Cheaper Fuel From Self-Destructing Trees

sciencehabit (1205606) writes "Wood is great for building and heating homes, but it's the bane of biofuels. When converting plants to fuels, engineers must remove a key component of wood, known as lignin, to get to the sugary cellulose that's fermented into alcohols and other energy-rich compounds. That's costly because it normally requires high temperatures and caustic chemicals. Now, researchers in the United States and Canada have modified the lignin in poplar trees to self-destruct under mild processing conditions—a trick that could slash the cost of turning plant biomass into biofuels."

Comments

Wood IS fuel

[Lodlaiden]

Apply heat and O2 to complete fire triangle.

Re:Wood IS fuel

[Chris Mattern]

But not a very good one. The energy to weight ratio sucks, it leaves large amounts of ash, and, being solid, can't be used in any of the myriad applications that require liquid or gaseous fuel. The problems with energy to weight and ash are large enough that as soon as coal mining was developed, coal almost completely replaced wood in people's fireplaces and stoves (until coal itself was replaced by gas and electricty and fireplaces by central heating). It's also quite polluting, as a matter of fact.

Evolving parasites.

[quantaman]

My gut says the reason it's so hard to deal with the current form of ligin is parasites would have evolved to eat anything simpler. Do they have any strategy for preventing parasites from finding the trick to breaking down the ligin in these modified trees?

Either way it does sounds pretty cool.

Re:So why use trees?

[Anonymous Coward]

If you actually read TFA you will find that they have succeeded in a trial using poplar trees, but they are now working on corn that has the modified lignin.

And while you wonder about hemp, I wonder about algae. Algae doesn't bother to produce support structures and you can grow a "crop" in ten days rather than a year. We need to improve our technologies for "bioreactors" (I think they tend to get plugged up) and we need to improve the process for converting algae to fuel (algae is wet and it has a high energy cost to remove the water as part of making a fuel).

http://en.wikipedia.org/wiki/Algae_fuel

I wonder if thermal depolymerization can be used to convert algae to fuel?

http://en.wikipedia.org/wiki/Thermal_depolymerization

Alas, TDP doesn't seem to have worked out as well as hoped. I remember reading excited news stories about offal being turned into clean diesel, but the company that tried it lost money and shut down.

Re:So why use trees?

[goombah99]

algae has many great aspect. It's achilles heels are 1) separation is very expensive 2) it's hard to get enough C02 into the water to do this at scale 3) it can get infected easily 3) inhomgenous growth requires active stiring or other tricks to bring a pond to harvest all at the same time 4) it's not that fast to grow-- poplars and switch grass are more efficient bio mass producers. Ethanol can be made from waste products too.

The upside of algae is that were starting to learn how to use some of it's byproducts and this offsets the costs. and incremental progress is being made on all these aspects. We haven't been growing algae as long as plants so there's potential headroom to grow. It can grow in seawater. lipids are better fuel than alchohol. And finally it's potentially less energetically expensive to sperarate lipids from water than alchohol from water. That step accounts for something like 1/3 of the cost of ethanol.