Abstract
Anaerobic digestion (AD) of organic materials offers
an alternative source of renewable energy, as bio-methane has a
potential to replace fossil fuels for energy production for heat and
power, vehicular fuel and as well as valuable material recovery. In
addition AD can address pollution problems by minimizing and
utilizing biodegradable waste. This is a well-researched and
technologically advanced technique with various successful small to
large scale plants in the developed world. For developing countries,
not much success has been reported due to operational and
maintenance challenges, low biogas production and public
perceptions among other several contributing factors. This paper
reviews AD process optimization focusing on parameters such as
temperature, pH, loading rate, hydraulic retention time and agitation.
Several studies have shown optimum biogas production from grass in
mesophilic, alkaline or neutral conditions at retention times of about
30 days. This review is the background and basis of our current work
on optimizing biogas production from selected South African grass
species.