Development of a method for on-line determination of chlorine impurity in crude oil by using fast neutrons

•A proof of principle measurement system for on-line monitoring of chlorine impurity in crude oil was developed.•14 MeV neutrons have been used for analyzing chlorine content in fuel oil samples.•Simulation models were implemented using MCNP6 and CEARCPG for design optimization of the measurement set-up.•The chlorine impurity detection limit achieved in this research was 71 mg/L.

An important challenge in the petroleum industry is to reduce the salt content to acceptable levels in crude oil. Continuous monitoring of crude oil salinity is thus an important aspect. However, development of safe and reliable on-line and non-intrusive monitoring systems is still a challenging task. In this work, a method for non-intrusive, on-line monitoring of the chlorine impurity in crude oil based on prompt gamma-ray neutron activation analysis (PGNAA) in conjunction with a portable pulsed neutron generator producing 14 MeV neutrons in deuterium-tritium (DT) nuclear reactions is proposed and tested. Simulations with Monte Carlo N-Particle version 6 (MCNP6) transport code combined with Center for Engineering Applications of Radioisotopes Detector Response Function (CEARDRF) and a specific purpose Monte Carlo code called Center for Engineering Applications of Radioisotopes Coincidence Prompt Gamma-Ray (CEARCPG) were used for the design optimization of the experiments. Preliminary results indicate that a minimum detection limit for chlorine impurity of about 71 mg/L is achievable for an integration time of 30 min.