Aminated polyacrylonitrile fibers for the removal of hydrogen sulfide from natural gas at room temperature

摘要

H2S is a common toxic gas in natural gas processing, and adsorption is a promising technology for hydrogen sulfide removal. However, current desulfurization agents suitable for low ambient temperatures and easy regeneration remain a challenge. In this paper, aminated polyacrylonitrile was directly synthesized in a one-step reaction from widely available engineering PANF (polyacrylonitrile fiber) for H2S removal at ambient temperature. The fiber samples at various stages were characterized in detail, and the adsorption behavior of PANF-DETA (diethylenetriamine) on H2S under different conditions (weight gain rate, temperature, moisture) was investigated. The results showed that the aminated fibers could rapidly absorb H2S by acid-base proton reaction. The optimal sulfur capacity of H2S reached 16.2 mg/g when the weight increase rate of aminated fibers was 60, which was 15 times greater than the adsorption capacity of pure polyacrylonitrile fibers. The saturated fiber can be effectively regenerated through alkali rinsing. After ten consecutive regenerations, the sulfur capacity of the aminated fiber is 13.6 mg/g, which remains at more than 80 of the initial capacity. Overall, fiber sorbents have excellent thermal stability, reusability, chemical stability. It can effectively adapt to various practical application environments and is a promising new type of adsorbent.