Self supporting Microbial Fuel Cell production

[Brian Jackson]

An amazing article was published today that represents a great breakthrough in the generation of hydrogen for fuel cell use while purifying waste water simultaneously. A tiny electric current (in lieu of oxygen) prevents fermentation. It's a short but fascinating read for those interested (or obsessed) with a solution to renewable energy with positive byproducts.

Is anyone thinking ahead of a home "septic tank" scaled down version? Seems this could be a self-sustaining process... Though not a "perpetual motion" device since it's not a closed system. But it would seem that a small portion of the energy generated could be used to cancel the fermentation while the excess hydrogen is used for fuel cell power.

I'll do more research, but this news has me very excited.

[Brian Jackson]

Apparently, their server is being hit pretty hard right now. Here's what the article reads:

Scientists overcome 'fermentation barrier'
Sunday April 24 2005 16:35 IST
IANS

LOS ANGELES: Scientists have managed to coax bacteria into producing hydrogen - a development that would reduce the cost of waste water treatment.

Using a little amount of electricity - about 0.25 volts - scientists at Pennsylvania State University found that a microbial fuel cell can overcome its "fermentation barrier", Xinhua reports.

The voltage is just one-tenth needed for electrolysis - the process that uses electricity to break water down into hydrogen and oxygen.

"Basically, we use the same microbial fuel cell we developed to clean waste water and produce electricity. However, to produce hydrogen, we keep oxygen out of the microbial fuel cell and add a small amount of power into the system," said Bruce Logan, a professor who led the study.

In a paper "Electrochemically Assisted Microbial Production of Hydrogen from Acetate", the researchers explained that hydrogen production by bacterial fermentation was limited by "the fact that bacteria, without a power boost, can only convert carbohydrates to a limited amount of hydrogen - and a mixture of 'dead end' fermentation end-products such as acetic and butyric acids".

The voltage to be given, scientists explain, is a small fraction of the voltage needed to run a typical six-volt cell phone.

But it overcomes the "dead end" created during fermentation and produces four times more hydrogen than would be typically generated by fermentation alone.

Besides, the new process is not limited to using only carbohydrate-based biomass. Theoretically, it yields hydrogen from any biodegradable, dissolved, organic matter and cleans wastewater.

In the procedure, when the bacteria eat the biomass, they transfer electrons to an anode. The bacteria also release protons - hydrogen atoms stripped of their electrons - which go into solution.

Anode's electrons migrate via a wire to the cathode, the other electrode in the fuel cell, where they are electrochemically assisted to combine with protons to produce hydrogen gas.

The voltage is applied to the circuit by connecting the positive pole of a programmable power supply to the anode and the negative pole to the cathode.

The new process demonstrates, for the first time, the real potential in capturing hydrogen from renewable sources.

[banaari]

I like it... in the face of doom-and-gloom, some proof that the human race can & will eventually pull itself out of the poop... or at least use it to fly their gyros.

Hehe - "Hey honey - hydrogen output's down ... we need to up the fibre in out diet..."

But seriously - anyone looking at alternative-fuel powered Rotaxi ?

[Brian Jackson]

"pull itself out of the poop"? Interesting you put it that way Seems more poop the better

[Thomas]

Farmers have been converting waste products into methane for centuries. Why let a good thing go to waste? Fermentation tanks are kept underground and segregated from any oxygen (air). The gas is syphoned off and pumped into pressurized canisters for use.

I'd Rather Be Flying
Thomas

[REDHORSE556CES]

Every time I eat a bag of burritos I convert methane into a lethal weapon!

[Thomas]

Don't stand too close to the BBQ or you might become a rocket.

[Brian Jackson]

Originally Posted by Thomas

Don't stand too close to the BBQ or you might become a rocket.

...hence we discover the true source of spontaneous human combustion

[aerodynamicdon]

Ever hear of 'wood gassification'? The principle
is using the fumes of slow burning wood (filtered),
in your car's carb. The devices look like hot water heaters
hanging off your vehicle. They were big in WWII in Europe. Plans can be had from MOTHER EARTH NEWS magazine. Plenty of hydrocarbon pollution, but a welder could build one in a couple of weekends. I saw one that ran on CORN COBS. The pipe joints were not tight
and the whole car was full of smoke. It was great.