they can make oil for $10/barrel
It costs us less than $5 US/bbl to refine cruel into various products. That includes the high cost of sulfur extraction and recovery, steam generation facilities, hydrotreating and hydrogen gas generation units, solvent extraction, distillation and cracking.
From my review of JBI's technology, they do not have the challenges of sulfur removal and other bad actors. The costs of running a 4 bbl/hr "refinery" are considerable less than the costs associate with producing products from crude.
claim that he can sell it for at least WTI-3.
WTI prices are for raw crude which contain high levels of sulfur, water, sediment, and other containments. Plastics are highly refined hydrocarbons. As the back-end of the JBI process is a microrefinery, I would expect them to receive much more than WTI for their fuel.