Page 166 - Materials Chemistry, Second Edition

150 3 Life Cycle Inventory Analysis

The following databases were considered in the unit processes:

Material/product Data basis

Fibre recovery The principal purpose of the processing is the recovery of the fibres
dissolved from the remaining compound, so-called rejects, by swelling
in a pulper. The reject (also contains drains and closures) serves as
input to processes cement plant or Ecogas plant. The fibres are usually
processed in the same paper factory into final products. The data basis
consists of confidential data of German and Finnish plants
Ecogas plant In the Ecogas plant the polyethylene separated from the composite is
brought into the gaseous phase and burned for energy production. A
part is used to fuel the Ecogas plant. The surplus is used in the attached
paper plant. According to data of the plant operators about 85% of
applied aluminium are recovered and used as material. The data basis
consists of confidential data of the plant operator
Cement plant The utilisation of rejects in the cement plant was converted as
co-incineration process in the system model. It was assumed that the
plastics parts replace hard coal during the incineration process and
aluminium parts replace the additional material bauxite. The data basis
consists of confidential data of the cement industry
Waste Used beverage cartons are disposed. Here, a waste incineration is
incineration assumed (MSWI). The waste incineration model applies to a technical
(MSWI) standard of the European Union guideline (European Union Incineration
Directive – Council Directive 2000/76/EC). In the model a grate-firing with
steam turbine followed by purification of exhaust gas is put at the basis.
The energy contained in the waste can partly be recovered (here 10% as
electricity and 30% as thermal energy)

Recycling of PET Bottles
By processing PET flakes are retrieved as products. At present the recovery
plants for PET bottles in Europe differ by age and procedure details, yet most
plants exhibit the same process sequences.

The following databases were considered for the unit processes:
Material/product Data basis

Material The process data used in this study were compiled and validated in the
a
recover: PET context of the study on behalf of PETCORE. For the processing of
flakes multilayer bottles according to information of the DSD a decrease of PET
yield around 2% is assumed