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MIT student blogger Sam M. '07

Soy Bomb by Sam M. '07

Doo d-d-doo d-d-doo d-do d-do. Ice tea!

DID YOU KNOW? Igor Stravinsky has a star on the Hollywood Walk of Fame.

Okay guys, you did get me on the whole immaculate conception business. Although I guess my sentence could still be technically correct–a komodo dragon could have an immaculate conception, assuming that it had a creator of an appropriate dispostion–the article was indeed about parthenogenesis.

Anyhoo, the last time I posted, like, a gazillion years ago, I mentioned that I was working on a project for ICE-T that involved the possibility of incorporating a formic acid fuel cell into a handheld cell phone. After three years of p-sets (which, by the end of last year, I was beginning to punt in spectacular fashion), it was really refreshing to get a class where the only instructions were, “Okay, read this paper, come up with a problem, and solve it yourself. We’ll be here if you need us!” It was less refreshing to do all this in one month, but so it goes.

Here’s what I wrote last time:

We’re designing (not building–the designing part is hard enough), a fuel cell that could theoretically be used to power a cell phone. A cell phone of the future. We’re not actually using hydrogen, because that could explode and kill you while you’re talking to your grandmother about apple pie recipes, and that would be fun for nobody. Instead we’re using 22 M formic acid, which is, needless to say, MUCH safer. Just don’t, you know, break your cell phone open or anything like that. Anyway, the formic acid is pressurized, so it goes through a reactor that’s about 3 cm x 3 cm while air (80% nitrogen, 20% oxygen) flows in countercurrent. Redox occurs, there’s a microfabricated nanoporous silicon membrane, and BAMF! Cell phone power!

My friend Jacqueline and I are doing all this: all the design parameters and cost estimations, all the pressures and temperatures and safety calculations, and writing a 10-page paper and a powerpoint presentation on the subject, in four weeks. Integrated Chemical Engineering, or “ICE,” the senior capstone subject in Chemical Engineering, consists of two modules: one lasting eight crazy weeks, and one lasting four far crazier weeks, during which you take all the theoretical nonsense that you’ve spent the past four years learning and apply it to two different chemical engineering problems. This is so you can prove that you actually know how to do chemical engineering before you go off to work at your six-figure investment banking job and stop caring about fluid mechanics.

You crazy kids asked a lot of questions that basically amounted to, “But wait. Wouldn’t you die?”

NO, Chester.

The first step in the project was to establish a set of constraints such that a user of the phone would NOT die, which is probably something that real engineers in industry look at, too. We decided that the pressure in the fuel cartridge could not be above 10 atmospheres, the design had to completely isolate the 22 M formic acid from the user, and that the temperature of the cell phone could not be above 40 C. This would prevent death by shrapnel, acid burn, or setting your hair on fire. Our final design had an operating temperature of 38 C. I was kind of happy about the prospect of not killing people with my cell phone, but some smart-alecky student pointed out after my oral presentation that this is actually above body temperature. You can’t fool all of the people all of the time!

Why don’t you stop being so picky and help save the world, Andrew?

Based on these constraints, we designed a fuel cell that would fit in a cell phone and seemed like it would work pretty well. You fuel it by buying 2 x 2 in cartridges that you stick in and replace as necessary. There’s no need to worry about toxic waste, because the products of the redox reaction in a fuel cell are carbon dioxide and water. In fact, it would actually be less wasteful than batteries because you don’t just throw the cartridges out when you’re done–they’re designed to be refillable! Since Wal-Mart is a major player in my hydrogen economy of the future, there would be formic acid kiosks in every Super Wal-Mart (between the McDonalds and the one-hour photo) where you could take your spent cartridges to have the waste water drained and the formic acid refilled.

We wanted to make sure that our hypothetical cell phone fuel cell would be a top-of-the-line model, so we e-mailed Professor Rich Masel of UIUC, who was listed by Wikipedia as the world’s foremost expert on formic acid fuel cells, to ask for the highest power density he had observed. Rich responded:

The performance has improved since these papers were written, but the results were done at my company and never published.

Looks like somebody felt a little threatened by our design!

In the end, we found that you could indeed operate a cell phone using a formic acid! But we discovered that the energy content of formic acid in a 2 x 2 inch cartridge would be enough power a cell phone for about one day, if you’re lucky. Then you’d have to take a new cartridge out of your pocket, or purse, or man-purse, or whatever, and slip it into your phone. Besides the fact that you’d be carrying around a couple cartridges of 22 M formic acid at all times, that’s going to add up to a lot of cartridges pretty quickly. And a lot of trips to Super Wal-Mart.

Also, any time you’re not actively talking on the phone, it’s going to heat up to 80 C (178 F), which will burn a hole in your pants. But that’s more of a problem for marketing than it is for us.

So, our final conclusion was that using formic acid fuel cells as a sustainable energy solution in portable electronic devices such as cell phones is just something that depressed grad students and cynical professors say to get funding for their research, because all you have to do is say the world “sustainable” nowadays and people will just shower you with money and firstborn children.

We are so smart!

14 responses to “Soy Bomb”

  1. AJ says:

    Awesome post, really entertaining to read. My college savings and firstborn child are in the mail.

  2. Reg says:

    carbon dioxide leads to the greenhouse effect :x

  3. Shannon says:

    I’m still laughing. Great post.

  4. milena says:

    Great post!!! very interesting.

  5. Daniel says:

    No italics for me, thanks… Great post! I’m working on a nuclear powered cell phone, but I haven’t yet taken into account whether the user of the cell phone would die… Interesting…

  6. Sarab says:

    Interesting post. I thought only old men were supposed to be cynical?

  7. Daniel says:

    Hmm, it seems the italics cannot be undone. Alas.

  8. Peter says:

    nice post, but back to one of the fundamental queations after a design draft, would you buy/ use your battery if you were a mobile phone merchant? by the way, water as an accumulated waste in the future could lead to some unpredicted environmenal hazard, like ozone back in the, well, past.

  9. Sam says:

    Perhaps you could also design a cartridge recharger while you are at it.

  10. Daniel — Yes, that’s a good idea. Even now, people are worried about getting brain cancer, so I’m not sure that holding a nuclear device next to your head would go over so well.

    Peter — Good point! Considering that our proposed design would give the user second-degree burns and requires refilling about four times as frequently as modern cell phone batteries, I would say that mobile phone merchants will probably not be jumping over formic acid fuel cells any time in the near future.

    Sam — We originally had the idea of having the user keep a vial of 22 M formic acid in their house with which to recharge the fuel cell on their phones, but considering how much people spill, like, their drinks in restaurants, we decided that this operation would be best left to the experts at Super Wal-Mart.

  11. Mike says:

    Great post! I got my wisdom teeth out a few days ago, and I can’t really smile or laugh since my cheeks are all swollen…Thanks for making my mouth hurt! It was worth it.

  12. nghi says:

    i’d shower you with my firstborn adopted children. happy holiday.