Kinetic Study on High-Temperature H₂S Removal over Mn-Based Regenerable Sorbent Using Deactivation Model

Area of Science:

• Chemical Engineering
• Materials Science
• Environmental Science

Background:

• High-temperature hydrogen sulfide (H2S) removal is critical for industrial processes and environmental protection.
• Manganese-based sorbents are promising for H2S capture, but their performance can be limited by deactivation.
• Understanding the kinetics and deactivation mechanisms of sorbents is essential for optimizing H2S removal.

Purpose of the Study:

• To investigate the kinetics of high-temperature H2S removal over Mn/Al sorbents prepared by co-precipitation.
• To evaluate the performance of Mn/Al sorbents compared to pure Mn2O3.
• To apply a deactivation model to predict H2S breakthrough curves during sulfidation-regeneration cycles.

Main Methods:

• Preparation of Mn/Al sorbents using the co-precipitation method.
• Experimental investigation in a fixed-bed reactor under high-temperature conditions.
• Kinetic analysis using a deactivation model to determine rate constants (k0, kd) and activation energies (Ea, Ed).

Main Results:

• Mn/Al sorbents exhibited significantly higher initial sorption rate constants (k0) and deactivation rate constants (kd) compared to pure Mn2O3.
• The enhanced performance is attributed to higher reactivity and reduced diffusion resistance in Mn/Al sorbents.
• Apparent activation energy (Ea) and deactivation energy (Ed) were determined for a sorbent with 35.4 wt% Mn content.
• The deactivation model accurately predicted H2S breakthrough curves throughout the sulfidation-regeneration process.

Conclusions:

• Mn/Al sorbents prepared by co-precipitation show superior performance for high-temperature H2S removal.
• The developed deactivation model provides a reliable tool for predicting sorbent behavior in cyclic processes.
• These findings support the use of Mn/Al sorbents for efficient and durable H2S capture applications.