History, Current Status, and Perspective of Hydrotreating

This has led to a strong decrease in sulfur emissions caused by transportation fuels for road traffic. For example, in 1975 and 1990, respectively, 100000 and 86000 tonnes of SO2 were emitted in Germany (only road traffic), whereas in 1999 the amount had fallen to 26 0001 SO2. [For comparison overall SO2 emissions (Germany) 7.5 mio. t in 1975, 5.3 mio. t in 1990, and 0.8 mio. t in 1999]. Thus the share of road traffic on the overall SO2 emissions is in many industrialized countries today much less than 10%. Today, less than 50ppmw (mostly even 10 ppmw) sulfur in gasoline and diesel oil is mandatory in industrialized countries, and fuels with even less sulfur are or will be on the market due to tax benefits. A similar trend can be forecast for countries in Asia such as China and India (Table 6.8.2), where until recently the sulfur limit has been much higher. 

The main reasons for stringent S-limits both for gasoline and diesel oU are (i) Exhaust gases that contain SO, cause air pollution and acid rain even in western 

Pakistan, Sri Lanka limit limit limit limit Lanka) 

Indonesia, India, Philippines, Thailand 1000 (India) 500 150 2500 (India) 2000 (China) 500 350 

The catalysts commercially used for hydrotreating are most commonly sulfided C0M0/AI2O3 or sulfided NiMo/Al203, such as 3wt.% CoO and 12-15 wt.% M0O3 supported on Y-AI2O3 (Farrauto and Bartholomew, 1997). 

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