Biofuels and Non-Water-Based Fuel Cells

I still have a lot of time before the trip, so I'll talk about things I'm looking up to prepare myself for Thailand as well as more on green chemistry/alternative energy.

When I was doing my work at UMass, I looked up the set of chemical reactions that occurs in the fuel cell. There are two reactions, half reactions, that occur at each end of the fuel cell at the positive end and negative end (like a battery).


For a typical proton-exchange fuel cell, it looks something like:

Anode:**	2H2 -> 4H+ + 4e-
Cathode:	O2 + 4H+ + 4e- -> 2H2O
Total:	2H2 + O2 -> 2H2O

** = logically, this is the first 'step'

An alkaline-exchange type can look like this:

Anode:	2 H2 + 4 OH- - > 4 H2O + 4 e-
Cathode:**	O2 + 2 H2O + 4 e- - > 4 OH-
Total:	2 H2 + O2 - > 2 H2O

** = logically, this is the first 'step'

In the end, this accomplishes more or less the same thing as the proton-exchange membrane, it's just in 'reverse'. 
However, that alkaline-exchange type, would probably end up running with methanol like this:

Anode:	CH3OH + 6OH- - > CO2 + 5H2O + 6e-
Cathode:**	3/2O2 + 3H2O + 6e- - > 6OH-
Total:	CH3OH + 3/2O2 - > 2H2O + CO2

** = logically, this is the first 'step'

When I first saw this, I was a little disappointed. The fuel cell was going to produce CO2, just like a regular vehicle now, so why did the whole project even matter?

Here is the Carbon Cycle:

Through the carbon cycle, carbon moves above and below the surface of the Earth as a natural process. You get carbon deposits from organic matter and over millions of years it is processed into fossil fuels. There's supposed to be a natural rhythm to the circle. Now when you burn up fossil fuels (or large volumes of living trees), you're forcing that stored carbon out of the cycle and back above the surface. There's a fixed amount of carbon on the Earth and if it all appears in one place at one time, then that's really bad. If we use it all up, then it'll exist as by-products of those fossil fuels in the atmosphere.

The thing to biofuels and sustaining the cycle is that burning a biofuel does not encroach on the carbon cycle. Some people aren't able to understand this concept. The distribution of atoms on Earth shouldn't change by much, baring radioactivity, foreign material from space entering the atmosphere, or things escaping (helium, etc. but apparently helium is also brought into the system as well). If you are producing a biofuel, then you are using plants which take in carbon dioxide from the atmosphere and convert it to plant materials which are harvested and then processed. When you burn the biofuel, you return that carbon back to the atmosphere. At the least, it is not increasing the amount of atmospheric CO2 (most of the mass of a plant comes from the gases it takes in, like H2O and CO2, not from the soil). Then the future plants grown to produce more biofuels can uptake that carbon dioxide to produce more plant mass. If the introduction of new carbon to the environment stops, natural processes will eventually return it back below the surface or it will be captured in trees and other biomass living on the planet.