Wastes from wood processing and the production of panels and furniture:
Packaging Wastes:
Construction and demolition waste:
Wastes from mechanical waste treatment (for example sorting, crushing, compacting, pelletising) not otherwise specified
Separately collected fractions from municipal wastes (household waste and similar commercial, industrial and institutional wastes):
The
incoming waste stream is waste wood[RS1] as listed above. Due to the
different origins, waste wood can be contaminated to varying degrees with
foreign substances. Therefore, the category is divided into four different
qualityies (A1 to A4), of which the first three can be used as input:
As presented in table 1 the technology produces electricity and/or heat, depending on the respective demands, and about 10 % of the input is converted into bio-char.
Table 1: Output products and their proportion of production.
Bio charcoal |
Heat |
Electricity |
Loss |
10% |
55% |
29% |
5% |
The
technology encompasses a multi-staged gasification system. The core of this
technology is a floating-fixed-bed reduction reactor. Due to its unique design,
it allows the gasification process to happen within a tubular reactor. This
prevents the backflow of gas and fuel material.
During the
gasification process, the particles pass through the floating-fixed-bed. As a
consequence of heterogeneous reduction reactions, the particles decrease in
size until they reach the top of the bulk. Depending on the individual particles’
sinking speed, the residual bio-char particle fraction is transported by the
product gas stream into a hot gas filter system. After passing a cooling unit,
the produced gas is cleaned by a fuel specific water scrubber before being fed to
a combustion engine (see Figure 1).
Figure 1: Setup of
floating-fixed-bed-gasification process (source: http://www.syncraft.at/)
The biochar produced from waste wood is classified as a waste product. To convert it into a product, strategies and concepts need to be developed and an adequate legislative setting needs to be established (e.g. end-of-waste criteria, Article 6 (1) and (2) of the Waste Framework Directive 2008/98/EC).
The gasification
of waste wood is a promising approach to transform waste wood into renewable
energy and bio-char suitable as a filter medium for numerous applications.
However, in order to achieve a process and to produce useable bio-char, certain limiting factors need to be overcome.
There are
three main factors that can compromise the gasification process and the production
of quality bio-char:
In general,
the more homogeneous and the better preserved the input material, the more
stable is the gasification process.
Compared to
other alternative uses of waste wood, this appears to be one of the most
promising technologies to expand the life cycle of waste wood and produce
renewable energy.
A prototype
of this technology, using waste wood, is implemented and produces bio-char. To
obtain activated bio-char, which is the ultimate aim of the CE solution, more
test runs are needed and the pre-processing steps need to be refined.
Yes