Multi-Feedstock Processing

A majority of biodiesel plants say they use multiple feedstocks, so the process technologies needed to handle varying feedstocks like RBD soy oil and high FFA waste oils are the subject of an upcoming feature article I'm writing for "Biodiesel Magazine."
By Ron Kotrba | January 07, 2009
For our March issue of Biodiesel Magazine I'm writing a featured article on multi-feedstock processing. On our fall 2008 Biodiesel Plant Map, a majority of biodiesel producers tell us they are multi-feedstock processors, and "multi-feedstock" constitutes 55 percent of feedstocks used. Not long ago, soy oil was listed on the map as the predominant feedstock.

I think the conversation comes up around our media office every now and then when people ask questions like, Do multi-feedstock biodiesel producers use a single stream through certain parts of the year, or do they combine feedstocks before production to meet certain process specifications? Or can they just switch between RBD soy oil and waste vegetable oils just like that, or do they have to tweak the process before switching?

There are different ways to process multiple feedstocks into biodiesel. So far I've gotten Greenline Industries to agree to talk with me about their process technology, which uses a blend system on the front end that takes a high FFA material and mixes it with a low FFA material to meet its process specs. Biodiesel Industries' Russell Teal agreed to speak with me about their process technology also. And today I'm going to try and line up an interview with someone from REG, which has a process flow diagram on its Web site indicating its technology utilizes a different approach to multi-feedstock processing compared to that of Greenline.

If anyone reading this blog entry between Jan. 7 and Jan. 14 would like to contribute to this article, or would like to share personal operating experience or insight into issues they've had using any particular multi-feedstock process technology, please email me at or (701) 738-4942. If I don't answer the phone please leave me a message.