Hydrogen Production from Hydrogen Sulfide via a Uniquely Designed Electrolysis Process: Experimental Investigation

The present work aims to develop a uniquely designed experimental test rig for hydrogen (H2) production from hydrogen sulfide (H2S) and perform performance tests. The experimental activity focuses on the FeCl3 hybrid process for H2S cracking, followed by H2S absorption, sulfur purification, and electrolysis for efficient H2 production. Hydrogen production is studied using KOH and FeCl3 electrolytes under varying temperatures between 20-80 ◦C. An electrochemical impedance spectroscopy (EIS) is employed to characterize the electrochemical cell under potentiostatic (0.5-2.0 V) and galvanostatic (0-0.5 mA) modes to analyze the system’s electrochemical response. The study results showed that hydrogen production increased by over 426 % from 20 ◦C to 80 ◦C. EIS analysis under potentiostatic mode showed Nyquist semicircle diameter reduced as the applied voltage increased from 0.5 V to 1.5 V, and phase angle shifted from -5.59◦ to -1.27◦, confirming enhanced conductivity. Under galvanostatic mode, the impedance dropped from ~25 Ω to ~21 Ω as current increased, demonstrating improved kinetics for efficient H2 production.