True Green Energy produces pellets for energy production
True Green Energy says it is going to produce pellets as part of its rubbish to energy production process.
At the moment it turns municipal solid waste (MSW) into electricity over a number of stages, first taking the paper, plastic, food, wood, and agricultural materials and drying and shredding them. The metals and glass are put aside to be recycled at a further date.
Now this rubbish will be turned into fuel pellets and then a gasification process at high temperatures will be used to break down the pellets.
About 5% of the pellet turns into ash and the rest changes into synthetic gas, which has a lower energy content than natural gas.
This is then burned in a micro turbine, generating electricity. The plant is based in the Philippines which has a lot of rubbish and yet needs a long-term source of power.
The reason the company converts the waste into pellets is because pellets are more energy dense and easier to handle and feed into automated systems. The pellets are 6-8mm in diameter and shorter than 38mm.
To create the pellets, the feedstock needs to go through a number of processes, including grinding, moisture control, extrusion, cooling, and packaging.
A die allows the biomass to be pushed through holes which under high temperature and pressure creates the pellets. They then need to be cooled and dried before being used, which normally happens by blowing air through the metal bin they are sitting in.
Waste from the San Fernando landfill in the Philippines could create about 300 – 1,000 pellets a day.