Last December merchant refiner HollyFrontier (HFC) became the latest member of its sector to announce its intention to begin producing renewable diesel. At the time the company intended to build a 8,000 bpd (123 million gallon per year) renewable diesel unit [RDU] at its 100,000 bpd Navajo Refinery in Artesia New Mexico. This week the company announced an expansion of that investment via the planned conversion of its existing Cheyenne Refinery to a second RDU with an additional 6,000 bpd (90 MGY) of capacity. HollyFrontier expects to invest up to $750 million in