How can I get diesel fuel without bio oil?

That would be nearly impossible now. Before the Ultra Low Sulfur Diesel regulation, North American diesel had sulfur which gave it an unpleasant scent but it also provided lubrication to the engine. Now that the sulfur is removed or rather diluted with synthetic diesel to meet the regulations, some lubricant is still needed therefore 2% biodiesel is often added to provide that lubrication even number 2 heating oil which is diesel with a dye to indicate that road taxes had not been paid, would have 2% biodiesel.

Sulfur was not the lubricant in #2 Diesel Fuel whether it is the old formula, the 500ppm sulfur, or the new ULSD 15ppm. There is no dilution with anything like "synthetic" diesel to reduce sulfur. Hydrogen gas is forced through #2 diesel fuel to remove the sulfur as it bonds with hydrogen to form hydrogen sulfide gas. This process also tends to make the fuel "drier" as it also removes other components which helped with lubrication. The result is a more corrosive, less stable, more hygroscopic fuel. The President signed a mandate requiring so many gallons of "renewable" fuels to be blended into our diesel fuel. They are blending in some form of "bio" whether it meets ASTM standards or not, and if under 5%, they do not label the pump as such. That is strange that most folks are more concerned about the sugar, sodium, and cholesterol content of foods from the FDA labels on the packages, but care not about what goes into fuel which propels our vehicles.