Fuel fired hydrogen generator
View Patent ↗A system for making and storing hydrogen comprises an IC engine, a thermal reactor to convert hydrocarbon fuels to reformate, and a separation means to separate the reformate into a hydrogen stream and a hydrogen depleted reformate stream. The hydrogen stream is compressed and stored. The hydrogen depleted reformate stream is split and sent to a thermal reactor and the IC engine. The IC engine drives the compressor for hydrogen as well as the compressor for the fuel inlet to the system. The described system and process achieves high efficiency in fuel conversion and hydrogen storage.
1. A system for producing compressed hydrogen, the system comprising:
a fuel reformer, the reformer reacting fuel, water and air to produce a hydrogen-containing reformate;
an internal combustion (IC) engine which produces mechanical energy for the system;
means for providing a purified hydrogen stream from the reformate;
a compressor for compressing the purified hydrogen; and
one or more connectors to provide the compressed purified hydrogen to a hydrogen storage means.
2. The system of claim 1 wherein the IC engine drives the hydrogen compressor to force purified hydrogen into the storage means.
3. The system of claim 2 , wherein the IC engine is powered at least in part by a hydrogen-containing gas (HCG).
4. The system of claim 3 wherein the HCG comprises at least one of reformate, purified hydrogen, and rejected impure hydrogen-depleted reformate.
5. The system of claim 1 , wherein the IC engine drives a fuel compressor.
6. The system of claim 1 , wherein the IC engine drives a turbocharger to compress air as it enters the system.
7. The system of claim 1 , wherein the means for providing a purified hydrogen stream comprises one or more of a hydrogen-selective membrane, a hydrogen-selective pressure swing absorption deviceber, a water gas shift reactor, and a preferential oxidation reactor.
8. The system of claim 7 wherein at least the hydrogen to be stored is purified sufficiently to be suitable for use with a fuel cell.
9. The system of claim 1 , wherein the hydrogen storage means comprises one or more of a pressure vessel and an enclosed metal hydride beda material reversibly absorbing hydrogen.
10. The system of claim 1 , wherein the fuel reformer is selected from a pure steam reformer, an autothermal reformer, a partial oxidation reformer, and a reformer which can operate in more than one of these modes.
11. The system of claim 1 , wherein the fuel reformer is heated by combustion of an oxygen-containing gas with one or more of reformate, purified hydrogen, hydrogen depleted reformaterejected impure hydrogen, fuel, and auxiliary fuel.
12. The system of claim 11 wherein the oxygen containing gas is the exhaust of the IC engine.
13. The system of claim 1 , wherein one or more of the steam reformer and its feeds of fuel, water and air are heated by heat exchange with at least one of the exhaust of the engine and the exhaust of a reformer-associated thermal reactor.
14. The system of claim 1 , wherein the IC engine comprises at least one of an Otto cycle engine, a spark ignition engine, and a compression ignition engine, a Diesel engine, a Wankel engine, and a Sterling engine.
15. The system of claim 14 wherein the engine is an Otto cycle engine.
16. The system of claim 1 , wherein the fuel for the reformer contains hydrogen and is one or more of a combustible gas and a combustible liquid.
17. The system of claim 1 , wherein the system is stationary.
18. The system of claim 1 , wherein the system is mobile.
19. The system claim 1 , wherein an expander is installed in the exhaust stream of the IC engine.
20. The system of claim 1 , wherein the hydrogen is compressed to at least about 500 psi.
21. The system of claim 1 , wherein the hydrogen is compressed to at least about 4000 psi.
22. A method of producing pressurized hydrogen for storage, comprising:
in an internal combustion (IC) engine, combusting a fuel and an oxygen-containing gas to produce an oxygen-containing exhaust stream and mechanical energy;
in a fuel reformer, reacting fuel, water, and an oxygen-containing gas to produce a hydrogen-containing reformate stream and a high-temperature reformer exhaust stream;
pre-heating at least one of the fuel, water, and air inputs to the fuel reformer by heat transfer with at least one of the hydrogen-containing reformate stream and the high-temperature reformer exhaust stream;
purifying the hydrogen-containing reformate stream to produce a purified hydrogen stream and a hydrogen-depleted reformate stream;
providing the hydrogen-depleted reformate stream to at least one of the IC engine and the steam reformer for use as a fuel; and
using mechanical energy from the IC engine to compress the purified hydrogen stream to a pressure suitable for storage.
23. The method of claim 22 , wherein at least a portion of the mechanical energy from the IC engine is used to compress fuel to produce a pressurized fuel stream for the fuel reformer.
24. The method of claim 23 , wherein water is added to the pressurized fuel stream to provide a fuel/water mixture to the fuel reformer.
25. The method of claim 24 , wherein the fuel/water mixture is preheated by heat exchange with at least one of the steam reformer exhaust and the high-temperature reformate stream to produce a mixture of pressurized fuel and steam for the fuel reformer.
26. The method of claim 22 , wherein the oxygen-containing gas for the steam reformer comprises the exhaust stream from the IC engine.
27. The method of claim 22 , wherein a first portion of the hydrogen-depleted reformats stream is combusted in the fuel reformer to provide heat for a fuel reforming reaction.
28. The method of claim 27 , wherein a second portion of the hydrogen-depleted reformate stream is combusted in the IC engine.
29. The method of claim 22 , further comprising pressurizing the oxygen-containing gas prior to combustion in the IC engine.
30. The method of claim 29 , wherein the oxygen-containing gas is pressurized using mechanical energy from the IC engine.
31. The method of claim 29 , further comprising using the high-temperature exhaust stream from the fuel reformer to drive an expander to pressurize the oxygen-containing gas prior to combustion in the IC engine.
32. The method of claim 22 , wherein the hydrogen is compressed to at least about 500 psi.
33. The method of claim 32 , wherein the hydrogen is compressed to at least about 4000 psi.
34. The method of claim 22 , further comprising storing the compressed hydrogen.
35. The method of claim 34 , wherein the hydrogen is stored in one or more of a pressure vessel and an enclosed metal hydride beda material reversibly absorbing hydrogen.
36. The method of claim 35 , further comprising using the compressed hydrogen in a fuel cell.
37. A system for producing compressed hydrogen, the system comprising:
a fuel reformer, the reformer reacting fuel, water and air to produce a hydrogen-containing reformate;
an internal combustion (IC) engine which produces mechanical energy for the system;
a compressor for compressing the hydrogen-containing reformate; and
one or more connectors to provide the compressed hydrogen-containing reformate to a hydrogen storage means.
38. The system of claim 37 , further comprising means for removing CO from the hydrogen-containing reformate.
39. A method of producing pressurized hydrogen for storage, comprising:
in an internal combustion (IC) engine, combusting a fuel and an oxygen-containing gas to produce an oxygen-containing exhaust stream and mechanical energy;
in a fuel reformer, reacting fuel, water, and an oxygen-containing gas to produce a hydrogen-containing reformate stream and a high-temperature reformer exhaust stream;
pre-heating at least one of the fuel, water, and air inputs to the fuel reformer by heat transfer with at least one of the hydrogen-containing reformate stream and the high-temperature reformer exhaust stream; and
using mechanical energy from the IC engine to compress the hydrogen-containing reformate stream to a pressure suitable for storage.
40. The method of claim 39 , further comprising removing CO from the hydrogen-containing reformate.