Study On Technology Of Removing Hydrogen Sulfide From Crude Oil

The existence of hydrogen sulfide in crude oil will not only lead to corrosion of the equipment and pipeline, catalyst poisoning in the oil refining industry, but also a serious threat to personal safety. Therefore, the search for economical and effective hydrogen sulfide removal technology has been a production issue that must be addressed urgently for many domestic oilfields.According to Tahe Oilfield waste water with high salinity and Tahe heavy oil with high content of hydrogen sulfide, this paper studied sodium hypochlorite with strong oxidation generated by electrolysis of sodium chloride solution to remove hydrogen sulfide from crude oil. By electrolyzing sodium chloride solution, this paper studied the various factors (electrode material, polar distance, solution concentration, voltage, temperature, pH value) which have impact on solution concentration and current efficiency by orthogonal experiments and determine the optimal electrolysis program. According to the static electrolysis experiments of removing hydrogen sulfide from the gas, this paper evaluated the treatment effect. In this paper,the dynamic experimental method of removing hydrogen sulfide from crude oil is proposed which is based on the experiments of removing hydrogen sulfide from the gas. By online mix process with sodium hypochlorite solution and crude oil, this paper studied the influences of the static mixer type, flow ratio and temperature on the the treatment effect.Experimental results show that chlorine value began to decrease after 190 minutes under the best conditions in the static electrolysis of saturated salt water. The current efficiency maintained the level of 70% before 100 minutes and maintained the level of 90% before 30 minutes. The DC unit consumption was from 5.37 kWh·kg-1 to 13.03 kWh·kg-1 when the current density was from 0.8 A/cm2 to 1.05A/cm2. When the current density was 0.4A/cm2 under the dynamic electrolysis of 240g/l sodium chloride solution, chlorine value was up to 13.82g/l and DC unit consumption was 3.05 kWh·kg-1. During the experiments of removing hydrogen sulfide from the gas, it can be up to the better removal effect no matter adopting the methods that sodium hypochlorite solution generated by electrolysis absorbed hydrogen sulfide, or that electrolyzing sodium chloride solution removed hydrogen sulfide. Applying the above two methods, the highest removal rate can be up to 99%. During the dynamic experiments of removing hydrogen sulfide from crude oil, static mixer type, fluid flow and temperature will impact on the removal rate of hydrogen sulfide. But the dynamic test results are not as well as the static test results. The maximum removal rate was 72.4% in the dynamic experiments, which was much lower than the static test results by 96.5%.