2007:04 Hantering av förpackat livsmedelsavfall - Avfall Sverige

DEWASTER ® - Sorting out the problems of mixed waste
Subsequently, Aalborg Municipality continued with further trials based on mechanical pretreatment/pressing
of OFMSW in 2001-2002 in preparation of an ambitious large scale source
sorting/collection scheme known as “Bio21Aalborg”.
The trials for the preparation of the Bio21Aalborg project proved that the DEWASTER® process was a
viable solution to the problems with use of OFMSW in bio gas production. However, the Bio21Aalborg
project for other reasons suffered political adversity, and ultimately the plans for the introduction of full
scale source sorting of MSW in Aalborg were abandoned in December of 2002.
Holbaek 2001-2003 – development of the DESIZER and FEEDER
While waiting for the outcome of the trials and political decision-making process in respect to the
Bio21Aalborg-project the development of the DEWASTER® technology continued in a project with the
Danish waste company Noveren concerning the treatment of OFMSW at Noveren’s waste handling/composting
facility in Holbaek, Denmark.
During the project all the separated waste from October 2001 until February 2003, all together approximately
3,000 tonnes, was processed. In the process the DEWASTER® press was developed to
the design known today and further ancillary technical equipment was developed to make DE-
WASTER® a full-fledged system for treatment of OFMSW.
DESIZER
During the project at Noveren it became clear that the sorting quality of OFMSW in Holbaek was insufficient
to make the DEWASTER® press run without stops. Especially bones and small hard objects
such as stones and metals in the OFMSW stocked up inside the DEWASTER® press causing extended
wear on the press augers and press basket and occasional downtime. In response to these
problems a unit with two rollers which does not allow hard objects exceeding a certain pre-defined size
to pass through to the DEWASTER® press was devised. This unit, now known as the DESIZER and
the use of metal separation equipment has decreased wear and stops on the press unit considerably.
FEEDER
During the operation at Noveren many different waste types were tested and it was discovered that
certain type of waste, especially. “wet” waste could result in large drop in output capacity due to insufficient
feeding of the DEWASTER® press. The initial solution to this problem was to force-feed the
DEWASTER® press using a sliding vane positive displacement pump capable of delivering a discharge
pressure of more than 30 bar.
Use of this pump was successful in respect to many waste types, but proved less than optimal in respect
to very wet waste types. Consequently a new double auger press with screens for discharging
the wet waste was developed and installed at the Noveren facility in October 2002. The unit, now
known as the FEEDER, significantly increased output capacity on wet waste.
Hamburg 2002 - The DEWASTER® mobile test unit
In November 2002 a mobile DEWASTER® plant in order to be able to test the DEWASTER® process
on waste from potential customers was completed. The mobile plant was first used from December
2002 until February 2003 to process CFW (Restaurant/large kitchen waste and super market waste)
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