Environmental Engineering Reference
In-Depth Information
bio-based materials. A recent update in the definition of biomass by the European
Committee on Standardisation (CEN) clarifies the term further, considering the
fact that fossil fuels themselves are originally sourced from biological material
and have undergone natural processes in their transformation:
Biomass is material of biological origin excluding material embedded in geological
formations and/or fossilised.
These above definitions set a useful marker for the application of 'bio-based' with
respect to the term bio-based platform molecule. It is the opinion of the authors
that interchange between bio-based and bio-derived is allowable in this context,
both essentially referring to the fundamental source of an article being from
biomass. Considering the above terms, a succinct definition for a bio-based
platform molecule would be:
A bio-based (or bio-derived) platform molecule is a chemical compound whose
constituent elements originate wholly from biomass (material of biological origin,
excluding fossil carbon sources), and that can be utilised as a building block for the
production of other chemicals.
However, if a direct comparison of a platform molecule to a fossil-derived base
chemical is required then the quantity of the chemical produced is also relevant.
As the bio-economy matures it will become apparent which of the bio-based
building-block chemicals are most like the fossil-derived base chemical by the
volumes they are produced and used in.
There are some instances where several compounds in a sequential reaction
pathway could each be viewed as platform molecules, further complicating
correct assignment of the true platform molecule. For example, fructose (feed-
stock) can be converted to HMF (platform molecule if isolated), but it can also
be converted directly to levulinic acid [25, 26] and γ-valerolactone [27] (both
via HMF but without isolation of the HMF). These two compounds could
therefore be described as bio-derived platform molecules, depending on the
production route, as they can be produced directly from biomass (Figure 4.2).
Cu/ZrO
2
catalyst, H
+
, +H
2
O
Δ
, -H
2
O, H
+
, +H
2
O, - formic acid (FA)
O
O
O
O
OH Pd catalyst
O
Δ
Δ
Biomass
-H
2
O, H
+
HO
+H
2
O, -FA
+H
2
, -H
2
O
γ
-valerolactone
(GVL)
O
5-(hydroxymethyl) furfural
(HMF)
Levulinic acid
Figure 4.2
Formation of levulinic acid and
γ
-valerolactone (GVL) either directly from biomass
or via 5-HMF.
