Biohydrogen from Agricultural Waste

The search for renewable and efficient energy sources has been increasingly comprehensive. In this sense, biological hydrogen production outstands as a promising alternative. Studies have evaluated biomasses rich in organic matter that can be converted into hydrogen, the gaseous fuel with the highest energy content per unit of weight and which still has water as a by-product in its combustion. Agricultural waste from harvesting (grains, cereals, straw, husks, and bagasse), livestock (manure and dairy products), industrial processing (fruits, vegetables, vinasse, and cassava wastewater), and domestic activities (leftover food) has a high potential to produce biohydrogen, mainly from anaerobic digestion. Therefore, this chapter presents relevant aspects of biological hydrogen production by dark fermentation using agricultural residues. The objective is to highlight the main interfering factors such as methods of pretreatment of lignocellulosic residues, anaerobic bioreactor configurations, temperature and pH of the medium, type of inoculum and its pretreatment, concentration of the feed, and possible combinations of substrates to increase the production efficiency.