If there was a contest for the ugliest processing tank in the biodiesel industry, I think we would win. This tank, which was purchased by a former business partner in 2008, has sat unused for way too long. We finally found a use for it as an esterification pre-treatment tank for incoming high FFA feedstock.
The price of WVO feedstock has increased dramatically and hasn’t fallen back off by much, so we’ve taken to buying lower quality feedstock (or soy, which can be cheaper in some cases, see my other blog article about that). High FFA feedstock needs to be cleaned up and esterified in order to convert it into biodiesel. This tank was originally an all stainless steel (316) conical tank. We added a water jacket and spray foam insulation (and then painted it black to make it even uglier) and added a stainless pump, stainless steel plumbing, and fittings to do high FFA WVO esterification and settling. Fortunately, many of the fittings and valves had been purchased previously and were just sitting around in storage at the plant.
We’ve run through some test runs with the tank and so far it seems to work very well. We will run large scale batches beginning next week to see how well it works. I’ll post more information about esterification pre-treatment and how it works in large scale batches for biodiesel feedstock in the coming weeks. We’ve done smaller batches in the past (1,000 gals) and it works very well at that scale. We hope to speed up the process by using larger tanks and pumps to perform the operation a truckload at a time.