Fossil fuels and products made from them vary in sulfur content according to different origins and refining operations. The following sulfur contents are known: 0.05–13.95% for crude oils1, 0.2–12% for oil shales2,16, 0.4–11.5% for tar sands3and 0.03–1% for syncrudes from coals4.5. The low sulfur contents of syncrudes from coals originate in the hydrogenation processes by which the coals are liquefied and at the same time partially desulfurized.