Environmental Engineering Reference
In-Depth Information
It can be seen that relatively small decoupling is seen in Belgium, Denmark and Germany
while the waste intensity in the CEE countries (871 tonnes per million USD) are many times
higher than the WE countries (129 tonnes per million USD). Romania, Poland and Slovakia
have the highest waste intensity while Iceland, Norway and Denmark have the lowest. There
is a falling tendency in five countries while the waste intensity is increasing in five other
countries.
Manufacturing waste is typically heterogeneous and with differentiated range of potential
impact on the environment. Although different wastes cause different environmental impact
potential, there is also a quantitative aspect as more waste means potentially higher pressure
on the environment.
The industrial structure, in terms of the prevailing sectors and branches, is an important
factor for the amount and the kinds of waste generated, some sectors being the source of large
quantities of hazardous waste with high environmental impacts. Waste also represents a loss
of resources both in the form of materials and energy. Indeed, quantities of manufacturing
waste can be seen as an indicator of the material efficiency of the manufacturing sector.
Excessive quantities of waste result directly from a large industrial production and
inefficient production processes. Indirectly it reflects low durability of goods and
unsustainable consumption patterns leading to high demand for manufacturing products and
thereby potentially high waste quantities. Waste minimisation in manufacturing production
processes is an increasingly important objective of manufacturing environmental strategies
also in the framework of environmental certification. Different countries and industrial
sectors are differently positioned in the process of optimising resource use, factory-level
waste minimisation and the adoption of certification instruments.
2.
T
HE
M
AIN
F
INAL
T
HERMAL
T
REATMENTS OF
W
ASTE
The thermal treatment which takes out energy from waste includes also combustion and
gasification processes. Combustion and gasification technologies of alternative fuels, like bio-
mass, fuels from wastes and from other types of industrial wastes, are gaining importance.
The energy conversion technologies are increasingly constrained by environmental
regulations on regional, national and international level. So it is necessary to move towards
advanced technologies like gasification systems in combined cycles.
Combustion and gasification processes of non-conventional solid fuels increasingly
require the integration of different skills, due to the high variability of physicochemical
parameters of the initial fuels. The nature of fuels influences choices in the processes and
systems. The complicated fluid-dynamic behaviour of multiphase systems is another factor of
influence [7]. So, when analysing the thermo treatment processes with energy recovery from
solid urban wastes and industrial wastes it is necessary to look for their environmental and
energetic performances.
The three technologies analyzed in this chapter are: a
waste to energy
plant of the latest
generation, a
molecular dissociator
and a
gasifier
licensed in Italy. The three of them aim to
dispose of every kind of waste, at the same time producing electricity and/or thermal energy
but in different ways and with different results.
