Ethylene (Ethene) is a Gas produced by processing Bio Fuel in a Pressurized Reaction Chamber (PRC). 2 Bio Fuel and 100 millibuckets (mB) of hydrogen in a PRC will generate 100 mB of Ethylene and a single Substrate.
Ethylene is a potent, long-lasting energy source. When burned in a Gas-Burning Generator 1000mB of ethylene will produce a total of 2000kJ (800,000RF) of power at 750J/t (300RF/t).
Use your prefered source of Bio-Fuel (i.e. Rotten Flesh, Seeds, Wheat) that is processed by a Crusher and Hydrogen from an Electrolytic Separator to produce Ethylene. Then burn it in a Gas-Burning Generator.
One Electrolytic Separator produces just enough Hydrogen for a 3x Speed PRC. For feeding this you need a 5x Speed Crusher with a constant supply of Bio-Fuel ingredients. The amount of Ethylene produced is enough for approx. 70 Generators which equals 21000 RF/t. Be aware, that the Ultimate Universal Cable can only cope with 12800 RF/t.