Page 182 - CW E-Magazine (16-1-2024)

Special Report

tose syrup produced from EU wheat The largest impacts are caused by of-life, a fossil-based material has the
starch. the fossil energy required to power sugar potential to further add contribution to
beet mills (assuming natural gas use). GWP due to either incineration or degra-
Global Warming Potential results A switch to 100% renewable energy will dation, while a biogenic carbon material
Excluding carbon sequestration, the reduce the impact from energy and further has the potential to lose the benefi t of
GWP is 0.57-kg CO eq. per kg designed improve the GWP results signifi cantly. the sequestered carbon. In addition, the
2
enzymatic polysaccharide on a cradle-to- Even co-generation provides substan- enzymatic biomaterials will fully bio-
gate basis when the fructose co-product tial GWP savings. Comparison of the degrade, while the appropriate fossil-
is used as a sweetener. Additionally, designed enzymatic biomaterial (DEB) derived incumbent material will typically
1-kg of the designed enzymatic polysac- impact to synthetic materials from fossil not biodegrade, but potentially generate
charide contains 0.39-kg biogenic car- carbon sources on a cradle-to-gate basis microplastic contamination.
bon. Hence, during the sugar beet plant is diffi cult due to the difference between
growth, 1.43-kg CO was removed from biogenic and fossil-based carbon. Ideally, CONCLUSION
2
the atmosphere. In contrast to fossil car- end-of-life is included for both products DEB manufacture integrated within
bon, emissions of biogenic carbon do not to make a more accurate assessment. a beet sugar biorefi nery offers attrac-
contribute to global warming because all tive opportunities to deliver direct low
emissions at end-of-life of the product Biogenic carbon is removed from environmental impacts across key criti-
(through incineration or biodegradation) the atmosphere when making DEB, cal assessment categories essential for a
were removed from the atmosphere dur- but in many applications, returns to the successful transition towards a circular
ing plant growth. atmosphere at the end of life through bioeconomy. The low greenhouse gas
incineration or biodegradation. On a balance is especially signifi cant, as green-
So, when an LCA is carried out only cradle-to-gate basis, however, the bio- house gas emissions related to the agri-
from cradle-to-gate (where end-of-life is genic carbon is physically sequestered cultural inputs and the enzymatic poly-
not included in the scope), the important in the designed biomaterial. At the end- merisation manufacturing process are
difference between fossil and biogenic
carbon embedded in the product must be
refl ected. To do so, the embedded carbon
can be considered as negative GWP and
positively infl uence the overall sum of
emissions in a cradle-to-gate perspective.
The credits for biogenic carbon uptake
exceed the sum of impacts and co-product
credits, providing a net benefi t of 0.86-kg
CO eq. per kg Designed Enzymatic Bio-
2
material (DEB) on a cradle-to-gate basis
when using substitution. This is indicated
by the black bar in Fig. 3. Fig. 4: Sugar beet: effi cient land & biomass use
lower than the biogenic carbon uptake
of the product itself.

These LCA results reveal that a con-
sequent utilisation of all products and
co-products from this integrated bio-
refi nery can improve GWP impacts. In
this application sugar beet is a particularly
suitable renewable feedstock that yields
several valuable co-products in a high
biomass utilisation effi ciency manner,
supporting the transition towards the
bioeconomy integration in existing rural
Fig. 3: Global Warming Potential of DEB production communities (Figure 4).

182 Chemical Weekly January 16, 2024

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