By contrast, crude oil is distinguishable by the presence of a relatively large unresolved complex mixture (UCM) due to poor resolution of the peaks during separation in a gas chromatographic column. This leads to the formation a or UCM in the GC trace large “hump” which is used as a marker to differentiate crude oil form Bunker "c" oil. Table 8 presents a comparison of some of the distinguishing features between refined and crude oils obtained from previous analyses conducted by IMA. [See plate 19, Appendix C as one example of a crude oil chromatogram trace from a sample in Trinidad]. A comparison of the common fuel oils show that Bunker oil or Fuel oil #2 (also referred “a” to as diesel) is recognizable by its light brown or yellow colour, Bunker oil typically “b” contains of a mixture of fuel oil #3 and fuel #4 respectively and Bunker "c" oil or fuel oil #6 is characteristically dark in colour and very viscous. Table 8: Summary of some of the distinguishing features between refined and crude oils for comparison. Parameters Fuel oil #1 Fuel oil #2 Fuel oil #3 Fuel oil #6 Crude oils (Bunker a) (Bunker c) range C10 C19 C10 C24 C10 C24 C10 C27 C10 C70 n-alkane – – – – – of n- C13 C14 C16 C17- C18 C19 -C21 Varies for – άMaxima alkane range different crudes *UCM Relatively Relatively Relatively Relatively Relatively large small UCM. medium UCM. UCM. small small and UCM. UCM. Usually mixed +Hydrocarbon Unimodal Unimod with Fuel oil Unimodal Mixed oil have GC profile GC profile #2 to give GC profile GC profile Bimodal GC mode Bimodal GC profile profile
By contrast, crude oil is distinguishable by the presence of a relatively large unresolved complex mixture (UCM) due to poor resolution of the peaks during separation in a gas chromatographic column. This leads to the formation a large “hump” or UCM in the GC trace which is used as a marker to differentiate crude oil form Bunker "c" oil. Table 8 presents a comparison of some of the distinguishing features between refined and crude oils obtained from previous analyses conducted by IMA. [See plate 19, Appendix C as one example of a crude oil chromatogram trace from a sample in Trinidad]. A comparison of the common fuel oils show that Bunker “a” oil or Fuel oil #2 (also referred to as diesel) is recognizable by its light brown or yellow colour, Bunker “b” oil typically contains of a mixture of fuel oil #3 and fuel #4 respectively and Bunker "c" oil or fuel oil #6 is characteristically dark in colour and very viscous. Table 8: Summary of some of the distinguishing features between refined and crude oils for comparison. Parameters Fuel oil #1 Fuel oil #2 (Bunker a) Fuel oil #3 Fuel oil #6 (Bunker c) Crude oils n-alkane range C10 – C19 C10 – C24 C10 – C24 C10 – C27 C10 – C70 άMaxima of n- alkane range C13 C14 – C16 C17- C18 C19 -C21 Varies for different crudes *UCM and +Hydrocarbon GC profile mode Relatively small UCM. Unimodal GC profile Relatively small UCM. Unimod GC profile Relatively small UCM. Unimodal GC profile Relatively medium UCM. Usually mixed with Fuel oil #2 to give Bimodal GC profile Relatively large UCM. Mixed oil have Bimodal GC profile
Final_Report_Investigation_and_Fingerprinting_Analysis_of_Oil_Spill_in_GOP_Triniadad_and_Tobago_December-2013-1.docx