Room temperature imidazolium-based ionic liquids as scavengers for hydrogen sulfide removal of crude oil

Determination of H2S amounts in crude oil was performed by a precise method instead of UOP163 that were developed in our pervious works. Evaluation of ILs and scavengers were done by two ways. The first one was based on variable concentration of ILs as the scavenger (dynamic method), and the second one was based on a constant concentration of the scavenger during H2S removal process (static method). In the static method, design of experiments was performed for all three tested ILs and three parameters such as time, temperature, and dosage (injection volume) of ILs were investigated. A wide range of time and temperature was also studied according to operating conditions in petroleum terminals. The dose of ILs was obtained from the dynamic method. According to the obtained results, these ILs had a significant effect on H2S reduction in crude oil, so that H2S concentration in some conditions was less than 1 ppm. In comparison between ILs and commercial scavengers’s performance can be properly understood that not only ILs reduced H2S concentration, but also their dosage was very low, and mole ratio of [IL]/[H2S] was 1:3 that it was negligible compared with commercial scavengers. Also the results showed that [EMIM][NTf2] was more effective than the other ILs in H2S removal.