|
Hi, forgive me for the vague title. I tend to do that, and you'll just have to forgive me for that. I'm a young schoolboy with many things to learn, and hopefully many things to look forward to.
Last week in class, I learned about this fancy thing called the Hydrogen Fuel Cell, and I was so fascinated by the idea that you could convert chemical energy to electrical energy with almost zero pollutants. I asked myself why such a thing wasn't commonplace, then I asked my teacher the same question. She gave her reply, which was something I should've thought of on my own. Hydrogen is colourless. Hydrogen is odourless. Hydrogen is also very flammable. Gas leaks would be hard to manage.
I am still obsessed that you can use Hydrogen as fuel. I wonder if there are people out there indefatigably working and researching for a way to make the Hydrogen Fuel Cell safer and more efficient.
Anyway, I really can't explain why I'm so excited about Chemistry. I've always thought that I'd end up doing something related to literature or language in University, but now it feels as if I'm headed down a different path. Maybe it's the continuous cyclic viewings of the SaganSeries and the FeynmanSeries, I don't know. There's something in me that yearns to learn more and more about the natural world.
I linked one episode of the FeynmanSeries above because I think it's an amazing perspective to look at the world. To be honest, I've never considered such a worldview before. Sure, I learned about the cells and the biology in school, but I've never tried to draw the connections between what I saw in real life and what I saw in books.
Then there's space, and wow. I feel so incredibly small and I feel as if the only thing I should do is learn more about this madhouse of a planet we inhabit. Man. I don't have anything coherent to say. Sorry.
And here's a short note on the title of the blog: I think I'm opening more doors now. I'm not confining myself to just the soft sciences. Maybe I'll do hard sciences one day.
Recommended Viewing:
The Sagan Series
  
|
i myself am an expert on opening doors, most recently the one to my room. ask me anything if you need help
|
lol mart  . Also azera I think I learned a little about hydrogen when I was doing a degree in materials science. Its difficult to use because hydrogen, as you know, is the smallest, lightest element. Storage and transportation is very difficult because its easy for it to leak out of the container.
But secondly, and this infuriated by thermodynamics professor, often in the production of hydrogen you lose more energy than you gain. That is the electrolytic process of separating hydrogen from oxygen (i.e. you need some process to obtain pure hydrogen in the first place, this is the easiest way) takes more energy than that which you would gain from burning hydrogen, let alone all of the industrial steps in between. That's why my professor thought the idea was so stupid lol. Poor guy passed away last year from cancer
I think the only way for this to work is in conjunction with green energy. If for some reason hydrogen fuel cells are better than batteries, one may want to convert electricity from windmills/solar cells into hydrogen fuel, even if you lose some energy in the process. From the little I know electric batteries are very heavy, and expensive, and can be damaging to the environment when some non-recyclable components are thrown away, so this might be a better option.
Now I'm doing a degree in physics because I think I'll love the sciences more than applied science. Along with that I've taken a course designed for specialist math students, which was...strangely appealing and extraordinarily challenging. I managed to write a paper on Pringsheim's theorem which was the hardest thing I've ever done (mainly because I had to learn three theorems on my own, with a bunch of foreign concepts like a countable union of nowhere dense subsets in a complete metric space - Baire's Category theorem, or Bernstein's theorem on monotone functions).
Oh well, don't want to tangent too much. I hope you find passion for the *first* degree you choose, so you don't end up like me.
|
Hydrogen leaks being dangerous is not the only problem.
As a gas, its low (energy) density means you either have to store a LOT of it in a vehicle (which is impractical), or compress it into a tank of liquid hydrogen (impractical for different reasons). Also, hydrogen is the most common element in the universe, but that's because the universe is mostly empty space and stars -- most of the hydrogen on earth is bound up in water molecules, and it's a surprisingly expensive endeavor to extract it on a large scale.
And then there's the issue of it being fantasically expensive to build the infrastructure needed to fill up consumer vehicles nationwide with stored hydrogen, but that's going to be true of all new energy tech. Eventually we'll just have to eat that cost.
|
On April 09 2013 00:11 Iranon wrote:
Hydrogen leaks being dangerous is not the only problem.
As a gas, its low (energy) density means you either have to store a LOT of it in a vehicle (which is impractical), or compress it into a tank of liquid hydrogen (impractical for different reasons). Also, hydrogen is the most common element in the universe, but that's because the universe is mostly empty space and stars -- most of the hydrogen on earth is bound up in water molecules, and it's a surprisingly expensive endeavor to extract it on a large scale.
And then there's the issue of it being fantasically expensive to build the infrastructure needed to fill up consumer vehicles nationwide with stored hydrogen, but that's going to be true of all new energy tech. Eventually we'll just have to eat that cost.
Compressing to liquid is the only option for a vehicle, gas is never going to happen. The biggest hurdle for fuel cells use in transportation is by far infrastructure, there are fuel cell buses already out there (buses use centeral refueling which eliminate lots of the needed infrastructure). By far the most economical solution as far as extracting hydrogen is natrual gas reforming. Take CH4 + O2 to get 2H2 and CO2. This of course removes some of the advantages of fuel cells because although you no longer are emitting CO2 at the car you are emitting more to get the fuel. There is however less CO2 emitted per mile traveled, and because the CO2 is all emitted at a centeralized source (the reformer) you could potentially used carbon capture and sequestration.
|
Totally agree, Azera: Chemistry is awesome. I'm in my third year of a chemical engineering PhD.
jamesr12 is correct in terms of where practical hydrogen fuel cells are sitting (note, steam reforming of methane creates CO, not CO2 (http://en.wikipedia.org/wiki/Steam_reforming)). Methane is reformed into H2, the H2 is exposed to a platinum catalyst (usually) splitting it into protons and electrons, and the electrons flow across a proton enhanced membrane (PEMFC, for short).
The HUGE problems are both carbon monoxide and sulfur. Suflur needs to be separated beforehand; any diesel manufacturer will tell you how difficult this can be! CO is produced in-process, which is bad because it will poison the platinum catalyst. Engineers have combated CO production by adding an extra step - a water gas shift reaction to make CO2. This isn't 100% effective (concentration at the ppm level poison the Pt), so researchers are also studying room temperature CO oxidation with gold catalysts. Other problems include the high temperatures (excess of 600°C) needed for reforming.
When it's all said and done, practical hydrogen fuel cells still operate on fossil fuels and generate CO2, so it's not a perfect replacement. However, I think it's a step in the right direction.
There is additional work with the Pt catalyst and the membrane itself, but I'm less familiar with it.
|
United States12129 Posts
|
Holy shit, thanks for all the replies!
|
A love for literature, the arts, and now science? You're turning into a well-versed intellectual before my very eyes. :D
As a side note, I couldn't retain half of the information you wrote in your blog (though I feel smarter just reading through it all), could you break it down in SC terms? :p
|
On April 18 2013 22:42 CreatorGX wrote:
A love for literature, the arts, and now science? You're turning into a well-versed intellectual before my very eyes. :D
As a side note, I couldn't retain half of the information you wrote in your blog (though I feel smarter just reading through it all), could you break it down in SC terms? :p
Haha you're too much CGX!
Which part do you want me to elaborate on?
|
|
|
|
|
|
EPT
