Research On Catalyst And Process For The Removal Of Naphthenic Acids For High Acid Petroleum By Esterification

The naphthenic acids may cause corrosion when they were processed in oil refineries. So they should be removed.It was shown that SnO was fit as an active component in catalyst by which naphtenic acids in crude oils reacted with methanol. Two ways to synthesize the catalyst were studied. One was infusion and the other was solid blends. The catalysts made by solid blends had higher activity than those made by infusion.When the pore diameter ofγ-Al2O3 was enlarged, the synthesize catalyst could make the large molecular acids go into the pores and make them esterified. It was indicated that a catalyst with the ratio of SnO:γ-Al2O3 = 3:4 was excellent, which could reduce the acid number of SZ36-1 petroleum from 2.8mgKOH/g to 0.34mgKOH/g. The catalyst was characterized by XRD, TEM, BET, IR.A continuous fixed bed for removing the naphtenic acids of crude oils for catalytic esterification was developed. The mainly influencing factors consisted of ratio of methanol and oil, reaction temperature and space velocity. Higher ratio of methanol and oil, reaction temperature or lower space velocity were favorable for the esterification. The optimum reaction conditions were that the ratio of methanol and oil was 2.0wt%, the reaction temperature was 300℃and the space velocity was 1.6h-1. In addition, life of the synthesize catalyst was good and the principle of catalytic esterification was validated by IR.The influence of basic nitrogen compounds was also studied and it was indicated that the basic nitrogen compounds had bad effect on the esterification. The salt in the petroleum may make the ester decompose.