Indirect desulfurization method - Indirect desulfurization method

This is a method of hydrodesulfurization of heavy oil in which atmospheric distillation residual oil is first distilled under reduced pressure, and the resulting distillate is separated into vacuum diesel and the asphalt portion of the residual oil (vacuum residual oil). The former is hydrodesulfurized using conventional methods, and then mixed with the latter to produce low-sulfur heavy oil. Although the desulfurization effect is lower than with direct desulfurization methods, the exact same operations can be used as for hydrodesulfurization of kerosene and diesel, and the catalyst has the advantage of a longer life.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

重油の水素化脱硫法で，常圧蒸留残油をいったん減圧蒸留して，留出する減圧軽油と残油のアスファルト分(減圧残油)に分け，前者を通常の方法で水素化脱硫したのち，後者と混合して低硫黄重油を製造する方法．直接脱硫法に比べて脱硫効果が低いが，灯・軽油の水素化脱硫とまったく同様の操作が利用でき，触媒寿命が長い利点がある．

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