Attero: energy from waste

Environmental and energy company Attero processes the waste of as much as 40% of households and very many companies in the Netherlands. In total, this is about 3.4 million tons, or 3,400,000,000 kilograms! Attero tries to recover as many reusable raw materials from the waste as possible. Some of the waste serves to generate renewable energy, such as electricity or biogas. Even the ash that remains after incineration in the power plant is put to good use, for example in road foundations.

Waste is a valuable source of reusable materials and energy. A lot of innovative technology is needed to get everything out of it. In Groningen there is a waste processing plant and a washing and fermentation plant for producing biogas. Senior subject specialist Ronnie Eefting, responsible for maintenance of the installations, tells us more about the processes: “The incoming household waste is separated in two large screen drums. First the metal goes out, separated into ferrous and non-ferrous. That is reusable. Then we separate the plastics and foils with a so-called Near Infra Red installation. This device sees the difference between different types of plastic, regardless of color or shape. There is no human eye involved anymore.

Once a piece of plastic, a bottle, container or piece of foil is recognized, it is shot off the conveyor belt with compressed air and collected separately for reuse in, for example, fleece sweaters, plastic poles or tennis balls. What then remains is partly suitable for incineration in the power plant and partly organic residual material. The latter goes to the washing and fermentation plant. There we extract biogas that we process to natural gas quality and inject it into the normal gas grid. So you can just cook on that, or run your car on that.”

“We have a full-continuum operation here. We do the daily maintenance with four people. Myself as a mechanic, a work planner, a mechanical and an electrical specialist. On Wednesdays, we alternately shut down the waste plant and the washing and fermentation plant for the larger maintenance work. That’s a matter of good planning and, if necessary, bringing in people from outside.”

“Quite a lot goes through the plants in dirt, metal, glass and sand. So pumps and conveyor belts wear out relatively quickly. Our manager, Arnoud Hollander, comes from the glass and recycling industry. He had already worked with Wivé and introduced them here. We started with a kind of test job. That involved a so-called roller. That is a kind of roller. The strips on that roller wore out so quickly that we had to replace them once every three months. In consultation with Ronald van Lent of Wivé, we replaced those strips with wear-resistant material. They are now entering their third year, so you could call that first order successful.

We then lined the inlets of the large drums with wear-resistant material, and also replaced several bends in the tubes used to suck up films. This is done at high speeds, which causes a lot of wear.”

“It clicks really well with Ronald. He knows exactly how we work and says it honestly if he thinks a certain measure doesn’t add enough value. You shouldn’t want to make everything wear-resistant either. It has to be economically sound. And technically. For example, we have a couple of large pumps with bushings that wear out. The resulting play on the shaft is an indication to us that maintenance is needed. If you make the bushings wear-resistant, that trigger is eliminated, with the risk that the pump will break down somewhere else. And then, of course, just when it is least convenient for us. So we let those bushings wear out nicely.”