jleader, you're right about the high concentration of heavy metals. They used to sell an "organic" yard fertilizer made from sewage, it was called Milorganite. It was eventually withdrawn from the market when they discovered it had extremely high levels of heavy metals.
But anyway, this all reminds me of seeing articles in the original Whole Earth Catalogs about sewage-to-methane systems. I don't see the point in this guy's hightech method for making long-chain polymer oil when all you really need to make is a simple hydrocarbon like methane for fuel. Lubricating oils are a miniscule market compared to energy-rich fuels, and burning methane works about as well as burning kerosine or fuel oil, if your engines are engineered right. Methane harvesters are a simple homebrew technology that has worked efficiently for many many years, it's about as high-tech as a compost pit.