Design of Combined Heat and Power for Waste Water Treatment Plant

Abstract

South Africa is faced with insufficient energy generation to cater for its domestic and industrial needs during peak hours. Waste Water Treatment Plants (WWTPs) have energy intensive operations that consume a lot of electricity as compared to other municipality buildings. WWTPs emits high greenhouse gases (GHG) such as methane, carbon dioxide (CO2), which are very harmful to both human and environment. Among other GHG emitted, methane is the most harmful gas on both human and environment, it is highly flammable, but it is a good source of energy. Consequently, to reduce conventional energy consumption and GHG emissions, WWTPs can be used to generate electricity from its harmful biogas wastes (methane) in order to complement their energy consumption. This project, therefore, proposes to design a co-generation plant known as Combined Heat and Power (CHP) system. This will generate heat (Thermal energy) and clean renewable power (electrical energy) using biogas (methane) from WWTPs. The heat generated will be used in the treatment processes, while the electricity will complement energy consumption of the plant, thereby reducing the operation cost and GHG emission. It is expected that the electricity consumption of the WWTPs will be reduced by 25-40% of the total energy consumption. The CHP system will be built on the WWTPs yard, hence be linked to the existing system on the plant that releases GHG.