Complex sentence: Fechter had recently turned his attention to inventing a fuel, carbo hydrylium, that burned cleaner than propane, which was reportedly ignited by one of the robots in the warehouse.
Split into simpler sentences: Fechter had recently turned his attention to inventing a cleaner-burning fuel, cargo hydrylium. This could now become a safer alternative fuel to propane, which was reportedly ignited by one of the robots in the warehouse.