The Hydrogen Economy Revisited
My Energy Quest in the Desert
Some readers are aware that I am presently in Arizona working on a project. At some point I will write an in-depth article about the things I am working on, but today I want to pull the curtain back just a bit.
In a series of articles in 2010, I wrote about methanol’s potential as an alternative fuel. I dealt with the common criticisms about methanol — toxicity, corrosion, energy density — and I argued that methanol was a more economical and better technical solution to diversifying our energy options away from oil than is corn ethanol. (In fact, it doesn’t have to be either/or, but methanol has never stood a chance against corn ethanol politics).
In response to my methanol articles, BiofuelsDigest wrote Methanol: Biofuel to love or hate?, which suggested that I might have a conflict of interest with my defense of methanol. My response to that was that I had zero financial interests in methanol, and my company had zero financial interests in methanol. We had never produced methanol, and we had no plans to produce methanol. So there was no conflict of interest except as someone who was interested in the technical and economic merits of methanol from an energy policy standpoint.
Fast forward to September 2013 — more than 3 years after I wrote those methanol articles — and I am now involved in a methanol project. Again, I am not yet ready to do a deep dive here, but I want to put some food for thought out there and open the floor to comments and criticism.
Hydrogen Economy 1.0
I was a critic of the original hydrogen economy as envisioned by President George W. Bush in his 2003 State of the Union address. I wrote an internal report for ConocoPhillips at that time critiquing the plan, and identifying multiple very large technical hurdles that would have to be overcome in order to realize a hydrogen economy.
One thing I have always said is that one major technical hurdle may prove to be challenging to a project, but stack up three or four and it ends up like nuclear fusion — always 30 years away. To illustrate, imagine that you have a 10 percent chance of solving a major technical problem over the span of a decade, and that this would enable success for a project. Now, increase that to three major technical problems and your odds of success have gone from 1 in 10 to 1 in 1,000. Incidentally, when you hear someone use that phrase — “30 years away” — what they are really saying is that they have no idea how they are going to get there.
Without a total rehash of all the issues (and there are a few), one of the major challenges for a hydrogen economy is transport and storage. The volumetric energy density of hydrogen is quite low, and a lot of energy is consumed in compressing hydrogen and moving it around. Another issue was that the hydrogen was being used in extremely expensive fuel cell vehicles that would be out of reach for ordinary consumers for the foreseeable future (i.e., we have no idea if they might ever be economical).
Hydrogen Economy 2.0
But instead of this scenario, imagine that the hydrogen is liberated from a liquid and then burned in an engine with a high compression ratio. Enter methanol.
Methanol undergoes a reaction with steam to produce hydrogen and carbon dioxide. This steam reforming reaction is:
CH3OH(g) + H20(g) → 3 H2 + CO2
Or, in plain English:
Methanol + Water + heat → 3 Hydrogen + Carbon Dioxide
The advantage of this reaction is that the hydrogen produced has almost 20 percent more energy content than the methanol input. This is possible because the reaction takes place in the range of 250 degrees C, which means the reaction can be driven by engine exhaust. So you essentially are capturing some of the energy back from the exhaust heat.
The result is that methanol’s energy density deficit to gasoline can be partially closed with both the higher energy content of the hydrogen and the higher compression ratio of the engine. (Ethanol, natural gas, and longer-chain hydrocarbons can also be reformed in this way, but most approaches require a temperature too high to be driven by engine exhaust — and this is the key to the methanol approach).
Now, further consider the possibility that — particularly for stationary power applications — the hydrogen could be separated out and burned and the carbon dioxide could be captured. Carbon capture could be as simple as pumping it into a greenhouse (albeit not extremely efficient), but more sophisticated methods of capture are possible. It’s just that they are for the most part uneconomical.
But imagine for a moment that this carbon dioxide capture problem is solvable. That opens up the possibility of running an engine with zero carbon emissions at a much lower cost than with a fuel cell. Further, if the methanol is produced from renewable sources (like biomass or biogas), you now have the possibility of running an engine that actually results in the sequestration of carbon (which was taken up by the renewable feedstock during photosynthesis).
Still Lots of Work Ahead
This hints at the project that I am working on in Arizona. As I start to explain it to people, some hear “hydrogen”, and then have a knee-jerk reaction that it can never work. But to paraphrase Obi-Wan Kenobi, “this is not the hydrogen you were looking for.” This is a different animal. At least it is derived from a different animal and used in a different way.
At a later date I will be able to talk about this project and the company’s objectives in greater detail. The company is still very much in stealth mode, and they are being very cautious with the claims they make. But for now, that gives at least a sense of the kind of problems that are keeping me busy.
Link to Original Article: The Hydrogen Economy Revisited