Today I happened to see a bio-fuel petrol station! I decided to check it out (even though I was traveling by tram in a part of town that I don’t normally visit so there was no possibility of any real purchase).
The station is Conservo . Their main products are E10 petrol (10% Ethanol and 90% Petrol), B20 bio-Diesel (20% bio-Diesel and 80% Petroleum based fuel oil), and B100 (100% bio-Diesel). All the fuel that they sell has a biological based component. The prices for the fuel seemed a little lower than is charged by other petrol stations, but it’s difficult to tell as fuel prices can change rapidly.
I spoke to one customer who had just filled up his 4WD with bio-Diesel about his experiences. He said that he sometimes used B20 and sometimes B100. He had found no down-side to using such fuels but had noticed that when under hard acceleration the bio-Diesel fuel seemed to cause less dark smoke (IE less soot).
All the fuels that they sell are produced in Australia. There are issues with imported bio-fuels which are sometimes produced with slash and burn agriculture and often increase the prices for essential food items (such as corn in South America). As the fuel is produced in Australia such issues should not apply. According to a brochure they have facilities to allow people to deposit used vegetable oil which can then be converted to bio-Diesel.
Inside the store they sell a variety of organic foods and drinks, I bought a bottle of carbonated organic apple juice which was quite nice and at $3 was not outside the price range that I expect from a petrol station (which do tend to charge high rates for refreshments). It was not an unreasonably high price for an organic drink.
In the store they sell and promote a range of producthttp://en.wikipedia.org/wiki/Flash_points that are positive for the environment. They have a display about using algae to produce bio-Diesel fuel which has some interesting information but unfortunately didn’t list the productivity of algae fields in terms of the number of tons per hectare per year (or month or other time period).
One really interesting point I read on their web site concerns the flash point  of fuel. The flash-point is the temperature which allows enough of the flammable substance to evaporate to produce an ignitable mixture. Petrol is listed as less than -40C, fossil-Diesel fuel is greater than 62C according to Wikipedia (greater than 55C according to Conservo) while Conservo list the flash point of bio-Diesel as greater than 110C. Wikipedia lists the flash point of canola (rape seed) oil as 327C. This is described as being a benefit of bio-Diesel. While it’s obvious that this is a disadvantage for Petrol, I find it difficult to imagine a situation where a fuel tank could reach a temperature greater than 55C but less than 110C.
In their Good for the Environment  page they claim that the exhaust from burning bio-Diesel is less harmful to human health than that from burning fossil fuels. My previous post about Vegie Cars  is getting some comments suggesting otherwise. So far I haven’t found good references either way, but the discussion has raised some really good issues.
Update: Petrol’s flash-point is less than -40C not +40C.