High Acid Distillate Esterification Off The Acid Catalyst

The presence of relatively high content of petroleum acids, e.g. naphthenic acids in crude oils or fractions is a bane of petroleum refiners and producers. Essentially, these acids especially naphthenic acids are corrosive to the equipment used to extract, transport and process the petroleum, tend to cause equipment failures, lead to high maintenance costs, and reduce product quality such as thermal oxidation stability. There is a need to develop efficient methods for treating acidic petroleum distillates.The present paper relates to an esterification process for reducing the acidity of a petroleum fraction containing organic acids with an effective amount of ethanol under conditions sufficient to form the naphthenic acids ester. The preparation process of a supported solid catalyst, the optimum conditions of esterification and the reaction kinetics were investigated.Various carriers and different active components were used to prepare several series of catalysts in order to measure the catalytic performance of catalysts. It was shown that SnO has high activity and good stability in the action conditions. Activated Al₂O₃, activated clay and activated carbon were selected as catalyst carriers which supported SnO by impregnation -precipitation and supported catalysts were prepared. The catalysts were applied in the esterification, and the experimental results showed that the catalyst's function was best when the activated Al₂O₃ was used as the carrier.After orthogonal trial carried out in autoclave, the preparation process of SnO/γ-Al₂O₃ and the optimum reaction conditions were obtained.