Neste will study converting an oil refinery in Porvoo, Finland, by the mid-2030s to refine renewable and waste feedstocks. Long-term capacity potential is up to 4 million metric tons per year, Neste says. The firm already operates such refineries in Porvoo, Singapore, and the Netherlands. Separately, Neste has formed a joint venture to produce renewable diesel at Marathon Petroleum’s refinery in Martinez, California. Marathon expects to complete conversion from oil refining next year.