Eggshell neutralizing and immobilizing property investigated for H2 production. Eggshell maintained fermentation pH (6.0–6.3) and provided immobilization support. Maximum H2 for batch (36.5 mmol/L) and repeated-batch (41.2 mmol/L). Semi-continuous production of 312.12 mmol-H2/L at 86.65% glycerol utilization. Valorization of eggshells improved H2 and reduced production cost by 85–95%.