Future - sewage treatment (renewable energy)

Small Hydropower Generation

It is a technology to produce electricity by using water elevation difference less than 2 m after installing a waterwheel for power generation at water discharging waterway from a sewage treatment plant.
It is an eco-friendly energy production technology to produce electricity by using sewage treatment water without any environmental damage. Since no large-scale infrastructure is required, and since the sewage treatment facility discharges a certain quantity of water, a facility may obtain stable energy throughout a year.

Energy System Using Sewage Water Heat

Domestic waste water from people maintain about 15℃ all seasons, and by using heat of this sewage water and highly efficient heat pump, energy is produced from this system. About 30% of energy may be saved from this system compare to conventional heating and cooling facilities, and at most 60% of greenhouse gas may be reduced with this economic energy.

Digestion Gas Power Generation

Digestion gas from sewage treatment process includes about 60% of methanol, and thus this may be used for power cogeneration to produce electricity and heat. In general, gas power generation is categorized into three types: gas engine, gas turbine, and fuel cell. Currently, four sewage treatment centers of the Seoul City are in charge of refining digestion gas and supplying it as fuel for city gas, and this may replace import of fossil fuel and reduce greenhouse gas.

Energy Recovery from Sewage Water Sludge

Sewage water sludge is mostly composed of organic substances, and it may be used as energy for sewage treatment facility or bank materials in construction using compost, manure for landfill, cement ingredient, or soil ameliorator by using various treatment techniques like consolidation, carbonization, composting, or fuel conversion.
Solidified sewage sludge fuel is to use carbonization process to make solidified fuel from sewage sludge. There are pellet type, oval briquette type, and charcoal type fuels, and this fuel is used as a substitute of fossil fuel.