Macroeconomics

Anaerobic digestion

Methane

Engineering

Energy recovery

Methanogenesis

Bacteria

Biology

Statistics

Energy (signal processing)

Economics

HeLa

Biochemistry

Food science

Waste management

Genetics

Organic chemistry

Mathematics

Lactic acid

Lactic acid fermentation

Environmental science

Hydrolysis

Chemistry

Food waste

Cell

Pulp and paper industry

Mixed acid fermentation

Fermentation

Production (economics)

Renewable Energy

Two-phase anaerobic digestion (TPAD) is a commonly used method for recovering energy from food waste, even though the relationship between fermentation type and methane production has not to be thoroughly investigated. In this study, homolactic acid fermentation (HOLA), heterolactic acid fermentation (HELA), butyric acid fermentation (BUA), and mixed acid fermentation (MA) were used in the first phase, and the corresponding methane production levels were compared. HELA and MA resulted in the maximum methane yields of 290 and 287 ml per gram chemical oxygen demand (COD), respectively, but they were not significantly higher than the yield of 279 ml/g COD from single-phase anaerobic digestion (SPAD). During methanogenesis, BUA led to the fastest hydrolysis and methane production rates, followed by MA and HELA. In spite of the similar potential for methane production and energy recovery, TPAD using either BUA, MA, or HELA as the fermentation phase exhibited at least 50% greater methane production efficiency than SPAD. Overall, HELA and MA were found to be the best choices in terms of treatment efficiency and energy recovery.

Effect of pre-fermentation types on the potential of methane production and energy recovery from food waste