Saturday, November 9, 2013

What's plan B for energy? Hint: It involves fungus.

Today the world is heavily dependent on fossil fuels to meet its energy demands, and that demand is increasing fast. And since fossil fuels won't last forever, we need a plan B. Experts say that we have 50 to 100 years of fossil fuel left to extract from the ground. So I wonder if there is substantial progress towards a promising plan B.

Figure 1. World Energy Consumption by Source*
In 2012, 87% of global demand was met with fossil fuel, which is down from 95% in 1965. Sounds like we're making some progress huh? Not according to the measurable end result. During that same period, annual global energy consumption has almost tripled from 200 to 550 exajoules. So global fossil fuel consumption went from 190 to 480 exajoules -- more than doubling our rate of fossil fuel consumption since 1965.

But running out of fossil fuels is not the only reason we need a plan B.

It's important for us to have energy independence from other countries. Self-sufficiency is important for many reasons, one of which is that we wouldn't need to protect our interests in those countries, since we wouldn't have any!

Another reason for a plan B is to have a fuel that doesn't result in a net addition of carbon dioxide (CO2) to the atmosphere, since that would have much less climate-changing effects than compared to using fossil fuels. That's why fuels made from plants are possible contenders. To clarify, engines running on biofuels also emit CO2 just like those running on fossil fuels, but because plants are the raw material for biofuels, and because they need CO2 to grow, the use of biofuels does not result in a net addition of CO2 to the atmosphere -- instead it just recycles what was already there. The use of fossil fuels, on the other hand, releases carbon that has been stored underground for millions of years, and those emissions do result in a net addition of CO2 into the atmosphere.

Ideal restrictions for a plan B

Besides reasons for needing a plan B, we also have some ideal restrictions. One restriction is that we shouldn't be creating fuels derived from food because that creates more competition for that food, which means driving up demand thus driving up the price of that food and all foods made from it, resulting in worldwide starvation for the poor.

We saw this happen recently with ethanol which is made from corn. The price of corn skyrocketed in 2012 because the US government forced fuel producers to produce a certain percentage of their fuel from biomaterial, and since the only viable biofuel in existence today is ethanol, and since ethanol is made from corn, that created more competition for corn, resulting in higher corn prices.**

So what's the hold up on plan B? Well the main hold up is that we haven't found another source of fuel that is as cheap to deliver to consumers as is fossil fuels. This is one of the ideal restrictions on a plan B. There's no point in trying to find a fuel that is more expensive to deliver to consumers because people wouldn't want to buy it. And we shouldn't force people to buy it, or rather, we shouldn't force people to buy alternative fuels or force companies to limit production of fossil-fuels, because that also results in starvation for the poor -- cheap fuel is necessary for making and transporting food so if you get rid of the cheap fuel, then you drive up the price of all food worldwide resulting in mass starvation for the poor.

But this may change very soon with a new testing probe created by chemists and colleagues at the Department of Energy's Pacific Northwest National Laboratory (PNNL), which was published in October in the journal Molecular BioSystems.*** The team created a test that should turbocharge their efforts to create a blend of enzymes potent enough to transform tough biomaterials like corn stalks, switchgrass, and wood chips into fuel, cheap enough to compete with fossil fuels.

It's possible to make this fuel today, but the process makes the resulting biofuel too costly compared to fossil fuels. This new testing probe opens up the possibility for laboratory research, that today takes months, to be reduced to days. So this will accelerate our way to making a process that does compete with fossil fuel on price. So we are making huge progress -- it's just not visible to consumers yet.

Introducing the fungus Trichoderma reesei

This is the fungus T. reesei.
Many of today's efforts to create biofuels revolve around the fungus Trichoderma reesei, which introduced itself to US troops during World War II by chewing through their tents in the Pacific theater. Seventy years later, T. reesei is a star in the world of biofuels because of its ability to produce enzymes able to digest molecules like lignocellulose, a long-chain polymer, the tough structural material that holds plants together.

The breakdown of large polymers into smaller ones that can then be further converted to fuel is the final step in the effort to make cheap fuels from plants and other biomaterials. Biomaterials are full of chemical energy stored in carbon bonds, and can be converted into cheap fuel, if only scientists can find a way to cheaply free the compounds that store the energy from lignocellulose.

T. reesei digests biomaterials by cutting through the chemical "wrapping" like a person with scissors cuts through a tightly wrapped ribbon around a gift, freeing the inner contents. The fungus makes dozens of cutting enzymes, each of which cuts different parts of the wrapping. Wright and other chemists are trying to combine and improve upon the most effective enzymes in order to create a potent enough chemical cocktail, a mix of enzymes that accomplishes the task with the most efficiency, enough to bring down the price of biofuel to that of fossil fuels.

To assess the effectiveness of mixtures of these enzymes, scientists must either measure the overall performance of the mixture, or they must test the component enzymes one at a time to see how each reacts to different conditions like temperature, pressure and pH.

The testing probe

Wright's team developed a way to measure the activity of each of the ingredients simultaneously, as well as the mixture overall. So instead of needing to run a series of experiments each focusing on a separate enzyme, the team runs one experiment and tracks how each of dozens of enzymes reacts to changing conditions.

A series of experiments detailing the activity of 30 enzymes, for instance, now might be accomplished in a day or two with the new technology, compared to several months using today's methods.

The key to the work is a chemical probe the team created to monitor the activity of many enzymes at once. The heart of the system, known as activity-based protein profiling, is a chemical probe that binds to glycoside hydrolases and gives off information indicating the effectiveness of each of those enzymes in realtime, effectively allowing scientists to do their work

So we are definitely making huge progress and it's because of advances in technology.

And it's because of human innovation. It's because of new ideas!

Fossil fuel is great. It's the best fuel we have today. And we definitely need better fuels, but we don't have them yet. So what we need is new ideas for better fuels, not government restriction on existing fuels because that would cause worse problems than it purports to solve.


* Figure 1. World Energy Consumption by Source, Based on Vaclav Smil estimates from Energy Transitions: History, Requirements and Prospects together with BP Statistical Data for 1965 and subsequent.
** To clarify, there was also a US mandate requiring ethanol to be produced as a percentage of the US gasoline supply.  
*** Reference: Lindsey N. Anderson, David E. Culley, Beth A. Hofstad, Lacie M. Chauvign√©-Hines, Erika M. Zink, Samuel O. Purvine, Richard D. Smith, Stephen J. Callister, Jon M. Magnuson and Aaron T. Wright, Activity-based protein profiling of secreted cellulolytic enzyme activity dynamics in Trichoderma reesei QM6a, NG14, and RUT-C30, Molecular BioSystems, Oct. 9, 2013, DOI: 10.1039/c3mb70333a. 

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