Page 84 - Materials Chemistry, Second Edition

L1644_C02.fm Page 61 Tuesday, October 21, 2003 3:07 PM

TABLE 2.4
Eco-Vectors of Input and Output Streams of Chair Manufacturing System
Stream IP1 IP2 IP3 IP4 IE1 W1

Vector v m, IP1 v m, IP2 v m, IP3 v m, IP4 v e, IE1 v m, W1
EL Wood Foam Polyamide Iron Electricity Solid
waste
Load Units EL/kg EL/kg EL/kg EL/kg EL/kW.h EL/kg
Coal kg 7.93 × 10 –2 3.89 × 10 –1 7.46 × 10 –1 6.87 × 10 –1 1.39 × 10 –1 0
Natural gas kg 3.27 × 10 –2 8.32 × 10 –1 1.41 9.10 × 10 –2 4.07 × 10 –2 0
Crude oil kg 5.10 × 10 –2 7.38 × 10 –1 8.12 × 10 –1 5.50 × 10 –2 2.88 × 10 –2 0
kg 1.05 4.06 7.00 2.05 5.27 × 10 –1 0
CO 2
kg 1.80 × 10 –3 1.78 × 10 –2 2.60 × 10 –2 3.60 × 10 –3 9.50 × 10 –4 0
NO x
kg 2.01 × 10 –3 1.91 × 10 –2 2.90 × 10 –2 4.50 × 10 –3 2.57 × 10 –3 0
SO x
BOD5 kg 9.26 × 10 –7 4.64 × 10 –4 3.60 × 10 –3 1.70 × 10 –4 1.34 × 10 –7 0
COD kg 1.45 × 10 –5 2.78 × 10 –3 1.50 × 10 –2 4.63 × 10 –4 1.99 × 10 –6 0
– kg 5.00 × 10 –6 6.30 × 10 –3 3.00 × 10 –2 6.90 × 10 –6 7.70 × 10 –7 0
NO 3
Solid waste kg 1.50 × 10 –1 5.95 × 10 –1 3.05 × 10 –1 7.60 × 10 –1 8.04 × 10 –2 –1
By the application of Expression 2.6, the value of the eco-vector, v , corre-
m,P
sponding to the environmental load associated with the chair can be obtained. Table
2.5 shows the calculation of the environmental loads as a function of inputs and
outputs.
These results show the procedure to calculate the environmental load assigned
to a product as a function of the environmental data of the different process inputs
and the loads generated by the process. From Table 2.5 it is possible to determine
the relative contribution of each input to the total value of the corresponding envi-
ronmental loads, as presented in Table 2.6.

2.7 CASE STUDY: LCA STUDY OF AN MSWI IN
TARRAGONA, SPAIN

For the MSWI plant introduced in Chapter 1, an LCA study (STQ 1998) was
developed as an Excel spreadsheet model on the basis of the Code of Practice
(SETAC 1993) and according to the steps in ISO 14040 (1997). The inventory was
based on providers’ information, literature data on raw materials and a detailed
analysis of the incineration process.

2.7.1 GOAL AND SCOPE DEFINITION OF THE MSWI LCA STUDY
The objective of the study was to identify, evaluate and compare the environmental
loads derived from the electricity production by the municipal waste incinerator of
Tarragona in Scenarios 1 and 2 (described earlier) in order to analyze the environ-
mental efficiency of the investment in an advanced acid gas removal system. Next,
the project is described according to the points indicated in ISO 14040 (1997).

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