Air NZ proposes Jatropa as a biofuel

[Kiwiguy]

Can somebody please explain to me the proud cock-a-hooting of Air New Zealand's management about Jatropa seed oil ?

FAA requires demonstration that jet fuel for civil aviation will not gel (crystalise) at temperates down to minus 40 celsius.

Jatropa biodiesel gels at zero celsius.

Is this just some form of PR masturbation ?

[Flying Binghi]

Link to further info please.

[Desert Dingo]

From other threads around here on the subject.
...only one engine will run on the blended biofuel-kerosene mix

[doubleu-anker]

Masturbation, is right. I don't BTW:)

What they really trying to spew out is, that it is still jet fuel with additives.

[Kiwiguy]

Your wish Flyingbhingi is my command....


Link to further info please.


I refer to an article at the website of ecoworld:

http://www.ecoworld.com/home/articles2.cfm?tid=353

The article is entitled:

"HOPE IN JATROPHA, India Gives Biofuels a Chance to Grow" October 15, 2004

by Brook & Gaurav Bhagat (Brook and Gaurav Bhagat are writers and independent filmmakers based in Jodhpur, Rajasthan, India.)

India's Government is pushing Jatropa the same way that Malaysia pushes Palm Oil. The article states:


One noteworthy drawback of especially undiluted biodiesel (BD100) is its cold-clogging point of 0 degrees Celsius. This is one of the reasons it is usually mixed with conventional diesel, especially in cold countries. This is not a problem, however, in most of India, except in winter in the higher altitudes of the Himalayas.


The clogging point is in fact the gel point, or when the biofuel crystalises. The FAA requires jet fuel not to clog at minus 40 Celsius.

Nearby the article also draws attention to another problem. That it acts as a solvent dislodging previous hydrocarbon deposits from earlier operation on petrochemicals. The dislodged deposits will also clog injectors.


It is true that, because of the solvent power of biodiesel, especially older engines or machines can get clogged, but this is because the biodiesel is actually cleaning it, dissolving the residues left by petrodiesel.


A third problem with Jatropha is that it is hygroscopic, or attracts moisture from the air. In other words you're buying into other problems:

* Water reduces the heat of combustion of the bulk fuel. This means more smoke, harder starting, less power.

* Water causes corrosion of vital fuel system components: fuel pumps, injector pumps, fuel lines, etc.

* Water freezes to form ice crystals near 0 °C (32 °F). These crystals provide sites for nucleation and accelerate the gelling of the residual fuel.

* Water accelerates the growth of microbe colonies which can plug up a fuel system. Biodiesel users who have heated fuel tanks therefore face a year-round microbe problem.

doubleu-anker, you don't know what you're missing... Voice of experience.:}

[Kiwiguy]

A further few points...

for comparison biofuel from Rapeseed will gel at -10C. Biofuel from tallow will gel above freezing around +16C !

Nobody mentions either that Jatropa biofuel pumps out around 25% higher Nitrous Oxide emissions thus may not comply with JAA requirements for NOX emissions.

NOX is a carcinogen so will result in airport ground handlers contracting cancers from fumes on the ramp.

NOX is also a greenhouse gas so that by burning Jatropa biofuels Air New Zealand will solve one environmental problem by exacerbating another.

Do the plonkers on the Board of Air New Zealand ever bother to consult with anyone before making these wild decisions or do they just spend millions of shareholder's dollars over a few glasses of Chardonay ?

[pakeha-boy]

Quote kiwiguy..."Do the plonkers on the Board of Air New Zealand ever bother to consult with anyone before making these wild decisions or do they just spend millions of shareholder's dollars over a few glasses of Chardonay ?"


,....and that mate is the jist of Airline Mgt in a nutsheel.....to which you summed it up very well.....by the way,interesting article.....

[Kiwiguy]

I didn't even know about the hygroscopic (water attracting) issues when I started the thread. It seems to me a cynical attempt at headline grabbing to climb aboard the Green bandwagon.

[Flying Binghi]

Thanks for the links Kiwi guy

What do you think would be the best alternative to Jatropa

[Desert Dingo]

Jet-A? :E

(added to get enough characters)

[Kiwiguy]

Jet-A?


ha ha ha ha ha ha.... Many a true word spoken in jest.

Cotton seed or sunflower oil seem the best prospects (that I know of). The yield per kg of cotton seed is very low. Not the energy yield. The crop yield.

All biofuels suffer the same issues however because they have higher oxygen content than fossil fuel. It is the oxygen in these biofuels which allows them to soak up water from the atmosphere.:sad:

The water freezes in biofuel molecules and encourages the biofuel to gel clogging fuel lines and injectors.:yuk:

In Al Gore's film he pointed out that you only have to reduce emissions by 7% to stop global warming and by 15% to reverse it. :8

It is thus more logical to stop chasing biofuels for jets and look at biofuel for private cars, trucks and buses. Aviation only accounts for 2% of global carbon emissions. Ruminent livestock account for 45% of greenhouse gases so stop eating beef. :D

It would be far easier for airlines serious about the issue to fund the take up of hybrid vehicles. I had a ride in a Prius the other day and was blown away by them.

IF Air NZ had a really switched on marketing department they would create a frequent flyer points scheme to buy a hybrid car.:cool:

At least using biofuels in private cars you don't have fuel gelling issues in the normal range of temperatures in NZ.;)

[Kiwiguy]

Another point occurred to me overnight, that the water attracting qualities of biofuels are unpredictable.

On a humid day bio-jetfuel would attract more atmospheric water and thus engine power would be more degraded on humid days than dry days.

That poses aircraft performance certification problems.

What do you do with a jet certified to use a runway of 1900 metres at a given weight, when biofuels degrade engine power ?

One day it can be certified for a 1900 metre runway and the next day it will need a 2400 metre runway.

Every revenue flight will become a test flight and given the growing pilot shortage and reducing skills of crews, do you really want performance which isn't foolproof ?

[Flying Binghi]

Kiwi guy,

I'm very pro Biodiesel - I dont see any other alternatives for jet aircraft and in the interests of having 'one' fuel, I think it is the most suitable for piston aircraft. (I'm also pro cattle or ruminent livestock - my veiws re the bad science claims on cattle farts I'll leave for jet blast)

My knoweledge of biodiesel is fairly limited, but I understand the gelling problems of biodiesel are overcome on the ground by keeping the tanks warm. If or until a suitable no-gell/low-gell blend can be developed, it may be aircraft fuel tanks will need to be heated.

I would have thought the green house gas impact of biodiesel would be neutral. The effect is probably simular to what happens in nature with forest fires producing all those bad gases that are then recycled back into new plant growth - just that the 'forest fire' happens in the aircraft engine.

Green flight int. make claims of succesfully flying an L39 on 100% biodiesel, and have plans to fly a jet around the world on 100% biodiesel.
www.greenflightinternational.com (http://www.greenflightinternational.com)

[Kiwiguy]

Personally I am not convinced that climate change isn't a natural phenomenon.

There is evidence of farming by Vikings in Greenland prior to the 14th century.

There is also proof that Caucasians naviagated the Northwest passage over Canada to the American west coast in prehistoric times.

In the Bahamas there is evidence of sea levels 148 metres lower than present.

I have no personal objection to biodiesel for cars/trucks/buses, but it has no place in aviation, except perhaps if they ressurrect giant airships which don't fly to great altitudes.

If you have to plumb a jet aircraft with heating system to prevent fuel clogging at altitude then you may aswell install a liquid flourine nuclear reactor and be done with it because the development costs will be on a similar scale.

For the conceivable future there will always be sufficient fossil fuel for jet fuel.

Promoting biofuel and hybrids will help to offload pressure on fossil fuel supplies.

The big question is are we going to witness everybody in China and India buying petrol cars as their living standards improve, or can we shift the whole world to use of biofuels and/or hybrids ?

I love to eat beef too.

It all goes to prove that the subject is not simple or straight forward.

Biofuels for jets however are non starters.

Geared turbines are probably the best way to acheive higher fuel efficiency for jets. PW8000 is one such concept engine.

[Flying Binghi]

Seen in the news today that Virgin Atlantic will test fly a 747 with Biofuel/Jet-A mix next month.

[tartare]

Guys,
they're (Air NZ) actually investigating algae generated biojet.
The process is derived by a ChCh based company... Aquaflow.
They'll use it in a non-paxing 744 later this year, blended with conventional JetA1.
They already know about the gelling issue.
It's all a very cynical attempt to appear green... believe me.;)

[Kiwiguy]

It's all a very cynical attempt to appear green... believe me.


I think the NZ herald are doing a story on this in the next day or two. Watch out for the interview response.