Efficient biohydrogen and advanced biofuel coproduction from municipal solid waste through a clean process.

Area of Science:

• Biotechnology
• Renewable Energy
• Waste Management

Background:

• Organic fraction of municipal solid waste (OFMSW) is a potential feedstock for biofuel production.
• Biohydrogen and biobutanol are considered clean energy sources and advanced biofuels, respectively.
• Utilizing waste streams for energy production aligns with circular economy principles.

Purpose of the Study:

• To produce biohydrogen and biobutanol from OFMSW.
• To optimize the pretreatment process using ethanol and organic acids (acetic and butyric acid) as catalysts.
• To evaluate the energy recovery potential from OFMSW through biofuel and biohydrogen generation.

Main Methods:

• OFMSW was pretreated using 85% ethanol with varying concentrations (0-1% w/w) of acetic and butyric acids at 120°C and 160°C for 30 minutes.
• The pretreated substrate was fermented to produce acetone, butanol, and ethanol (ABE) and hydrogen.
• Yields of ABE, hydrogen, and energy content were quantified per kilogram of OFMSW.

Main Results:

• Pretreatment with 1% acetic acid at 120°C yielded a hydrolysate rich in fermentable sugars (49.8 g/L).
• This optimized pretreatment led to the highest overall yields of ABE (270 g/kg OFMSW) and hydrogen (151 L/kg OFMSW).
• Specific yields included 114.1 g butanol, 43.8 g acetone, 15.1 g ethanol, and 97.5 L hydrogen per kg OFMSW, with a total energy production of 6000 kJ/kg OFMSW.

Conclusions:

• The study successfully demonstrated the co-production of biohydrogen and biobutanol from OFMSW.
• Process optimization using byproducts like ethanol and acetic acid significantly improved sugar release and subsequent fermentation yields.
• This integrated approach offers a sustainable pathway for waste valorization and renewable energy generation.