Biodiesels?alternative fuels made from plant-based sources like soybeans?have yet to really take off in popularity or use. Part of the difficulty is that, despite conflicting studies, they’re believed to contaminate regular diesel fuels, and thus can’t share containers or pipelines with petroleum-based fuels.

Enter a newcomer in the alternative fuel field: renewable diesels. The fuel is made from refined animal fat, lard, and tallow?all by-products of the meat processing world (in fact, the technology is being in part pioneered by meat giant Tyson Foods). Renewable diesels don’t give off benzene, which is thought to be carcinogenic, and they also generate far lower levels of other chemical emissions.

Best of all, because of the way renewable diesels are refined, they can be mixed with traditional petroleum-based diesels. To learn more and discover the challenges facing this fuel source, read the National Geographic Daily News site’s commentary.