there are some kit on ebay but they cost alot i think its £1500. i think it said you don't pay duty as long as its for your personal use & i think there was an upper limit you can make, but its quite a lot.It was probably the proposal in increase the amount of bio fuel in diesel from 5% to 10%. The argument is that the land taken to grow crops for bio fuel and the energy needed to refine it has a net negative environmental impact vs good ol' crude.
This is a separate argument from someone wanting to make use of used chip fat to run their diesel car. Which is apparantly very easily done with a home brew kit and some additives.