Enhancement by SiC Nanoparticles of the Removal of Hydrogen Sulfide from Natural Gas by a Traditional Desulfurizer

With the purpose of comparing the effects on the absorption of hydrogen sulfide from natural gas of the addition of SiC (30-nm-diameter) nanoparticles into two common desulfurization solvents (TEA and MDEA), certain properties of MDEA-based and TEA-based SiC nanofluids were studied, such as the stability, rheological behavior, and thermal conductivity. Sedimentation experimental tests and zeta potential (ζ) results showed that the two types of nanofluids displayed ideal stabilities . Rheological measurements showed that the two types of SiC nanofluids were Newtonian fluids and that the viscosities of the TEA-based SiC nanofluids far outweighed those of MDEA-based SiC nanofluids. We also discovered that the thermal conductivities of the two types of nanofluids increased with the concentration. Dynamic experiments on the absorption of hydrogen sulfide from natural gas by MDEA-based and TEA-based SiC nanofluids showed that the desulfurization effect of MDEA-based SiC nanofluids exceeded that of TEA-based SiC nanofluids. The maximum saturated sulfur content of MDEA-based SiC nanofluids was found to be 3.11 mg/mL with 0.8 vol % SiC nanoparticles, and the maximum breakthrough time was 350 min. To explain the mechanisms of removal of hydrogen sulfide by nanofluids, SiC nanoparticles with diameters of 100 nm were added to MDEA to evaluate the effect of the removal of hydrogen sulfide by nanofluids with different diameters. The addition of SiC nanoparticles improved the heat and mass transfer of pure MDEA, thus improving the desulfurization efficiency and reducing the energy consumption.