Page 88 - Materials Chemistry, Second Edition

72 3 Life Cycle Inventory Analysis

Benzene 251
263 production

841 LAB-
Crude oil
extraction Refinery production
721
n-paraffin
production 516
516
1000 kg
Sulfonation
and LAS
neutralisation
S pro- 100
duction

99 127
NaCl- NaOH
mining production

System boundary Cl 2

Figure 3.7 Flow chart of LAS produc- (Cl ) is the co-product of sodium hydroxide
2
tion. LAS – linear alkyl benzene (predom- (NaOH) in the electrochemical production
inantly n-dodecylbenzene) – is transferred from common salt (NaCl) and leaves the
by sulfonation into LAS. Numbers with- system (allocation necessary); a further co-
out unit refer to kilogram of the substance product is hydrogen (not indicated).
specified in the left unit process. Chlorine

sulfonate). In this synthesis four components (n-paraffin, benzene, sulphur tri-
oxide via sulphur and sodium hydroxide) are gradually produced and set into
reaction. 30)

3.1.5
Reference Values

With the exception of Figure 3.7, the definition of unit processes and their
integration into flow charts have so far not implied quantification. However, in
business practice basic information on unit processes of production systems are
often procured related to operating time (per hour or per annum) or are related
to various other reference values depending on the cause of measurement or

30) Janzen, 1995; Berna, Cavalli and Renta, 1995.