Process for reducing total acid number of crude oil

Abstract

The invention comprises a method for reducing the amount of carboxylic acids in petroleum feeds comprising the steps of (a) adding to said petroleum feed a catalytic agent comprising an oil soluble or oil dispersible compound of a metal selected from the group consisting of Group VB, VIB, VIIB and VIII metals, wherein the amount of metal in said petroleum feed is at least about 5 wppm, (b) heating said petroleum feed with said catalytic agent in a reator at a temperature of about 400 to about 800 DEG F (about 204.44 to about 426.67 DEG C) and a pressure of about atmospheric to about 1000 psig (about 6996.33 kPa) in the substantial absence of hydrogen, and (c) sweeping the reactor containing said petroleum feed and said catalytic agent with an inert gas to maintain the combined water and carbon dioxide partial pressure below about 50 psia (344.75 kPa).

Description

field of invention

[0001] The present invention relates to a method for reducing the total acid number (TAN) of crude oil, wherein the acid number is based on the amount of carboxylic acids, especially naphthenic acids, present in the petroleum. Background of the invention

[0002] In crude oil or fractions thereof, there are relatively high concentrations of petroleum acids such as naphthenic acids, which are a problem for petroleum refining and further processing. In fact, the acids found in all crude oils are more or less corrosive, which can cause equipment damage, high maintenance costs, more frequent minor repairs than necessary, reduced product quality, and environmental disposal question.

[0003] There is a large body of patent literature and publications dealing with the removal of naphthenic acids by conversion or absorption. For example, many aqueous species can be added to crude oil or crude oil fractions to convert naphthenic acids to other species such as sa...

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