Environmentally acceptable fuels for Pulse jets (or turbines

[Viv]

Environmentally acceptable fuels for Pulse jets (or turbines?)

I was minded to start a thread on the subject of environmentally acceptable fuels for pulse jets after reading the very topical question posed by another forum member of "what are pulse jets useful for" a good question and I hate to admit I did not have an immediate answer.

The question does immediately bring to mind our love of noise and fire but along with that is the feeling that maybe the future of our hobby has some limits, limits that will come in to being with declining acceptability of burning fossil fuels for no other purpose than having some fun out on the drive way and upsetting the neighbors.

Commercially it is no longer a problem as in the last five years we have seen the potential markets for pulse jets in UAV propulsion replaced by advancements in batteries and electric motors, soon these will be joined by hydrogen fuel cell technology and hydrogen reformer technology, for this later case the military already has a 5 kw fuel cell generator running at far higher efficiencies than standard diesel generator sets.

The commercial UAV market was the most exciting possibility but it was easy to see even a few years ago that it would be replaced by an easy to use and easy to design technology such as electrical power, the clear need now is for endurance performance that spans days in the air not hours, no combustion powered engine can hope to match electricity for that task.

This leaves only clean combustion for commercial heating applications but again we run back in to the problem of what fuel to use?

So heres the question for this thread, what is the ideal alternative fuel to use for pulse jets instead of our traditional favorite propane?

It could be liquid or gas, plenty of people have experimented using liquid fuels with varying degrees of success but I don't think any one has published results for a purely fossil free liquid fuel?

Alternative gas? well the accolade here has to go to Pyro Joe! he is the only one to have run a wood gasifier on forum and had a gasifier pulsating to some degree, maybe Joe has the answer? certainly he has the lead on the rest of us at the moment.

With that I will stop and throw it open to the rest of the forum for comment and ideas (we should include turbines too?)

Merry Christmas and seasons greetings to all

Viv

[ace_fedde]

Well, those who live on a farm have a great advantage; They can make their own methane from manure/feces. Even at home you can do that with your own sewage.
Only then you might just get enough methane to fire up your PJ once a year

For those who are thinking of doing something like this: Don't leave or let air in the system

Fedde

[Viv]

Well, those who live on a farm have a great advantage; They can make their own methane from manure/feces. Even at home you can do that with your own sewage.
Only then you might just get enough methane to fire up your PJ once a year

For those who are thinking of doing something like this: Don't leave or let air in the system

Fedde

lol I had to laugh at what crossed my mind reading your idea Fedde, its thinking outside the box certainly but I wondered if it would work with BS? if so my ex business partner as we all know will be well placed to power a large agricultural grain dryer all on his own

Back on topic, I guess home produced methane is not going to be welcome in a suburban environment add to this home distillation of alcohol based fuels

Viv

[PyroJoe]

In the near future I think Solar arrays will change the energy game, it is hard to beat a
free falling 1000 Watt/meter energy source delivered on site. True it doesn't shine all the
time but as nano technology comes on line, electrical energy storage of un-imaginable scale can be
constructed. There are so many break throughs recently, it is almost a constant innovation
blizzard.

I like ethanol as fuel, it is relatively safe and mixes easily with ambient air. How to
produce it in a sustainable process becomes a big question. Maybe algae will hold an answer, as
a very prolific biofuel source:

"Kertz said he can produce about 100,000 gallons of algae oil a year per acre, compared to
about 30 gallons per acre from corn; 50 gallons from soybeans."

Glen Kertz, ANTHONY, Texas
http://edition.cnn.com/2008/TECH/scienc ... index.html

Looking into the future I can see a system where algae produces ethanol (or something similar)
and is used for thermal/kinetic/chemical gain, then the exhaust gas (carbon dioxide and water)
is bubbled through the algae bed for recycle back to fuel.

Often wonder about Marconnet, and if he utilized "Town Gas". Town gas was used for operating
town lanterns years ago. Many regions trapped and supplied "swamp gas" as town gas. If Marconnet used swamp gas in his combustors he could have been a century ahead in the bio gas PJ arena.

If I have made any advances it can be attributed back to the forum. We have a good group of
fellas here, finding new and unusual ways of applying combustion.

Joe

[Viv]

Hi Joe

Good answers, I like algae too as a feed stuff but maybe more for algae to diesel production rather than methanol, that probably explains my interest in diesel power too

Here is a link to an excellent post by Zippoit on compressed bio gas viewtopic.php?f=18&t=5502&p=67488#p67488

"Audi has an A4 that ran 227mph on this stuff, maybe there is something to it?

Its the purified form of what crops in a no-oxygen environment emit while decomposing, similar to wood-gas in a gassifier. Its mostly Methane with a good chunk of CO2 in it aswell. Supposedly has an octane rating of up to 140 [!/?], could find a use in some project jets/rockets. How hard would it be to setup a mini bio-gas still in the backyard, throw some corn in with your rabbits droppings?

http://www.topgear.com/uk/car-news/biogas-2009-05-29"

Viv

[PyroJoe]

Hi Viv,
Methanol is not as safe as ethanol IMO. There is no need to harvest the algae as feed stock, and I think it is probably faster/cheaper to create the short bonds found in ethanol, compared to the long chain esters. True, diesel may have a higher energy density, but at what cost?

http://www.algaeoilfuel.com/ethanol/

"Producing ethanol from algae has many upsides. First and foremost the processes being used by some companies do not require fresh water, a major drawback, especially in areas with arid climates. There is also no need to harvest algae. Instead, during the process, algae consumes sunlight and more than 90 percent of the system’s CO2 through photosynthesis, wherein the sugars are converted into ethanol. The ethanol is immediately pumped out and evaporates into the bioreactor which is captured every night."

Joe

more:
http://www.cnet.com.au/algae-farm-in-me ... 289867.htm

"Algenol's process is very different in that the algae are not cultivated. Instead, algae produce ethanol in gas form that is siphoned off from the bioreactor tubes and condensed to a liquid, Woods explained.

He claimed that the system can produce 56,000 litres per hectare per year, far more than corn's rate of 3,500 litres per hectare per year or sugar cane's at 8,300 litres per hectare per year. The Mexican site is located a few miles away from a power generation station. By pumping carbon dioxide from the station into the algae bioreactors, the salt water algae farm can boost production to 94,000 litres per hectare per year, he said."

[ace_fedde]

Well, those who live on a farm have a great advantage; They can make their own methane from manure/feces. Even at home you can do that with your own sewage.
Only then you might just get enough methane to fire up your PJ once a year

lol I had to laugh at what crossed my mind reading your idea Fedde,

No comment

its thinking outside the box certainly

I like it when people say I do "thinking outside the box", but unfortunatly I cannot thank you here for saying so because it was not thinking outside the box here.
Both processes are being practised at least in Holland, both in rural and urban environments, so:

I guess home produced methane is not going to be welcome in a suburban environment

bzzz, one point less

but I wondered if it would work with BS? if so my ex business partner...

No, no, no! bzzz disqualified (will react no more one that)

In Holland we have for ages a natural gas (methane) distribution system that delivers to almost all building and houses. We run our heaters, boilers and cooking devices on it.
We also have for ages people who live on houseboates that are not connected to that system. Somehow, because the natural gas is so cheap, bottled propane is pretty expensive.
So some boatowners installed a septic tank that (like every septic tank) produces methane and cook on it. For ages already, and in urban environments.
They cook on their own @#%&

As you know Holland is pretty small but we have pretty intensive livestock farming (factory farming). That caused farmers ending up not fertilizing their land with manure, but polluting it with manure. We have simply to much @#%&.

Furtunatly we have good regulation now for it but stays the "surplus". Enter "manure fermentation" as we call it. A giant controlled airless septic tank.
More and more farmers invest in those (pretty simple) installations that produce methane without adding any energy, just bacteria do the job.

New problem is now that some farmers found out that they can make more money out of corn by dumping it in that process rather than selling it as food... Let's forget about the hungry people, as long as we have fuel...

After fermentation the minerals stay and can, with caution, still be used as fertilizer.

The gain is here double: Not only is a green fuel obtained but also we prevent the methane produced by rotting processes to escape in the atmosphere. Methane is a much stronger greenhouse gas than CO2.

Fedde

[ace_fedde]

I like algae. I'm planning to start some tests coming spring and summer. I would like to see a closed loop (semi) automatic algae cultivator/press on every roof top.

Here's some more about algae:
http://www.oilgae.com/

And this site looks a bit deeper into "solutions", but to me sometimes to much "doom":
http://www.lowtechmagazine.com/2008/04/ ... -biof.html

Fedde

[ace_fedde]

And for people who want that last one in (Belgium) dutch:
http://www.lowtechmagazine.be/2008/04/a ... dstof.html

[Viv]

Hi Guys

Well so far I would say we have some good grow your own or brew your own alternatives but nothing ready to run or produce as you run

Looks like the pulsating wood gas gasifier is still out in front until some one posts another idea in the ready to run category

Viv