"The company has deals to plant 250,000 acres of jatropha in Brazil, India and other countries expected to eventually produce about 70 million gallons of fuel a year."
This does not sound promising. Scaled linearly to the current level of oil production, this would cover more land area than Brazil and India put together.
(Current production is 90 million oil barrels/day [0] or 1.4 trillion gallons/year. If this biofuel yields 70 million gallons/year out of 250,000 acres, that's 280 gallons/year / acre; dividing out that's about 5 billion acres, or 18 million km^2. Brazil and India put together are 12 million km^2 [1]).
Perspective on the 280 gallons/acre figure [2]:
"Estimates of Jatropha seed yield vary widely, due to a lack of research data, the genetic diversity of the crop, the range of environments in which it is grown, and Jatropha's perennial life cycle. Seed yields under cultivation can range from 1,500 to 2,000 kilograms per hectare, corresponding to extractable oil yields of 540 to 680 litres per hectare (58 to 73 US gallons per acre).[17] Time magazine recently cited the potential for as much as 1,600 gallons of diesel fuel per acre per year.[18] The plant may yield more than four times as much fuel per hectare as soybean, and more than ten times that of maize (corn)."
This does not sound promising. Scaled linearly to the current level of oil production, this would cover more land area than Brazil and India put together.
All biofuel options have this limitation. Peak production for canola oil is around 100 gallons/acre. Yields for algae are higher, around 5,000 - 10,000 gallons (120-240 bbl) /acre for open-air operations (some greenhouse-based operations claim higher productivity though there's a great deal of skepticism over these), but scaling algae biofuel productions up has been extremely problematic to date. All values on an annual basis.
At present rates of consumption in the US (20 million bbl/day, or 7.3 billion annually), you'd need 30 - 75 million acres devoted to fuel production, if I'm getting my math right. Yield claimed here are for 280 gal/acre, or 6.7 bbl/acre.
The vast majority of oil goes to transportation (where it provides 95%+ of the energy used). In some cases (rail, urban/metro private vehicles, transit, canal traffic) electricity or batteries can be substituted. For others (shipping, and especially air traffic) there are few alternatives to liquid fuels, though ships could move on pelletized biomass and/or wind.
Cutting transportation energy requirements would help, but the expectation of much of the world that it will have access to Western levels of per-capita resource utilization would put a huge burden on biological productivity. I don't see the expectations being fulfilled.
Other alternatives include synthesis of hydrocarbons using electricity. The US Navy is researching such methods, which might be able to synthesize aviation fuel using surplus generating capacity from nuclear-powered aircraft carriers (aviation fuel effectively limits cruise duration as it must be frequently resupplied, cost is another factor), and the ability to obtain both carbon and hydrogen from seawater is a benefit, but the process requires _billions_ of gallons of water to be processed. Again, scale of operations is a significant constraint.
"At present rates of consumption in the US (20 million bbl/day, or 7.3 billion annually), you'd need 30 - 75 million acres devoted to fuel production, if I'm getting my math right. Yield claimed here are for 280 gal/acre, or 6.7 bbl/acre."
My math disagrees with yours, I'm getting 1.1 billion acres? That's about 1/5th of the figure I got for the globe.
I was giving acreage for algae at 120 - 240 bbl/acre.
At 6 bbl/acre for jatropha as described in the article, you'd need 1200 million acres. On the high end, that's a region 1370 miles on a side -- roughly half the area of the US (very roughly -- I'm using a 1000 mi x 3000 mi rectangle as an approximation). Wikipedia says 3,717,813 mi^2, 570,000 of those are Alaska. Yeah, 60% of the non-Alaskan land area of the country.
There are 409 million acres of arable farmland in the US (about 17% of the total land area).
Your 1/5 estimate works out as the US consumes about 20% of global oil extraction.
You only need this to produce enough to cover petroleum use cases without viable alternatives. Push come to shove, we will get electric cars working. We can skip oil for any large scale power production.
Why are you assuming growth on one plane? Can't these crops be stacked? Also from a hedging perspective, alternative supply from this (assuming fuel is interchangeable) doesn't need to be equal to oil.
Density of plantings affects available sunlight (neighboring plants shield one another).
Any sort of structure in agriculture is hugely expensive because of scale. You're not talking about putting up a backyard trellis, you're talking about building a structure that would cover tens of millions of acres, hundreds of thousands to millions of square miles. That's tremendous.
Farmers normally consider infrastructure such as irrigation ditches, pipes, and harvesting equipment, which comparably are effectively nil scale, to be significant costs of cultivation.
If you think about it, the fact that most farming takes place on little more than scratched earth, and often not even that, speaks to the low level of infrastructure required.
So....is it still oil? What is the molecular difference between bio-fuel and regular ol' jet fuel? What is the difference after it is burned? Seems ridiculously cool.
What's your definition of "oil"? It's still hydrocarbons, and can still be refined into at least some of the same compounds that so-called "mineral oil" (petroleum) is.
The big difference is that it's more or less carbon-neutral. The carbon released from burning petrochemicals was underground for tens or hundreds of millions of years, and hence increases atmospheric CO₂ concentrations. Like all biofuels, on the other hand, the carbon released from burning jatropha-derived fuels was sucked from the atmosphere as the plant grew.
I don't think there's any real difference between biofuel and regular fuels except that biofuels might (don't quote me here) be a bit less energy dense which is just an engineering problem.
The big problem with biofuel is that it takes farmland to grow it on which means said farmland isn't making food crops.
Pardon me for being a bit pedantic here but not all bio fuels require farmland.
Bacterial based processes (generally e.coli) work in digestor/reactors), algae based fuels simply need access to sunlight (can be grown in tubes attached to the side of buildings). Further some starter crops can use land that is not deemed arable by farming standards.
The scale at which algae would have to be produced to provide even a small fraction of existing petroleum consumption would mean you'd be growing it on rather more area than you've got affixed to building facades.
For the US alone, sever tens of millions of acres, at 15,625 square miles (40,468 km^2) per 10 million acres.
If you were, say, build your 10 million acres of algae grow tanks along the length of US Interstate 80 (2,899 miles), they'd extend 2.6 miles to either side of the highway, for its full length. And that's about 25% of what would be required to replace present oil consumption, so figure on extending your tanks out another 7.8 miles on either side, or string tanks along Interstates 10, 40, and 70 as well (mind the routing around the Great Lakes). Oh, and algae don't freeze well, that's going to cut into your growing season.
Plus you've got to provide water, nutrients, stirring, and keep pathogens and scavengers off the crop.
If it's seawater, how are you going to return it to the ocean. You can't dump salt water on land -- it poisons the soil. Even freshwater evaporating in dry climates leads to salinization.
What's that going to cost you in energy inputs (pumping costs)?
Though the thought occurs to me that the Salton Sea in southern California might make a possibly suitable grow region.
The differentiation is in the length of the hydrocarbons. Most biofuel oil is equivalent to diesel fuel (heavier grade than gasoline), but that's largely tuneable in refinement.
Why does everyone obsess over fuel for transportations? It's the most difficult thing of all to make from renewables.
Just plant some switch-grass and shovel it - as is - into a coal plant. No ethanol or anything else. Take the resulting ash (mostly potassium, i.e. potash), and use it as fertilizer, then and do it again.
Because transportation accounts for about 1/3 of all energy use, and oil accounts for 95%+ of all transportation energy.
Because good transportation fuels are hard to find. If you're on a fixed track (rail, trolly), you can electrify. If you're not going too far and can keep your vehicle weight low, batteries become an option. If you've got a big enough structure, you can consider solid fuels (ships). For overland untracked transport (trucks), you might be able to use steam power (allowing solid fuels) at considerable losses of convenience and increase in mechanical complexity.
For heavier-than air craft you're pretty much SOL.
Transportation isn't just moving people around, but everything: food, raw materials, finished goods, and more.
And liquid fuels are also convenient for powering other equipment, especially for mobile, temporary, or remote locations.
Finding a replacement for liquid fossil-fuel based hydrocarbons is the holy grail.
Coal and oil fundamentally changed human existence in ways that are very, very difficult to convey. They've made possible not only all of modern technology, but even the world of 1850, primitive as we would consider it, would be impossible without fossil fuels. Take them away and you're going back before that time, but with 14x the population. Trust me, that's the sort of thing that keeps me up nights.
Though he's rather much the cornucopian, Daniel Yergin's The Prize, both a book and TV series, really impress how much the world changed with the discovery of petroleum in 1859. I highly recommend it:
The are plenty of electrical plants that burn oil.
Relatively few. On a cost basis, oil's been more expensive than coal or gas. The former is still widely used (and serves as the bulk of electrical generation in much of the world). Solar and wind are approaching parity with coal, but are not dispatchable. They're available when they're available, and you can shed excess, but there's no accelerator pedal: you can't turn on the sun (or the wind) when you need them.
Solar thermal gives the option of banking energy for a few hours (about 6 presently, proposals for several days' capacity exist). This would address load balancing to a significant extent, but solar thermal plants must be specifically constructed, they're not suitable for opportunistic deployment as solar PV is.
Because even if you rationed oil for transportation, it's still going to grow sparse - and there's no reason to believe that the demand for transportation is going to go down. At best, the rationing scheme will slow down the current problem, and then you're back to where they are right now, trying to find viable and cheaper replacements for oil.
They obsess over it precisely because it's the most difficult of all. High energy density is required for flight. Apparently people would like to keep relatively cheap flight a thing that stays around.
not optimistic (know the company personally). Communicated to the founder that he should pivot to specialty lubricants (for example low temperature lubricants that are used in satellites), wasn't interested.
This does not sound promising. Scaled linearly to the current level of oil production, this would cover more land area than Brazil and India put together.
(Current production is 90 million oil barrels/day [0] or 1.4 trillion gallons/year. If this biofuel yields 70 million gallons/year out of 250,000 acres, that's 280 gallons/year / acre; dividing out that's about 5 billion acres, or 18 million km^2. Brazil and India put together are 12 million km^2 [1]).
Perspective on the 280 gallons/acre figure [2]:
"Estimates of Jatropha seed yield vary widely, due to a lack of research data, the genetic diversity of the crop, the range of environments in which it is grown, and Jatropha's perennial life cycle. Seed yields under cultivation can range from 1,500 to 2,000 kilograms per hectare, corresponding to extractable oil yields of 540 to 680 litres per hectare (58 to 73 US gallons per acre).[17] Time magazine recently cited the potential for as much as 1,600 gallons of diesel fuel per acre per year.[18] The plant may yield more than four times as much fuel per hectare as soybean, and more than ten times that of maize (corn)."
Also: [3]
[0] https://en.wikipedia.org/wiki/Petroleum
[1] https://en.wikipedia.org/wiki/List_of_countries_and_dependen...
[2] https://en.wikipedia.org/wiki/Jatropha_curcas#Biofuel
[3] https://en.wikipedia.org/wiki/Biodiesel#Yield