Climate-friendly electric conveyor belt between E.ON and Ragn-Sells

Electric conveyor belt – instead of traditional transport by truck. Through the collaboration between E.ON's new energy recycling plant and Ragn-Sells’ treatment plant at Högbytorp, outside of Stockholm, bottom ash can be transported without climate impact.

In January 2020, E.ON's new energy recycling plant, which consists of a biogas plant and a combined heat and power plant, was taken into use at Högbytorp outside of Stockholm. In the co-generation plant, which is directly adjacent to Ragn-Sells' recycling and treatment plant, energy is recovered from residual products through combustion to produce electricity and district heating locally. In the process, large amounts of energy ashes are formed, which Ragn-Sells in turn handles at its plant.

- One of the reasons why E.ON chose to build this facility this close to us was the transportation of their waste. Traditional handling of waste ashes is with trucks, but E.ON wanted to choose a different path, says Anders Gustafson, market area manager at Ragn-Sells Treatment & Detox.

Causes no contamination

Since mid-June, the bottom ash is transported on an electric ash conveyor belt between E.ON's CHP (Combined Heat and Power) plant and Ragn-Sells' treatment plant at Högbytorp. Inside E.ON's facilities, a first magnetic separation of material takes place before the bottom ash is fed on to the conveyor belt at their property, across the property boundary and into Ragn-Sells plant. The ash conveyor belt is 110 meters long and has a speed of 0.38 meters per second, which gives a flow of 7 to 10 tonnes of bottom ash per hour.

- Since the belt operates on sustainable electricity, it does not cause any pollution at all. There are other benefits as well; we do not need to schedule trucks, the ash is automatically fed to the belt according to combustion rate as long as the boiler burns, Anders Gustafson continues.

The metals are recycled to 100 percent

Along the conveyor belt there are dust extractions with purification that ensures that the ash does not dust. The ash conveyor belt is angled, so that the material cannot fall off on the sides and passes through a tunnel. The entire facility is camera monitored for increased operational reliability and so that it can be maintained during operation and at E.ON's service stops. The belt will be operating for 24 hours a day, all year round.

The bottom ash lands in a pocket at Ragn-Sells' facility which is emptied twice a day. The bottom ash consists of about 10 percent metals. The rest is stone, gravel, tiles and other materials that cannot be burned in the CHP plant.

- In our treatment plant, we pick out all metals that can be recycled to 100 percent and return these as feedstock for use in new production processes. The remaining material is used as internal construction material at the facility, for example when we build landfills for hazardous waste, says Anders Gustafson.