For a minute there I thought I had to get off my couch, when all the while the fact is we don't have to do anything much but keep things afloat for just a few decades more! In fact, we'd best shut up about PO, because if our offspring finds out we knew about it all along, they'll turn and wring our necks come 2036!
Joined: May 28, 2007 Posts: 125 Location: Tempe, AZ
Posted: Sat Jun 02, 2007 2:16 pm Post subject: Re: The Hydrogen economy - The physics
This site claims that we would "only" need to use 20% of the earth's NPP to supply the same amount of energy that crude oil currently does. 20%? Man, that's a lot! Especially considering that they appear to be taking into account every weed shrub, forest, corn field, back yard and golf course on the planet. They also talk about irrigating "waste" land as an alternative. I don't know that our environment would appreciate this. We would probably create new problems for ourselves if were to start irrigating the Sonoran desert.
So, I figured out what a Nm3 is. It's a "normal" cubic meter. This unit is used to measure a volume of gas at standard temperature and pressure (STP). Yes, STP is more than a cool band and the company that sponsored Richard Petty. Anyway, being able to store 16 Nm3 of hydrogen in solid state is pretty sweet. The only questions are: How long does it take to fill the container? How cold does the container have to be to charge it efficiently? How warm does it need to be to release the hydrogen at a usable rate? And, how are the hydrogen storage units warmed and cooled?
Posted: Sun Jun 03, 2007 4:23 pm Post subject: Re: The Hydrogen economy - The physics
yesplease wrote:
MonteQuest wrote:
We already consume 40% of the earth's NPP. How much more food can we take from the other livings things on earth so we can continue "happy motoring."
Consume? Don't you mean impact?
No, I mean we consume it as energy. _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Posted: Sun Jun 03, 2007 4:35 pm Post subject: Re: The Hydrogen economy - The physics
MonteQuest wrote:
No, I mean we consume it as energy.
The vast majority of impact on the Earth's NPP comes from our crudely destructive practices, i.e. we don't physically consumer 40% of the Earth's NPP, we consume something less (roughly 27% according to Vitousek et al's intermediate estimate) so that figure isn't substantiated in any academic papers I know of. Perhaps you're referring to the Vitousek et al's intermediate estimate of our consumption of the Earth's terrestrial food supply?
Quote:
Results of research carried out at Stanford University, published in 1987 by Vitousek et al indicates that humans have destroyed outright 12 per cent of this terrestrial net primary productivity and, at the time of the study, now eight years old, humans were co-opting or using an additional 27 per cent for its own use. Thus one species - Homo Sapiens - has appropriated close to 40 per cent of the terrestrial food supply, leaving only 60 per cent for the millions of other plants and animals, and for the additional billions of human numbers yet to come.
Other studies also fall below the 40% figure.
Quote:
Rojstaczer et al. [2001] in an approach similar to Vitousek et al. [1986] used improved data and robust statistical methods to estimate that humans use roughly 32% of global NPP
Posted: Sun Jun 03, 2007 4:47 pm Post subject: Re: The Hydrogen economy - The physics
yesplease wrote:
MonteQuest wrote:
No, I mean we consume it as energy.
The vast majority of impact on the Earth's NPP comes from our crudely destructive practices, i.e. we don't physically consumer 40% of the Earth's NPP, we consume something less (roughly 27% according to Vitousek et al's intermediate estimate) so that figure isn't substantiated in any academic papers I know of. Perhaps you're referring to the Vitousek et al's estimate of the Earth's terrestrial food supply?
Oh, I see your point. Ok, we have "appropriated" 40% of the earth's NPP, leaving 60% for all other living things. _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Posted: Sun Jun 03, 2007 4:49 pm Post subject: Re: The Hydrogen economy - The physics
MonteQuest wrote:
Oh, I see your point. Ok, we have "appropriated" 40% of the earth's NPP, leaving 60% for all other living things.
Pretty much. The only reason I dislike that term is because it implies that an all out nuclear war would result in the appropriation of 95% plus (or whatever it is) of the Earth's NPP. Equating appropriation with wanton destruction just seems like PC vocab so that people don't see just how destructive what we do is imo... We only need a small fraction of what we appropriate, but for the sake of greed we end up destroying a lot. It's not like we need to impact the NPP that much, we could drop that to below 10% and support many more than we do now, but that would require a rearranging of our social hierarchy, and we can't have that. _________________
Some of the information on the site may have merit. I have seen quite a few sites that talk about "brown's gas" or "hydroxy" which are both just mixtures of oxygen and hydrogen gas after electrolysis. Most of these sites, if not all of them, are built by weirdos who think that perpetual motion is real. However, they do talk about the ability of hydroxy and brown's gas to reduce vehicle emissions of poisonous gasses like CO NOx and unburnt fuel. It sounds like the hydroxy gas has an oxygenating effect much like ether or alcohol does. Unfortunately, these sites are so full of crap that it is hard to be sure without further research.
Posted: Sat Jul 14, 2007 6:52 pm Post subject: Re: The Hydrogen economy - The physics
TO me H2 fuel cells mean splitting H2o, getiing H2 from oil is obviously wacked. Doesn't the 1st law of thermodynamics mean that when ....
.....breaking the moleculear bond of H2o requires "work", as per the 1st law of Thermodynamics. Right there the cost of that "work" is a deal breaker.... right?
SO using electricity to break the bonds of H2o, is less efficient than just putting the electricity into an electric car....
Posted: Sat Jul 14, 2007 11:07 pm Post subject: Re: The Hydrogen economy - The physics
RogerFox wrote:
SO using electricity to break the bonds of H2o, is less efficient than just putting the electricity into an electric car....
Have I wrapped my brain around this correctly?
Yup.
Hydrogen will always be an energy consumer and not a source.
To use solar/wind to make hydrogen assumes "extra" electrical capacity that we can waste to do so and "extra" fossil fuel energy to make the solar/wind installations.
If we don't do it while energy is cheap and readily available, we won't ever do it.
And even then, it will be cost prohibitive for most people, both for the cars themselves and the hydrogen infrastructure to support them. _________________ A Saudi saying, "My father rode a camel. I drive a car. My son flies a jet-plane. His son will ride a camel."
Live in Arizona? Check out: http://sustainablearizona.org and read my blog.
Posted: Fri Aug 31, 2007 1:45 pm Post subject: Re: The Hydrogen economy - The physics
Why not use the biomass for hydrogen?
If you transform the biomass to hydrogen in fluidised bed steam reformers, you can filter the Cu, Cd, Pb, Zn and other stuff, give back all those CaO, MgO, P2O5 and K2O as mineral fertilizer and use 1% of the produced hydrogen for Haber Bosch ammonia synthesis. This way you actually increase the soil.
Out of 20 tons/ha of biomass you get around 2,2 tons of hydrogen. As energy input for farming the land you can assume 100 liters of diesel/ha which is about 1,4% of the energy you get out of the biomass. If you used fuel cell tractors this number would be even lower. No additional fertilizer or pesticides needed.
The overall EROEI could be even higher than 100. But even if it was only a third of that, we should use it for our climate and our soils.
Posted: Mon Sep 17, 2007 2:38 pm Post subject: Re: The Hydrogen economy - The physics
I am rather surprised at the negative statements concerning the use of hydrogen.
I have studied this extensively and I have become a convert (scientifically speaking) to the use of hydrogen.
Hydrogen is a waste of many industrial processes. If harnessed it could be on the open market or more likely be used at that location for electrical generation.
Hydrogen can run easily in internal combustion engines and therefore provides the thing we desperately need...A free market in energy.
Can you imagine if you car could run on hydrogen and/or gasoline? Would you pay $3 a gallon or would you make it at home for less that $ at home?
With hydrogen used in our engines and cars all renewables (solar, wind etc) now compete directly equally with the oil and coal markets.
Joined: Apr 28, 2005 Posts: 3431 Location: West shore Lake Eire, MI, USA
Posted: Mon Sep 17, 2007 4:35 pm Post subject: Re: The Hydrogen economy - The physics
agomemnon wrote:
I am rather surprised at the negative statements concerning the use of hydrogen.
I have studied this extensively and I have become a convert (scientifically speaking) to the use of hydrogen.
Hydrogen is a waste of many industrial processes. If harnessed it could be on the open market or more likely be used at that location for electrical generation.
Hydrogen can run easily in internal combustion engines and therefore provides the thing we desperately need...A free market in energy.
Can you imagine if you car could run on hydrogen and/or gasoline? Would you pay $3 a gallon or would you make it at home for less that $ at home?
With hydrogen used in our engines and cars all renewables (solar, wind etc) now compete directly equally with the oil and coal markets.
Where exactly are you getting this 'hydrogen waste' from?
How are you transporting it?
How are you storing it?
How much does each of these steps cost in energy and materials? _________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Posted: Tue Sep 18, 2007 11:07 am Post subject: Re: The Hydrogen economy - The physics
Tanada wrote:
agomemnon wrote:
I am rather surprised at the negative statements concerning the use of hydrogen.
I have studied this extensively and I have become a convert (scientifically speaking) to the use of hydrogen.
Hydrogen is a waste of many industrial processes. If harnessed it could be on the open market or more likely be used at that location for electrical generation.
Hydrogen can run easily in internal combustion engines and therefore provides the thing we desperately need...A free market in energy.
Can you imagine if you car could run on hydrogen and/or gasoline? Would you pay $3 a gallon or would you make it at home for less that $ at home?
With hydrogen used in our engines and cars all renewables (solar, wind etc) now compete directly equally with the oil and coal markets.
Where exactly are you getting this 'hydrogen waste' from?
How are you transporting it?
How are you storing it?
How much does each of these steps cost in energy and materials?
Perhaps its best to help point in some of the directions that helped me change my viewpoint.
One company that helped was ECD. Energy Conversion Devices. Ovonics.com is the website. Check it out especially their section on hydrogen and hydrogen storage.
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We only need a small fraction of what we 
