Water injection to increase hydrogen production by on-board reforming of fuel for automotive internal combustion engines

Patent metadata

Field	Value
Publication number	US-11118543-B2
Application number	US-202016817241-A
Country	US
Kind code	B2
Filing date	Mar 12, 2020
Priority date	Apr 24, 2018
Publication date	Sep 14, 2021
Grant date	Sep 14, 2021

Abstract

The performance of an automotive gasoline fueled spark-ignited internal combustion engine (ICE) optionally operated with a dedicated exhaust gas recycle system is enhanced by reforming the fuel in the presence of injected water to increase the yield of hydrogen which permits higher compression ratios and suppresses engine knock associated with pre-ignition of the fuel. Reforming can occur (a) in the cylinder with the reaction of a fuel-rich mixture and steam from the water injected into the intake manifold of one or more dedicated exhaust gas recirculation cylinders; (b) in a catalytic reformer located upstream of the engine; (c) in a catalytic reformer located downstream of the engine that receives fuel and the exhaust gas stream from the dedicated exhaust gas recirculation cylinder(s), and returns cooled reformate to the intake manifold; and (d) in a catalytic reformer that receives fuel and the exhaust gas stream from the engine exhaust gas manifold, and delivers reformate to the intake manifold.

First claim

The invention claimed is:

1. A method of operating a spark-ignited, gasoline-fueled internal combustion engine (ICE) having an associated on-board catalytic reformer, characterized by:
a. pre-heating a mixture comprising a predetermined amount of water and fuel in a vaporizer to produce a vaporized steam and fuel mixture;
b. introducing the vaporized steam and fuel mixture and a predetermined amount of air into the on-board catalytic reformer to produce a reformate stream comprising hydrogen and carbon monoxide, the carbon monoxide being subjected to the water-gas shift reaction to produce additional hydrogen and carbon dioxide to form a hydrogen-enhanced reformate stream;
c. reducing the temperature of the reformate stream to a temperature within a predetermined range to produce a cooled reformate stream,
wherein a temperature senor is provided to monitor the temperature of the reformate stream, the temperature sensor operably connected to an on-board heat exchanger, and passing the reformate to the on-board heat exchanger in controlled heat exchange relation with ambient air to cool the reformate to a temperature within the predetermined range;

d. injecting water into the reformate stream;
e. introducing the hydrogen-enhanced reformate stream with injected water, fresh fuel and ambient air into an intake manifold of the ICE; and
f. combusting the enhanced reformate, air and fuel in the presence of the injected water in the ICE to produce a hot exhaust gas stream.

2. The method of claim 1 in which the temperature sensor transmits a signal to an on-hoard engine management system (EMS) which controls the operation of the heat exchanger in response to ambient air conditions.

3. A method of operating a spark-ignited, gasoline-fueled internal combustion engine (ICE) having at least one dedicated engine cylinder that operates as a reforming cylinder that is a source of recycled exhaust gas, characterized by;
a. mixing engine intake air and a cooled exhaust gas recycle (EGR) stream in an EGR mixer to produce a mixed air/EGR stream;
b. introducing the mixed air/EGR stream into the intake manifold of the ICE for passage to the cylinders of the ICE;
c. injecting water vapor into the air/EGR mixture in the intake manifold to produce a mixed stream of air, EGR and water vapor;
d. injecting an amount of fuel into the at least one dedicated exhaust gas recycle reforming cylinder with the air, EGR and water vapor mixture before or during an intake stroke and prior to the combustion cycle to provide a fuel-rich mixture;
e. combusting and reforming the air, EGR, steam and fuel-rich mixture in the at least one dedicated exhaust gas recycle reforming cylinder to produce a mixture comprising hydrogen and carbon monoxide, the carbon monoxide being subjected to the water-gas shift reaction to produce additional hydrogen and carbon dioxide which is combusted in the reforming cylinder to produce a hot exhaust gas stream;
f. cooling the hot exhaust gas stream containing hydrogen and carbon monoxide to a temperature within a predetermined range an on-board heat exchanger or automotive intercooler to produce the cooled recirculated exhaust gas stream of step (a) and passing the cooled exhaust gas stream to the EGR mixer,
wherein the heat exchanger or intercooler is cooled by ambient air; and

g. injecting a predetermined amount of fuel into the remaining ICE cylinders for complete combustion with the air, EGR and water vapor present in those cylinders and discharging the exhaust gas stream into the atmosphere.

4. The method claim 3 in which at least a portion of the cooled exhaust stream is passed from the heat exchanger or intercooler to a condenser to condense and recover water from the exhaust gas stream.

5. The method of claim 4 in which the water from the condenser is passed to an on-board water storage vessel for use in the process or introduced directly into a vaporizer with the fuel.

6. A method of operating a spark-ignited, gasoline-fueled internal combustion engine (ICE) having at least one dedicated exhaust gas recirculation cylinder that is a source of recycled exhaust gas and an associated on-board catalytic reformer, characterized by:
a. injecting water vapor into a mixture of a predetermined amount of fuel, air and cooled reformate produced by the on-board catalytic reformer into the intake manifold of the ICE for combustion under fuel-lean/oxygen-rich conditions;
b. combusting the fuel, air and a cooled reformate stream in the respective cylinders of the ICE to produce a hot exhaust gas stream containing residual oxygen;
c. injecting fuel (i) into the at least one dedicated exhaust gas recirculation cylinder with the combustion products, or (ii) into the hot exhaust gas stream at the dedicated exhaust gas recirculation cylinder exhaust gas port, or (iii) into the hot exhaust gas stream from the at least one dedicated exhaust gas recirculation cylinder upstream of the on-board reformer;
d. passing the hot exhaust gas stream containing fuel and residual oxygen from the at least one dedicated exhaust gas recirculation cylinder to the on-board reformer;
e, catalytically reforming the hot exhaust gas stream containing fuel and residual oxygen in the on-board reformer to produce a reformate stream comprising hydrogen and carbon monoxide;
f. cooling the reformate stream to a temperature within a predetermined range in an on-board heat exchanger to produce the cooled reformate of step (b),
wherein the heat exchanger is cooled by ambient air;
g. mixing an engine intake air stream and the cooled reformate stream to produce a mixed air/reformate intake stream; and
h. introducing the mixed air/reformate mixture into the intake manifold of the ICE for passage to the cylinders of the ICE and combustion with injected fuel.

7. The method claim 6 in which at least a portion of the cooled exhaust stream is passed from the heat exchanger to a condenser to condense and recover water from the exhaust gas stream.

8. The method of claim 7 in which the water from the condenser is passed to an on-board water storage vessel for use in the process or introduced directly into a vaporizer with the fuel.

9. A method of operating a spark-ignited, gasoline-fueled internal combustion engine (ICE) having an on-hoard catalytic reformer, characterized by:
a. operating the ICE under fuel-lean/oxygen-rich conditions to produce a hot exhaust gas stream that contains residual oxygen;
b. discharging a predetermined portion of the hot exhaust gas stream into the atmosphere;
c. passing the remaining portion of the hot exhaust gas stream to an on-board heat exchanger for cooling to a temperature within a predetermined range and injecting fuel into the cooled exhaust gas stream containing residual oxygen upstream of the reformer to produce a mixed fuel and hot exhaust gas recycle (EGR) stream,
wherein the heat exchanger is cooled ambient air;
d. catalytically reforming the fuel and hot exhaust gas mixture in the reformer to produce a reformate stream comprising hydrogen and carbon monoxide;
e. cooling the reformate stream to produce a cooled reformate stream;
f. mixing an engine intake air stream and the cooled reformate stream in an EGR mixer to produce a mixed cooled reformate and air stream;
g. introducing the cooled reformate and air mixture into the intake manifold of the ICE;
h. injecting water into the combustible fuel mixture in the intake manifold with the cooled reformate hydrogen/carbon monoxide and air mixture;
i. injecting fuel into the intake manifold or engine cylinder of the ICE; and
j. igniting the combustible mixture to produce the hot exhaust gas stream of step (a) that contains excess oxygen.

10. The method o

Assignees

• Saudi Arabian Oil Co

Inventors

• Voice Alexander Karl
• Costanzo Vincent Stanley

Classifications

• F02D41/0027

  the fuel being gaseous (non-electrical control F02D19/02) · CPC title

• C01B3/48

  followed by reaction of water vapour with carbon monoxide · CPC title

• F02M26/35

  with means for cleaning or treating the recirculated gases, e.g. catalysts, condensate traps, particle filters or heaters · CPC title

• F02M26/43

  in which exhaust from only one cylinder or only a group of cylinders is directed to the intake of the engine · CPC title

• F02M31/20

  for cooling ({F02M31/005 takes precedence; use of cold F02M17/52;} cooling of charging-air or of scavenging-air F02B29/04) · CPC title