Page 567 - Refining Biomass Residues for Sustainable Energy and Bioproducts

516 Refining Biomass Residues for Sustainable Energy and Bioproducts

commonly used laundry detergents are often produced as a mixture or combinations
of a wide array of surfactant molecules along with granular enzymes to increase
their cleaning efficiency. Fig. 23.3 depicts LCA in the synthesis of linear alkylben-
zene sulfonate (LAS).
LCA of six different household detergents used in Europe was done exempting
environmental and human toxicity impacts from the study (Golsteijn et al., 2015),
thereby questioning the true impact of the LCA in a true sense. As per the study,
the use of detergent and the source of ingredients are found to be major environ-
mental contributors than processes of manufacture, transport, and disposal of deter-
gents in terms the energy used and water used for processing (Saouter and Hoof,
2002). The high-energy demand of detergent use is due to the necessity to increase
the heat of the water in European countries and almost 98% of the biological oxy-
gen demand is contributed by the disposal.
Table 23.2 enlists some of the LCAs conducted on surfactants. The LCA of
detergent builders, such as sodium tripolyphosfate (STPP) and zeolites, indicate
that their effect on the environment is less in relation to the benefits they provide to
different sectors, also discouraging environment harmful detergent builders, such as
nitrilotriacetic acid (Morse et al., 1995). However, STPP the major phosphate-based
compound in detergents greatly contributes to eutrophication characterized by
large-scale algal development, leading to a ban in their use in detergents at least in
some countries (Singh et al., 2014). Thus the choice of less toxic and degradable
inputs for detergent synthesis also is relevant, thereby leading to the development
of various phosphate-free environment-friendly surfactant candidates. The LCA of
LAS, one of the predominantly used synthetic anionic surfactants, has been found
to drastically affect the production of fossil fuels, alter the extent of land usage, and
contribute generation of respiratory inorganics (Thannimalay and Yusoff, 2014).

Figure 23.3 LCA inventory for synthesis of synthetic detergent linear alkylbenzene
sulfonate. LAS, Linear alkylbenzene sulfonate; LCA, life-cycle analysis.