Biofuel Residues/Wastes: Ban or Boon?

Biofuel production generates significant amounts of low-value residues and wastes. This results in concern over the sustainability of the biofuel industry and its impact on the environment. Bioconversion offers opportunities for the economic utilization of biofuel residues and wastes with concomitant remediation of wastes. Due to their characteristics, these residues/wastes can serve as low-cost substrates for bioconversion to high-value products. Attempts have been made to produce several bio-based products, such as single-cell proteins, single-cell oil, enzymes, bioplastics, and organic acids. The authors review biofuel residues/wastes generation and their use in value-added processing. In addition, special attention is given to economic analyses of value-added processing of biofuel residues.