European Bio-Energy Projects

READY
Objectives
The objective of the original development
was to design a process fulfilling the
required quota whilst being economically
and ecologically acceptable. While these
goals could be fulfilled, further
improvements (mainly on the energy yield)
shall make the process ecologically and
economically better. The objective of the
research programme, with the acronym
READY (RESHMENT Advanced Energy
Yield), is to improve the energy yield by a
number of adaptations to the process and
the equipment applied during it.
While the overall energy yield (heat) will
not be changed dramatically, the use of
electrical energy shall be greatly reduced
and the production of electrical energy
shall be improved.
The process will be sustainable in itself
meaning that only reusable or recyclable
products shall be aimed at. Recycling of the
Zn/Pd fraction is still costly because of the
large halogens content. Therefore, an
objective is to find a means to lower the cost
of such recycling by pre-processing it before
sending it to the secondary Zn-industry.
In order to fulfil the EU directive, not only
must technologies be available but the
market must also allow the building and
operating of such plants. Another objective
is, therefore, to study the feasibility of
implementing such plants in the EU,
considering the socioeconomic
environment.
RESHMENT – A novel
approach for revalorisation
of shredder residues
Introduction
The valorisation of shredder residue (SR),
particularly from the automotive sector, has
become an objective in the EU with the directive
2000/53/EC. This directive asks for a weight
quota for reuse, recycling and recovery of endof-life
vehicles, which are usually shredded in
order to recover and recycle metals. The
remainder, a broad mixture of plastic, tissues,
paper, wood and inorganic materials including
metals, must be processed as well in order to
fulfil the quota. Also this residue contains toxic
materials, particularly heavy metals.
The RESHMENT process was developed in order
to fulfil the required quota. At the same time it
is able to inertise toxic residues from MSW
incinerators using a small part of the energy of
the SR at very high temperature, avoiding the use
of other (fossil) energy sources for such
inertisation. The process still possesses a great
potential for further improvement, particularly in
its energy yield. The first commercial plant with
55’000tpy is being planned in Switzerland and
further development will improve its already
interesting economics.
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Problems addressed
The large consumption of electrical energy in this
process is due to two reasons: the milling unit
used to prepare the waste for the smelting
cyclone is a big consumer, and the other major
user is the oxygen production used for the
metallurgical process applied. Electrical power
production is limited by the steam parameters
of the heat recovery system because of the
corrosive nature of some of the waste products
contained in the SR. The problems to be
addressed, therefore, are the following:
• Is it possible to increase the size of the
particles fed to the smelting cyclone without
compromising its efficiency, leading to a lower
requirement from the mill?
• Is it possible to improve the mill so that it
consumes less energy to produce the required
particle size?
• Can oxygen be partly replaced by air without
compromising the metallurgical process?
• What measures can be taken to improve the
steam parameters in the waste heat boiler?
In order to approach these problems, the basic
flame behaviour, reaction kinetics and flow
pattern of the smelting cyclone shall be explored
applying CFD technology. Practical tests will
prove the model built and allow adaptations to
fit it environmentally. The model shall be used
to explore the possibility using larger particles
and air. Practical tests will again prove the
modelling.
Zn/Pd fraction pre-processing shall be studied
on a lab-scale level, while the feasibility study will
explore the possibilities to place a plant into a
suitable location where the environmental impact,
as well as economic considerations and logistics,
will play a major role.