Isn’t diesel a by-product of petrol refining?
Traditionally diesel required little additional treating after distillation with sulfur levels of 1000 parts per million or more. Today Australia’s fuel quality standard dictates that sulfur levels should not exceed 50 parts per million (moving to 10 parts per million from 2009). These much lower sulfur contents mean diesel requires additional processing in the refinery to remove the sulfur, for example through diesel hydrotreating units. More information: Caltex is currently building an additional diesel hydrotreating unit at its Lytton refinery with the final cost anticipated to by around $320 million, which when commissioned will increase Caltex’s ability to produce extra low sulfur diesel from the refinery by 40 per cent.
