Home Hydrogen Generator

ericgibbs said:

In the event of an impact/crash the petrol tank is liable to rupture and the petrol be ignited by the crushed battery wiring.

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You've been watching too many American films! - the chances of crashed cars catching on fire is extremly low.

Nigel Goodwin said:

You've been watching too many American films! - the chances of crashed cars catching on fire is extremly low.

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Hi Nigel,
Just Googled for 'car crash fires', it a very suprising number worldwide.
Its not just in the movies!.

IIRC, you spoke some time ago about 'risk management' in public places, how do you assess risk, as a passenger/driver in a car?

http://www.fire.org.uk/advice/FA/odpm_fire_pdf_028815.pdf

Extract from a UK report:

Read the last line of that clip!

Notice also it says "road vehicle fires" and not "crash fires", the majority of vehicle fires aren't during a crash.

Nigel Goodwin said:

Read the last line of that clip!

Notice also it says "road vehicle fires" and not "crash fires", the majority of vehicle fires aren't during a crash.

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I did read the last line..
If it makes you happy, I will drop/retract the 'crash' word...
and substitute 'road vehicle fires'..

The point I was making and still making is, the present attitude to H&S regarding 'new' ideas for fuels.
We seem to accept that petrol and other hydrocarbon fuels are an acceptable risk, but cleaner fuels like hydrogen are 'dangerous'.

I would support the OP's idea of the introduction of 'cleaner' fuels.

Do you recall in the 1950's being promised that each home would have its own nuclear reactor by the year 2000, about the size of a domestic refuse bin.

ericgibbs said:

I did read the last line..
If it makes you happy, I will drop/retract the 'crash' word...
and substitute 'road vehicle fires'..

The point I was making and still making is, the present attitude to H&S regarding 'new' ideas for fuels.
We seem to accept that petrol and other hydrocarbon fuels are an acceptable risk, but cleaner fuels like hydrogen are 'dangerous'.

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Hydrogen is massively more dangerous that petrol, you can drop a match in a puddle of petrol and it will mostly extinguish the match - hydrogen isn't anywhere near as 'friendly' as that

I can foresee a future where hydrogen power becomes commonplace, but first you need methods to cheaply and cleanly produce it, and safe methods to transport, store, and use it.

Considering recent H&S expansions, it would be no good equalling petrols safety standards, it would probably be required to greaty exceed it - which won't be easy?.

I would support the OP's idea of the introduction of 'cleaner' fuels.

Do you recall in the 1950's being promised that each home would have its own nuclear reactor by the year 2000, about the size of a domestic refuse bin.

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I'm not quite that old!

I saw an article the other day saying that the Universe is 97% hydrogen, talk about a 'BIG BANG', perhaps someone in a previous Universe was stupid enough to have struck a match and created this Universe from the big bang...

ericgibbs said:

hi John,
Slightly off topic.
Then some young inventor comes along and says, I have developed an engine that runs on highly inflammable petrol. To make it run any distance the car needs to carry around 20gallons of petrol in a flimsy tank made from 2mm thick mild steel. (snip)

In the event of an impact/crash the petrol tank is liable to rupture and the petrol be ignited by the crushed battery wiring.

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Along that same line, I believe both of our countries restrict Freon refrigerants. R12 is essentially unavailable in the US, R22 will soon be banned, and R134A will probably follow. What did we use before Freon? Ans: ammonia (mostly in commercial plants)and sulfur dioxide in consumer products. Those were also deemed too dangerous.

Well, why not use compressible hydrocarbon gasses, like a mixture of propane, butane, isobutane, and isopentane? A friend in Minnesota did just that and has been using it for 20 years in trucks without problem. The only complaint he has had was from people nervous about the "fire hazard." A/C units don't leak in normal use and only contain a few liters of liquid at most. His response, what about the other 200 gallons of petrol you are carrying?

Unfortunately, logic is lost in the politics of fear. John

If anyone is thinking of producing methane, they should read **broken link removed**.

Usually, homemade methane can not be compressed into a liquid due to its high oxygen content, it will detonate under pressure.

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On the subject of petrol/gas and car fires, petrol can be sprayed onto a hot exhaust and will not ignite, brake fluid will. I believe that most crash fires are started by brake fluid.

On the subject of Hydrogen in cars, Hydrogen is liquid at 5000psi, Butane at 80psi. A Hydrogen cylinder is a potential bomb even without ignition. Both figures are from memory but are (I think) in the right ball park.

Mike.

Pommie said:

On the subject of Hydrogen in cars, Hydrogen is liquid at 5000psi, Butane at 80psi. A Hydrogen cylinder is a potential bomb even without ignition. Both figures are from memory but are (I think) in the right ball park.

Mike.

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Good point -- hydrogen is usually shipped at a much higher pressure than butane. However, remember there is also the critical temperature to consider. Hydrogen is a gas at temperatures above -240 °C; the critical temp for butane is +153 °C. Liquid hydrogen is maintained in cryogenic vessels for that reason. John

jpanhalt said:

Good point -- hydrogen is usually shipped at a much higher pressure than butane. However, remember there is also the critical temperature to consider. Hydrogen is a gas at temperatures above -240 °C; the critical temp for butane is +153 °C. Liquid hydrogen is maintained in cryogenic vessels for that reason. John

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I don't think this is going to reduce the fear of using hydrogen?

I think my previous statements regarding safety were misunderstood.

I see no safety problem with using hydrogen, any more than natural gas. But if my neighbors start to build 5000 psi pressure vessels on a commercial scale I'll be really concerned. This thread is titled "Home Hydrogen Generator".

I saw on TV a truck full of gasoline had an accident and the gasoline flowed down a street covered with snow and caught on fire. It was spectacular and nobody was hurt. Lots of black smoke.
A hydrogen accident won't burn, it will explode. BOOM.

This is like steering an aircraft carrier...

jpanhalt said:

hydrogen is usually shipped at a much higher pressure than butane. However, remember there is also the critical temperature to consider. Hydrogen is a gas at temperatures above -240 °C; the critical temp for butane is +153 °C. Liquid hydrogen is maintained in cryogenic vessels for that reason. John

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But, what does any of that have to do with the generation and storage of relatively small and low pressure quantities of gaseous hydrogen?

The actual storage, transfer and transportation of the gas doesn't really concern me too much (for reasons I've given). And, I'm not sure how we got to liquid hydrogen here. Okay, I do know how but, it still doesn't resolve the question of....(here we go again)...

If, using an automated system and "free energy", can sufficient hydrogen be produced to make it economically viable (for the families generating, the accompanying hydrogen utility company and the nation at large).

Or, to put it into a more ABC level, with a modest solar array, can you perhaps generate sufficient hydrogen to (after all costs of collection, transportation, storage and distribution) at least cover the family's own hydrogen car needs with a little left over that the government can magnamoniously give it to the poor?

The Sky is Falling, The Sky is Falling........

audioguru said:

A hydrogen accident won't burn, it will explode. BOOM.

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A poorly designed hydrogen system, without proper pressure relief, venting and protection from nearby heat sources will indeed explode. As will ANY closed cylinder of any gas, flammable or inert.

Acetylene welding gas can only be stored at about 400 psi, in the tank, and must be regulated to under 15 psi when it escapes the acetone in the lines and torch head. but, you don't see Chicken Littles running around in circles yelling that the sky is falling every time somebody does a little oxy-acetylene welding. Because it's a known problem, they instead teach the safety procedures in welding classes.

Then it remains for the "terminally stupid" to create the problems. Like the woman who was returning an empty acetylene cylinder for her husband. The valve was leaking in the car and she (likely so "untechnically inclined" that she couldn't recognize the odor of acetone...or maybe because her years of smoking had ruined her sense of smell)....Long story short...her next ciggy was her last.

...Oh, yeah...and we can't forget that we need the Chicken Littles to breed the hysteria....would you agree, audioguru?

crashsite said:

Or, to put it into a more ABC level, with a modest solar array, can you perhaps generate sufficient hydrogen to (after all costs of collection, transportation, storage and distribution) at least cover the family's own hydrogen car needs with a little left over that the government can magnamoniously give it to the poor?

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As you probably already realise?, NO! - with a MASSIVE solar array, you could probably generate enough to run your own car? - but solar panels aren't very efficient, and rely on lots of very bright sunlight to give decent output.

Then using the energy to split water into hydrogen and oxygen isn't a very efficient storage system either!.

audioguru said:

I saw on TV a truck full of gasoline had an accident and the gasoline flowed down a street covered with snow and caught on fire. It was spectacular and nobody was hurt. Lots of black smoke.
A hydrogen accident won't burn, it will explode. BOOM.

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Except if its the Hindenburg, perhaps a little before your time..

Solar panels are not cheap and certainly not free energy. Here in Australia solar costs about AU$10 per Watt. At this price it takes 26 years of 8 hours a day bright sunshine to get your money back (grid = 13c/kWh). If you buy in bulk and import direct from China you can half this price and get your money back in 13 years. If you convert this energy to Hydrogen via electrolysis then the efficiency will be significantly lower and the payback period will probably be back to 20 odd Years. Note, interest rates here are currently 7% and so you double your money every 14 years, it makes much more sense to leave your money in the bank for 14 years and then do it. Or when your money had doubled you could wait for 14 ..... etc. OTOH, when oil gets to $500 per barrel.

Mike.

G'Day Mike,
Its a pity some goverment body cant make the decision to free issue solar panels to areas that get a decent amount of sunshine.

You may have heard that in the UK we are going to build a new coal fired power station,IIRC in Kent, first in about 25 years.
Also we considering going back to nuclear energy. The French seem to be running nuclear OK.

Plans are also on the table for the Severn river barrage.

From what we are told renewable energy sources are around the 1% to 2%
Quite a number of wind farms are running OK, perhaps this source could be used to crack sea water to H and 0.

I think the bottom line is, as a society we are in deep trouble..

Regards

Hi Eric,

I didn't know about the coal fire plant but I think the whole world is giving nuclear a second look. I don't think the new coal one will be much of a problem when China is commissioning a new one every 2 weeks. I also think that if wind is supplying less than 2% then it is not worth the eyesore that they are.

You may not know this but Australia is the biggest emitter of CO2 per capita than anywhere else on the planet. This is simply because all power stations are coal fired due to the abundance of coal here. It seems ironic to me that Aus is going to convert some power plants to oil and import the oil in order to reduce the per capita footprint. The really ironic thing is that Aus supplies most of the coal to fulfill China's needs.

As for solar, if panels can be bought for the equivalent of 1$ per Watt then it starts to make sense. I would certainly buy 10kW worth and it would work well for me as the biggest load would be the air con when it's hot. I could also store some for the pool as that takes an amazing 10kWh per day to run and it is most efficient to run it when it's dark. The equivalent of 1$/W solar panels is $500/barrel oil (or more likely $200 and some efficiency improvements) and that may not be too far away, oil seems to be doubling in price every 4 (edit was 2) years. I don't however imagine my power usage will be anywhere near as high if that were the case. Maybe it would be a good thing.

Mike.

Well, I (obviously) like the idea of figuring out the puzzle of "returning the energy" to water. I also acknowledge its inefficiency and difficulty. But, I also believe those are mere technical problems and I am an eternal optimist when it comes to humans being confronted by the near impossible and making it a reality. In that vein, I was impressed by this little tutorial of what may be the most esoteric experiment ever done:

**broken link removed**

A problem with trying to "efficient-ize" the hydrogen cracking problem is one that we electronic experimenters know all too well. How can you justify designing and building something when you can buy it better and cheaper. Unfortunately, our global economy requires us to wait for crisis before it allows us to actually spend some real effort (and money) on a solution.

At the same time, I believe there's opportunity for those who will figure it out and either circumvent the crisis or, at least, be Johnny-on-the-spot when it occurs. Unfortunately, my name isn't, "Johnny".