초록
<P><B>Abstract</B></P> <P>This study presents kinetic and thermodynamic analysis of crude glycerol fermentation for hydrogen production. Fermentation parameters have been optimized using central composite design (CCD) of experiments as: pH = 6.7, temperature = 36 °C, crude glycerol concentration = 7.4 g/L. Kinetic and thermodynamic analysis has been done using Haldane substrate inhibition model, Arrhenius plots and Eyring equation. Kinetic parameters <I>V</I> <SUB>max</SUB> and <I>K</I> <SUB>m</SUB> increase, while <I>K</I> <SUB>I</SUB> reduces for crude glycerol, as compared to pure glycerol. Moreover, activation energy (217 kJ/mol) and Δ<I>G</I> (103 kJ/mol) for crude glycerol are lesser than pure glycerol. Consequently, hydrogen yield in crude glycerol fermentation (0.627 mol H<SUB>2</SUB>/mol glycerol with 44% v/v H<SUB>2</SUB> in product gas) is significantly higher than pure glycerol. Role of Na<SUP>+</SUP> ions in improving crude glycerol fermentation has been experimentally confirmed. Kinetic and thermodynamic parameters for crude glycerol fermentation determined in this study have quantitatively substantiated its potential for biohydrogen production.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Kinetic and Arrhenius analysis of the crude glycerol fermentation for H<SUB>2</SUB> production. </LI> <LI> Optimum H<SUB>2</SUB> yield = 0.627 mol H<SUB>2</SUB>/mol glycerol, H<SUB>2</SUB> concn. in product gas = 44.05% v/v. </LI> <LI> Higher reaction velocity (<I>V</I> <SUB>max</SUB>) and smaller inhibition constant (<I>K</I> <SUB>I</SUB>) for crude glycerol. </LI> <LI> Lesser activation energy and ΔG for crude glycerol fermentation than pure glycerol. </LI> <LI> Experimental confirmation of enhancement of glycerol fermentation by Na<SUP>+</SUP> ions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>