Environmental Engineering Reference
In-Depth Information
80.0
Oxalic
acid
Bio-based platform molecules
Fossil-based base chemicals
70.0
60.0
Succinic acid
Glycerol
Methanol
50.0
Ethanol
40.0
Levoglucosenone
30.0
5-(chloromethyl)
furfural
Lysine
Eugenol
Lauric acid,
Methyl laurate
20.0
Guaiacol
10.0
Ethene,
Propene
Benzene
Limonene
0.0
0.0
2.0
4.0
6.0
8.0
% Hydrogen (H) by mass
10.0
12.0
14.0
16.0
Figure 4.12
% Hydrogen (by mass) versus % oxygen (by mass) for fossil-derived base chemi-
cals (X) and bio-based platform molecules (O).
opportunities for varied applications. One such example is 1,4:3,6- dianhydrohexitols
(isosorbide, isomannide and isoidide) formed from the three C
6
reduced sugars
sorbitol, mannitol and iditol (Figure 4.13), each possessing distinctly different
reactivity in polymerisations (due to the varied hydrogen bonding of the hydroxyls
to the ethers) and characteristics of the final polyesters due solely to the initial
isomeric form of the free starting sugars [120]. Achieving a similar variability in
fossil-derived polyesters would require the use of chiral catalysts or auxiliaries in
the monomer synthesis, adding greatly to the cost of their production, while the
effect can be obtained from these bio-based monomers simply by the inherent
chirality of the natural sugar feedstocks.
4.7 List of Platform Molecules
A list of current suggested platform molecules is provided in Table 4.5, grouped
together on the basis of the process technology use to produce them from biomass.
The list has been compiled using the authors' knowledge of the area and by the
application of the definitions described previously. As the field of bio-based
platform molecules matures, it is likely that some chemicals from this list will
become more prevalent than others (the main drivers being economics and
feedstock availability). In a fully matured bio-based chemical industry, the
definition of a platform molecule will be refined to those that become available on
a large scale and at a low cost. An extensive list has been given here to
