Using slaughterhouse waste in a biochemical-based biorefinery - results from pilot scale tests

Area of Science:

• Biotechnology
• Environmental Science
• Chemical Engineering

Background:

• Organic waste streams, such as slaughterhouse waste, chicken manure, and straw, present challenges for sustainable valorization.
• Existing biorefinery concepts often focus on carbohydrate hydrolysis, which may be limited in protein-rich feedstocks.

Purpose of the Study:

• To pilot a novel biorefinery concept for producing platform chemicals and biofuels from diverse organic waste.
• To investigate the potential of non-septic fermentation of protein-rich waste materials.
• To assess the feasibility of producing 2,3-butanediol and acetone-butanol.

Main Methods:

• Hydrolysis of mixed organic waste feedstocks (slaughterhouse waste, chicken manure, straw).
• Bacterial fermentation focusing on amino acid utilization.
• Analysis of fermentation products, including platform chemicals and organic acids.
• Assessment of residual liquid for biogas production potential.

Main Results:

• Hydrolysis yielded low amounts of readily degradable carbohydrates.
• Amino acids from protein-rich waste were fermented, but ammonia release increased pH.
• Product formation shifted towards acidogenic compounds (butyrate, propionate, γ-aminobutyrate, valerate) instead of target solventogenic products.
• The biorefinery process was ineffective for 2,3-butanediol production.
• Residual liquid exhibited significantly enhanced biogas production potential.

Conclusions:

• The biorefinery concept effectively converts protein-rich waste into valuable organic acids.
• The process is not suitable for 2,3-butanediol production due to pH shifts from amino acid fermentation.
• Combining biorefining with anaerobic digestion offers a feasible approach for waste valorization, energy recovery, and nutrient recycling.