REACTIVITY OF HEAVY OILS IN CATALYTIC AND THERMAL CRACKING. PART II: SARA FRACTIONS AND HEAVY OILS

摘要

This work deals with reactivity of heavy oil SARA (saturates, aromatics, resins, asphaltenes) fractions during thermal and catalytic cracking, and the relations of heavy oil SARA composition to conversion level in both thermal and catalytic cracking. It was found that reactivity decreases in the order: saturates > aromatics > resins > asphaltenes. The highest reactivity of the heavy oil saturate fraction was due to its lowest activation energy. During thermal cracking based processes, a definite order in the reactivity of the different SARA fractions was not observed. The reason for the disorder in the thermal reactivity of the different SARA fractions might be rooted in the lack of order in the content of the free radical accelerators naturally presenting in the different heavy oil SARA fractions. We suppose that in the presence of free radical accelerators like peroxides for example the higher hydrogen content heavy oils and oil fractions would achieve a higher thermal conversion.