Integrierte Vermeidung und Verminderung der Umweltverschmutzung

2.1.9.2.2 Field of application
Required by all processes.
2.1.9.2.3 Description of techniques, methods and equipment
Chapter 2
Thermal energy is needed for heating processing lines and buildings. The heat generated by the
combustion of fossil fuels is transferred to the consumers by means of heat transfer media,
which, depending on the requirements, are steam, hot water, air or thermal oil.
The basic boiler/generator design generally consists of a combustion chamber, where fuel
combustion takes place. The heat is initially transferred by radiation, followed by a tubular heatexchanger
for heat transfer by convection. The hot flue-gas and heat transfer media are
separated from each other by a specially designed heat-exchange system. Thermal efficiencies
of heat generators very much depend on the application and fuel type. Efficiencies, calculated
on the basis of lowest calorific value, range from 75 to 90 %. Some products are heated up by
means of direct radiation with open flames or convection with directly heated process air. In this
particular case, natural gas or extra light fuel oil is burned.
In-house combined generation of heat and power (CHP) is a valuable alternative for FDM
manufacturing processes for which heat and power loads are balanced. The following
cogeneration concepts are used in the FDM sector; high pressure steam boilers/steam turbine,
gas turbines or gas engines or diesel generators with waste heat recovery for steam or hot water
generation. The overall fuel utilisation factor of CHP systems exceeds 70 % and is typically
about 85 %. Energy efficiency can be up to 90 or 95 % when the exhaust gases from a waste
heat recovery system, such as a steam boiler, are used for other drying purposes. The fuel
conversion efficiency greatly exceeds that of any design of a commercial power station, even
the latest generation of combined cycle gas turbines, which can achieve a conversion efficiency
of 55 %. Sometimes surplus electricity can be sold to other users.
Natural gas and fuel oil are the most convenient fuels. However, a few installations still burn
solid fuels such as coal or process wastes. The utilisation of process wastes can be a convenient
and competitive source of energy, and additionally helps to reduce the cost of off-site waste
disposal.
2.1.9.3 Water use (U.3)
2.1.9.3.1 Objective
A large part of the FDM sector cannot operate without a substantial amount of good quality
water. Without sufficient good quality water it is impossible to produce high quality products.
In the FDM sector, hygiene and food safety standards have to maintained.
A systematic approach to controlling the use of water and reducing water consumption and its
contamination is generally effective.
Each application of water requires its own specific quality. In the FDM sector, the quality
requirements depend on whether or not contact between water and the food product is possible.
Water that comes into contact with the product must, with a few exceptions, at least be of
drinking water standard. Both chemical and microbiological quality aspects are important. It is
advisable to conduct a regular check of the microbiological parameters of the water at the most
critical places, i.e. at the point of use. This is normally incorporated in the hazard analysis
critical control point system (HACCP). The quality standards for drinking water are laid down
in the Council Directive 98/83/EC [66, EC, 1998].
RHC/EIPPCB/FDM_BREF_FINAL January 2006 53