Valorization of process wastes from soft-wheat processing industry through biofuel production

Area of Science:

• Biotechnology
• Waste valorization
• Renewable energy

Background:

• Soft wheat product (SWP) manufacturing generates significant process waste, often discarded.
• Investigating waste streams for valuable co-product generation is crucial for sustainable industry practices.

Purpose of the Study:

• To assess the viability of co-producing fatty acid methyl esters (FAMEs, or biodiesel) and bioethanol from SWP manufacturing waste.
• To determine the efficiency of fat extraction and conversion to FAMEs and the subsequent conversion of carbohydrate fractions to bioethanol.

Main Methods:

• Two types of SWP waste (low and high moisture) were analyzed.
• Fat was extracted using hexane and converted to FAMEs via alkali-catalyzed transesterification.
• Carbohydrate-rich fractions underwent amylolytic hydrolysis and yeast fermentation for bioethanol production.

Main Results:

• High fat extraction rates (92.42%-93.17%) and FAME yields (13.81-14.55 g/g waste) were achieved with good conversion efficiencies (85.19%-89.04%).
• Bioethanol production was slow, with lower yields (16.54-18.02 g/g waste) and fermentation efficiencies (43.32%-48.29%).
• A significant solid residue (50.93%-53.08%) remained after co-production.

Conclusions:

• SWP waste is a viable source for FAME production with adequate yields and efficiencies.
• Bioethanol yields and fermentation efficiencies from SWP waste are currently limited, potentially due to dough modifiers and antimicrobial additives.
• Further research is necessary to optimize bioethanol production from these waste streams.