 It was stored in steel cylinders for shipment and had the advantage that it possessed the highest specific energy of all artificially produced gases, but unlike coal gas, it was free from carbon monoxide.Blau gas was burned for lighting and heating; a less-pure form known as Pintsch gas fueled railroad car lights and stoves in the late 19th and early 20th centuries.Blau gas was most famous, however, as the buoyancy compensating fuel for the LZ 127 Graf Zeppelin.