Development of oxidation absorption solvent for containing sulfur dioxide tail gas in sulfur recovery unit

Objective  Under the background of GB 39728-2020 Emission standard of air pollutants for onshore oil and gas exploitation and production industry and GB 31570-2015 Emission standard of pollutants for petroleum refining industry, the SO₂ mass concentration in emission tail gas is strictly regulated, and the domestication substitution is carried out for the treatment process of tail gas containing-sulfur dioxide.

Methods  A tail gas oxidation absorption solvent CT8-27 with independent intellectual property rights was developed, and its desulfurization performance was evaluated through indoor experiments. Through ion morphology distribution maps, the distribution coefficient δ was introduced to evaluate the desulfurization performance and selectivity of the solvent.

Results  Based on the evaluation data, it can be seen that after the tail gas with high SO₂ content was removed by CT8-27, the mass concentration of SO₂ in the purified tail gas was reduced to less than 24.9 mg/m³, and the co-absorptirity of CO₂ was less than 10%. In addition, it was determined that the key factor affecting the desulfurization performance and selectivity of the solvent system was reasonable pH value.

Conclusions  The desulfurization performance of tail gas oxidation absorption solvent CT8-27 is comparable to that of imported solvents, and it shows good absorption selectivity, which can realize the domestication substitution of the imported solvent.