Document Type : Review Paper
Swedish Centre for Resource Recovery, University of Borås, 501 90 Borås, Sweden.
Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), AREEO, Karaj, Iran.
Biofuel Research Team (BRTeam), Karaj, Iran.
Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Microbial Industrial Biotechnology Group, Institute of Biotechnology and Bioengineering, Isfahan University of Technology, Isfahan 84156-83111, Iran.
Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, California, USA.
One of the greatest challenges facing the societies now and in the future is the reduction of green house gas emissions and thus preventing the climate change. It is therefore important to replace fossil fuels with renewable sources, such as biogas. Biogas can be produced from various organic waste streams or as a byproduct from industrial processes. Beside energy production, the degradation of organic waste through anaerobic digestion offers other advantages, such as the prevention of odor release and the decrease of pathogens. Moreover, the nutrient rich digested residues can be utilized as fertilizer for recycling the nutrients back to the fields. However, the amount of organic materials currently available for biogas production is limited and new substrates as well as new effective technologies are therefore needed to facilitate the growth of the biogas industry all over the world. Hence, major developments have been made during the last decades regarding the utilization of lignocellulosic biomass, the development of high rate systems, and the application of membrane technologies within the anaerobic digestion process in order to overcome the shortcomings encountered. The degradation of organic material requires a synchronized action of different groups of microorganisms with different metabolic capacities. Recent developments in molecular biology techniques have provided the research community with a valuable tool for improved understanding of this complex microbiological system, which in turn could help optimize and control the process in an effective way in the future.
- Biogas; a promising renewable alternative for natural gas with similar applications.
- Biogas can be produced from different types of organic wastes.
- AD process is accompanied with several environmental advantages compared with incineration, landfilling, and composting.
- Besides energy, AD process generated a nutrient-rich biological fertilizer.
- Recent developments in metagenomics techniques have provided valuable tools to achieve improved AD process.