(145c) Crude Oil Corrosivity Measurement Using Radioactive Tracer Technology

New sources of crude oils with unknown corrosion potential present significant opportunities and uncertainties for refiners. Traditionally, total acid number (TAN) measurements are often used to gauge corrosivity, but with poor results. Loss-in-weight corrosion test methods suffer from poor sensitivity, long exposure times and low reproducibility. Gravimetric coupons can sometimes gain weight due to adhesive product buildup. Radioactive tracer technology has been used for more than fifty years by the automotive industry to measure real-time wear in operating engines. This technology has been adapted to develop two techniques to measure high temperature crude corrosivity in a timescale short enough to avoid thermal degradation of reactive acids. The first technique allows for high sensitivity real-time measurement of alloy corrosion when exposed to high-temperature crude oil in a flow loop under high shear stress conditions. The second utilizes a pressurized stirred reactor. This latter technique has been used to measure both dissolved corrosion product buildup in the oil as well as adhesive corrosion product buildup on the test coupon. In both cases, corrosion product buildup sensitivity is in the 100 ppb range, with measurements made as quickly as one hour at temperature.