you should always rely on your own DD if honestly interested in an business investment. I'd suggest as rank beginning some citations on a wiki article as one possibility to set up to speed, or just google oil recycling and come up with some of the Oil Bigs, they all have a plan. AFAIC, recycling oil is such a low margin, volume/know how/facility driven business (especially if piling on costs of RE-cracking & RE-catalyzing it to make ...wait here ... oil out of oil ) that its probably not worth expending the DD time past the easily uncovered candidates. Keep in mind that in addition to the tech & delivery track record, the integrity and stability of company lead figures, the reliability of their projections and their business dealings with others may make all fundamental DD worthless.
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