Generating renewable electricity from wastewater biogas
The Chol Charoen factory produces tapioca starch from dried cassava that is grown locally. This process creates vast amounts of wastewater which is stored in a series of lagoons. The large size of these lagoons and the warm temperature creates perfect conditions for the breakdown of organic compounds in the wastewater. This produces large amounts of methane, a powerful greenhouse gas, with a pungent smell.
To learn more about the Sustainable Development Goals verified by the standard for this project, please check the project's registry link above.
The project is located in a very remote area in the province of Chachoengsao around 175 km from Bangkok. At the Chol Charoen site, the existing open lagoon wastewater system has been modified into a closed loop system that captures the methane emissions released from the lagoons. Anaerobic digesters convert this methane, or biogas, into clean heat and electricity. The four covered lagoon digesters have a combined capacity of 248,178 m3 of wastewater. The electricity is used in the plant and surplus energy is fed into the national grid.
Thanks to the project, the environment and the quality of life in the area have drastically improved. The treatment process prevents greenhouse gas emissions being released into the atmosphere and the clean energy displaces energy derived from fossil fuels. The new system recycles effluent water from the plant and releases nothing into surrounding natural water sources, ensuring that groundwater water levels remain constant and uncontaminated for the local community. The involvement of local employees in the project activity will help to enhance the skills of the workforce in the region by training them in different technical areas. In addition, the collaboration between external experts and locals is expected to promote long-term sustainable partnerships. Finally, the clean electricity generated helps to improve Thailands energy security by reducing dependency on imported energy.
