprising at least one reactor absent from the first set.

29. The method of claim 20 wherein the energizing step further

comprises energizing initially a plurality of reactors, and responsive to

sensing a steady-state operating condition, de-energizing one or more

reactors.

30. The method of claim 29 wherein the steady-state operating

condition is selected from the group consisting of engine running time, engine

oil pressure, engine oil temperature, engine coolant temperature, reactor

solution temperature, and engine exhaust chemistry.

31. A method of generating variable output of hydrogen and oxygen

in a plurality of electrolytic reactors for supplementing a hydrocarbon fuel in an internal combustion engine intake system, each reactor electrically coupled

to an electrical power source and comprising a sealed cathode chamber

having an anode disposed therein, the method comprising:

maintaining the reactors in electrolyte communication;

providing a reservoir in electrolyte communication with at least

one of the reactors;

circulating through the reactors an amount of electrolyte solution

comprising about 2 to 4 percent sodium hydroxide, 10 to 20 percent

alcohol, and a balance of deionized water;

sensing solution level in the reactors;

controlling reactor solution levels responsive to the sensed level;

energizing one or more of the reactors each with 60 to 80 amps by

means of the electrical power source responsive to engine demand; and

directing hydrogen and oxygen product from the reactors to the

engine intake system.

32. The method of claim 31 wherein the circulating step further

comprises circulating the electrolyte solution through a heat exchanger.

33. An electrolyte solution for generating hydrogen and oxygen gas

by electrolysis, the solution comprising water, alcohol, and dissolved lye.

34. The solution of claim 33 comprising between about 2 and about

4 percent dissolved lye, between about 10 and about 20 percent alcohol, and a

balance of deionized water.

35. The solution of claim 33 wherein the lye comprises sodium

hydroxide.

36. The solution of claim 33 wherein the alcohol comprises

methanol.

37. An electrolyte solution for use in an electrolytic reactor for

generating hydrogen and oxygen gas as a fuel supplement for an internal

combustion engine, the solution comprising about 10 to about 20 percent

methanol and a balance of sodium hydroxide dissolved in pure water.