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kojax
Post  Post subject: The Methanol Economy. 2 CH3OH instead of H2  |  Posted: Mon Aug 15, 2011 12:17 pm
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There has been lots of talk about Hydrogen as a potential substitute for fossil fuels to drive automobiles with, but clearly it brings with it a lot of problems, due to it's poor energy by volume, seepage, and the difficulty of constructing pipelines suitable to transport it. However, suppose we look past hydrogen and look at something that can be made from hydrogen instead: Methanol.

Methanol has the same basic properties as gasoline. It can burn in ordinary combustion engines, though it has only half the energy density of gasoline, so an automobile's mileage would get cut in half. Otherwise, it's pretty much the same product. It's actually slightly safer, because it's less prone to explode.

To obtain Methanol, one starts with hydrogen, and then utilizes a process called the "Reverse Water Gas Shift Reaction" to react the Hydrogen with CO2 and produce CO (Carbon Monoxide) and water.

CO2 + H2 → CO + H2O (deltaH = +9 kcal/mole)

After obtaining CO, the CO can be reacted with more Hydrogen to make Methanol (or pretty much any hydrocarbon you want) by using the Fischer-Tropsch process.

(2n+1) H2 + n CO → CnH(2n+2) + n H2O

Essentially, the only necessary ingredients to start with are H2O, CO2, and energy to drive the reactions (including electrolysis to get Hydrogen from water). However, unfortunately, I haven't been able to find numbers that will tell me how much energy is being lost in these processes. Perhaps the process isn't practical because too much of the energy is lost?


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kojax
Post  Post subject: Re: The Methanol Economy. 2 CH3OH instead of H2  |  Posted: Mon Aug 15, 2011 12:19 pm
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I wasn't allowed to post links in my first post, because it was my first post, so here are the links to describe the processes.

http://en.wikipedia.org/wiki/Electrolys ... s_of_water

http://www.marspedia.org/index.php?titl ... t_Reaction

http://en.wikipedia.org/wiki/Fischer%E2 ... ch_process

Note that Fischer-Tropsch has been in use since World War II (or before).



http://www.technologyreview.com/BizTech ... 96,p1.html


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kojax
Post  Post subject: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 17, 2011 3:29 pm
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Methanol has about 15 times the energy storage density of a lithium ion battery of the same size. That might be limited by inefficiencies inside the fuel cell used to reconvert it back into electricity, wherein some of the methanol gets lost by oxidizing. The exhaust output is just CO2 and water.

http://en.wikipedia.org/wiki/Direct_methanol_fuel_cell

One of the fuel cell's inventors, George Olah mentioned in passing during an interview that the process is reversible, so electricity can be used to create methanol from CO2 and Water again. Probably a military base with access to some other power source, like solar panels, would be able to create more of it on the spot with the right equipment.

http://www.technologyreview.com/biztech ... Cbr%20/%3E.

Do you think this might be the pathway that ultimately leads to getting powered armor suits onto the battlefield? No need for a power cord if you're already carrying a sufficient amount of electrical energy with you. And recharging gets replaced by refueling. The tech is even usable indoors. Micro fuel cells that utilize it are currently permitted on airplanes.

http://en.wikipedia.org/wiki/Direct_met ... l#Methanol


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iNow
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 17, 2011 3:35 pm
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Hi Kojax - How is this thread different from the one you created (to which I've linked) below? Perhaps the two should be merged? I'm okay keeping them separate if appropriate, just unsure.

post791.html?sid=0598e8b5c2cca9212e80aebb2a9798d6#p791

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kojax
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 17, 2011 11:43 pm
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iNow wrote:
Hi Kojax - How is this thread different from the one you created (to which I've linked) below? Perhaps the two should be merged? I'm okay keeping them separate if appropriate, just unsure.

post791.html?sid=0598e8b5c2cca9212e80aebb2a9798d6#p791


The topic doesn't seem to be doing very well in the environmental thread, and I am actually a great deal more interested in discussing the military applications, so could you merge them to here in the military section?


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iNow
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 17, 2011 11:50 pm
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kojax wrote:
The topic doesn't seem to be doing very well in the environmental thread, and I am actually a great deal more interested in discussing the military applications, so could you merge them to here in the military section?

No problem at all. This is done. Also, note that you'll need to be slightly more patient here when it comes to responses. This forum is just over a week old, so membership is still increasing and will raise likelihood of solid replies.

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iNow
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 17, 2011 11:53 pm
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kojax wrote:
Essentially, the only necessary ingredients to start with are H2O, CO2, and energy to drive the reactions (including electrolysis to get Hydrogen from water). However, unfortunately, I haven't been able to find numbers that will tell me how much energy is being lost in these processes. Perhaps the process isn't practical because too much of the energy is lost?

That's what I've always heard, too. It essentially takes more energy to perform the process than the energy created. It seems well inline with thermodynamics, actually. :)


kojax wrote:
Do you think this might be the pathway that ultimately leads to getting powered armor suits onto the battlefield? No need for a power cord if you're already carrying a sufficient amount of electrical energy with you. And recharging gets replaced by refueling.

I definitely think that's possible, but I am inclined to believe there are better technologies out there than this. I'm not sure how comfortable I'd be personally running around a battle field with a few gallons of methanol strapped around me.

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iNow
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Thu Aug 18, 2011 8:13 pm
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It looks like the primary focus right now is biofuels.

http://www.whitehouse.gov/the-press-off ... try-and-en
Quote:
President Obama today announced that the U.S. Departments of Agriculture, Energy and Navy will invest up to $510 million during the next three years in partnership with the private sector to produce advanced drop-in aviation and marine biofuels to power military and commercial transportation. The initiative responds to a directive from President Obama issued in March as part of his Blueprint for A Secure Energy Future, the Administration’s framework for reducing dependence on foreign oil. The biofuels initiative is being steered by the White House Biofuels Interagency Work Group and Rural Council, both of which are enabling greater cross-agency collaboration to strengthen rural America.

“Biofuels are an important part of reducing America’s dependence on foreign oil and creating jobs here at home,” said President Obama. “But supporting biofuels cannot be the role of government alone. That’s why we’re partnering with the private sector to speed development of next-generation biofuels that will help us continue to take steps towards energy independence and strengthen communities across our country.”



http://www.smartplanet.com/blog/intelli ... ag=nl.e660
Quote:
The Obama administration has announced a major initiative to expand biofuel production, pumping much needed capital into the sector.

A coordinated program between the U.S. Departments of Agriculture, Energy and Navy will invest up to US$510 million over the next three years to support biofuels for U.S. commercial and military transportation.

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kojax
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Wed Aug 24, 2011 1:13 am
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iNow wrote:
kojax wrote:
Essentially, the only necessary ingredients to start with are H2O, CO2, and energy to drive the reactions (including electrolysis to get Hydrogen from water). However, unfortunately, I haven't been able to find numbers that will tell me how much energy is being lost in these processes. Perhaps the process isn't practical because too much of the energy is lost?

That's what I've always heard, too. It essentially takes more energy to perform the process than the energy created. It seems well inline with thermodynamics, actually. :)


Yeah it's definitely a storage mechanism, not a way to generate power. Even batteries have losses associated with them, though. I'd like to be able to ascertain exactly percent of the original energy is returned, but it will take some research still.

There are certain situations in power generation, where even getting a very small sliver of the energy back would be a good reason to try. For example: Coal plants have to keep their boilers running day and night at a fairly constant pace regardless of demand. It might be nice to get some energy out of that during the off peak hours. Even an amount as small as 5% would be 5% of something, instead of 100% of nothing.



Quote:

kojax wrote:
Do you think this might be the pathway that ultimately leads to getting powered armor suits onto the battlefield? No need for a power cord if you're already carrying a sufficient amount of electrical energy with you. And recharging gets replaced by refueling.

I definitely think that's possible, but I am inclined to believe there are better technologies out there than this. I'm not sure how comfortable I'd be personally running around a battle field with a few gallons of methanol strapped around me.


That is a serious concern. However it is at least safer than carrying a tank full of gasoline. Methanol is harder to ignite and the fires are a lot easier to put out. You can just use water, even.

http://en.wikipedia.org/wiki/Methanol#S ... tive_fuels


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x(x-y)
Post  Post subject: Re: Methanol Fuel Cells on the Battlefield  |  Posted: Thu Aug 25, 2011 7:02 pm
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iNow wrote:
Also, note that you'll need to be slightly more patient here when it comes to responses. This forum is just over a week old, so membership is still increasing and will raise likelihood of solid replies.


This forum seems to be declining in activity since its peak just after it came out, to be honest. The "hard sciences" section is all but dead, and the only really active sub-forum is the "Coffee Shop" and even that is pretty desolate. Perhaps people are on holiday...

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