Page 172 - Materials Chemistry, Second Edition

156 3 Life Cycle Inventory Analysis

Grid electricity Electricity
Germany 523 kJ

Shrink foil
Polyethylene LDPE granules Blown film (LDPE) LDPE foil
(LDPE) 0.4 kg extrusion 0.4 kg Transport 400 km

Figure 3.32 Subsystem LDPE foil Production from Figure 3.30.

Secondary
fibre

Carton Material Reject Energy recovery
recovery in cement plant Cement,
fibre clinker

Reject

Gasification plant Aluminium
products

Figure 3.33 Subsystem beverage carton recycling from Figure 3.28 (see descriptions of unit
processes for recycling procedures).

With data records compiled by the authors of the study, the allocation by
mass is normally calculated according to the outputs of co-products. Some data
records taken from literature also use the heat value or the market value as
allocation criteria (e.g. the heat value with PlasticEurope data for plastics).
The respective allocation criteria are documented depending on relevance
for individual data records. For published data it is usual to only refer to the
appropriate source.

Multi-input Processes Multi-input processes predominantly occur within
disposal. Appropriate processes are modelled in a way that allows an even
and causal allocation of material and energy flows of used packagings to
these processes. The modelling of disposal of packaging materials as waste
in an incineration plant is a typical example of a multi-input allocation. For