A novel energetically efficient combinative microwave pretreatment for achieving profitable hydrogen production from marine macro algae (Ulva reticulate)

Abstract

This study aims to enhance the hydrogen (H₂) production from marine macro algae (Ulva Reticulate) by microwave combined with hydrogen peroxide (H₂O₂) under alkaline condition. Microwave (domestic type) (M) pretreatment of algal biomass at its optimal power (40%) resulted in 27.9% COD solubilization at 15 min time interval. When this optimal microwave power was combined with H₂O₂ (MH) an increment in COD solubilization was achieved at 24 mg H₂O₂/g macroalgae dosage. Under alkaline condition (pH 7-12), microwave and H₂O₂ combination (MHA) yielded better result than MH. At optimal alkaline condition (pH 10), MHA pretreatment shows a COD solubilization of 34%. Microwave in alkaline condition induces decomposition of H₂O₂ and more OH radical synthesis. This synergistically promotes solubilization. The MHA process considerably diminish time and specific energy required for biomass disintegration. Among the samples, highest H₂ yield of 87.5 mL H₂/g COD was observed for MHA.

Keywords: COD solubilization; H(2)O(2) dosage; Hydrogen; Marine macro algae; Microwave.