According to The Last Beach Cleanup "History shows that the primary “advanced recycling” process called “pyrolysis” actually incinerates plastic waste to fuel itself and recycles only a small portion of the plastic waste.  In effect, much of the plastic waste is burned. "  

The claims being made in this tweet are misleading as to the impact ("answering the demand for plastic recycling", "help keep used plastics from going into landfills") of this technology which uses high-energy input technology to chemically convert plastic waste to oil.