Potholes on the road to a green future

September 8, 2009 2:49 PM

Inspired by a recent Wall Street Journal* article, Robert Rapier, chemical engineer, peakist, blogger, and currently chief technology officer for a bioenergy company, reviews the pretenders, contenders, and niche players in the emerging field of green energy, with particular consideration of liquid fuels. Meanwhile, the boffins at Foreign Policy consider the risks of the coming of the green energy era, and depict the end of the oil age. (Both part of FP's extensive look at the end of oil; previously.)

Being an engineer, Rapier discusses some hard numbers that give a sense of the dimensions of the challenge the industry faces. From his contenders article: “Consider for a moment the amount of energy locked up inside the 1.3 billion tons of dry biomass that the Department of Energy suggests can be sustainably produced each year. Woody biomass and crop residues - the kind of biomass covered in the 1.3 billion ton study - contains an energy content of approximately 7,000 BTUs per pound (bone dry basis). The energy content of a barrel of oil is approximately 5.8 million BTUs. Thus the raw energy contained in 1.3 billion tons of dry biomass is equivalent to the energy content of 3.1 billion barrels of oil, which is equal to 42% of the 7.32 billion barrels the United States consumed in 2008.

This calculation tells you a couple of things. First, the 42% represents an upper limit on the amount of oil that could be displaced by 1.3 billion tons of biomass. The true number would be much lower because energy is required to get the biomass to the biorefinery and then to process it. So replacing oil with biomass isn't going to be a trivial task, and a process must be capable of turning a respectable percentage of those biomass BTUs into liquid fuel if it is to be a contender.

*Paywall, if encountered, may be averted by searching article title on google and entering from there.

posted by Diablevert (19 comments total)

I've said it before here on the blue, but, hey, why not say it again.

In the past 100 years, we've gone from burning a little fuel to produce huge amounts of food, to burning huge amounts of food to produce a little fuel.

If I were an alien anthropologist, I would surmise this situation to be an increasingly desperate attempt by the part of homo sapiens to keep their machines functioning until their inevitable civilizational collapse.
posted by Avenger at 3:15 PM on September 8 [4 favorites]

Replacing oil with biomass is good, but we have to cut down on our consumption as well. And production of this will also come from a number of different places (algae, biomass, garbage, etc).

The main benefit is getting off oil, but diversification of sources is a nice side effect.
posted by SirOmega at 3:34 PM on September 8

Biomass as fuel. An overpopulation problem. Hm.
posted by rokusan at 3:41 PM on September 8 [1 favorite]

Biomass as fuel. An overpopulation problem. Hm.

You can't just leave us hanging.
posted by Diablevert at 3:46 PM on September 8

reviews the pretenders, contenders, and niche players in the emerging field of green energy biofuels.
posted by Kirth Gerson at 3:57 PM on September 8

So replacing oil with biomass isn't going to be a trivial task, and a process must be capable of turning a respectable percentage of those biomass BTUs into liquid fuel if it is to be a contender.

Oil is finite, certainly, and it is important to get the discussion going in the public, but his argument about the limits and consequences of switching to biomass are underpinned by some conservative premises (mitigating the impact of renewables, other sources of biomass, energy infrastructure and efficiency improvements, etc.).

It may simply be in his nature as an engineer to be conservative — perhaps excessively so — about the margins or wiggle room within which civilization will move from oil. This may color his analysis somewhat.
posted by Blazecock Pileon at 4:08 PM on September 8

Biofuel is people!
posted by jamstigator at 4:09 PM on September 8

It may simply be in his nature as an engineer to be conservative...This may color his analysis somewhat.

I think that's a fair. But it's also kind of why I posted it. A lot of the media coverage of these technologies tends to be shallow and boosterish; big headlines when a company announces some new tech or cash infusion that potentially could do x, y, and z, and then nothing at all about whether x, y, or z ever happened and if not, why not. Rapier is someone who I always find interesting because he's in the field and obviously cares about the issues but is sober and clear about the problems, too. EROEI issues are very hard to get across in a headline, and I don't think many people appreciate their magnitude.
posted by Diablevert at 4:31 PM on September 8

jamstigator: "Biofuel is people!"

Seriously, though. I'd rather my corpse be turned into bio fuel than burned, much less buried. Cemeteries are a waste of space and just because you're buried doesn't mean you'll actually decompose anyway. So why not turn our leftovers into something useful?

I know quite a few people who have no interest in being buried. Usually they'd prefer to be burned and scattered but I'm sure some of them wouldn't object to being turned into mileage or other useful end products upon their demise.
posted by Hairy Lobster at 4:41 PM on September 8

Seriously, though. I'd rather my corpse be turned into bio fuel than burned, much less buried.

If we're discussing Waterworld, yeah... wash behind your ears. Gills are an "Outlier" trait.
posted by vectr at 4:44 PM on September 8

...I'm sure some of them wouldn't object to being turned into mileage or other useful end products upon their demise.

Long road trips could get very interesting if we could use bodies for fuel...not sure I'd want to get in a car with my family again.
posted by never used baby shoes at 4:46 PM on September 8 [1 favorite]

Oh man, I gotta FP's standard has been falling faster than global oil reserves. I used to read regularly, but since they've been bought out the articles are getting worse and worse - shallower than a bed pan, and in some cases with a similar content. That article could have been written by n undergrad pol sci student - and not even a really bright one. Disappointing.

The WSJ article is great, however. Christ, what a boondoggle biofuels in the US are.
posted by smoke at 5:38 PM on September 8

I always have this vision of the agriculture lobby as some alien collective organism ("The Agrilob") that gains sentience when enough of its sub-units ("our smallest farm is forty thousand acres") touch pseudopods, with its enormous bulk squeezes into a pair of Oshkosh overalls. At the end of specialized tentacles, thick with neurons and nutrient fluid, dangle a handful of Family Farms. The agrilob pushes these tentacles into Congress and has its pitiful, parasitized puppets dance for senators and representatives, and moan about how long it has been since the last Farm Aid, and they could really use more funding so Farmer Rick, his aging John Deere tractor, and their sad dozen milkcows could hang on to pass down our fine American tradition to just one more generation.

It must be smacking its lips at the thought of biofuels and another decade-worth of boondoggle and easement of regulations. "We've got an energy crisis coming on, don't you know? Let's drain the Everglades!"
posted by adipocere at 6:00 PM on September 8 [5 favorites]

Hairy Lobster: " I'm sure some of them wouldn't object to being turned into mileage or other useful end products upon their demise."

What could be more romantic than heating your widow(er)'s house for their first winter without you?

The way things are going, soon it will be the only bequest most of us will be able to make.
posted by Joe Beese at 6:45 PM on September 8

End of the oil age. Meh.

My idealist side says we'll switch to hydrogen based fuels gained from the electrolysis of water by solar and wind plants. Some smart cookie will figure out something like metastable metallic hydrogen and it will usher in a new golden age of energy.

My pragmatic side says if we run out of oil we'll see a scaling up of making it by capturing energy rather than digging it up from the ground.

Oil companies aren't going to say "well shit we're out of oil, let's pack up and go home". They'll want to do everything in their power to get cheap energy (whether it's captured, pumped or mined), sell it for a tidy profit and keep control of energy supplies in general so that they keep on collecting from that golden goose.

And I fear they'll probably succeed because it'll still be cheaper than replacing our entire infrastructure for some alternative fuel.
posted by Talez at 8:02 PM on September 8

On the bright side, Soylent Fuel might (might!) cause people to think twice before making spurious car trips... Maybe we could arrange it so that those who use the most Soylent Fuel are first in line to become Soylent Fuel.
posted by kaibutsu at 8:05 PM on September 8

What could be more romantic than heating your widow(er)'s house for their first winter without you?

Nice. A posthumous dutch oven. It would be like I was still right there in bed next to her.
posted by srboisvert at 4:07 AM on September 9

Rapier is great, I'm glad to see he's getting wider play. I'm not paying to read the WSJ article, so I don't know if it makes this point that is a common theme in his writing, but one thing Rapier points out about biofuels is that there are end-to-end problems.

Its not just that their relatively low energy density (compared to oil) means more energy needs to be devoted to transporting and processing them. If they get dropped in as an oil-substitute, then they end up being burned in internal combustion engines which are, at best, ~30% efficient (and on average, must less). On the other end, plants just aren't that efficient. Photosynthesis is relatively inefficient (theoretical max of ~25%) and only a portion of that captured energy ends up as biomass since a good chunk is consumed by the plant's metabolism. The cumulative losses are huge, and then there are issues like availability of fresh water, etc.

On the other hand, both thermal and photovoltaic are already in practice reasonably efficient at converting sunlight to electricity and getting better. Electrical transmission losses are relatively low, and electric motors are quite efficient at turning electricity into useful work. Battery efficiency isn't bad either. The big issue is that the energy density of batteries is pretty low. Still, its not inconceivable that right now build-out with existing technologies could allow solar power running electric cars to replace most of the passenger miles driven in the US without devoting all that much land to the solar collectors. We'd still need liquid fuels for longer haul travel and aircraft.
posted by Good Brain at 6:09 PM on September 9

Robert Rapier's reaction to ppl talking about him.
posted by rough ashlar at 10:30 AM on September 10