Residue additives improved gasoline

There is even more potential to improve gasoline yield as well as LPG olefins such as isobutene by using a catalyst that incorporates the properties of a ZSM-5 additive. This type of catalyst may also provide better conversion of light-cycle oil and residues because it has larger pores than ZSM-5. ... 

Very early lubricants were made by the simple distillation of petroleum to recover the lower boiling gasoline and kerosene fractions to give a residue useable as a lubricant. Lubricant quality could be improved by very simple additional processing to remove some of the less desirable components such as asphalt, wax and aromatics. Lubricants of this era relied on the inherent properties of the base oil because virtually no additives were used. 

The first feed to be used in catalytic cracking units was virgin gas oil. However, from the 1970s on, cheaper residual fractions are also used as the cost of erode oil increased. Demand for higher octane ratings, particularly as lead-free gasoline was introduced, led to improvements in catalyst formulation. Later, when residual fractions were added to catalytic cracker feeds, more active catalyst matrices were needed together with additives to absorb poisons and control sulfim emissions. 

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