The beginning of the amazing events at Krakatoa in 1883 date to May 20 when there were initial rumblings and venting from the volcano, which had been dormant for about 200 years.
A refinery margin is the revenue associated with refining petroleum, expressed as a value per volume (e.g. $/L), net of the cost of the crude oil input. The simplest refining
The next level of refining is called a cracking refinery. This refinery takes the gas oil portion from the crude distillation unit (a stream heavier than diesel fuel, but lighter than. ) and breaks it down further into gasoline and distillate components using catalysts, high temperature and/or pressure. The last level of refining is the coking refinery.