A234 Resource Management and Circular Economy by KAELYN YAO XUANWEI

Transport of Waste to Waste-to-Incineration Plants

23036533_2 — 2024-11-12 14:48:47 UTC

Waste collection vehicles transport collected incinerable waste to the Waste-to-incineration plants.

The waste collection vehicles are first weighed on a weighbridge before discharging the load into the refuse bunkers, after discharging the load, they are weighed again - Allowing the plants to keep track of the amount of waste that is disposed of by each vehicle

Waste Discharge into Refuse Bunkers

23036533_2 — 2024-11-12 14:49:04 UTC

Waste is stored in refuse bunkers to prevent odours from escaping into the environment, keeping the air in these bunkers below atmospheric pressure

Overhead Grab Cranes - Its purpose

23036533_2 — 2024-11-12 14:56:17 UTC

Overhead grab cranes help to mix the waste stored in the refuse bunkers thoroughly, and grabbing waste to be fed into the furnace through a charging chute

After the incineration process

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Metals contained in the ash, are recovered and recycled

The remaining ash is collected and sent for disposal in the offshore Semakau Landfill

Furnace - The process is used to reduce the volume of the waste to 10% of its original volume

23036533_2 — 2024-11-12 15:16:37 UTC

The furnaces use auxiliary oil burners to start up the combustion, where the normal operating temperature in the furnace being 1000 degrees Celsius, and when the temperature is maintained, the combustion process of the refuse is sustained without needing to use auxiliary fuel further. - Pre-heated air is drawn from the refuse bunker, containing oxygen helps to maintain the combustion process as well

There are moving stoker grates systems within the furnace, composed of horizontal rows of moving and fixed grate. Each grate is mounted and facing in the upward direction of waste flow to allow the moving grates to move back and forth over the fixed grates to mix and push the waste forward, agitating the waste and moving it downwards for bottom ash collection - containing unburnt carbon, as well as inert compounds

Boiler - Used to cool down flue gas, as well as to use the steam produced to generate energy (electricity)

23036533_2 — 2024-11-12 15:21:38 UTC

Flue gas is channeled through a boiler, which helps to cool down the flue gas to below 250 degrees celsius, through a network of tubes containing water, to allow the cleaning process to commence. As the flue gas cools down, water that is flowing through steel tubes within the boiler is heated and steam is generated.