Adding Hydrogen To Vehicle Engine

Maybe, maybe not. You can increase power by injecting raw water into the cylinder, too, to create steam during combustion.

Porsche is going to DFI (Direct Fuel Injection) in about a year. While the technique has been around for a while with diesel engines it is just getting started in gasoline engines. Porsche claims an 8% increase in fuel mileage and I would suspect more horse power too.

Just getting started is wrong, Mitsubishi have had it for years, VW has been selling it also for 2 years or more as have several others, its only the US market that is just waking up from its sleep....

It might alter the flame speed, I suppose? <Wheeze>

Looking at the websites that support this technology for automotive use, they seem to share an uncommonly high bs to information coefficient; this is not promising (N.B. the sites on other some other claimed applications of so-called Brown's gas are even more dubious).

Nevertheless, if you can safely store the additional hydrogen and oxygen (stichiometric for water- a potentially explosive mix), you can certainly get more peak power from a small engine. You are likely to get somewhat better efficiency from the engine during the periods that this is added to the engine, becase of higher combustion temperatures. Given practical efficiencies of electrolysis, I'd doubt that you'd get an overall increase in system efficiency, but the ability to use a smaller engine for the same job may provide a somewhat similar effect. Against this, you could have higher burning temperatures, higher peak shock, and potentially oxidising exhaust gases - so you need to be certain the engine will withstand this.

In a word, no. This form of scam/faulty engineering energy saving/producing device has been around for many decades, and seems to keep getting "re-invented" every few years.

What people seem to forget is that while adding Hydrogen into the combustion chamber can slightly increase engine efficiency and slightly reduce fuel consumption, at the same time the current to power the electrolyser has to come from somewhere (It comes from the alternator), BUT as you pull more current out of the alternator it places more load on the engine INCREASING fuel consumption. Also, the amount of Hydrogen given off by an electrolyser running at (say) 12V 15A is minimal (we are not talking jets of Hydrogen here, we are talking bubbles). These devices have all been well and truly dis-proven using proper scientific tests and actual real time fuel and engine power analysis by numerous people and groups over the years.

There is no free lunch here. Any gains in fuel efficiency are most likely due to driving speeds, differing road conditions, tail winds or any of the numerous other conditions and events that will effect how far the vehicle will go on a full tank of gas.

About 40 years ago, there was a chemical additive that promised this sort of thing. We bought a bottle (probably about $60 in today's money) and had it run through the IR spectrometer in the Chemistry Dept. It was basically carbuerator cleaner. So, it would often give you extra power and mileage the first tank. Then most people would quit checking.

Well at least it did do something productive (so its not a total scam). Many of the "Miracle" additives and devices REDUCE the vehicles efficiency, or cause damage (or do both).

I still like the magnet around the fuel line to "align" the fuel molecules <LOL>. Somehow quality control failed and a variant is now available in this country from a vehicle accessory store (who shall remain nameless).

A fool and his/her money are soon parted.

______________________________________________________________

"Lose weight FAST! Send me all your loose pocket change".

Thanks everyone. The way I tend to look at these things is if you can do a analysis of what's coming out of the tail pipe and it's clean, you're not going to be able to do much to improve the usage of your fuel. There's obviously no energy gain from the actual burning of the hydrogen as it's cost you power to create it and all you get back is what you put in, less a tithe to efficiency. Different if you're using cheap grid power or solar to create the hydrogen and then putting a tank full in.

Interesting though, as the operator of the setup in question swears it saves fuel but I've heard similar claims for all sorts of widgets over the years. I'd like to see long term log book data.

hey Woody, i have been using a home-made electrolyzer for about 3 years- I have proved, over many fills, a 7% increase in economy, over same type of driving, same areas- what one has to be aware of ; use the same brand of fuel; fill exactly to same amount; run vehicle till tank empty(beware level of pickup- ensure that vehicle stops on level ground- tank dead empty)- add measured amount of fuel (in my case 10l) to get you mobile again. Just to clarify, if I don,t use electrolyzer, I get 7%, ie standard mpg, less. I first started experimenting with a naive view that a car could run on water- this is absolutely impossible( I am talking of on- board production of hydrogen,or even so-called Brown,s gas,ie hydroxy)- because the amount of energy needed to split the water would take another on-board engine running a 100,s of amps alternator, to get enough gas. I can say that the addition of hydroxy to the unleaded fuel the car uses definitely is definitely not harmful in any way- in fact, the engine is clean as a whistle inside( I have not had to tune it up for 90,000 kms, & still don,t have to- I think that the addition of hydroxy makes the unleaded burn better)- I just change the oil/filter/etc at 10,000 kms. To sum up, my electrolyzer consists of a glass tomato jar with a metal screw lid- s/s electrodes are insulated from the lid- the water is rain water with miniscule amount of caustic soda added to give 3 amps cold current at 12 v(nom)- as electrolyte heats up, current increases to 9 amps- it definitely is possible to over water the carby-ie jets blockup, no run etc- but the figures I have given work for my motor(1.6l). The output gas from the electrolyzer is put into the top of the aircleaner. Oh, & the oil stays cleaner far longer(6000 kms longer). I have no vested financial interest in this matter- just contributing my experience.

That's very interesting Neil. What you are saying is very similar to what the person whose gadget prompted this question. He's running 15 amps into his and feeding a 4.1 litre engine which runs on either LPG or unleaded. He's a scientific type and I would have thought would have been reasonably objective in his comparisons. It's not hard to do comparisons if you do it over a large number of fills. 5000kms with hydrogen and 5000kms without and compare total fuel used. Unfortunately so many comparisons are done on one tank and there's so many variables. I get very dubious over massive claims. Your 7% is interesting. What do you think is happening?

As I said, I have tested this device over 90,000km- I know it works- i really don,t care if anyone believes it or not- as 1 reply said- try it- it,s easy- almost any one can do it- as I said in my post, I think it improves the burn of the unleaded fuel-(all other settings are unchanged)- I pulled a spark plug out @ 90,000km- looked as clean as new- gap had increased from 30 thou to 50 thou- but still no misfiring, & still 7% increase in fuel economy. As to those who say there is nothing new under the sun, this is mainly correct- there have been & still are scams promising(Isaw it last week" burn up to 40 % of water as fuel- only $2,000 installed")- however, all must remember that only 15% of the energy in the fuel is delivered to the driving wheels- the rest is wasted as heat. Anything that can improve that wasted amount is viable.

Dear all,

I am certainly not an expert on this subject but my interest for it yielded some results over the years. Here is one document worth reading mentioning some sources.

Randolph Toom

--------------------------------------------

ONBOARD GENERATION OF HYDROGEN-RICH GASEOUS FUELS - A REVIEW

- A Review International Journal of Hydrogen Energy Vol.19, No.7, pp. 557-572, 1994,
Received for publication 1 September 1993 By: Y. Jamal and M.L.Wyszynski *

School of Manufacturing and Mechanical Engineering University of Birmingham, Birmingham B15 2TT, UK.

ABSTRACT

Hydrogen has a good potential as an alternative fuel for spark ignition engines. It can extend the lean flammability limit of conventional fuels in order to achieve higher thermal efficiency and lower exhaust emissions.

This paper reviews the use of hydrogen and hydrogen-enriched gasoline as a fuel for SI engines and the techniques used to generate hydrogen from liquid fuels such as gasoline and methanol, on-board the vehicle. The processes of thermal decomposition, steam reforming, partial oxidation and exhaust gas reforming are evaluated.

A considerable amount of both theoretical and experimental work has been done in this field. Predictive and experimental results of the various investigators are reviewed and summarised.

INTRODUCTION

The scarcity of fossil fuels and the associated pollution problems have attracted the attention of researchers towards the search for alternative fuels. With any alternative fuel, its availability of the source, as well as the emissions of pollutants are most important from the aspect of energy preservation and environment, respectively, while its potential effects on the engine performance and the form of storage will be significant issues from the stand point of the engine and vehicle technologies.

An alternative energy carrier that has great environmental advantages is hydrogen. It is a clean fuel, when burned in air, produces non-toxic exhaust emissions except at some equivalence ratios, where its high flame temperature results in significant NOx levels in the exhaust products. The use of gaseous fuels inducted with air does, however, limit the total power output of the engine due to the reduction of volume of air aspirated.

The current approach for the reduction of emissions relies on three-way catalytic converters. An alternate and more basic approach to the emissions problem is to modify the initial combustion process in the engine by using lean mixtures. The primary advantage of lean burn is that it increasingly reduces NOx and CO. The problem with it is that engine power declines rapidly, while unburned hydrocarbon emissions increase because of misfire [1]. Unfortunately, an engine still produces unacceptably high NOx exhaust pollutants near the lean flammability limit of gasoline. In a practical sense, lean-burning engines are limited by the onset of engine misfiring as the lean flammability limit of any fuel is approached. For this reason emission standards for NOx could not be achieved in the engine by operating lean, using only gasoline. Mixtures of hydrogen and gasoline, on the other hand, can burn lean enough to meet this requirement [2].
Hydrogen may be used to extend the lean limit of conventional fuels in order to achieve higher efficiency and lower pollutant emissions. Because of its wide flammability limits and high flame speeds the Hydrogen-rich fuel lends itself readily to ultra lean combustion and should allow the use of higher compression ratios. Combining the increase in heating value, the recovery of waste energy from the engine exhaust, lean operation and higher compression ratios provides potentially high increase in thermal efficiency for the hydrogen-enriched fuels over that of the conventional fuels. However, there are significant problems associated with the use of hydrogen, especially concerning production and storage. Hydrogen is commercially produced by electrolysis of water and by coal gasification. These methods are not widely used because they are more expensive than steam reforming of natural gas or partial oxidation of heavy oils [3]. Most of the worlds hydrogen is currently derived from hydrocarbons such as oil or natural gas, via the catalytic steam reformation [4, 5]. There are generally three ways to store hydrogen in an automobile: as a gas dissolved in a metal (metal hydride), as a cryogenic liquid or as a compressed gas. Hydride storage is the simplest and the safest, but it increases vehicle weight and results in a severe fuel economy penalty. Liquid hydrogen is light, but due to its low energy density occupies three times as much volume as gasoline. Storage as a compressed gas is inexpensive and provides for ease of operation but its weight and bulk is the main problem.

One solution to the storage problem is the onboard hydrogen generation from a suitable high energy density patent fuel such as gasoline or methanol. With this form of storage, the technical problem is how to generate the hydrogen. There are a number of methods to generate hydrogen from such fuels. The most common amongst those are partial oxidation, steam reforming, thermal decomposition and exhaust-gas reforming. Partial oxidation is not usually considered to be attractive in terms of efficiency because it is an exothermic process, and the resulting hydrogen containing fuel gas has a lower calorific value than that of original feed stock. However, it is an interesting means of generating free hydrogen gas for use as a charge supplement in ultra lean combustion exercises [6].

On the other hand, steam reforming is an endothermic process, the fuel gas thus produced has higher calorific value than the feed stock, and the efficiency of the process is quite favourable, particularly if the heat energy requirement is supplied from a source which would otherwise be wasted, like hot engine exhaust gases [7]. Thermal decomposition of hydrocarbons results in the formation of hydrogen and carbon. The difficulty of gasifying or handling the solid carbon makes hydrocarbon decomposition not suitable for on board hydrogen generation. Methanol can be catalytically decomposed into hydrogen and carbon monoxide at temperatures of the order of 250°C [8].

The reaction is endothermic and requires a heat source to provide energy. This energy can usually be supplied by the engine exhaust gas. In exhaust gas reforming fuels are reformed catalytically by direct contact with a portion of hot products of combustion utilising the fact that exhaust gases contain a certain quantity of steam. The fuel gas thus generated contain quantities of hydrogen, carbon monoxide and nitrogen, thus providing a potential for lean combustion leading to lower emissions and higher engine thermal efficiency than conventional fuel [9]. The objective of this paper is to review the use of hydrogen as a fuel for gasoline engine, in particular as a supplementary fuel, and to discuss the different methods of onboard hydrogen generation. The main parts of the paper:

USE OF HYDROGEN AS A FUEL

Properties Of Hydrogen , Table.1 Comparative Properties of Hydrogen , Spark Ignition Engine performance of Hydrogen , SI Engine Performance of Hydrogen Enriched Gasoline , Fuel reforming techniques as Thermal Decomposition , Steam Reforming , Partial Oxidation , Exhaust-Gas Reforming and the DISCUSSION have been omitted in the on-line abstract.

CONCLUSIONS

1. Spark ignition engine can be operated efficiently at light loads using hydrogen fuel alone.

2. Some charge dilution to avoid knock is essential to permit operation with hydrogen at higher power output.

3. Hydrogen supplementation of gasoline combustion has been shown to yield reduction in fuel consumption.

4. Hydrogen-rich gaseous fuels can be burned under ultra lean conditions to yield very low NOx emissions without running into lean flammability limit problems.

5. The lean burning conditions give possibilities for very low CO emissions.

6. Enrichment by pure hydrogen does not appear to be a sufficient means of reducing HC emission as measured by total HC methods.

7. Consideration of the hydrogen/gasoline/air combustion process, coupled with the observation of steady state test-bed performance, suggested the possibility that the hydrogen and gasoline oxidation processes are independent and may result in two flames.

8. Onboard hydrogen generation from liquid fuels, either hydrocarbons or alcohols, is technically feasible.

9. The economy benefit from running lean almost compensates for the energy requirements for making hydrogen from gasoline in an atmospheric reactor.

10. Some of the waste heat from the vehicle exhaust gas can be reclaimed by converting it to chemical energy in the fuel.

11. Optimum performance of a reforming reactor occurs at the lowest possible excess oxidant factor just short of the soot formation limit.

12. The use of a catalyst in the reforming reactor allows a closer approach to equilibrium H2 yields.

13. The use of reformed fuel (compared to liquid raw fuel) may result in higher engine thermal efficiency in the low power range, with the improvement due to the increase in the heating value of the gaseous fuel resulting from the reforming reaction.

14. Use of reformed fuel (compared to liquid fuel) in a spark ignition engine may result in lower exhaust emissions, particularly of the heavier and aromatic hydrocarbons and NOx.

15. In all cases considered, a considerable loss in maximum power capacity of the engine occurs as a result of the use of gaseous fuels and by operating under lean conditions. Effective utilisation of onboard hydrogen generation calls for lightweight high displacement engines to overcome this disadvantage.

16. An automobile could not be operated over the required power range when it was fed exclusively with reformed fuel. A supplementary fuel supply would be required to reach the higher loads.

REFERENCES

1. C. Cragg, Cleaning up Motor Car Pollution New fuels and Technology. Financial Times Management Report, FT Business Information, London, 1992.

2. F. W. Hoehn and M. W. Dowdy, Feasibility Demonstration of a Road Vehicle Fueled with Hydrogen Enriched Gasoline. SAE Paper No. 749105, Presented at the Ninth Intersociety Energy Conversion Engineering Conference, San Francisco, California ,August 26-30, 1974.

3. C. A. Kukkonen, Hydrogen as an Automotive Fuel. SAE Transaction Paper 810349, (SP-480), Vol. 90, Section 2, 1981.

4. M. Steinberg and H. C. Cheng, Modern and Prospective Technologies for H2-Production from Fossil-Fuels. International Journal of Hydrogen Energy, Vol. 14, No. 11, pp 797-820, 1989.

5. N. C. Thomas, The Role of Hydrogen as a Future Fuel. Science Progress, Vol. 72, No. 285, pp 37-52, 1988.

6. J. Houseman and D. J. Cerini, Onboard Hydrogen Generator for a Partial Hydrogen Injection Internal Combustion Engine. SAE Paper 740600, Presented at The National West Coast Meeting of the Society of Automotive Engineers, Anaheim, California, August 12-16, 1974.

7. M. R. Jones, J. W. Dunn and M. L. Wyszynski, Thermodynamic Feasibility Studies of the Exhaust-Gas Reforming of Hydrocarbon Fuels. I Mech E International Conference: Automotive Power Systems Environment and Conservation, Paper No. C394/014, Chester, England, September 10-12, 1990.

8. J. Houseman and G. E. Voecks, Hydrogen engines based on liquid fuels, a review. Hydrogen Energy Progress, Proceedings of 3rd World Hydrogen Energy Conference, Vol. 2, pp 949-968, Tokyo, Pergamon Press, Oxford, 1981.

9. M. R. Jones, Feasibility Studies of the Exhaust Gas Reforming of Hydrocarbon and Alcohol Fuels, PhD Thesis, Automotive Engineering Centre, School of Manufacturing and Mechanical Engineering, University of Birmingham, April 1992.

10. C. A. Amann, Future Automotive Fuels from a United-States Standpoint. International Journal of Vehicle Design, Vol. 13, No. 5-6, pp 407-427, 1992. 11. M. A. Deluchi, Hydrogen Vehicles: An Evaluation of Fuel Storage, Performance, Safety, Environmental Impacts, and Cost. International Journal of Hydrogen Energy, Vol. 14, No. 2, pp 81-130, 1989.

12. Karl S. Young, Hydrogen fuel storage using activated carbon for vehicles. SAE Paper No. 911703 (P-245), 1991.

13. C. A. Amann, The Passenger Car and the Greenhouse Effect. International Journal of Vehicle Design, Vol. 13, No. 4, pp 305-334, 1992.

14. Ennio Peres Da Silva, The UNICAMP experiments with hydrogen vehicles. SAE Paper No. 911704 (P-245), 1991.

15. John Templeman, Fill Er Up - With Hydrogen, Please. Business Week (Industrial/Technology Edition), Iss. 3202, pp 62-63, March 4, 1991.

16. Bill Siuru, R & D in the Fast Lane. Mechanical Engineering, Vol. 111, Iss. 10, pp 62-67, Oct 1989.

17. R. H. Thring, Alternative Fuels for Spark Ignition Engines. SAE Transaction Paper 831685, (SP-559), Vol. 92, Section 4, 1983.

18. T. N. Veziroglu and F. Barbir, Hydrogen - The Wonder Fuel. International Journal of Hydrogen Energy, Vol. 17, No. 6, pp 391-404, 1992.

19. T. Petkov, T. N. Veziroglu and J. W. Sheffield, An Outlook of Hydrogen as an Automotive Fuel. International Journal of Hydrogen Energy, Vol. 14, No. 7, pp 449-474,1989.

20. Ematage, A. L., Microprocessor Engine Management applied to Hydrogen / Petrol Operation. PhD Thesis, University of Technology, Loughborough, United Kingdom, 1987.

21. R. F. Stebar and F. B. Parks, Emission Control with Lean Operation Using Hydrogen-Supplemented Fuel. SAE Transaction Paper 740187, Vol. 83, Section 1, G M Research Laboratories, Paper presented at SAE Automotive Engineering Congress, Detroit, Michigan, February 25 - March 1,1974.

22. Laurence O. Williams, Hydrogen Power An Introduction to Hydrogen Energy and its Application., Pergamon Press, London, 1980.

23. H. B. Mathur and L. M. Das, Performance Characteristics of a Hydrogen Fueled SI Engine Using Timed Manifold Injection. International Journal of Hydrogen Energy, Vol. 16, No. 2, pp 115-127, 1991.

24. Bob Johnstone, Research & Innovation: Stepping on the Gas. Far East Review, Vol. 155, Iss. 24, pp 90, June 18,1992.

25. J. G. Finegold and W. D. Van Vorst, Engine Performance with Gasoline and Hydrogen: A Comparative Study. Paper Presented at The Hydrogen Economy Energy (THEME) Conference, Miami Beach, Florida, March 18-20, 1974.

26. E. M. Goodger, Alternative Fuels Chemical Energy Resources Macmillan Press, London, 1980.

27. M. D. Marton, Gaseous Automotive Fuels from Steam Reformed Liquid Hydrocarbons. SAE Paper 780457, 1978.

28. J. F. Cassidy, Emissions and Total Energy Consumption of a Multicylinder Piston Engine Running on Gasoline and Hydrogen-Gasoline Mixture. NASA Technical Note D-8487, Lewis Research Centre, Cleveland, Ohio, May 1977.

29. G. Yu, C. K. Law and C. K. Wu, Laminar Flame Speeds of Hydrocarbon + Air Mixtures with Hydrogen Addition. Combustion and Flame Vol. 63, pp 339-347, Elsevier Science Publishing,, New York, 1986.

30. B. E. Milton and J. C. Keck. Laminar Burning Velocities in Stoichiometric Hydrogen and Hydrogen-Hydrocarbon Gas Mixtures. Combustion and Flame Vol. 58: 13-22, Elsevier Science Publishing, New York, 1984.

31. R. Bresheas, H. Cotrill and J. Rupe, Partial Hydrogen Injection into Internal Combustion Engines Effect on Emissions and Fuel Economy. Presented at the First Symposium on Low Pollution Power Systems Development, Ann Arbor, Michigan, October 14-19,1973.

32. F. B. Parks, A Single-Cylinder Engine Study of Hydrogen-Rich Fuels. SAE Transaction Paper 760099, Vol. 85, Section 1, 1976.

33. M. J. Rauckis and W. J. McLean, The Effect of Hydrogen Addition on Ignition Delays and Flame Propagation in Spark Ignition Engines. Combustion Science and Technology, Vol. 19, pp 207-216, 1979.

34. G. G. Lucas and W. L. Richards, The Hydrogen/Petrol Engine S The means to give good part load Thermal Efficiency. SAE Paper No. 820315, 1982.

35. E. Sher and Y. Hacohen, On The Modelling of a SI 4-Stroke Cycle Engine Fueled with Hydrogen-Enriched Gasoline. International Journal of Hydrogen Energy, Vol. 12, No. 11, pp 773-781,1987.

36. D. Sfinteanu and N. Apostolescu, Efficiency, Pollution - Control and Performances of Hydrogen-Fueled Passenger Cars. International Journal of Hydrogen Energy, Vol. 17, No. 7, pp 539-542, 1992.

37. Fukutani and N. Kunioshi, Fuel Mixing Effects on Propagation of Premixed Flames. 1. Hydrogen Plus Carbon Monoxide Flames. Bulletin of the Chemical Society of Japan, Vol. 65, No. 10, pp 2569-2572, 1992.

38. S. J. Yoo and C. I. Lee, Feasibility Evaluation of Reformed Methanol Usage to Spark Ignition Engine. SAE Paper No. 871166, 1987.

39. G. E. Voecks, S. Dawson and J. Houseman, Operation of a Catalytic Methanol Decomposition Reactor for Vehicular Use. Jet Propulsion Laboratory, Proceedings, 4th International Symposium on Alcohol Fuels Technology, Guaruja, Brazil, October 5-8,1980.

40. L. Pettersson and K. Sjostrom, Onboard Hydrogen Generation by Methanol Decomposition for the Cold Start of Neat Methanol Engines. International Journal of Hydrogen Energy, Vol. 16, No. 10, pp 671-676, 1991.

41. T. Sakai, I. Yamaguchi, M. Asano, T. Ayusawa and Y. K. Kim, Transient Performance Development on Dissociated Methanol Fueled Passenger Car. SAE Paper 871169, 1987.

42. T. Sato, M. Tanaka and K. Agawa, A Study on the Reformed-Methanol Engine., SAE Paper 861237, 1986.

43. D. M. McCall, T. R. Lalk, R. R. Davison and W. B. Harris, Performance and Emissions Characteristics of a Spark Ignition Engine fueled with Dissociated and Steam - Reformed Methanol. SAE Transaction Paper No. 852106, Vol. 94, (SP - 638), 1985.

44. N. D. Brinkman and R. F. Steber, A Comparison of Methanol and Dissociated Methanol Illustrating effects of fuel properties on Engine efficiency Experiments and Thermodynamics Analysis. SAE Transactions Paper No. 850217, Vol. 94, 1985.

45. I. Yamaguchi, T. Takishita, T. Sakai, T. Ayusawa and Y. K. Kim, Development Research on Dissociated Methanol Fueled Spark Ignition Engine. SAE Paper No. 852201, (P-169), Proceedings of 4th Joint Symposium on Internal Combustion Engines, January 1984.

46. R. L. Bechtold and T. J. Timbario, The Theoretical limits and Practical Considerations of Decomposed Methanol as a Light-duty vehicle Fuel. Paper A-5, Proceedings VI International Symposium on Alcohol Fuels Technology, Ottawa, Canada, May 21-25, 1984.

47. E. Anthonissen and J. J. Wallace, Dissociated Methanol Engine Testing Results Using H2-CO Mixtures. Proceedings of the 18th Intersociety Energy Conversion Engineering Conference, Orlando, (SAE 839091), Florida, August 21-26, 1983.

48. B. Lindner and K. Sjostrom, Operation of an Internal Combustion Engine under Lean Conditions With Hydrogen Produced in an Onboard Methanol Reforming Unit. V International Alcohol Fuel Symposium on Alcohol Fuels Technology, Auckland, New Zealand, May 1982.

49. Martin V. Twigg, ICI, Catalyst Handbook. 2nd Edition, chapter 5, Wolfe Scientific, London, 1989.

50. J. Houseman and D. J. Cerini, Onboard Hydrogen Generation for Automobiles. 11th Intersociety Energy Conversion Engineering Conference, SAE Paper 769001, New York, Presented at the 11th IECEC, Proceedings, pp 6-15, 1976.

51. M. S. Newkirk and J. L. Abel, The Boston Reformed Fuel Car. SAE Transactions Paper No. 720670, Vol. 81, 1972.

52. J. Houseman and F. W. Hoehn, A Two-Charge Engine Concept: Hydrogen Enrichment. SAE Transactions Paper No. 741169, Vol. 83, Presented at the International Stratified Charge Engine Conference, Troy, Mich., October 30 - November 1, 1974.

53. F. W. Hoehn, R. L. L. Baisley and M. W. Dowdy, Advances in Ultra lean Combustion Technology using Hydrogen-Enriched Gasoline. Proceedings of the 10th Intersociety Energy Conversion Engineering Conference, SAE Paper 759173, 1975.

54. Jet Propulsion Laboratory California Institute of Technology, Hydrogen Enrichment Concept Preliminary Evaluation. Final Report, US Energy Research and Development Administration, Technical Information Centre TEC-75/007, JPL Document 1200-237, Prepared for EPA under Interagency Agreement EPA-IAG-D4-0548, December-15, 1975.

55. F. L. Kester, A. J. Konopka and E. H. Camara, Onboard Steam Reforming of Methanol to Fuel the Automotive Hydrogen Engine. Intersociety Energy Conversion Engineering Conference, SAE Paper 759175, New York, 1975. (p 1176)

56. J. G. Finegold, Reformed Methanol Vehicle System Considerations. Proceedings of the 18th Intersociety Energy Conversion Engineering Conference (IECEC), Orlando, Florida, , SAE Paper 839092, 557, August 1983.

57. J. W. Jenkins of Johnson Matthey plc., Catalytic Generation of Hydrogen from Hydrocarbons. European Patent Publication No. 0 262 947,1988.

58. O. B. Lindstrom, Fuel Treatment for Combustion Engines. USA Patent 3918412, 1975.

59. K. Sjostrom, Sren Eriksson and G. Landqvist., Onboard Hydrogen Generation for Hydrogen Injection into Internal Combustion Engines. SAE Paper 810348, (SP-480), 1981.

60. R. Jones and M. L. Wyszynski, Exhaust-Gas Reforming of Hydrocarbon Fuels. SAE Paper No. 931096 (P-263), presented at the SAE - IMechE Conference: Vehicle Thermal Management Systems, Columbus, Ohio, 28 March - 1April 1993.

61. Bradley and C. G. W. Sheppard, Combustion Tests with Reformed Fuel. Ref.Exp, 1992. (Unpublished report, University of Leeds).

62. C. R. Ferguson, Internal Combustion Engines Applied Thermosciences. J Wiley & Sons, New York, 1986.

63. E. Sher and N. Ozdor, Laminar Burning Velocities of n-butane/air Mixtures Enriched with Hydrogen. Combustion and Flame, Vol. 89, No. 2, 214-220, 1992.

64. H. West, The On-line Characterisation of Hydrocarbon Species in Engine Exhaust Gases using a Mass Spectrometer, with Applications to the Reduction of Harmful Hydrocarbon Species by Fuel Reforming. PhD Thesis, School of Manufacturing and Mechanical Engineering, University of Birmingham, April 1993.

Source : http://www.nutech2000.com/webtext/milage/hydrogensup.htm

Great post.

9. The economy benefit from running lean almost compensates for the energy requirements for making hydrogen from gasoline in an atmospheric reactor.

This squares with my thinking on the subject, and making H2 from water is no more efficient than making it from gasoline. So one would expect a net loss in fuel efficiency, even if the fuel injection system was set to run lean.

Check GEET device of Paul Pantone - Plasma Fuel for Cars. This can give you some ideas.

Thank you. Excellent reference.

I know from well instrumented lab and road testing of engines we in engineering did back in the paleozoic at Univ of Alberta there are devices and systems out there that change everything! I remember people complaining about big companies having bought up and sitting on patents, but patents expire and the best things were never patented. On the surface the feeble hydrolysis of water to hydrogen and oxygen is less than a zero sum game, but if you really test it I am confident it will not be what you expect. The GEET device is a different system - a variation on a long line of suppressed devices involving combining and altering the fuel / exhaust / water through catalyzed reformation of the mix. These are in effect systems to use waste heat to facilitate chemical reactions which in some cases can very effectively cause there to be more fuel &/or cleaner fuel &/or fuel that burns significantly differently from straight gasoline.. Which brings me around to OCTANE rating. I learned in school, and we tested and found it to be true - that octane is merely an indication of the rate of flame propagation across the fuel/air mixture at pressure and temperature in the enginer cylinder. I've been amazed at how many people - even in the oil industry think higher octane gasoline = better performance out of their engine. If the compression ratio and timeing in your car is such that 87 octane gasoline is appropriate - you will only burn your exhaust valves if you run it on 93 octane - because the flame front with the higher octane gasoline will likely be still progressing across the combustion chamber when the exhaust stroke starts. When you mess with gasoline be careful to pay attention to whether the engine is knocking or whether you have flames coming out the ports if you disconnect the exhaust manifold - because adding anything to the gasoline - or altering the gasoline itself will result in changes to the flame propagation rate.

What impacts performance and fuel economy are the efficiency of the conversion of the energy in the fuel to mechanical energy, and the energy content of the fuel. In the very distant old days some gasolines had higher energy content and could give you higher mileage &/or better performance. Gasoline today is a fairly uniform product w/r to energy content. All these devices which catalyze perversions of the fuel stream or inject H2 and O2 are likely reducing the energy content of the fuel stream - just as is currently being done routinely by adding ethanol or methanol to the gasoline, but if they significantly alter the efficiency of burn / conversion of chemical energy to mechanical energy their claims can be very real.

I have a dual fuel car - gasoline and natural gas. NG is a much lower energy content fuel than gasoline, but I get much better mileage in terms of BTU/mile running on NG because it burns so much better (clean and thoroughly) than gasoline does. I can't understand why with the urgent rush to energy independence - Bio Methane - aka NG isn't being developed in the U.S. Ethanol / Methanol is a relatively lame approach promulgated by brain dead politicians.

I saw someone's favorite quote was something to the effect of any engineer/scientist who says something is impossible is wrong. Put another way - today's heresy is tomorrow's orthodoxy.

While I agree with Jack's post (#4), the only way I can see that you can prove it to yourself is to build one and connect it to your engine.

It shouldn't be difficult. After reading Neil's post (#9), I got curious enough to want to try it myself, just to see. If it doesn't work, it's a simple matter to take it off, right?

As I understand it, the oxy-hydrogen mix is generated at (roughly) a continuous rate and applied to the input of the carburettor as it is generated. That means the mix will be "wasted" whenever the vehicle is stationary. If the principle works, it can still only be beneficial under suitable traffic conditions - even if it is simply compensating for otherwise poor carburation control by keeping the engine clean...

BTW, I would estimate that (once warmed up) you are diverting between 1 and 3% of your average power to the generation of the mix.

As described to me, the gas is drawn into the engine via a small vacuum line so "no suck, no gas"; at least until it builds pressure and pushes through.

I'm not sure on the 1-3%. 15 amps is comparable to high beam head lights and on a 4.1 litre engine I wouldn't think you could pick that. I've done a lot of long distance night driving pulling about 40 amps for lights and my mileage is actually better than the comparable daytime trip. Partly due to less traffic but mainly due to cooler and denser air. I suppose I should try a night trip with the lights off for comparison but I'm not that dedicated!

You have to wonder what any of this stuff would do with a fuel injected computer controlled fuel system.

The fleet average fuel economy (or lack of economy) in the US is 20 mpg. This translates into an average HP consumption of 25 HP (much higher than for a 60 mph cruise, for which most cars requires less then 15 hp). ( The HP translation comes from a spreadsheet I use to model vehicle behaviour, and I've calibrated it with data from several real-world cars.) 25 HP = 18.65 kW

15A x 13.2 V = 198 W

198/18650 = .0106 = 1%

For a high-efficiency car (such as a Prius) getting 40 MPG, then the energy consumed in creating the H2 + O2 gases would be 2%.

Nowadays, 99% of the fuel that goes into an engine is completely burned in the engine (and the remaining 1% is burned in the cat converter). If the electrolysis system is simply generating more fuel, then fuel efficiency should decline slightly, because it takes more energy to create the gases than you get out. The quantities are so small, however, than I don't think you could reliably measure it. (1% more energy consumed, .7% returned for a net loss of .3%) The seasonal variation is energy density in the fuel (about 1%) would have a larger effect.

One poster above said he runs the tank down to empty, then adds 10 gallons. This won't work accurately. You've got to top the tank up to the point where you can see the fuel in the filler neck, and measure down from the nozzle restrictor to the fuel level. Then drive a couple hundred miles, record the precise, mileage, and refill to exactly the same point, at the same pump, so the car slope is the same (there is apt to be an air bubble at the top of the tank that is not vented by the filler neck). Then do the math. Using the fuel gauge to indicate "empty" is hugely inaccurate. Running the car until it needs to be towed would be more accurate than relying on the gauge, but less accurate than the standard method I described, and a huge inconvenience, as well.

Changes in driving habits (over the same route) can change fuel economy by 7 % (from 20 to 21.4) and changes in the route driven, loads carried, etc. can change it by far more than that (easily 50%). So realistically, the only way you can test to measure a 7% change is on a dynamometer. If instead, you do two long term road tests (you'd need to go through at least ten full tanks for both alternatives to get close to reliable averages) then the 10,000 miles accumulated affects the test: the tires wear (reducing rolling resistance), the engine wears (which, early in its life, will noticeably improve fuel efficiency, and late in its life will decrease it) etc, etc. A dyno is the only way of coming close to a real, reliable measurement.

Looking at it statistically, (for road tests) each tankful is one sample. So it takes a ton of tankfuls to get to a point where 7% is significant at a high confidence level. Go through enough tankfuls, and you are testing a different car beginning end.

What plausible explanation would there be for a net increase in mileage? If the gases are acting as a catalyst, then 1. h2 and o2 are very unlikely catalysts. 2. catalysing a reaction that is already 99% complete in the required amount of time seems pointless. Increase in water content (water injection effects)? Doubt it. Fooling the lambda loop to lean out fuel? 7%? Doubt it. But the conjecture seems pointless, without there being unbiased dyno tests to support the mileage claims.

On the other hand, it seems I've read about trucking companies that use these things -- maybe I'll look around the web a little.

To more accurately measure mileage - route the gasoline through a closed graduated cylinder rigidly mounted high in the passenger's compartment, have it valved and tubed to fill from the fuel pump, and by switching valves - to replace the fuel pump as the fuel supply to the engine. This worked in the old days with carburetors - probably needs to be more elaborate with fuel injection. As your prep for your test fill the graduated cylinder. Switch to the cylinder as the source for fuel, and record mileage by means of a precise 5th wheel odometer attached to the rear bumper, the odometer on your dash board is too crude. The driving test should be repeatable - i.e. flat road, no traffic or there will be no basis to compare even the most precise of measurements.

The person's whose device prompted this query was running mainly on propane. He claimed similar results when running on unleaded.

I also run on propane (30 - 40 litres a day of the stuff) and have found that it's fairly easy to get an good picture of consumption as being a dual fuel vehicle you can run the tank empty. When you fill you have an automatic limiter which provides reasonably consistent fills. When I first went to propane I played about a lot with distributor curves and found quite small changes in consumption to be detectable

The problem with fuel saving gadgets is that there's a certain amount of wishful thinking and really the biggest economy device is the drivers right foot. Hence my fondness for long term figures.

The problem with fuel saving gadgets is that there's a certain amount of wishful thinking and really the biggest economy device is the drivers right foot. Hence my fondness for long term figures.

Yep.

I would have to guess the small amount of H2 injection does affect the flame travel for a bit more power.

Reminds me that in the early 1960s, some farmers installed LPG injection on diesel powered tractors for HP increase. It did work to increase hp 15-25%, but the engine crankshafts and bearings were not sized to handle the extra pressures that resulted.

If you are inclined to this type of experimentation, be careful with that right foot!

Correct, and this is still applied today on long haul trucks. You should be able to find it somewhere in the internet. Some also do it with pure propane. Fuel economy is one thing , emissions reduction is another advantage. Especially particles are reduced.

Randolph

Hey Woody, if you are using auto lpg, or even domestic lpg, the ratio of propane to butane, or other, is extremely variable!. Auto lpg is supposed to be 96% prop & 4% butane, but in practice can be wildly out- domestic lpg is supposed to be 100% butane, but in practise can be same as auto lpg, which can be any mixture!. I have auto lpg ticket, & know that the same tanker that refills domestic tanks, then goes on to refill auto lpg tanks(no they dont have 2 seperate tanks )- I have found that the so-called auto lpg burns exactly the same as so-called domestic lpg, in both situations- BUT THE AUTO IS HALF THE PRICE!!- so guess what informed people do?.

I presume the domestic 100% butane is a slip of the keyboard? You are of course totally correct. Auto LPG is often cut with all sorts of things whereas LPG for other purposes should be close to 100% propane. What happens in areas with limited auto LPG consumption is that the same truck fills both. Sometimes it means that two service stations, side by side, but who are supplied from different companies are actually selling different products. Beware cheap LPG, it can be hard to drive on a bargain! I've established it numerous times that you can count on an average 10% more distance on pure propane and in extreme cases the dregs of the cheapy mix can do horrible things as your engine tries to run on all sorts of obscure hydro carbons.

Oh no, Mr Nutwood!. Domestic consumption of lpg in Australia- ie what you burn in your cylinders, from small to large- is supposed to be 100% Butane!. Ask any Govt authority- auto lpg is supposed to be 96% propane,4 % butane, but as you know, can be any mix- SO CAN DOMESTIC LPG- no enforcement is carried out- it seems the oil companies can do what, & charge what, they like-ie they are above GOVT,s(as we know, when questions are asked why prices are higher than world parity, the govt reps always say they think the oil co,s are correct- wouldn,t be anything to do with increased rev from excise, would it?).

I'm sorry Neil, you're confusing me here "ie what you burn in your cylinders, from small to large- is supposed to be 100% Butane!." Am I missing some joke here or are you completely mixing up butane and propane? They are totally different gases with totally different properties. Butane is good for lighters because of it's boiling point but wouldn't be a good thing in your stove!

I assume this is all about a typo in post #26 that Neil Kwyrer hasn't noticed yet??

I don't know to be honest (wasn't it #27?, near enough anyway!). I assumed the original "domestic=100% butane" reference was a slip of the keyboard but he's just re-made the assertion. Who knows? Must confess it's made me a bit sceptical of Neils other claims of the merits of the hydrogen system, which is a pity as I'd like input from people who've given it a go. Bit like being told about someones great new navigation system and just as you're walking off thinking "what an interesting idea" they mention they were only able to develop it once they realised the earth was flat!

PS Please don't bother. Of course I know the earth is flat, it's just an example!

Yes, it's difficult to know whether how much is 'slip of the digit', and how much is internal confusion. Even the Australian supplier websites seem to specify "mostly Propane" - if and where you can find any data at all, that is.

Internal confusion I think!. Just to clarify, gas is my business. I spend my working day piping it, controlling it, drawing up designs for it's application, calculating effects of it and I can confirm 100% that non auto LPG in Australia is pure (within some limits!) propane. Depending where you are and who you buy from auto LPG may be 100% propane but may well have "other gases" in it. Generally if you can figure out what's what, sourcing pure propane is worth paying a bit more for as you'll get a measurable 10% better mileage from it. There's also the risk with the mixtures that they'll separate in storage.I once purchased a part tank of cheap LPG from the very bottom of the bulk cylinder (ran out before I was full) and the vehicle was almost undriveable. I had to stop and manually retard the timing to stop the pinging and enable me to get to another service station and fill the tank. Even then it overheated and ran like a dog until I was able to run the tank out and re-fill.

Bahhhh..I mean propane!

cr3

Anybody ever heard of the Fisher Carburetor?

Nah... didn't think so.

Must be Vulcain 2.