Beaucoup de gouvernements encouragent la consommation de carburants agricoles, notamment en Europe, au Japon et aux Etats-Unis. Certaines de ces politiques ne sont pas fondées sur une rationalité économique solide : les biocarburants resteront très chers à produire. Mais même si ces politiques aboutissent, nous pensons que la part des biocarburants en 2030 sera de seulement 7 % de l'ensemble de la production mondiale de carburants. Pour atteindre ces 7 %, il faudra une surface agricole équivalente à la superficie de l'Australie, plus celles de la Corée, du Japon et de la Nouvelle-Zélande...		A lot of governments, especially in Europe, the United States, and Japan, are encouraging use of agricultural fuels. Some of these policies are not founded in solid economic rationality : biofuels will continue to be very expensive to produce. But even if these policies were carried through with, we think the share of biofuels in world fuel production in 2030 will only be 7%. To reach those 7%, it will be necessary to use a farmland surface equivalent to the combined total areas of Australia, Japan, Korea, and New Zealand combined...
Cette concurrence avec la surface consacrée à l'agriculture traditionnelle risque d'avoir des conséquences sur le prix des récoltes. Oui, c'est déjà le cas, et ce n'est pas bon. Et puis il y a aussi des difficultés liées à l'environnement : de plus en plus d'études prouvent que les biocarburants ne réduisent pas automatiquement les émissions de gaz à effet de serre, comparés au pétrole. C'est aussi un gros souci. Donc pour ces raisons à la fois économiques et environnementales, 7 % de la production totale de carburants est un chiffre très, très optimiste. Les carburants agricoles ne remplaceront jamais le pétrole de l'OPEP, comme certains l'espèrent.		This competition with traditional agricultural land use runs the risk of consequences on crop prices. Yes, this is already happening, and it's not a good thing. And then there are environmental issues : an increasing number of studies prove that biofuels do not automatically reduce greenhouse gas emissions, compared to petroleum products. This too is a major worry. So, for both economic and environmental reasons, 7% of total fuel production is a very, very optimistic number. Agri-fuels will never replace OPEC oil, as some people hope.

This doesn't address your question about the use of waste, but, in the face of rising world demand for liquid fuels, recycled waste doesn't seem likely to make more than a very small contribution.

When locusts move on, they leave nothing behind

We ran the figures for the EU and even if the EU used their entire oil output (well, we didn't include olive oil) for diesel, it would barely be able to reach the 6% target set by the Commission. The only sensible way to put all our oil into diesel engines is to recycle all the waste cooking and motor oil into diesel. Othwerwise you can power your diesel but you can't cook or lubricate the engine.

According to Eurostat, transport fuel consumption for 2002 in the EU-25 was :
petrol, 5.2 e6 TJ ; diesel, 6.6 e6 TJ.
5.75% of these gives:
petrol, 0.3 e6 TJ ; diesel, 0.38 e6 TJ
Ethanol : 0.3 e6 TJ petrol  / 22 MJ/l = 13.6 e9 l
Biodiesel: 0.38 e6 TJ diesel / 34 MJ/l = 11.2 e9 l
If all the area (statistics, DG Agriculture) currently dedicated to potential ethanol feedstocks were used for ethanol, production could be an estimated:
·    10.5 e9 l of ethanol potential from the current EU-25 cultivated area of sugar beet (2.1 e6 ha @ 5000 l/ha)
·    19 e9 l of maize ethanol potential (from 6.5 e6 ha @ 3100 l/ha)
·     33.5 e9 l of common wheat ethanol potential (from 13.4 e6 ha @ 2500 l/ha)
·     23 e9 l of barley ethanol potential (from 23 e6 ha @ 1000 l/ha).
If only the surplus percentage (in excess of 100% self-sufficiency) of these crops were to be used, the estimates would be:
·    30% sugar beet: 10.5 e9 l x 30% = 3.15 e9 l ethanol
·    9% common wheat: 33.5 e9 l x 9% = 3 e9 l
·    13% barley: 23 e9 l x 13% = 3 e9 l
Surplus production (9 e9 l ethanol) would not suffice to cover the needed 13.6 e9 l. Only an extension of the area of ethanol feedstock crops, or a transfer of crops from animal feed to ethanol, would cover needs.

As for biodiesel, the total area of the two principal feedstocks, rapeseed and sunflower seed, would produce an estimated:

·    5 e9 l from rapeseed (4.5 e6 ha x 1100 l/ha);
·    2.2 e9 l from sunflower (2.2 e6 ha x 1000 l/ha)

Total production (7.2 e9 l) would not suffice to cover the needed 11.2 e9 l.