While there are many different feedstocks available to use for making biodiesel, the one you should use is going to be determined by a handful of factors. Mainly, geography, intended use, pre-processing/processing capabilities, and weather. We will start with geography. One of the main benefits of biofuels is that it does not have to be transported halfway around the world to be processed and used. It can be locally sourced and processed, thereby reducing emissions caused by transportation, and creating a local economy around the processing. Different regions of the world will have various oils and greases that are available to process. Where tropical areas may use palm oil, or jatropha, cooler climates may use camelina or rapeseed. Urban areas may be predisposed to using yellow or brown grease, due to their abundance.
Feedstock choices may also be determined by the finished products intended use. Fuel that is intended to be used as aviation fuel will undoubtedly be of higher quality (and cost) due to the inherent danger involved with a failure. Whereas fuel intended for a generator of off-road vehicle may not require such a high grade.
Another consideration when deciding on feedstock is the facilities pre-processing and processing capabilities. If a specific plant has minimal pre-processing capabilities, you most likely would not want to use waste oils and greases, or even crude soy oil for that matter. The oils that come into this facility would need to be processed first to remove contaminants that might spoil the product or worse, damage the equipment. Lastly, the weather, yes, the weather plays a critical part in the determination of the best feedstock for your plant. If you are located in an area that has severe weather, you will need to choose a feedstock that produces a biodiesel that has a lower cold flow pour point to keep the fuel from turning into a gel in the tanks.
As you can see, there is a bit of thought that is required before settling on a feedstock for your facility. A little forethought, however, will save considerable heartache down the road, and is well worth the effort!