Effect of high temperature and sulfur vapor on the flammability limit of hydrogen sulfide

In the process of removing hydrogen sulfide from natural gas, it is easy to form an accumulation of hydrogen sulfide in the gas phase space of the liquid sulfur tank, which can lead to an explosion accident. In order to avoid an explosion accident in the liquid sulfur tank, the flammability limit of hydrogen sulfide needs to be determined. Thus, it can be effectively monitored and targeted protective measures can be taken. The temperature of the gas phase space of the liquid sulfur tank exceeds 100 °C and sulfur vapor is present. In such a complex environment, there is no relevant study on the flammability limit of hydrogen sulfide. In this study, a system used to test the flammability limit of hydrogen sulfide in high temperature environment was established. In addition, the sulfur vapor environment can also be simulated. The experiments were carried out at temperature from 25 °C to 160 °C. The effect of temperature and sulfur vapor on the flammability limit of hydrogen sulfide was analyzed. The results showed that the upper flammability limit of hydrogen sulfide increases and the lower flammability limit decreases with the increase of the initial temperature. In addition, the effect of initial temperature on the flammability limit of hydrogen sulfide gradually diminishes in an exponential relationship. It was also found that the presence of sulfur vapor makes the flammability limit range of hydrogen sulfide narrower, but the effect is relatively weak. The results of this study can provide a basis for the detection of hydrogen sulfide concentration in the gas phase space of liquid sulfur tank, thus enhancing the safety of the production process.