Water-Powered Car: Breaking the Molecular Bond & Burning Hydrogen

[buffordboy23]

Did you watch the whole ep?

No, I didn't watch the whole episode as I already mentioned. I only watched the portions of the episode that was presented in this video and others. The main highlights that I saw include testing the device in an isolated context (their production of hydrogen/oxygen as seen from the bubbles is pathetic compared to other units that I have seen), trying to start the vehicle with the device (already discussed), and inputting pure hydrogen into the carburetor (car started, but backfire occurred). Apparently, from posts on other forums, they tried to run a diesel on vegetable oil as well.

Besides, if they did do the appropriate test, I wouldn't be fully convinced because of the dismal production of hydrogen and oxygen as seen in the isolated context and also when attached to the vehicle when trying to start it. The device is not all that it can be. I am not saying that it would work, if it was all that it could be, but that the conclusion would be more convincing.

Perhaps, someone can elaborate more on this episode if they watched it. Were there other tests besides the three that I mentioned?

 

[DaveC426913]

Besides, if they did do the appropriate test, I wouldn't be fully convinced because of the dismal production of hydrogen and oxygen as seen in the isolated context and also when attached to the vehicle when trying to start it.

How can you be sure it could do better? How much gas can be produced given the specs of the rig? Is it not possible that the tests done by the claimants are exaggerated?

(Did you know that on the shopping channel when they show those convcection cookers, they "overclock" them to 220volts so they'll cook faster?)

 

[buffordboy23]

How can you be sure it could do better? How much gas can be produced given the specs of the rig? Is it not possible that the tests done by the claimants are exaggerated?

(Did you know that on the shopping channel when they show those convcection cookers, they "overclock" them to 220volts so they'll cook faster?)

Sure, I agree that there are advertising schemes, but I know this from personal experience. I have built an electrolysis unit myself, hooked it to my car battery, and by comparison I make this judgment.

See my post (#45) for power needs, including the efficiencies, to produce 1 gram of hydrogen--for every gram hydrogen, there are 4 grams oxygen. What size container do you think we would need to store these gases at 25 C and 1 atm? The density of hydrogen is about 0.0899 g/L and oxygen is 1.429 g/L, which equates to about 15 liters.

I am just not seeing it in the video. Besides, I expect that the battery power could operate consistently at about 500 W, which means 3 grams of hydrogen and 12 grams of oxygen, or about 45 liters of combined gas in one hour (or 1 liter every 80 seconds).

 

[buffordboy23]

...to produce 1 gram of hydrogen--for every gram hydrogen, there are 4 grams oxygen.

Actually, it's 8 grams oxygen, so add 3 liter-multiples based on 1 gram of hydrogen to previous figures.

 

[buffordboy23]

Basically, a 2% mass fraction of hydrogen relative to gasoline results in a "specific fuel consumption" (sfc) value of about 0.5, where 1.0 represents the sfc at 0% mass fraction.

This was from post #48. I realized many readers might not understand what sfc is. The discussion about it on wikipedia seems pretty good:

http://en.wikipedia.org/wiki/Specific_fuel_consumption_(shaft_engine)

 

[atom888]

I have to give my curiosity to hydrogen. Hydrogen flame can burn tungsten, which is around 10,000 Kelvin. A normal torch just can't go any higher than some value. What saying is that giving a time interval T, the entropy generate by normal torch is much higher than hydrogen torch. We can surely translate this into efficency without any equation. Another one is that we can extract better work out of higher temperature different. Thought I can't exactly give application to prove this, but we can see it clearly in theory.

Bufferboy, what I was saying about efficiency is that instead of intake ambient air (which contain a lot of nitrogen (78%)) we provide the engine with gases that actually useful (from electrolysis). The exhaust will contain all gasses at some temperature => nitrogen come in at ambient temperature, nitrogen come out with higher temperature taking some of the combustion juice with it.

 

[buffordboy23]

Bufferboy, what I was saying about efficiency is that instead of intake ambient air (which contain a lot of nitrogen (78%)) we provide the engine with gases that actually useful (from electrolysis). The exhaust will contain all gasses at some temperature => nitrogen come in at ambient temperature, nitrogen come out with higher temperature taking some of the combustion juice with it.

I see now.

Unfortunately, we have no choice and must include a large amount of nitrogen because of the amount of air needed to permit the combustion of gasoline. The stoichiometric ratio of air to gasoline is 14.7:1. So assuming a car uses about 1 gram of gasoline per second (which is a decent approximation), it also needs 14.7 grams of air, meaning oxygen comprises only about 3 grams. It is impossible to generate a lot of extra oxygen mass in such a short amount of time to offset the dominant nitrogen mass fraction, but a small yet possibly beneficial amount could be added. I explored this issue before. Based on some calculations and assuming that the car's original equivalence ratio is equal to 1, then the addition of oxygen from electrolysis under ideal conditions would be no better than 0.97 at the vehicle's optimum fuel mileage.

Hydrogen and oxygen will both be useful for the thermal efficiency of combustion. Hydrogen leads to more efficient combustion because of its many inherent characteristics and it also permits lower equivalence ratios (more air) to be used in a vehicle. The added oxygen will further enhance the combustion in conjunction with hydrogen.

Unfortunately, the most recent graph that I posted only looks at hydrogen addition. If it included oxygen, then in general we would see better specific fuel consumption values but I can't specify how much.

I recently did some calculations, which took the associated efficiencies into account, on the number of grams of gasoline needed to produce 1 gram of hydrogen. The result is 8-13 grams depending on different conditions. I realize that some readers may question this low value so I will post some data later.

 

[atom888]

I just did a rough calculation of air ratio by your value given.

Alright, giving 14.7 g of air going into combustion. The oxygen is 3 gram and 11.7 gram of mostly nitrogen. The energy loss to nitrogen is the different in enthalpy between nitrogen at ambient temperature and nitrogen enthalpy of exhaust (I lost my thermal book to look up table value). Let say we introduce 2.5 gram of electrolysis gas. The ratio is .5g of hydrogen and 2g of oxygen. The gas intake now is offset by 14.7 - 2.5 = 12.2g .

Continue with his later I gtg...

 

[buffordboy23]

I just did a rough calculation of air ratio by your value given.

Alright, giving 14.7 g of air going into combustion. The oxygen is 3 gram and 11.7 gram of mostly nitrogen. The energy loss to nitrogen is the different in enthalpy between nitrogen at ambient temperature and nitrogen enthalpy of exhaust (I lost my thermal book to look up table value). Let say we introduce 2.5 gram of electrolysis gas. The ratio is .5g of hydrogen and 2g of oxygen. The gas intake now is offset by 14.7 - 2.5 = 12.2g .

Continue with his later I gtg...

This is way too much gas from electrolysis in 1 second though. I'll give a description of some important ideas for determining how much additional gas products that we can put in using electrolysis.

First, let's calculate the theoretical work (energy) needed to produce 1 gram of hydrogen. Our chemical equation is the following:

2(H20) (l) ---> 2(H2) (g) + (O2) (g) dH = 483.6kJ

Since this equation produces four grams of hydrogen, multiply it by 1/4.

1/2(H20) (l) ---> 1/2(H2) (g) + 1/4(O2) (g) dH = 120.9kJ

Now the amount of work we need to input into the system to split water is given by the Gibbs Free Energy equation:

dG = dH - TdS

where dG is the change is free energy, dH is the change in enthalpy, T is the temperature in kelvins, and dS is the change in entropy.

Let's now compute dS. dS is given by

dS = SUM[nS(products)] - SUM[mS(reactants)]

where n and m are the coefficients of the substances in the chemical equation. My chemistry textbook gives values the following values in units of J/(mol*K):
H2 (g) -- 130.7
O2 (g) -- 205.2
H20 (l) -- 69.9

If you solve for dS, you should find dS = 0.0817 kJ/(mol*K)

Substituting our computed dH and dS values into the Gibbs Free Energy equation, we have

dG = 120.9 - T*(0.0817)

in units of kJ. It is evident that as temperature increases, the input energy (work) is reduced--the temperature of the water will rise because of heat dissipation due to various car components and inherent resistances.

Assuming the standard condition temperature of T = 298 K, you will find that the theoretical work needed to produce 1 gram of hydrogen is dG = 96.55 kJ.

Now let's assume some efficiencies. Assuming that the electrolysis device ranges from 60-80% efficiency and that the electrical energy generation and mechanical efficiency of the automobile is 30%, our total range of efficiency is 18-24% (I quoted these values on a previous post from a journal article). Taking these efficiencies into account gives the following values at 298 K:

18% efficiency -- dG = 536.39 kJ
24% efficiency -- dG = 402.29 kJ

Now divide these values by 3600 seconds to find the joules per second or watt-hours needed to produce the gram of hydrogen:

18% efficiency -- 149.00 W*h
24% efficiency -- 111.75 W*h

So how much hydrogen then can we produce in hour. This is where my results become speculative. An alternator can typically supply a maximum current of 100 amps and has voltage at about 14.4 volts. If the head lights and all accessories are off, then the car typically needs less than 10 amps to operate the necessary electrical devices (ignition coil, etc.). So let's assume that 90 amps are available for electrical work, then by the relation P=I*V,

P=1,296W*h.

This is the upper ceiling for the power that we can use to produce hydrogen while keeping the battery charged. However, I can't say for certain if the battery can output this amount power any given moment--the cold cranking amps commonly have values above 100 amps--because it may be constrained by the internal chemical reactions. Let's assume that it does, so that we can calculate the maximum amount of hydrogen that can be produced via electrolysis. Before we do, note the following: since we are looking at the power from the alternator being transferred into work at the electrolysis device, we don't have to take the 30% efficiency value from earlier (it is still important though) but only the efficiency of electrolysis. If you take our theoretical work energy needed 94.55 kJ from earlier and apply the electrolysis efficiency range using similar manipulations from above, you find the following work requirements.

60% electrolysis efficiency -- 44.70 W*h
80% electrolysis efficiency -- 33.52 W*h

If we divide our maximum output power from the alternator/battery by these values we find the maximum number of grams of hydrogen that can be produced in one hour:

60% electrolysis efficiency -- 28.99 g/hr
80% electrolysis efficiency -- 38.66 g/hr

Multiply these values by a factor of 8 to find the number of grams of oxygen produced.

Now we are ready to look at the maximum amount of hydrogen that we can put into the engine for combustion each second. Divide by 3600 seconds:

60% electrolysis efficiency -- 8.1 x 10^-3 g/s
80% electrolysis efficiency -- 1.1 x 10^-2 g/s

A good approximation for the amount of gasoline used each second by a car is 1.0-1.5 grams. The best case scenario for this analysis is 1.1% mass fraction of hydrogen relative to gasoline. You can determine the rest of your values from here.

As a last analysis, let's determine how many grams of gasoline we need to produce 1 gram of hydrogen. The combustion energy per kilogram of stoichiometric mixture is 2.79 MJ. The stoichiometric ratio of air to gasoline is 14.7:1, so the amount of gasoline needed to produce 2.79 MJ of energy can be found from the relation

x + 14.7x = 1000 grams

which shows that x = 63.69 grams of gasoline

We can now determine our objective from the following relation:

grams of gas to produce 1 gram of hydrogen = (Work to produce 1 gram H2) * (gasoline mass per combustion energy ratio)

Note that we do not need to consider the efficiencies if we use one of dG values that already includes them. For example, we previously determined that we need dG = 536.39 kJ based on an 18% total efficiency:

grams of gas to produce 1 gram of hydrogen = [(536.39 kJ) / (1 gram of hydrogen)]*[(63.69 g gasoline)/(2.79MJ)] = 12.23 grams of gasoline

This amount will obviously be consumed over whatever time interval is necessary to produce 1 gram of hydrogen. It also doesn't imply that the idea works, only that the gas consumption to produce one gram of hydrogen is not very much (about .5% of a gallon of gasoline, or a reduction of .15 miles per gallon if you get 30 miles per gallon).

 

[atom888]

your calculation is detailed on electrolysis respect to gasoline. I just want to make a quick observation of energy wise in the process.

The final equation I have is an energy balance equation which include .

energy loss due to reduction in nitrogen + hydrogen reaction - enthalphy of water exhaust - energy for electrolysis.

If I assume the energy for electrolysis cancel out hydrogen reaction (100% efficiency), then it just down to energy save by reducing nitrogen and energy loss to increase temperature of water molecules. So far, I do not see a significant shift besides a zero in this equation. If this is the case, then the the process as you descibed, is hydrogen nature of combustion dependant.

 

[buffordboy23]

If this is the case, then the the process as you descibed, is hydrogen nature of combustion dependant.

The hydrogen is the key element that could make the idea plausible. See the graph on post #48. I was toying around with some values earlier and I was coming up with more energy, but I am not going to post anything until I know for certain. You'll need car specs to do the calculations using the graph from post #48.

 

[chemisttree]

Post #48 doesn't tell us enough. You need to provide details about the setup of the engine, throttle position and torque (peak or off peak). A lot of things can affect SFC in an engine and the graph isn't enough to judge the realistic effect of hydrogen injection.

The previous graph you posted was of a methane fuelled engine running at 0.6 of shoichiometric!

What were the dimensions of the cathode and anode for your electrolyzer? wire gauge, length, electrode separation, etc.?

 

[buffordboy23]

Post #48 doesn't tell us enough. You need to provide details about the setup of the engine, throttle position and torque (peak or off peak). A lot of things can affect SFC in an engine and the graph isn't enough to judge the realistic effect of hydrogen injection.

True, a lot of factors are involved that complicates a direct transformation to a car engine. Car components and setups vary as well across different manufacturers, so if the idea is plausible then perhaps some cars are more suited. I attached one page from the document that discusses your requested information and also how they manipulated the data. The article's citation is the same as from post #48.

The previous graph you posted was of a methane fuelled engine running at 0.6 of shoichiometric!

The purpose of that posting was to show that the idea can be a success but with strict limitations. It doesn't prove that it directly transfers to gasoline SI engines but is enlightening in some other regards.

What were the dimensions of the cathode and anode for your electrolyzer? wire gauge, length, electrode separation, etc.?

I have tried to use a couple different setups. I discussed a few of these in previous posts so you can look there. The main problem I find is that the device is not very durable and needs high maintenance.

 

[buffordboy23]

Post #48 doesn't tell us enough. You need to provide details about the setup of the engine, throttle position and torque (peak or off peak). A lot of things can affect SFC in an engine and the graph isn't enough to judge the realistic effect of hydrogen injection.

True, a lot of factors are involved that complicates a direct transformation to a car engine. Car components and setups vary as well across different manufacturers, so if the idea is plausible then perhaps some cars are more suited. I attached one page from the document that discusses your requested information and also how they manipulated the data. The article's citation is the same as from post #48.

I do plan to pursue an analysis of the viability of this device using the graph on post #48 over different driving conditions using car data and specifications. When finished, I plan to post my results on this forum.

However, there has been some skepticism regarding how the graph on post #48 would transform over to an SI engine in an actual car. So, before I begin my analysis, I am open to any ideas on how I should "fairly" apply this transformation for this analysis. The experimental setup and test engine specifications used to obtain the graphical data on post #48 can be found within post #63.

Thank you for your input.

 

[buffordboy23]

Recently, I stated that I would complete an analysis on the viability of the device over a range of driving conditions. I feel that this is no longer necessary, because I came across a new journal article that is likely to mirror what my analysis should show. The citation of this article is the following:

Y. Hacohen and E. Sher. FUEL CONSUMPTION AND EMISSION OF SI ENGINE FUELED
WITH H2-ENRICHED GASOLINE. Proceedings of the 24th IECEC, Arlington, VA, USA, 1989

I attached three images that detail the experimental work and effects of hydrogen addition over various engine conditions. I have added lines within Figure 3 which are used for the following analysis:

Figure 3 shows that at a stoichiometric ratio of about 0.95, the difference is bsfc between no hydrogen addition and 1% hydrogen addition is 9%.

Assuming that a vehicle is traveling at 60 miles per hour and obtains 30 miles per gallon (low-load conditions) with a iso-octane density of 688 g/L (from wikipedia) the amount of gasoline used each second is shown:

\frac{60 miles}{hr} \frac{1 hr}{3600 s} \frac{1 gal}{30 miles} \frac{1000 L}{264 gal} \frac{688 g}{L} = 1.45 grams gasoline / second

Now with 1% hydrogen addition, the gas savings (9%) is

(1.45 grams/second) * (0.09) = .13 grams/second

Using the combustion energy ratio obtained from post #59 (63.69 grams/2.79 MJ), the amount of saved energy each second is

(.13 grams/second)*(2.79MJ/63.69) = 5,695 J/s = 5,695 W

Assuming a 30% mechanical and electric generation efficiency gives the amount of power that can be used to produce hydrogen each second.

(5,695 W) * (.30) = 1708 W (Note that this power is much more than what most alternators can actually provide -- see comments at bottom)

Now with 60% and 80% electrolysis efficiencies we have the following power allocation to produce hydrogen:
60% -- 1024 W
80% -- 1366 W

The theoretical energy value to produce 1 gram of hydrogen is dG = 96.55 kJ (from post #59), so the amount of hydrogen produced per second is
60% -- (1024 W)/(96.55 kJ) = 0.0106 grams hydrogen per second = 0.73% hydrogen mass fraction
80% -- (1366 W)/(96.55 kJ) = 0.0141 grams hydrogen per second = 0.97% hydrogen mass fraction

Both of these values are short of the 1% relative hydrogen mass fraction value needed so that no energy losses occur.

Unfortunately, I can only analyze the data provided, so I would like to provide some comments for your consideration. First, it is highly unlikely that any of these devices can produce 1% hydrogen mass fractions given the nature of the car components; this would be about 50 grams of hydrogen per hour, well above the upper ceiling values for typical car alternators that I computed on post #59. Therefore, the actual hydrogen ratio will be smaller in value. The car kits sold on the internet supposedly produce 2 grams of hydrogen per hour from what I have heard; personally, I believe that 10 grams per hour is obtainable.

Second, if you look at figure 3, you will see that the bsfc values between 1%, 3%, and 5% mass ratios vary by a little amount (maybe 2%), so how would a 0.5% hydrogen mass ratio be plotted on this graph? Would it vary from the 1% mass ratio by 2% as well, or would it be smaller or larger? You must determine this for yourself.

Lastly, by assuming the mechanical and electric generation efficiency and electrolysis efficiency values of 30% and 60%, respectively, (18% total efficiency) we see that to produce 1 gram of hydrogen we need about 5 times more energy than the theoretical value. This fact shows that if we try to produce a higher mass fraction ratio that we lose more and more energy; for example, if we used the 5% mass ratio plot in our analysis, we would be even further away with our final numbers than with our analysis of 1%. If we assume that 0.5% and other smaller mass ratios follow similar behavior according to the plots on the graph, then we would actually find that we are gaining energy, and thus conserving fuel.

 

[bioman06]

Hi Guys

I am new to this forum, so correct me if i am wrong.I have been looking at powering a 4cyl gas engine to run on hydrogen only, i am still a long way away, but one thing came to mind.

would there be corrosion on the internal components EG: pistons,liners, valves.?I have been told that having the above ceramic coated will prevent the corrosion.
Let me know what your thoughts are on this.

Best Regards

Bioman

 

[chemisttree]

I have tried to use a couple different setups. I discussed a few of these in previous posts so you can look there. The main problem I find is that the device is not very durable and needs high maintenance.

Yes, and in your previous posts you provided no details... again. I will ask again...

What length and gauge of wire did you use for your electrodes? It is such a simple question! Why the cryptic response?

 

[buffordboy23]

Yes, and in your previous posts you provided no details... again. I will ask again...

What length and gauge of wire did you use for your electrodes? It is such a simple question! Why the cryptic response?

No, it's not a cryptic response like you suggest. From my perspective, it appeared that you wanted to know general design details, which I discussed for the most part on previous posts and thought would be sufficient. It now appears quite obvious that you want detailed specs so that you can test or analyze it.

Like I said before, I used a variety of setups. Initially, I used a plastic peanut butter jar, but later changed all setups to a one-quart glass mason jar with twistable plastic lid--the plastic jar had heat deformation. I eventually wielded together a customized holder for the one-quart jar for stability during driving.

For the wiring to the battery, I now use 12 AWG 600 V copper wiring. The ground is wired into the negative terminal of the battery and the hot wire is attached via a monkey-clip to the positive terminal for easy removal since the unit does not have a switch to activate the circuit. The other ends of the copper wire have stainless steel terminals that are attached to the plastic lid via stainless steel bolts, wing nuts, and washers. This wiring has an installation for fuse usage. I currently have a 30 amp fuse in the unit; 25 amp fuses have been blown during operation.

A vinyl tube close to 10 mm in diameter runs from a hollowed bolt attached and sealed to the lid to the air filter compartment. The air filter case was modified with the installation of a hollowed bolt and sealed around the perimeter and the tube was inserted over the diameter of the bolt.

As for the electrodes, I have used a variety of materials. Initially, I used copper wire about 2 mm in diameter. The electrodes broke down rather quickly, so I switched to stainless steel wiring of same diameter. Both metals were shaped into a square wave for use as the electrodes. The maximum width was about 2.5 inches and the total height of each electrode was about 5 inches; the number of square wave periods within these dimensions range from 5-8 periods. I also used stainless steel plates as electrodes that were 5 inches in height and about 1.5 inches in width. As for the distances between the electrodes, I used various distances ranging as small as 3/8 inch to 1.5 inches. I used between 1-3 tablespoons of baking soda in various setups. I also have tried using silicone oil on the plates to try improving the surface wettability. With some setups, I found that I was going through water very fast--1/4 quart remaining after one hour--because of boiling issues. No matter what device I have used, it requires high maintenance on a daily basis.

If you have any more questions, please let me know. I do believe that an optimum setup exists for efficiency but have yet to determine these parameters. Your feedback regarding this would be appreciated since your a chem guru. I do know that bubbles (void fraction) between the electrodes tend to increase the overall resistance and decrease efficiency. Testing the electrolysis unit on a car is not the best setup for a controlled experiment, so if you know of any cheap electrical power units that can be plugged into a wall outlet and that provide voltages and amperage similar to a car battery please let me know.

 

[buffordboy23]

Hi Guys

I am new to this forum, so correct me if i am wrong.I have been looking at powering a 4cyl gas engine to run on hydrogen only, i am still a long way away, but one thing came to mind.

would there be corrosion on the internal components EG: pistons,liners, valves.?I have been told that having the above ceramic coated will prevent the corrosion.
Let me know what your thoughts are on this.

Best Regards

Bioman

Bioman, you have a very challenging task if you are trying to run an SI engine only using hydrogen. Read the scientific literature for the details that you need; many modifications to the engine are necessary from what I have seen to run on pure hydrogen. Another problem is storing the hydrogen safely and in a compact area.

 

[mheslep]

The celebrity mechanic John Goodwin (converted Neil Young's Lincoln to biofuel) has done some hobby shop work w/ hydrogen supplemental injection on a diesel engine (a converted Hummer):

... While researching alternative fuels, he learned about the work of Uli Kruger, a German who has spent decades in Australia exploring techniques for blending fuels that normally don't mix. One of Kruger's systems induces hydrogen into the air intake of a diesel engine, producing a cascade of emissions-reducing and mileage-boosting effects. The hydrogen, ignited by the diesel combustion, burns extremely clean, producing only water as a by-product. It also displaces up to 50% of the diesel needed to fuel the car, effectively doubling the diesel's mileage and cutting emissions by at least half. Better yet, the water produced from the hydrogen combustion cools down the engine, so the diesel combustion generates fewer particulates--and thus fewer nitrogen-oxide emissions.

"You can feed it hydrogen, diesel, biodiesel, corn oil--pretty much anything but water."

"It's really a fantastic chain reaction, all these good things happening at once," Kruger tells me. He has also successfully introduced natural gas--a ubiquitous and generally cheap fuel--into a diesel-burning engine, which likewise doubles the mileage while slashing emissions. In another system, he uses heat from the diesel engine to vaporize ethanol to the point where it can be injected into the diesel combustion chambers as a booster, with similar emissions-cutting effects.

Goodwin began building on Kruger's model. In 2005, he set to work adapting his own H1 Hummer to burn a combination of hydrogen and biodiesel. He installed a Duramax [standard GM diesel engine] in the Hummer and plopped a carbon-fiber tank of supercompressed hydrogen into the bed. [probably means a 10,000 PSI tank from Quantum]. The results were impressive: A single tank of hydrogen lasted for 700 miles and cut the diesel consumption in half. It also doubled the horsepower. "It reduces your carbon footprint by a huge, huge amount, but you still get all the power of the Duramax," he says, slapping the H1 on the quarter panel. "

http://www.fastcompany.com/node/60868/print
The range on diesel alone would be 400 miles on standard Hummer tanks, and we can't tell here exactly how much H2 is used, but it may be that, in addition to the energy provided by the H2 itself, that indeed the efficiency of the diesel burn is enhanced beyond the normal diesel/O2 burn.

 

[seacoastauto]

The purpose of this electrolysis device that splits water is to increase the fuel efficiency of the automobile, as also suggested by mrjeffy321. The electronic control module (ECM) controls many functions of how the car engine operates and makes modifications accordingly. In this case, the most important one is the amount of fuel that is injected into the cylinders. With the addition of hydrogen and oxygen, the combustion of gasoline is more efficient, so the ECM "tells" its attached components to inject less fuel into the cylinders because the car's energy needs are satisfied.

This is not entirely correct. For cars with ECMs, a MAP enhancer must be installed in order for the system to work (work as reported, that is).

When brown's gas is added to the air stream, additional O2 gas is picked up by the O2 sensors in the car's exhaust stream. The ECM responds by ADDING more fuel to the system. This actually decreases the car's efficiency. This is where the MAP enhancer comes in. The MAP enhancer is situated between the ECM and the oxygen sensors. They are usually adjustable and modify the signals (changes the voltages) from the O2 sensors such that the ECM thinks there is less O2 in the exhaust stream than there actually is. The ECM then responds by reducing the amount of fuel delivered to the engine in an effort to preserve, what it thinks is, the optimum fuel/air ratio.

The ECM is actually "blind" to the actual effiency of the car; it's just responding to false signals given to it by the MAP enhancer.

 

[TVP45]

The purpose of this electrolysis device that splits water is to increase the fuel efficiency of the automobile, as also suggested by mrjeffy321. The electronic control module (ECM) controls many functions of how the car engine operates and makes modifications accordingly. In this case, the most important one is the amount of fuel that is injected into the cylinders. With the addition of hydrogen and oxygen, the combustion of gasoline is more efficient, so the ECM "tells" its attached components to inject less fuel into the cylinders because the car's energy needs are satisfied.

This is not entirely correct. For cars with ECMs, a MAP enhancer must be installed in order for the system to work (work as reported, that is).

When brown's gas is added to the air stream, additional O2 gas is picked up by the O2 sensors in the car's exhaust stream. The ECM responds by ADDING more fuel to the system. This actually decreases the car's efficiency. This is where the MAP enhancer comes in. The MAP enhancer is situated between the ECM and the oxygen sensors. They are usually adjustable and modify the signals (changes the voltages) from the O2 sensors such that the ECM thinks there is less O2 in the exhaust stream than there actually is. The ECM then responds by reducing the amount of fuel delivered to the engine in an effort to preserve, what it thinks is, the optimum fuel/air ratio.

The ECM is actually "blind" to the actual effiency of the car; it's just responding to false signals given to it by the MAP enhancer.

This is not quite accurate. Oxygen sensors respond only to excess oxygen in the exhaust stream, no matter where that oxygen comes from. In general, auto ICEs, being presumed to have fairly complete combustion, should have nearly zero excess oxygen.

Brown's gas is a mixture of hydrogen and oxygen from the hydrolysis of water and has no excess; burning the hydrogen requires all the oxygen produced by the hydolysis.

The so-called controls put in series with the sensor merely bias the sensor signal so that the engine then runs lean. A lean engine often gets better mileage (you can do the same thing by just using a smaller engine), though the effect is not terribly large and has some undesirable side-effects.

Altering the signal thusly is not good for the engine and is illegal in many locales. At the least, you cannot pass an emission inspection with that bias in place.

I have built many multi-gas burners (including hydrogen) and have monitored them with this kind of oxygen sensor (generically called a Nernst cell) and they required no change in the bias to adjust for the type of fuel, provided that reasonably complete combustion took place. Obviously such things as coke ovens put out a lot of CO that burns poorly and doesn't always produce the optimal results at standard settings; this is not true of gasoline.

 

[buffordboy23]

With the addition of hydrogen and oxygen, the combustion of gasoline is more efficient, so the ECM "tells" its attached components to inject less fuel into the cylinders because the car's energy needs are satisfied.

Seacoastauto,

Your right that this statement of mine is incorrect. This was one of my initial posts where not all of my facts were straight. Many of my initial posts contained some poor logic.

When brown's gas is added to the air stream, additional O2 gas is picked up by the O2 sensors in the car's exhaust stream. The ECM responds by ADDING more fuel to the system. This actually decreases the car's efficiency.

I agree with TVP45. This statement is incorrect. If we assume that the hydrogen is combusted with 100% efficiency, then all of the oxygen produced from electrolysis will be used up as well, so the O2 sensors won't detect an excess.

Even if this combustion process were not completely efficient, the oxygen left over is likely to be small. Based on previous calculations taking into account the typical alternator output, it is unlikely that a 1% mass-fraction of hydrogen relative to gasoline can be produced. So with the good assumption that a car uses 1.5 grams of gasoline per second, we have 0.015 grams of hydrogen and 0.12 grams of extra oxygen at this mass-fraction-ratio compared with the 4.5 grams of oxygen available from the stoichiometric ratio.


TVP45,

I agree about the said consequences--better mileage and undesirable side effects--of running a car lean. Interestingly, research shows that hydrogen addition can permit a car to run leaner without being prone to these undesirable effects. For example, researchers at MIT have developed a microplasmatron fuel converter--which parallels the physics used to discuss the controversy behind the viability of the electrolysis devices--that appears to have very promising results in regard to emission reductions and engine efficiency (fuel economy) when used in conjunction with a turbocharger:

http://www.psfc.mit.edu/research/plasma_tech/pt_plasmatron.html

There is an informative pdf link on that page as well.



As I have been learning more about cars, I wonder if there is potential for a complimentary mechanism to exist. With one of my electrolysis cell setups, the water boils away rapidly as steam--3/4 quart in one hour. I've determined that I put about 0.2 grams of steam into the air intake each second compared with the 22 grams of ambient air. If the outflow from my electrolysis cell is after the location of the Air Intake Temperature sensor (IATs) (air filter box) and before the Mass-Air-Flow sensor (MAFs) (at the end of the air intake duct), I would expect there to be a "contradiction" between the IATs, MAFs, and O2 sensor at the ECM.

I think it makes sense to say that the IATs voltage reading is used to determine what the ECM interprets for the mass airflow from the MAFs voltage reading. Essentially, the hot-wire of the MAFs will be warmer due to the steam, so the voltage reading would indicate that there is less air present than in actuality, and perhaps, causing the ECM to shorten the pulse width for fuel injection, and thus making the car run slightly leaner. Of course, the O2 sensor would then detect this excess oxygen. If this effect is large enough, which I have yet to determine, does anyone have a clue as to how the pulse width of the fuel injection might change?

With this setup, I have obtained my best results by far. It could be solely due to the production of more hydrogen at a lower cost at this water temperature as shown by the Gibbs free energy equation, dG = dH - T*dS, or as many others would say, a perpetual placebo effect that I choose not to acknowledge. =)