PERFORMANCE OF SODIUM-IMPREGNATED ACTIVATED CARBONS TOWARD LOW AND HIGH TEMPERATURE H₂S ADSORPTION

Abstract

In the present work, the H₂S adsorption performance of several activated carbon–based sorbents was studied using the temperature program adsorption technique under the temperature range of 30°–550°C. The activated carbons applied in this study include (i) commercial-grade activated carbon, (ii) the commercial-grade activated carbon modified by steam activation to enhance higher specific surface area, and (iii) the activated carbon impregnated with alkaline compounds (i.e., NaOH and Na₂CO₃). It was found that the impregnation of activated carbon with NaOH and Na₂CO₃ can efficiently promote the H₂S adsorption capacity of activated carbon in the range of temperatures studied. At 30°C, the Na₂CO₃-impregnated sample showed better adsorption capacity than the NaOH-impregnated sample, whereas their adsorption performance was almost identical at higher adsorption temperatures. Interestingly, although the activated carbon modified by steam activation showed better surface properties than commercial-grade activated carbon, its H₂S adsorption capacities were relatively lower. This could be due to the loss of potassium from activated carbon during the modification by steam activation.

Keywords:

• Activated carbon
• Adsorption
• Hydrogen sulfide
• Sodium

Acknowledgments

This research was supported by National Research University (NRU) grant of King Mongkut's University of Technology Thonburi, and PTT Public Company Limited. Financial support from the Thailand Research Fund (RTA5480003) and the Royal Golden Jubilee Ph.D. Program (Grant No. PHD/0162/2550) is acknowledged.

Notes

*Exhausted sample from the adsorption testing.