Bioregenerable selective sorbents and bioreactors for hydrogen sulfide removal from natural gas.

摘要

he following five sulfide adsorbents were incorporated into Bio-Sep RTM beads: zinc oxide (ZnO), zinc phosphate (Zn3(PO 4)2), manganese (II) carbonate (MnCO3), copper (II) hydroxide phosphate (Cu2(OH)PO4), and cobalt (II) hydroxide (Co(OH)2). The bead formulations were tested for sulfide adsorbance, bead durability, and bacterial growth capability and the bead formulation containing ZnO, NomexRTM, and powdered activated carbon (PAC) was chosen as Bio-SepRTM S. Sulfide adsorbance tests revealed an approximate first order rate constant for sulfide adsorption of 1.66 min-1 for Bio-SepRTM S which was significantly faster than 0.02 min 1 for Bio-Sep. Laboratory-scale stirred-tank reactors (STR) and packed-bed reactors (PBR) utilizing Bio-SepRTM S were successful for H2S removal from a gas stream. Phospholipid fatty acid (PLFA) analyses were conducted for Bio-SepRTM and Bio-SepRTM S beads from 4-L STR trials for H2S oxidation. Bio-SepRTM S beads contained 81% of T. denitrificans culture within the beads while Bio- SepRTM contained only 35% within the beads. Both reactor types (STR and PBR) utilizing Bio-SepRTM S tolerated higher H2S feed compared to Bio-SepRTM. The increased percentage of bacterial population within Bio-SepRTM S in STR trials and tolerance of higher H2S feed indicated greater biomass retention for Bio-SepRTM S. No improvement was seen in the volumetric productivity for STR utilizing Bio-SepRTM or Bio-Sep RTM S compared to previously-reported values. Additionally, the PBR utilizing Bio-SepRTM had a volumetric productivity of approximately 1.0 mmol/h·L. The PBR utilizing Bio-SepRTM S had a volumetric productivity of approximately 2.3 mmol/h·L which was higher than previously-reported values for reactors without breakthrough.;A demonstration-scale plant for natural gas desulfurization was designed with an estimated capital cost of