According to a recent paper in PNAS on the water footprint of biofuels, Jatropha is the worst: Water Footprint for biofuels

It's a good point. The trick is in not letting 'Big Oil/AG' steamroll local farmers and herders, as is happening in some marginal lands across India. It might be a balance that impossible to hold.

http://www.treehugger.com/files/2008/07/jatropha-production-expands-indi...

'Wastelands' Not Always Unused
Furthermore, groups such as Navdanya have pointed out that many of the lands called “wastelands” by government actually are used by rural populations for grazing and other agricultural uses. Having no adequate land rights, and vital to these people’s survival can be put at risk in the rush to embrace Jatropha cultivation.

In a YesMagazine interview with Vandana Shiva, there is a helpful series of descriptions of how these 'Marginal Land Crops' will very likely yield more poverty and loss..

http://www.yesmagazine.org/article.asp?ID=570

There may be little rainfall in the deserts of Rajasthan, but the culture of Rajasthan evolved to manage that amount of rainfall, and they have developed miraculous technologies for harvesting and storing what rain they get. They have sophisticated underground storage systems and water-harvesting systems so that not a drop is wasted. These technologies still sustain cities like Jodhpur and Jaipur. They have enough drinking water because they've developed a conservation culture, and they grow crops that don't need much water. The moment you think the desert of Rajasthan should be growing rice paddy or cotton, you create scarcity.

Scarcity is not a result of uneven endowments—that is diversity. Scarcity is having a mismatch between a culture and nature's giving. Cultures have evolved cultural diversity to mimic the biological diversity of climates and ecosystems. It's when that relationship is disrupted that you get unsustainable population growth.

... Instead of leaving seeds in the hands of the peasants who co-evolve them in partnership with nature, seeds become a monopoly in the hands of five or six global corporations. Instead of water belonging to millions of local communities, water too is to be controlled by five or six global water giants. These are recipes that use economic systems to appropriate for the few the base of survival of the majority. The 80 percent who are dispossessed of the wealth of nature move into economic insecurity, because their livelihood as peasants, as fishermen, as farmers, as tribals, as forest dwellers, all depend on having the fisheries, the land, the forest, to make a living. When those rights are taken away, they become economic refugees—they become disposable people.

Bob

Point well made. I think we all agree here that it is possible to power jet Aircraft with biofuels but that BioFuel is not going to sustain it when the price of Jet fuel goes trough the roof when depletion hits proper.
I agree that the future for biofuel is for local use not fueling airplanes or SUV's. Jatropha can give small rural farmers the possibility to produce a diesel fuel substitute localy to power their small cultivatators, rotavators and prevent us sliding back to using only oxen/horses subsistenance farming. The processed oil has more uses and does not need to be kept and fed trought out the winter.

Sorry! I did not write this clearly enough. For the small villages in Africa and India they can use the raw fuel that they get from the plants - however if you are going to be using it as a jet fuel then you have to process it to biodiesel in the same way as with other vegetable oils.

The economics do not appear to be playing out well in India in regard to the establishment of large plantations, though the small scale (hedge-type) operations can operate on a scale where there is little environmental negative impact and some benefit locally. But when they try and scale this up, there are some stories that the yields obtained are inadequate. This story is from 2007, but it doesn't appear to be getting much better.

But the “green gold”, as the dark berry-shaped seeds that are crushed to help produce biofuel are called, remain very difficult to find.
“We will be lucky if we get 2,000 tonnes of seeds this year,” says Sarkar, the 36-year-old regional manager of D1 Oils Plc., a biofuel firm listed on  the  London Stock Exchange.

D1 Oils, in which BP Plc. has recently picked up 50% equity, has set up a 21,000 tonnes-a-year biofuel plant in the western Tamil Nadu town of Coimbatore in a joint venture with Mohan Breweries & Distilleries Ltd. . . . . . .

Last year, daily wage earner Santosh Yadav, who lives in Garka village in central Chhattisgarh, assisted in planting 4,000 saplings along a 2km stretch of the national highway known as Singanpur. Today, only half the saplings survive.
“We’ve heard these plants will give us petrol and diesel. But we can’t see it,” says Yadav, who earned an average Rs67 a day for the fortnight he worked through the National Rural Employment Guarantee Scheme (NREGS).

Burjoes,

I agree on some points:
1) yields are input dependent and while you may see claims of high yields, there are not based on any commercial activity of an established plantation with accurate record keeping, rather extrapolation from select cultivars fruit production.
2) the meal from Jatropha seeds contains a lectin (curcin in this case) and phorbol esters, toxic stuff that the plant produces to protect itself from grazing. You may raise goats in a Jatropha field and they would never touch it. If ingested in certain quantities (if you could actually take the taste of the first seed), you may be inconvenienced, but case of deaths are very rare. These toxins may be extracted or neutralized by thermal treatment, but the quality of the nutrients suffers.
3) No straight Jatropha oil was used in the jet fuel blends - the oils have to be hydrotreated (e.g. UOP process) into hydrocarbons (no nitrogen, no oxygen no sulfur). The lower cloud point in the stuff might be obtained by reforming the straight molecules into branched hydrocarbons. The environmental advantage is that it is aromatic free, the annoying part is it is aromatic free and the jet engine seals need aromatics to keep from leaking.
4) There is no way we will replace all the jet fuel by vegetable oil derivatives: we would need to plant 250,000 ha of palm, collect, press the oil and hydrotreat the whole production of one year just to cover one day of world use.
5) Jatropha curcas is not invasive. The Australians have declared it so because mostly of the toxicity. I have seen Jatropha trees more than 25 feet high planted by the Portuguese and Philipinos in Hawaii. No growth observed anywhere else, except for washed seed saplings down a gulch. Since there is no animal eating this, there is no natural transport.

My garden had a stoner chipmunk once. (regular poppies) Her babies were rather pitiful.

But, as the hedge-growing shows, it can find a place in rural economies which run on a different metric.

Gail, You hit the nail on the head with the comment on harvesting. There is a reason this crop has not taken off. It is very labor intensive. The crop is continuous so the harvesting is also. Hand picked when ripe. Very time consuming.

Gail,
I know very little about jatropha,but in general the yield of any crop drops off precipitiously as growing conditions deteriorate.The situation is pretty much analogous to the energy return on investment problem in fossil fuels.Yields decline as measured inputs decline but faster.For example you may get 150 bushels of corn with normal rain fall,but you will get a lot less than 75 bushels with half the normal rain.You might not get any grain at all,depending on when it falls,but you would still get some fodder-leaves and stalks.

The flip side of this situation is that as production of a cropsuch as jatropha is moved from the politically palatable "marginal land" to ordinary land yields go up fast.Exponentially fast,in relation to the costs per acre of growing the crop.

It is easy to see where this can lead.

It will be bad enough that the people living on and working this so called marginal land will be displaced if jatropha takes off. I fear it will much be worse if we get hooked on such crops.The less fortunate among us may not be able to afford food at some point even in the more prosperous countries if it comes down to a choice between cars and food.

Jatropha bushes planted closely in long rows are used as cattle enclosures in the Sahel and southern Sahara. They are also used as a fence around a village to keep out the desert wind, marauders, animal and human. My impression is that there is a lot of experience with this plant, but not among people in the money economy.

Jatropha is also known by the name "physic plant", and its fruit as "physic nut" - Not physics, but physic without the s, a very different word. When consumed, it has a pronounced cathartic effect on the bowels. It is distasteful to cattle, and possible even to camels. This is one of its characteristics that enables its use as fencing. If the cattle would eat it, they would just munch their way to freedom - but they don't.

It seems to me that the oil content is high enough that the villagers could use the oil in lamps for lighting, or heat for cooking, but I have never read that they do. Why? Maybe the labor of harvest is too great even for people who have an immediate use for the oil. (The Eskimo used whale oil for light and heat before they were civilized.) Or maybe they just cut branches for cooking fuel, and don't have a need for artificial light during the time that their tradition has reserved for making love.

I've seen photographs of the plant. It appears to be a dense tangle on interlocking branches, much like hedges in civilized suburbia. Mechanical harvesters do not work well on such plants. There is generally too much damage to the plant as the harvester tries to get at the fruit. But maybe ... robotics and computer vision ???

IMHO, jatropha is part of a future in which our descendants live more like the villagers of the Sahel do today than a future in which the descendants of the villagers have learned to submit to will and needs of the civilized world. E.g. jatropha hedge is clearly less energy intensive than steel fence posts and barbed fence wire for enclosing cattle, and energy issues are the big worry aren't they?

Hydrotreated vegetable oils (HVO) burn more efficiently than jet fuel, mostly because of the absence of aromatics - which require more energy to break. Such findings are consistent with test on methyl esters which, even oxygen in present in the molecule, delivers the same performance as conventional jet fuel does. The drawback might be that HVOs burn at higher temperatures, which generates more NOx.

True, why save the "Jet Age"? Give it a grave and be done with it before we all are in the grave. The question should not be, why not biofuel. The question should be, why jet aircraft. It is not needed, other than to satisfy the impotent male in BAU.

Relax, take a sailboat.

I believe corn is used because it's a sugar source for fermentation, and oil crops are used because they are oil sources for various processes. In situations of scarcity, the question would likely be one of what the hardware available requires. If a poor farmer has a diesel tractor, I think he'd be more likely to grow an oil crop, while a rich farmer in a gasoline economy would be more likely to grow an ethanol crop.

I don't think it's appropriate to compare production per acre in terms of volume whilst leaving out energy content and the various inputs. Regardless, I think the underlying question here is: what is this biofuel for?

I believe lipids based liquids like methyl ester (biodiesel) or hydrogenated fat (green diesel) have less future than Fischer Tropsch liquid like Choren Sundiesel.

I believe you are correct. And speaking of Choren, I have an announcement to make pretty soon involving them. It appears that our futures are on a collision course. :-)

If your going to use CNG you can make biomethane

Biogas production from energy crops and crop residues (pdf)

Jerusalem artichoke, timothy-clover and reed canary grass gave the highest methane potentials of 2,900–5,400 m3 CH per ha, corresponding to a gross energy potential of 28–53 MWh and 40 000–60 000 km ha in passenger car transport.

According to An argument for using biomethane generated from grass as a biofuel in Ireland

Using ethanol produced from wheat, 3.9% of Irish agricultural land is required to produce 5.75% of transport fuel. Ethanol produces less energy from a crop, than the energy in the biogas generated when the crop is digested. The ethanol production process uses up to 60% of the produced energy in the final ethanol product. It is shown for compressed biomethane generated from silage that the total parasitic demand of the process is of the order of 25%.

So Who bells the cat? (as in 'Limit these solutions)

'Limit' is the operative verb in your post.. this fuel, like many of the proposed biofuels would become a large industry business model, and the resources they require would be ACQUIRED to make them happen. Like wind or palm oil.. it might be perfectly fine on a small farm.. but if you want to blanket the Steppes and the Alleghanies with them, there will be some proportionate problems.. likely even some disproportionate ones.

Suppose you were stranded on a desert island. The ability to refuel with coconut oil will get you home.

Coconut oil also turns to butter around 25C
http://en.wikipedia.org/wiki/Coconut_oil

I saw some TV footage of straight filtered coconut oil being used in a diesel vehicle on Vanuatu. As they headed off I wondered if a 20C cold snap would freeze their fuel lines and they wouldn't make it back.

An interesting parallel with ethanol is the animal feed byproduct. The leftovers from oil extraction called copra makes a good feed additive with a mild but gritty butterscotch taste. It should be soaked in water as it swells to 2-3 times the dry volume and could cause intestinal colic.

Biofuels don't cut it

Electric cars are about four times more energy efficient than fuel based cars. This is because fuel engines mostly creates heat and thus wastes the majority of the energy units available. Combine this with biofuel plants not being very efficient solar energy harvesters relative to semiconductor based solar electricity, and the result is this huge difference.

Follow the link to see the graphic.

Without doing any numbers, my WAG is that man made technology is more efficient. If you have ever watched a plant grow you will understand. A simple solar water heater with about 1m square collector area will do a much better job of heating water than ANY plant generated biomass grown on the same area by a long shot. So much so that it probably makes up for the energy embedded in the SWH from it's materials and production.

Alan from the islands

time to see the planes fall away
i hate noise anyway

say goodbye to the travelling high
it ain't coming back onto the track

anyone who raises my food prices
or fucks the planet up more
to even the score
so they can keep flying
is gonna find a bomb under their bed
when they get back from the
latest red-eye flite

we are so lucky
that people are easy to kill

solar is a sham
wind is a scam
nuclear makes good bombs
fusion makes good pork
oil is almost gone
coal is full of mercury
but aren't those humans already mad as hatters?
tides bring nice rocks
and show the shellfish's cocks

plastic recycling is a scam
you can burn it to cook your ham
just like the third world does today
so you will do tomorrow

let's bust up the earth till she screams
in reams and reams of black seabreams

a roil of oil full of delicious spoil
milk chocolate from the rocky womb
squeezed out by a drill-dick

people just want to be happy
but i am here to tell them that they aren’t going to be happy
i am here to tell them that the world’s gonna be a shithole real soon

they will be homeless, jobless, busted, in jail or dead soon
90% of the world’s fish are extinct
the planet is almost dead already
humans will soon be killing each other over the last scraps of food

there will be no rescue
there will be no divine fucking intervention
there will not be a ‘better day’
better days already passed long ago

there will be ‘worse days’, and ‘worser days’ after them
there will be killing, murder, rape, rape of children, killing and eating of children
on a scale not yet seen before
don't worry about dogfood
your dog will soon be food
there will be acts committed that we don’t even have words for yet
and that will be just the beginning

just the beginning of a new deathlife for the survivors
their own private horrorshow filled with coming attractions