In response to a question in another thread, here is a brief comparison between biodiesel and renewable diesel.
Biodiesel has a number of important problems.
- It has a lower energy density than diesel, leading to lower efficiency
- It can only be used in low % blends in normal engines
- It needs very high quality feedstock (both expensive and more valuable as food)
- It cannot be stored for too long
A number of companies have developed processes to convert oils and fats into a better substitute for diesel than traditional biodiesel.
Both of these processes, as far as I can tell, produce a complete substitute for Diesel, which have none of the downsides of biodiesel.
It seems to me that both of these processes are far superior to the second rate product that is currently being sold.