Fuel crisis?

Your question is sort of complicated. 99% of the propane on the market today is seperated from crude in a refinery, so it is not man made. Most of the ethanol on the market is made from corn, so in a way I suppose it is man made. It is possible to make different petroleum fuels from coal, or coal syn-gas (which I suppose can be considered man-made) but since you are using coal as the raw material, it cannot be considered renewable. To answer your question there are various ways to make the above fuels, however certain processes are limited by.... you guessed it $$$$$$$!!!