Page 133 - Materials Chemistry, Second Edition

Life Cycle Assessment of Biodiesel from Palm Oil 119

environmental emissions associated with biofuel systems and those suggested by
previous researches (Guinée et al. 2001; Edwards et al. 2007; Buchholz et al.
2009). These impact categories are evaluated using LCA software such as Simapro
(developed by PRé Consultants), Gabi 4.2 (developed by PE International), Um-
berto (developed by IFU Hamburg GmbH), while the databases from Eco-Indi-
cator 99 or 95, CML 2001 or 1996, Environmental Design of Industrial Products
(EDIP 1997) or EDIP 2003, etc., are used to evaluate the final environmental
impacts. Other LCIA methods that are implemented in Ecoinvent database include
cumulative energy demand, ecological scarcity 1997, environmental priority
strategies in product development (EPS 2000), IMPACT 2002, IPCC 2001 (cli-
mate change).
The main regulated pollutants evaluated in this chapter include CO, particulate
matter, non-methane hydrocarbons, nitrogen oxides (NO x ), etc. Solid wastes,
water, and CO 2 emissions as well as overall energy requirements are also evalu-
ated. Each of these emissions and pollutants are classified into their main envi-
ronmental impact category. For instance, CO 2 and CH 4 emissions were classified
under climate change, NO 2 and SO 2 , on the other hand, contribute to acid rain
formation and some degree of direct effect on human health hence classified
accordingly.

4.3.2 LCIA Characterization

This step involves the quantification of the extent to which each pollutant or
emission contributes to different environmental impacts. Standard characterization
factors conforming to Eco-Indicator 99 (EE99, EA) evaluation procedures are used
in this stage. In this method, human health category is measured in DALY/kg FU,
while ecosystem impacts and resource depletion are also measured in PDF*m2*a/kg
FU and surplus energy/kg FU. These are available in Gabi 4.2. On the other hand,
using CML 2001 database for the impacts evaluation generate different impact
categories units. For instance, acidification potentials of NOx and SO 2 are based on
proton formation potentials (PFP) (i.e., 0.7 for NOx and 1 for SO 2 ) expressed as SO 2
equivalent per FU. Thus, the total acidification potentials of 10 g NO 2 and 5 g SO 2
are given by (10 9 0.7) ? (5 9 1) = 12 g SO 2 equivalent per FU. This is esti-
mated by multiplying the amounts of the emissions by their proton formation factors
and aggregating the results of these multiplications for each impact category.
Again, global warming potentials are based on CO 2 equivalent, while ozone
layer depletion potentials are measured in CFC-11 equivalent. These character-
ization factors can be extended through normalization, grouping, and weighting. In
normalization, the results of the impact categories are usually compared with the
total impacts in the area of interest, for instance, in this chapter, Malaysia.
Grouping also involves the sorting and ranking of the impact categories. In
weighting, the different environmental impacts are weighted relative to each other,