An enormous fire erupted an ExxonMobil refinery in Texas on Thursday. The Baytown refinery caught fire, leading to huge black plumes of smoke into the air, visible from downtown Houston. Source: ABC13.com According to Reuters , the fire erupted at a lube oil hydrotreating unit, which removes sulfur from oil, a 20,000 barrel-per-day section of the refinery that produces diesel fuel. Related: Shocking