> ...even though a diesel engine run on veg oil is emissions free.
This just isn't true. Local emissions of bio-diesel are comparable to petro-diesel.
When you factor in that C02 is absorbed during manufacture, biodiesel is estimated to have 45%-65% lower net emissions than petro-diesel, but that ignores the fact that you just repurposed viable farmland (or in some cases rainforest) and changed its C02 profile, potentially reducing or erasing any net benefit.
This just isn't true. Local emissions of bio-diesel are comparable to petro-diesel.
When you factor in that C02 is absorbed during manufacture, biodiesel is estimated to have 45%-65% lower net emissions than petro-diesel, but that ignores the fact that you just repurposed viable farmland (or in some cases rainforest) and changed its C02 profile, potentially reducing or erasing any net benefit.
https://en.wikipedia.org/wiki/Environmental_impact_of_biodie...
Another challenge is what to do with all the waste glycerol (100kg per ton of biodiesel), since prices crashed a few years back