The bio-digester utilizes the biodegradable waste in the landfill community by decomposing it to generate methane, and ultimately converting it into electrical energy. The structure of the bio-digester will have a large tank that will hold the waste and specific bacteria which will help to decompose the waste. Through a chemical process, methane gas will then be an end-product of the decomposition which will then be collected. The collected methane gas will be channeled through a filtration system and ultimately connected with a methane powered generator. The energy produced by the generator will then be used to power the community and can be sold to the city in order to alleviate its energy shortage.
To make the construction of the bio-digester feasible and applicable in project sites, the em[POWER] Energy Group will first construct a prototype at the Rutgers EcoComplex in New Jersey. The prototype will then be used to research optimal and efficient materials and processes for the bio-digester. This research will all be recorded and documented and will be used in collaboration with the construction of the bio-digester in project sites. The em[POWER] Energy Group will be working with various organizations and volunteers at the same time in Karachi to research the efficiency of the bio-digester to help the progress of the bio-digester in both locations.
Methane Plant Design – Process Diagram:
Stage 1: Methane Production
2) Introduce the sorted garbage into the bio-digester
3) Introduce enzymes, protein, and water to induce a chemical reaction to optimize methane produce (this process will also need to be researched and refined in our prototype stage)
4) Once methane is produced, the gas will move to the next stage of the process. The flow rate of the gas, as well as its composition, will be measured and recorded by the data recorder.
Note: Our current design has the bio-digester as 8ft deep, 10ft wide and 40 ft long. Total volume of 3200 cu ft. It will have a cycle ranging from 15-20 days
Stage 2: Methane Collection
1) From the bio-digester, use PVC or other type of pipes to transfer the methane to the next stage (the type of piping to be used must be discussed).
2) Use meters to determine the composition and test the quality of the gas produced in the first stage. Based on the results of the tests, adjust the enzymes and waste-to-water ratio for optimal output.
Stage 3: Filtering
1) Pass the unfiltered gas through a system of filters in order to separate the methane from other gases, water, and various other contaminants which may be harmful to the engine
- De-mister component will remove water vapor from the unfiltered gas
- Compressor will compress and collect the gas before moving on to the next filter
- Coalescing filter will remove any water/oil/dirt/contaminants from the gas
- Sulfur treatment will remove the sulfur from the gas and output the filtered methane
Note: This stage is only necessary if a significant amount of other gases (such as sulfur) is produced by the bio-digester.
Stage 4: Methane Compression and Storage
1) Pipe the methane to a compressor and store the gas in a pressurized container.
2) The pressurized container will send signals back to the diverting valve. Once the container is full, the valve will then divert the gas to the flare, which will burn the excess methane and convert it into carbon dioxide. The temperature of the flare, as well as the amount of gas flared, will be measured and recorded by the data recorder.
Stage 5: Energy Production
1) Introduce methane to power generator.