Hydrophobic and dispersible Cu(I) desulfurization adsorbent prepared from Pistia stratiotes for efficient desulfurization

Abstract

Improving the adsorption capacity of adsorbents is a good way to boost their desulfurization efficiency. Optimizing the dispersion of metal nanoparticles and enhancing the stability of the metal valence state are essential to maximizing the adsorption capacity of the metal-loaded desulfurization adsorbent. Pistia stratiotes can absorb the Cu in water and evenly disperse it throughout the plant, allowing the production of a highly dispersed Cu(I) adsorbent (PSAC-Cu(I)). During the usage and storage of PSAC-Cu(I), Cu(I) oxidizes to Cu(II) when it comes in contact with oxygen and water, reducing its adsorptive capacity; hence, we modified PSAC-Cu(I) hydrophobically using polydimethylsiloxane (PDMS) to generate PSAC-Cu(I)-P(200). The outcome of the two-month exposure experiments showed that only 4.7% of the Cu(I) of PSAC-Cu(I)-P(200) was oxidized in the humid atmosphere, whereas PSAC-Cu(I) was almost fully oxidized. Moreover, the dibenzothiophene adsorption capacity of PSAC-Cu(I)-P(200) in a model oil with a water concentration of 250 ppmw is 68 mg g−1, which is 1.62 times that of PSAC-Cu(I). When 10 wt% toluene was added to the model oil, the adsorption desulfurization capacity of PSAC-Cu(I)-P(200) decreased to 86.8% of the original. This shows that PSAC-Cu(I)-P(200) has good stability and excellent adsorptive desulfurization performance.