Conversion of Waste Plastic to Lubricating Base Oil

Abstract

A new process has been developed for the conversion of waste plastic to lubricating base oil. It has also been demonstrated that waste plastic and Fischer−Tropsch (FT) wax can be co-processed to produce lube range molecules. The process uses a thermal, noncatalytic, atmospheric pressure pyrolysis process that converts high-molecular-weight molecules to lower-molecular-weight molecules in the lube oil range. Hydroisomerization is then used to convert this product to low-pour-point oils of unconventional base oil (UCBO) quality. The major byproduct is diesel, with little production of C4− gas. Initial experiments in bench-scale laboratory pyrolysis units were followed by tests in a 1 gal/day pilot plant. The feedstocks that were tested consisted of polyethylene (PE), 96% PE−4% poly(ethylene terephthalate) (PET), FT wax, and a 50/50 mixture of PE and FT wax. The product distribution and lube quality showed surprisingly little variation for these feedstocks. The pyrolysis yields of 385 °C+ product were in the...