The Race for Green Fuels – Biology vs. Chemistry

Thousands of labs, companies and governments around the world are currently in an epic race—the race to produce a cheap, clean and sustainable fuel to power our cars, homes and factories. The road to green fuel and energy savings is not an easy one, and there are many possible paths to victory, including bio engineering, bio-mimicry and good old-fashioned chemistry. It is not yet apparent which, if any, of these new technologies will pave the way for clean energy, but one thing is certain: we cannot continue to depend on fossil fuels to meet our energy needs. What follows is a look at some of the more promising biological and chemical innovations in the race for green energy.

1. Photo Catalyst Hydro Fuel (Chemistry)

MIT chemist Dan Nocera claims he has developed a process that mimics photosynthesis, the process plants use to transform energy from the sun into consumable sugars. His method, however, would be far more efficient. He uses the power of the sun to extract hydrogen ions from simple H2O, and with three gallons of river water and a day’s worth of sunlight, he says he could power a typical American home.

The key is a new catalyst Nocera developed. It uses the energy gathered from a 30 square meter photo voltaic array to separate out the hydrogen from water, then stores that hydrogen in a tank for later use. From there, it could be converted into a liquid fuel (for, say, running a car) or recombined with oxygen in a fuel cell, recouping almost all of that solar energy even when the sun isn’t shining. This would be the most efficient use of solar energy yet devised. [1]

2.A Viral Approach to Hydrogen (Biology)

On the other side of MIT, a team of researches have developed a way of getting hydrogen out of water that skips the solar panels all together. Instead, they have developed a virus that gets the job done without any fancy components, mimicking photosynthesis on a more primal scale. The viruses take in energy from the sun and use that energy to split off hydrogen from water molecules.

A number of biological attempts have been made in the past to siphon off hydrogen from water, most prominent among them being experiments with blue green algae. This approach is notably different for not adopting plant components, but simply their methods. The viruses are programmed to line up in a specific, scaffolding-like formation which then triggers the water-splitting reaction.

The only problem? At this stage, the process can only produce oxygen. The precious hydrogen atoms are broken down into their component protons and electrons. A secondary reaction, currently being researched, would reassemble the hydrogen into a usable form. [2]

3.The Tooth Shall Set You Free (Biomimicry)

One challenge to overcome in the quest for solar energy is the sun itself. It’s always there, out in space, releasing staggering amounts of energy, but here on Earth, we don’t always get the full force of it. Noon time in Arizona, it’s easy to soak up rays, but what about sunset in Antarctica? Modern solar panels just aren’t advanced enough to be practical in all situations. That’s where teeth come in.

Inspired by the crystal structure of dentin, a compound found inside our teeth, German scientists claim to have developed a new method for gathering solar energy. The molecular structure of dentin allows it to absorb certain wavelengths of light while blocking others. This is a valuable property when it comes to energy production, and one scientists intend to put to good use. They envision an array of tooth-like structures mounted on a silicon base, set to absorb as much light as possible in almost any environment, “virtually independent of the angle of incidence of the sun.” [3]

4. Digesting Cellulose (Biology)

Biofuels are nothing new—after all, our bodies run on biofuels; sugar, fats and proteins. You may remember the recent push to develop clean ethanol (a gasoline additive) from corn. However, most now agree that using corn to make fuel is a losing proposition. It burns no cleaner than traditional fuel additives, requires a large amount of dedicated farm land, and when put into practice causes corn prices to skyrocket, leading to a fuel vs. food dichotomy. [4]

5. Converting Cellulose (Chemistry)

There are other ways to get energy out of cellulose that don’t involve bugs or yeast. A company called Virent is focused on getting fuel from woody biomass using nothing but a little bit of chemistry. The cellulose is broken down in a sugary slurry and refined, much like crude oil, by a cocktail of chemical catalysts. The result is a carbon neutral fuel: hydrogen. The process can even be tweaked to yield higher energy fuels like butane and propane.

Unlike competing chemical processes, Virent’s slurry technique is done at low temperatures. Rival company Range Fuels uses extreme temperature and pressure rather than a chemical catalyst to extract fuel from cellulose. The cold method is more efficient for a number of reasons, chief among them the fact that high temperatures tend to break down the sugars that the process is ostensibly trying to extract. This would result in considerable energy savings. [5]

6. BioPower’s Wave and Tidal Energy Collector (Biomimicry)

Some of the greatest breakthroughs in scientific history have come not from reengineering or re-purposing living organisms, but by observing what those organisms do and copying it. This form of technology is known as biomimicry. One example of how biomimicry can result in clean energy for humans is BioPower’s new ocean-based energy gathering system.

BioPower, based out of Sydney Australia, has recently announced two new energy systems, bioWAVE™ and bioSTREAM™. By imitating the structure of sea-based organisms like coral and seaweed, these technologies are able to survive in the turbulent environment of the deep sea, bobbing and swaying with the motion of the ocean. The constant movement of the tides packs considerable power, and these new systems are able to harness that power to generate electricity, much like a hydro-electric plant uses the flow of a river. Perhaps most impressive is BioPower’s claim that their system will operate completely out of view and in harmony with marine life, giving it a considerable boost, environmentally speaking, over competitors such as wind turbines and dams. [6]

7. Fuel-Producing Algae (Biology)

One of the oldest forms of biofuel production is just now coming into its own: blue-green algae. Most biofuels need to be extracted from crops, but these specialized organisms don’t need to be farmed and broken down. They have no leaves or stocks, and can be trained to eat waste and produce ethanol, or even diesel fuel.
There are downsides to using algae to produce fuel. They must be stored in “bioreactors” to protect them from wild algae, and extracting the fuel from the mash is difficult. But one major player is already using algae to generate fuel: the United States Military. The U.S. Air Force uses up to 75 million barrels of fuel each year. It is expensive, and difficult to transport, but critical to nearly all air force operations, so it comes as no surprise that the military might be interested in producing their own fuel on-site.

Barbara McQuiston, special assistant at DARPA says that they now have the price of algae crude down to $2-3 per gallon, meeting their base goal, and that they are now only months away from full scale production. Congress had ordered the DOD to derive at least 50% of their fuel from renewable sources by 2016, and the agency is on track for producing 50 million gallons of algae crude in 2011. Many of the breakthroughs that have changed the way we live originated with the military. Plastics, nuclear energy, radar, and microwaves all began as military projects. Perhaps cheap, abundant biofuel will be the same. [7]

8. Sound Activated Crystals (Chemistry)

There seems to be as many ways to extract hydrogen from water as there are ways to use it, but a team of scientists from the University of Wisconsin-Madison have developed a particularly sound method. They use sound.

The process hinges around a specially designed piezoelectric crystal, a chemical structure that produces energy when it bends. The twist is instead of simply generating power, these crystals will be submerged in water, and the charge they generate will rip apart H2O molecules, yielding hydrogen. The lead scientist on the team, Huifang Xu, calls this the piezoelectrochemical effect.

In order to generate current, the crystals must also be exposed to vibrations in the form of sound. But not only can the crystals use any sound at all to generate power, they can actually be engineered toward a specific sound, such us the sound of rushing water, to leverage maximum efficiency. Similar crystals only manage to convert about t 10% of the kinetic energy into useable electricity, but Xu’s crystals could convert 16% or more into hydrogen gas, which can be burned for clean energy later. [8]

Optimally, biofuels will be derived from a biomass we have no other use for: cellulose. There are many obstacles that stand in the way of this endeavor, however. For the same reason that humans can’t eat wood chips for breakfast, lunch and dinner, it is difficult to derive energy from cellulose. But some species, such as the humbe termite, actually can and do eat cellulose.

Researches like Caltech’s Mel Simon are looking for an enzyme in termite guts that will let us do what they do: break down the cellulose found in grasses, corn husks and other woody plants to generate energy. The right enzyme has not been hit upon yet, but there are hundreds of promising suspects. When the right one is found, clean biofuel could theoretically replace up to a third of the gasoline used in America.