One might think that this doc may have just written all that stuff to see what a reaction he might stir up.
There are several threads on this forum wherein bioD and other bio fuels are discussed.
Specifically regarding homebrew attempts, I have been reading a book by Canadian Bill Kemp,
Biodiesel, Basics And Beyond: A Comprehensive Guide to Production And Use for the Home And Farm.
He has done all the research and presents his case for correct brewing succinctly. He investigates six homebrew processes and, based on the actual science, finds fault in each. He then goes on to tout the necessity to meet the ASTM spec on bioD and then lays out how he meets the spec with his off-the-shelf homebrew plant and QC lab. Pick it up at the library or check it and the reviews out online at Amazon.
Several other publications, both books and articles report on the science and basically refute Doc's generalities. NO2 has been measured and compared to gasoline (bioD does emit a higher amount). However, in ALL other categories of pollutants, bioD is demonstrated as the way to go. It even may prolong engine life since it somehow lubes better than dinoD.
Per the 1st Ammendment, everyone has the right to say anything, without checking any facts. The bioD science is easily refernced. Google it, then answer with facts and citations.
Good luck.