Why Don’t We Have Functional Biofuel Yet?


Over the last several decades, we’ve poured
billions of dollars into biofuel research…so why can’t you fill up with it at the gas
station yet? Where are the biofuels?! After all, the gas you put in your car is
essentially an ancient biofuel: it used to be organic matter—mostly algae, actually—that
over millions of years was compressed within the earth into fuel, hence the term fossil
fuel. It consists of hydrocarbons, which we can
burn, breaking those bonds to release energy that powers stuff, like our cars. So surely in this age of modern science, we
can engineer new fuels out of those same raw materials, right? Turns out—not so simple. See, the idea behind biofuels is that we use
organic matter, like straw or corn or sugarcane, and turn it into liquid fuel. Ideally, the gases that are released when
we burn that fuel are equivalent to the emissions that are absorbed by growing them in the first
place, so the whole cycle is what we call ‘carbon neutral’—it produces zero net
emissions. Plus, we won’t run out of them, because
we can just grow more. That’s why biofuels are so attractive. We could have energy security and reduce emissions,
even create whole new agricultural sectors. But the amount of energy that’s packed into
really potent fossil fuel is pretty hard to rival. Take ethanol, a common first generation biofuel. It’s an alcohol, which requires plant biomass
to be fermented, distilled, and dehydrated to take it from the crop we grow in the field
to what you put in your tank. In the U.S., for example, we’ve mostly used
corn, and just growing it in the first place requires intensive resources—not just energy,
but land, water, fertilizer that causes pollution—and growing corn for ethanol can directly compete
with food production. After growing it, we have to process the raw
corn into fuel—this is time, money, and energy expensive. Plus, actually putting ethanol in cars is
a bit of a stumbling block. In general, if we want to use different fuel,
we’ll have to change the way we make most cars, especially in the U.S. And ultimately, creating ethanol is so resource
intensive, these fuel products can actually end up producing even more emissions than
fossil fuels throughout their lifetime! Scientists have recognized these failures
in recent years and have developed more efficient, second generation ethanols out of cellulosic
material, the denser, inedible parts of crops. This doesn’t compete with existing food
pipelines and actually results in more energy payoff. But the distillation process remains expensive
and energy intensive–it may be more energy dense material, but it’s also harder to
break down into fuel in the first place. Brazil has had more success with sugarcane
ethanol production, but all ethanols still have yet to break even in terms of practical,
widely-used energy parity. Ok, but ethanol’s not the only biofuel out
there. We also make biofuel out of algae, which–again–involves
cultivating and harvesting these microorganisms, then putting them through an energy-intensive
process that squeezes those lipids out of the algae cells. We then refine those oils, and turn them into
fuel. Same kind of problems here as with ethanol—we
haven’t been able to turn this process into something that, on the whole, creates less
emissions AND is less expensive than regular fuel because of all the resources that go
into processing it. Plus–these organisms are plagued by predators
in large cultivation ponds, and keeping them alive in industrial quantities is tough…but
lots of cool research is going into fixing these particular problems. What if we took an already processed food
by-product, like used french fry grease, and used it as fuel? We just need to refine it a bit, through a
process called transesterification, into something call hydrotreated vegetable oil (HVO). This can and has been used to fuel large cargo
ships, and produces less carbon dioxide and polluting particulates than the traditional
fuel for these large, energy-intensive vehicles. These materials are more energy rich than
first gen biofuels like pure ethanol–but, you guessed it, the conversion process is
still really expensive. And biofuel like this works primarily with
diesel engines, which aren’t as common in some places around the world, like in the
U.S.. In some places like Sweden however, HVO already
makes up a vast majority of their biofuel, and biofuel in general makes up about a fifth
of their transport fuel sources. So it is a promising contender. We’ve been trying to make biofuel work commercially
since the early 1900s. And we’re still not there yet, but we are
innovating. Scientists are now genetically editing plants
to make them produce more of the fatty oil we use to make the fuel, hopefully allowing
us to get a higher energy yield from the resources we put into cultivating that organism. And some experts think that even as the market
shifts toward electrifying cars and trucks on the road, biofuel is still a valid option
for powering big, pollution-heavy vehicles like container ships and airplanes. Maybe the real problem is how we’ve been
talking about all this–everyone wants to hype biofuel as the thing that’s going to
save the world, but we’re still on the journey. Hopefully we won’t give up quite yet because
there’s really exciting technology in the pipeline that could get us there, and that
needs support. But the clock is ticking and it feels like
time, and patience, is running out. What do you think about biofuels? Still promising, or will something else beat
green fuel to the road? Let us know in the comments below, and if
you want to always check in on big questions like this one, don’t forget to subscribe
to Seeker. Thanks for watching!

About the Author: Michael Flood

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