Two articles. The first is this guy in the Philippines, who has discovered that oil does grow on trees. Now, 15kg of fruit to make one liter of oil, and assuming a generous 300 kg of fruit, you get 20 liters per tree per flowering cycle (no idea on how often the trees bear fruit every year). The guy says he’s planted 50000 trees, so that makes 1 million liters of oil (assuming best yield), which is about 6300 barrels of oil.
Good idea, nice way for the Philippines to make a little extra money, not gonna solve the fossil fuel needs of the world.
Next up is a good idea for rocket propulsion. Fuel pellets.
Right now, rockets go up using one of two methods, liquid fuel engines, or solid rocket boosters. The pros & cons of each are as follows.
Liquid Fuel (liquid Oxygen, liquid hydrogen): Pros – lots of impulse, can be throttled to improve efficiency, can be shut off in an emergency, clean exhaust; Cons – Complicated & expensive (fuels have to be stored cryogenically, then warmed up before mixing)
Solid Fuel: Pros – Simple & cheap (fuel & oxidizer are pre-mixed together), lots of bang for the buck; Cons – toxic exhaust, is a big firework (once it’s lit, it burns until the fuel is exhausted), can not be throttled or shutoff in an emergency.
The goal of a lot of Rocket Scientists is to get the best of both; cheap fuel, good specific impulse, simple setup, and the ability to throttle or stop the engine. To date, this has been done using a solid fuel core and a liquid oxidizer (a hybrid engine). Shoot the oxidizer through the solid core and flick your Bic to get the bang, then you can adjust the burn, or shut it off, by controlling the flow of the oxidizer.
The fuel pellet method is like a baby version of Project Orion, sans the radiation.
In Laos they are doing something similar with bio oils, but using the output in the manufacture of paving material rather than vehicle fuel, etc. It’s pretty neat, actually, although the tech is in its infancy and appears to not hold up so well.