Anaerobic digestion is a process in which microorganisms break down biodegradable materials in the
absence of oxygen. The process is widely used to treat wastewater sludges, industrial and farm wastes
because it provides volume and mass reduction up to 50% from the input material [3]. It is considered a
renewable energy source because the methane-rich biogas produced is suitable for energy production and
can replace fossil fuels. As part of an integrated waste management system, anaerobic digestion reduces
the amount of methane that would be sent into the atmosphere if the waste was just sent to the landfill.
The advantage of using anaerobic digestion in an urban environment to treat organic waste as opposed
to composting it is that anaerobic digestion produces biogas with a high percentage of methane (CH4)
which can be used as fuel whereas composting produces mostly carbon dioxide (CO2) which could not be
used as fuel. The methane in biogas can be burned to produce both heat and electricity (CHP) using
internal combustion engines or microturbines in a cogeneration arrangement where the electricity and
waste heat generated are used to warm the digesters or to heat buildings. Any excess electricity can be
sold to suppliers or put into the local grid. In order to configure an anaerobic digestion system in an urban
environment, special consideration must be paid to standing gas, fire, and building codes as well as health
and safety regulations for handling the waste [4].
Biogas can also be used to fuel generators to produce steam and electricity. In some cases, the
electricity can be sold to a local utility, possibly in a net metering arrangement. This option should be
explored early, however, to make sure the utility is amenable to such arrangements. The objective of this
paper is to study the performance of mixed fruit and vegetable wastes in a single stage fed-batch
anaerobic reactor for biogas production.