Page 372 - Materials Chemistry, Second Edition

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was carried out in two ways: potential impact and site-specific impact assessments.
By this, the most important aspects about LCA, impact pathway analysis (IPA) and
environmental risk assessment (ERA) approaches were analyzed.
This example is in the heart of chemical engineering. The LCA study carried
out is a cradle-to-gate study. This means that one industrial process, situated in the
petrochemical complex of the Tarragona region (Spain), with its associated environ-
mental loads due to raw material and energy consumption is considered. Two related
sub-processes, electricity generation and steam production, both by on-site small
fossil-based thermal plants, are simulated more in detail. The data for the other
materials are taken from the LCA software database. Based on the LCA results one
process is to be further assessed by site-specific impact assessment. In this example
we will try to carry out a more generic IPA first and then a more detailed ERA to
deal with open questions not solvable with the IPA software Ecosense.

8.4.2 GOAL AND SCOPE DEFINITION
In this case study, the environmental impact analysis is applied to the separation
process from a naphtha stream in order to evaluate the environmental effects of all
process stages, including its requirements of electric power and steam. The system
separates isopentane from naphtha about 16 t/h production. In this sense, 16 t/h
production has been considered the functional unit for the LCA. The separation plant
consisting of a distillation column, the electricity generation and the steam produc-
tion were the three main steps taken into account. Figure 8.13 shows the flow diagram
of the studied system with the inputs and outputs considered.

8.4.3 POTENTIAL IMPACT ASSESSMENT
In order to carry out the inventory analysis, the aforementioned three main stages
were considered: steam production, electricity generation and separation of isopen-
tane. The required information in the collection data step was obtained from the real
process. Nevertheless, in the case of steam generation, some values were taken from
the TEAM database. TEAM is the software used (see Chapter 2) to carry out the
LCA for the process and to evaluate the total amount of a specific pollutant in any
stage. This software calculates the environmental loads produced by a functional
unit starting from given process data.
TEAM consists of an integrated group of software tools to model and analyze
any system. A modeling tool is used to describe physical operations. It allows a
large database to be built and the LCI to be calculated for any system (inventories
conducted for a product life-cycle or other consistent systems). The analysis tools
for applying LCIA methods (i.e., potential impacts) based on the inventories results
allow further evaluation of the system under study. The scheme created in TEAM
to obtain the inventory and potential impacts is represented in Figure 8.14.

8.4.3.1 Inventory

The main data considered and introduced in the TEAM software for creating the
inventory are summarized in Table 8.18. The process has two different inputs for

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