Hydrogen generator?

[FordGuy100]

Ok, I've done some more research. Basically I've gone onto youtube and watched a crap load of vids to see whats worked for people. It looks like people running more than 12 volts are seeing a better production of hydrogen. My thinking would be to possibly rig up a 120volt inverter. You would need to have a lot of plates for it to work good I would think, or at least safely. I heard that every gap there is a decrease of 2 volts, and electrolysis of water requires 2.1 volts (though I've seen it work with less). So that means with a 120 volt invereter you would need something like 60 gaps , that would be a big hydrogen generator .

 

[ralphinnj]

It is a TOTAL load of BS. Don't waste your time or energy. The energy needed to break apart hydrogen from water (yielding oxygen gas and hydrogen gas) EQUALS what you will get back when you re-introduce them into te combstion chamber and make...guess what...water). Here is the bad news: the efficiency of breaking water to oxygen and hydrogen is less than the efficiency of burning it in your engine. This is a SCAM, and anyone doing it will never yield better true mileage.

Here is something to think about: The heat of combustion of hydrogen is about 3x that of diesel (61,000BTU/lb for hydrogen, 19,300BTU/lb for diesel). Those scam kits give you a 1-liter container that you fill with water, add the electrodes and then attach to your battery system. The off gas is routed to your intake. Simple system, but worthless.

Anyway, let's consider the energy equivalent of this 1-liter container. 1-liter of water is 1000g. Water has a molecular weight of 18g, so since hydrogen has an atomic weight of 1 and oxygen has an atomic weight of 16, you can calculate that 2/18ths of the weight of any container of water is the hydrogen contained in it. In other words (just trust me on this if you are not a chemist/engineer), 1000g of water, which is about what they give you in these kits, is about 111g hydrogen. That is ~0.25 pounds. Since it has ~3x the energy content of diesel, that 0.25 pounds of hydrogen (which is what you could maximally extract from that 1-liter jug) is about the same as 0.75 pounds of diesel fuel. A gallon of diesel weighs about 7.15 pounds, so real rough, 0.75 pounds is about a tenth of a gallon.

So, in the best case scenario, where you get the hydrogen for free, the entire container equates to a tenth of a gallon of extra diesel fuel. The "inventors" (quacks) say the container lasts a few tank fulls of fuel, so imagine how small the gains will be of geting an extra 0.1 gallons spread out over, say, 100 gallons of normal fueling. A 0.1% efficiency increase, which you couldn't even measure.

Anyone who swears this stuff works is dissillusioned. As I said, the energy needed to split off the hydrogen exceeds (or at best equals) the energy you will get back. So, in fact, using this should result in a net negative impact to fuel efficiency, if it could be measured. It is worthless, don't waste your time. But it is an interesting chemistry/engineering exercise to prove that it is BS.

Ralph

 

[FordGuy100]

It is a TOTAL load of BS. Don't waste your time or energy. The energy needed to break apart hydrogen from water (yielding oxygen gas and hydrogen gas) EQUALS what you will get back when you re-introduce them into te combstion chamber and make...guess what...water). Here is the bad news: the efficiency of breaking water to oxygen and hydrogen is less than the efficiency of burning it in your engine. This is a SCAM, and anyone doing it will never yield better true mileage.

Here is something to think about: The heat of combustion of hydrogen is about 3x that of diesel (61,000BTU/lb for hydrogen, 19,300BTU/lb for diesel). Those scam kits give you a 1-liter container that you fill with water, add the electrodes and then attach to your battery system. The off gas is routed to your intake. Simple system, but worthless.

Anyway, let's consider the energy equivalent of this 1-liter container. 1-liter of water is 1000g. Water has a molecular weight of 18g, so since hydrogen has an atomic weight of 1 and oxygen has an atomic weight of 16, you can calculate that 2/18ths of the weight of any container of water is the hydrogen contained in it. In other words (just trust me on this if you are not a chemist/engineer), 1000g of water, which is about what they give you in these kits, is about 111g hydrogen. That is ~0.25 pounds. Since it has ~3x the energy content of diesel, that 0.25 pounds of hydrogen (which is what you could maximally extract from that 1-liter jug) is about the same as 0.75 pounds of diesel fuel. A gallon of diesel weighs about 7.15 pounds, so real rough, 0.75 pounds is about a tenth of a gallon.

So, in the best case scenario, where you get the hydrogen for free, the entire container equates to a tenth of a gallon of extra diesel fuel. The "inventors" (quacks) say the container lasts a few tank fulls of fuel, so imagine how small the gains will be of geting an extra 0.1 gallons spread out over, say, 100 gallons of normal fueling. A 0.1% efficiency increase, which you couldn't even measure.

Anyone who swears this stuff works is dissillusioned. As I said, the energy needed to split off the hydrogen exceeds (or at best equals) the energy you will get back. So, in fact, using this should result in a net negative impact to fuel efficiency, if it could be measured. It is worthless, don't waste your time. But it is an interesting chemistry/engineering exercise to prove that it is BS.

Ralph

The difference though with us is that we are not looking at running a system with only 1 liter of water....I'm looking into a system that contains a couple gallons....trust me, a big system. I'm looking into at least a minimum of 2 liters per minute, at least. This is all experimentation. Using NH3 I wouldnt doubt that 2.5-3 liters per minute would be all that hard for a big system.

Here's what we need to figure out. How much hp does it take to turn a 100 amp alternator to pump out 40 amps?

I was skeptical like you in the begining....trust me I was. I still am a little skeptical...but with the price of fuel these days I am looking into everything.

By the way...if I'm easy 1/10 of a gallon of diesel would push my truck at 55mph around 1.9miles....so that 1 liter per minute in theory (not calculating amperage draw on the alternator increasing drag) would net me 1.9 mpg better. Thats for 1 liter per minute....with say 2.5liters per minute that would be a theoretical increase of 4.75mpg. I would say at that rate....you would come out ahead. Increasing the load on the alternator is like turning on the A/C...and with my A/C on max I only see around a 2mpg drop.

 

[ralphinnj]

You aren't considering the most important fact: IT TAKES MORE ENERGY TO MAKE THE HYDROGEN THAN YOU GET BACK FROM IT.

Do you understand what I am saying? You will use some form of energy (battery, alternate fuel source, something) to drive the electrolysis reaction. By the way, that is all you are doing: electrolysis of water yields hydrogen gas and oxygen gas. Anyway, you need an energy source to drive the electrolysis. If you use your battery or some other electrical device driven off of your motor, it will take that energy from the normal diesel combustion process (where it is onverted to rotational then electrical through the alternators, etc.). So you take, say, "x" ebergy to make your hydrogen gas. Now you shove it back into the engine and you get "y" back. MY POINT IS THAT "y" IS ALWAYS LESS THAN "x"

You will not be successful. Trust me, you are wasting your time.

Ralph

 

[FordGuy100]

You aren't considering the most important fact: IT TAKES MORE ENERGY TO MAKE THE HYDROGEN THAN YOU GET BACK FROM IT.

Do you understand what I am saying? You will use some form of energy (battery, alternate fuel source, something) to drive the electrolysis reaction. By the way, that is all you are doing: electrolysis of water yields hydrogen gas and oxygen gas. Anyway, you need an energy source to drive the electrolysis. If you use your battery or some other electrical device driven off of your motor, it will take that energy from the normal diesel combustion process (where it is onverted to rotational then electrical through the alternators, etc.). So you take, say, "x" ebergy to make your hydrogen gas. Now you shove it back into the engine and you get "y" back. MY POINT IS THAT "y" IS ALWAYS LESS THAN "x"

You will not be successful. Trust me, you are wasting your time.

Ralph

Yes I DO understand what you are talking about.

Yes, I know what electrolysis is....you gotta realize I have taken chem...I got selected to go into advanced chem...ect....I know some stuff.

This is what I would like to call experimentation. What would happen if it doesnt work...I'm out what....$50, big fricking deal. When I do get this all done, I will state results. I promise you that I wont lie....I'll tell you the truth....if it doesnt work I'll tell ya.

I'm getting together with my lab buddy from chem class...and my chem teacher....we'll see what we can come up with.

 

[ralphinnj]

Ok, good luck. Here is what you guys should think about:

From a purely energy standpoint, the idea of generating hydrogen gas from water using your cars alternator will never yield more energy than not doing it.

BUT....and there usually always is a but, we make the assumption that the combustion EFFICIENCY remains constant. That whole derivation I did leading to an equivalent of 0.1 gallons of extra fuel (where I assumed you got the hydrogen for free anyway) assumed it was not doing anything particularly unique to the combustion process. If, the hydrogen changes the reaction in the combustion chamber and makes it more efficient, then you could be onto something. But, I highly doubt it. It's been tried.

To really make a difference, you have to understand the combustion process better. You need to imagine you are in the combustion chamber, and you can see that injector spraying those fine droplets of diesel fuel that instantly begin to combust in a mass-transfer-limited process that works from the outer surface to the center of each droplet. When you see black smoke out the pipe, those are fine droplets that did not burn all the way. Anyway, there is a LOT going on in that cylinder, and that is where the action is.

You probably also don't know that of the total combustion energy contained in diesel fuel, something like 18% actually gets to the ground. Yeah, if you have a 180RWHP vehicle, in theory, the engine is "making" around 1000HP, but a lot of it is lost as heat or emissions, or friction, etc. or even incomplete combustion.

The real gains in fuel efficiency will come to those who figure out how to improve the efficiency and gain back all that lost energy. Gimmicks like the above are not going to solve this problem. We need people to think about what I just wrote and figure out how to improve efficiency in the combustion chamber through a detailed understanding of how the reactions occur, what factors we can control, and which we cannot. For example, by the operating temperature of the engine, the theoretical maximum efficiency is limited already (you may recall that from one of your classes). But I know we are not running at that eficiency, so there is room for a lot of improvement.

Ralph

ps, I have a Ph.D. in chemical engineering, and trust me, I know what I'm talking about here...my thesis work dealt with the reactions of heavy oil feedstocks, some not that different from diesel fractions.

 

[FordGuy100]

Ok, good luck. Here is what you guys should think about:

From a purely energy standpoint, the idea of generating hydrogen gas from water using your cars alternator will never yield more energy than not doing it.

BUT....and there usually always is a but, we make the assumption that the combustion EFFICIENCY remains constant. That whole derivation I did leading to an equivalent of 0.1 gallons of extra fuel (where I assumed you got the hydrogen for free anyway) assumed it was not doing anything particularly unique to the combustion process. If, the hydrogen changes the reaction in the combustion chamber and makes it more efficient, then you could be onto something. But, I highly doubt it. It's been tried.

To really make a difference, you have to understand the combustion process better. You need to imagine you are in the combustion chamber, and you can see that injector spraying those fine droplets of diesel fuel that instantly begin to combust in a mass-transfer-limited process that works from the outer surface to the center of each droplet. When you see black smoke out the pipe, those are fine droplets that did not burn all the way. Anyway, there is a LOT going on in that cylinder, and that is where the action is.

You probably also don't know that of the total combustion energy contained in diesel fuel, something like 18% actually gets to the ground. Yeah, if you have a 180RWHP vehicle, in theory, the engine is "making" around 1000HP, but a lot of it is lost as heat or emissions, or friction, etc. or even incomplete combustion.

The real gains in fuel efficiency will come to those who figure out how to improve the efficiency and gain back all that lost energy. Gimmicks like the above are not going to solve this problem. We need people to think about what I just wrote and figure out how to improve efficiency in the combustion chamber through a detailed understanding of how the reactions occur, what factors we can control, and which we cannot. For example, by the operating temperature of the engine, the theoretical maximum efficiency is limited already (you may recall that from one of your classes). But I know we are not running at that eficiency, so there is room for a lot of improvement.

Ralph

ps, I have a Ph.D. in chemical engineering, and trust me, I know what I'm talking about here...my thesis work dealt with the reactions of heavy oil feedstocks, some not that different from diesel fractions.

Well then, my words dont have crap against yours then

I will have to do some more studying up on it. At this point all I have really done is built a couple different H generators (using stuff laying around the shop), and watched a bunch of vids on youtube looking at different setups.

 

[Zookie400]

ralphinnj-

nowhere in your rambling do you touch on stoich.

rethink your BS this time taking stoich into consideration, and giving us real world fuel consumption vs. alternator output #'s, ON A PSD.

although it may take more energy to make the hydro than the return, you dont post anything about the cost going in, and the savings coming out of the whole process. it might not be good use of energy, but we arent trying to save energy, we are trying to save money.

fordguy100- you will get better yield with higher voltage, but it greatly loses efficiency and you will be using a lot of amperage. just with my tinkering, my standpoint is to not go above 24v, and make sure there isnt going to be arcing...hydrogen explosions are serious. im keeping mine at 12 volts because its highly unlikely that 12v will arc across the water vapors. i am going to look into how much more efficient the pulse driving runs it also....a lot of people are seeing lower amps with decent H yield.

 

[ralphinnj]

Hey Zookie, if you want to get into stoichiometry....give me your best shot!

Here is what 5L/min of gas generation does (this is more than most of the units I have seen do):

PV=nRT P=1, V=5L, R=0.0821, T=~300
0.203004466 moles/min
0.022556052 moles H2/min
0.045112104 g H2/min

20MPG at 50MPH
1 hour 50 miles
2.5 gallons
9.45 Liters
8.0325 kg's
8032.5 g's
133.875 g's diesel/min

The top calculates how many grams of hydrogen 5L/min would generate....about 0.045g. The bottom calculates how much diesel fuel you consume per minute assuming 20MPG and a 50MPH speed, and arrives at about 134g/min.

That works to a factor of almost 3000 (2968 to be exact)! So, people think that by adding 1 part in 3000, they will have an impact on fuel efficiency? Give me a break. More like an impurity level.

To make enough hydrogen to make a difference, here is what you need (and once again, I will assume the hydrogen comes for free, because we already know you can't make electrolysis "generate" energy):

To get a 10% increase in fuel efficiency, I will assume you need 10% more fuel heat. We know hydrogen has 3x the heat content per gram when combusted, so we need to add 3.33% by weight hydrogen to the fuel stream. In the example above, if we are using 134g/min of diesel, we would need to supplement with 0.03333*134=4.46g/min hydrogen. 4.46 grams of hydrogen works to 495 Liters/min of electrolysis gas! If you had a 1" ID hose from the electrolysis vessel to the air intake, the gases would be flowing at 53 feet/sec = 36MPH.

So, unless the hydrogen is acting in some catalytic fashion (which, trust me, it does not), 5L/min of brown gas won't do a thing. To generate enough to have about a 10% increase in fuel efficiency, one would need closer to 100x that volume, which corresponds to about 22g of water a minute being electolyzed. That works to 5-6 gallons of water per tankful of diesel (assumes 40 gallon tank).

Again, the energy needed to make the hydrogen will exceed the gain in the engine (since all you do in the engine is combust it back into water), so the above is moot anyway. I was just doing it to show you the magnitude of what you will need to generate to even be in the ball park, assuming you got the hydrogen for free (no energy input).

The manufacturers of these products never go into the real science because if they did, they would not be able to fool people. The bottom line is 2 main points:

1. From a purely energy perspective, you can't make more energy than you have. If you use the vehicles stored energy (electrical system) to drive the electrolysis, those systems will need to be re-topped and that ultimately comes from burning a little more diesel.

2. Assuming the electrical draw (to run the electrolysis) is small compared to what is wasted all the time just running the electrical system (I'm just guessing these devices are inefficient since the belts are always turning), which means you get your hydrogen for free (as I have stated in assumptions before), the systems everyone I have ever heard discussed produce NO WHERE NEAR the amount of gas you would need.

Two major holes in the side of the ship if you ask me.

Ralph

 

[ralphinnj]

although it may take more energy to make the hydro than the return, you dont post anything about the cost going in, and the savings coming out of the whole process. it might not be good use of energy, but we arent trying to save energy, we are trying to save money.

So, how does spending $50-100 on a bunch of parts, then spending a few hours tinkering with it to get it running, then getting no actual better fuel economy translate into saving money?

Ralph