Methane production from wheat straw pretreated with CaO₂/cellulase.

Area of Science:

• Biomass Conversion
• Anaerobic Digestion
• Biochemical Engineering

Background:

• Lignocellulosic biomass is a sustainable feedstock for methane (CH4) generation via anaerobic digestion.
• Pretreatment methods are crucial for enhancing the efficiency of lignocellulosic biomass conversion.
• Current pretreatment strategies require optimization for improved methane yields.

Purpose of the Study:

• To investigate the efficacy of a novel hydrothermal coupled calcium peroxide (CaO2) and cellulase co-pretreatment for lignocellulosic biomass.
• To optimize the pretreatment conditions for maximizing methane (CH4) production.
• To compare the performance of this combined pretreatment with individual pretreatment methods and a control group.

Main Methods:

• Lignocellulosic biomass was subjected to hydrothermal pretreatment combined with calcium peroxide (CaO2) and cellulase.
• Total organic carbon (TOC) in the hydrolysate was measured to assess biomass solubilization.
• Anaerobic digestion was performed, and methane (CH4) yield was quantified for different pretreatment groups.
• Optimization of CaO2 concentration and cellulase dosage was explored.

Main Results:

• The hydrothermal coupled CaO2 co-cellulase pretreatment significantly increased total organic carbon (TOC) by 92.39% compared to enzymatic pretreatment alone.
• The highest methane (CH4) yield of 214 mL g-1 total solids was achieved with 6% CaO2 and 15 mg enzyme per g-cellulose, a 64.81% increase over the control.
• The order of promotion for anaerobic digestion was: hydrothermal coupled CaO2 co-cellulase > hydrothermal coupled CaO2 > enzymatic alone > control.
• Excessive cellulase beyond 15 mg per g-cellulose slightly reduced methane yield.

Conclusions:

• Hydrothermal coupled calcium peroxide (CaO2) and cellulase co-pretreatment is a highly effective strategy for enhancing methane (CH4) production from lignocellulosic biomass.
• This method significantly improves biomass solubilization and subsequent anaerobic digestion efficiency.
• Optimized application of CaO2 and cellulase is key to maximizing biogas yields from renewable resources.