Hiba N. Abu Tayeh, 
Manal Haj-Zaroubi, 
Hassan Azaizeh

The food industry is a large sector that includes fruits, vegetables, edible oil, dairy products, seafood, meat, and others. During processing, high amounts of food waste are produced. Food waste has high organic content where it is intensely studied worldwide as a potential substrate for biogas, liquid biofuel, and biohydrogen production via biological processes.

Renewable fuels and biofuels have gained increasing importance because of the combustion of fossil fuel resources resulting in environmental pollution and concerns associated with the produced gases. International awareness and the attempt to reduce greenhouse gas emissions are also criteria that increase bioethanol and biogas production.

Several limitations and challenges can face bioethanol production including the formation of inhibitors during the pretreatment process, the high cost of the enzymes used for biomass hydrolysis, and the dehydration process to obtain at least 99% ethanol purity. The characteristic of food waste affects the principles of anaerobic digestion. The process parameters during the digestion and the pretreatment and the need for codigestion with another biomass represent a great challenge. The current review deals with the challenges facing the industry with using food waste for bioethanol and/or biogas production.