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
indicator of profits. A high refining margin does not necessarily mean a refinery is highly profitable. For example, complex refineries have more flexibility to convert crude oil into the most valuable slate of products. However, that flexibility comes at a cost. A complex refinery requires a greater initial investment and will require a higher