Bogor City uses domestic waste to generate clean energy for cooking

Through the Urban-LEDS II Project in collaboration with the ICLEI Indonesia Office, the City Government of Bogor continues to support Indonesia in the country’s drive to achieve its Nationally Determined Contributions (NDC) targets by 2030. Bogor recently implemented a pilot project which extracts methane gas from a Communal Wastewater Treatment Plant (WWTP) and food wastes, turning it into cooking fuel.

Bogor City’s commitment to low emission urban development 

As part of the Urban-LEDS II project, the ICLEI Indonesia Office formally handed over the waste to energy solutions pilot project to the PUPR Agency last 6 October 2021. Serving as signatories were Head of PUPR Agency, Mr. Chusnul Rozaqi, M.M. (left) and Country Manager of ICLEI Indonesia, Mr. Ari Mochamad (right). (Photo credit: Bonbin Studio, 2021).

Located in the West Java Province, Bogor City is situated approximately 45 kilometers to the south of Jakarta and is part of the Greater Jakarta Area locally known as Jabodetabek. Serving as a key Indonesian city, Bogor serves as an education tourism hub for Jabodetabek as well as houses the Bogor Presidential Palace where the country’s President resides, holds meetings, and receives state guests. As a service city, Bogor is reliant on the tertiary sector involving industries in wholesale and retail, automobile and motorcycle maintenance, processing, construction, transportation, and warehousing.

Due to its rapid urbanization, Bogor faces challenges related to waste management. Greenhouse gas emissions from this sector are magnified by improper and unsustainable waste treatment and disposal practices. As such, the Bogor City Government is promoting waste reduction and diversion strategies, including waste-to-energy technologies, to mitigate the sector’s carbon footprint.

Mr. Rohadjie Trie of CV Energi Persada during the Operation-and-Maintenance Training with the beneficiary community. The training was carried out to ensure the sustainability of waste management practices of the biogas facilities (Photo credit: Bonbin Studio, 2021).

As part of the this thrust, an Urban-LEDS II pilot project titled “Utilization of Methane Gas from the Decomposition of Domestic Wastewater” was recently implemented in the Communal WWTP of the Sindangsari sub-district in East Bogor as proposed by the City Government through its Public Works and Spatial Planning Agency. ICLEI – Local Governments for Sustainability Southeast Asia Secretariat (SEAS) and the ICLEI Indonesia Office, together with biogas digester system service provider CV Energi Persada, carried out civil works by repairing the existing biogas digester located at the communal toilet and adding five (5) portable biogas units with an investment value of approximately 10,000 EUR. 

This project aimed to support Bogor in its effort to reduce GHG emissions from its waste and energy sectors.  Through utilizing methane gas produced by the WWTP and the community’s organic wastes, the project can help reduce LPG consumption by approximately 10 kilograms per month for one household, or a total reduction of 50 kilograms per month for the project’s five beneficiaries. 

As calculated using the National Greenhouse Gas Inventory Guidelines methodology developed by the Ministry of Environment and Forestry, the use of methane gas as an LPG substitute for cooking is estimated to reduce GHG emissions by 19.0239 tCO2e per year. 

Methane gas from WWTP and organic waste from Sindangsari Sub-district community

Two waste management technologies were implemented in the pilot project in Sindangsari. The first is a fixed dome type biogas digester reactor with a 5 cubic meter capacity. This technology provides methane energy for one house and uses an anaerobic process to produce methane gas from domestic and organic waste. The process takes approximately 30-40 days.

Layout of the 5 cubic meter fixed dome biogas digester reactor installed in the Sindangsari sub-district. Human wastes enter the reactor from the inlet (#1) and will be collected in the digester (#2) to be anaerobically processed by bacteria. Methane gas produced from anaerobic processes will rise and be accumulated in the dome (#3). The gas collected in the fixed dome will then push the remaining slurry to the outlet section (#5) due to the pressure of the biogas produced. The outlet in Sindangsari is connected to the WWTP to process and filter the wastewater, ensuring that the discharge into the river is clean and does not pollute the environment. Lastly, the methane gas then flows to the biogas stove through a pipe (#4).

Moreover, the ICLEI Indonesia Office also saw an opportunity to utilize organic wastes generated from households of the sub-district. Five (5) Portable Anaerobic Digester units  with a capacity of 1.2 cubic meters were installed and connected to the beneficiaries’ houses. These units are able to process organic waste from five households and transform them into cooking fuel. It increases the number of homes that could use methane gas for cooking. 

The organic wastes are first soaked in a bucket filled with water to speed up the fermentation process prior to being put into the digester’s inlet pipe. Bacteria will then help the anaerobic fermentation process, with the produced methane gas rising up and flowing through a pipe connected to the biogas stove. The outlet will accommodate the slurry that is pushed up due to the pressure from the biogas that has been produced. Finally, the slurry will come out through the overflow pipe for use as a liquid fertilizer.

Benefits of an improved resource circulation in the community 

Using biogas for cooking instead of LPG minimizes the risks of fire-related disasters caused by gas leakage. Moreover, the portable biogas digesters provide a stronger sense of community among residents, teaching them the value of waste segregation. They also redirect organic waste streams to lessen the load on the community’s sanitary landfill.

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