Which is the most promising bio-
based chemical?
When new processes and products enter the
market it’s human nature to ask who does
best in the competition. For the uninvolved
observer it may be simple curiosity, for
investors it’s a matter of money – and lots of
it - to decide whether to jump on the bio-
based bandwagon and which car to take.
In 2004 the US National Renewable
Energy Laboratory (NREL) defned 12 top
value added chemicals from biomass. These
products seemed to be the most promising
at that time but a lot has happened in
the last decade. In the follow-up report of
2016 there is again a list of 12 promising
chemicals. The overlap between the two lists
is moderate and consists of glycerol, succinic
acid and para-xylene.
The European Union, too, strives to
identify the chemicals that are predestined
to be made from biomass. RoadToBio is an
EU-funded project set up in mid-2017 to
deliver a roadmap by 2019 illustrating the
‘sweet spots’ for Europe’s chemical industry.
In a frst step, a long list with 120 chemicals
at technology readiness level (TRL) of 6 or
higher was compiled that show potential for
the chemicals market. In parallel, the value
chains of 500 petrochemicals were analyzed
from a purely technical point of view. 85%
of the value chains ofer entry points where
a petrochemical could be replaced by a
bio-based one. The chemicals that were
cited most often as replaceable are ethylene,
propylene and methanol.
RoadToBio analyzes the interface
between bio-based and petro-
chemical
The NREL report and RoadToBio project
have in common that they both examine
products with a TRL 6 or higher meaning
that the production process has reached
pilot scale. Furthermore the studies so
far both work along the value chain of
petrochemical products. A typical product
tree starts from a low value feedstock like
ethylene and branches into many higher
value intermediates like polyethylene,
ethylene oxide and vinyl acetate. The
intermediates again have multiple uses;
vinyl acetate can end up in an adhesive as
well as in paint.
Whenever a chemical can in theory be
replaced by a bio-based one this is called
an entry point in RoadToBio. Overall, of
the 120 chemicals identifed in the long
list for further analysis, only 49 have entry
points into existing petrochemical value
chains, while the other 71 are dedicated
chemicals. Dedicated chemicals are those
which have no fossil-based counterpart and
thus ofer unique production routes. Lactic
acid as base for the bioplastic polylactic
acid is a prominent example for a dedicated
chemical. In contrast, drop-in chemicals are
bio-based versions of existing chemicals.
A third group, smart drop-in chemicals,
are also chemically identical to their fossil
counterparts but provide an additional
advantage compared to ordinary drop-ins.
This can be a faster and simpler production
pathway or less energy use.
In the NREL analysis some products such
as ethylene and methanol were consciously
excluded as they would compete with
chemicals derived from natural gas, which
is not realistic. It remains to be seen if
RoadToBio researchers take a similar route
in the next step, in which they will analyze
drop-ins and dedicated chemicals for their
market potential.
Four chemicals that appear on both
the top 12 NREL list and among the 49
RoadToBio chemicals with potential entry
points are succinic acid, para-xylene,
1,2-propanediol and glycerol.
And the winner is…cooperation
If predicting the success of a bio-based
product were easy governments worldwide
would not employ legions of scientists
and commission studies to do so. Only
time will tell which of the cited bio-based
chemicals will become a blockbuster
and whether RoadToBio will come to
the same conclusions as the NREL study.
The petroleum price and governmental
interventions are only two of the more
unpredictable factors in the multi-
parameter matrix which determines the
economic success of a bio-based product.
One of the commonalities of the four
chemicals discussed above is that they are
drop-in chemicals. They are chemically
identical to their fossil counterparts and
for further processing it doesn’t play a role
whether they are made from petroleum or
from biomass.
On closer inspection the production
processes of promising drop-in chemicals
are an eclectic mix of chemical and
biotechnological. Fermentation steps are
followed by chemical transformations;
whether a metal catalyst or an enzyme is
used is just a matter of what works best.
Anything goes as long it is technically
feasible. A process is no longer either
chemical or biotechnological, cooperation
is the new normal. Winners in the quest for
the holy grail of bio-based chemicals are
defnitely the scientists from all the diferent
disciplines involved. They have learned to
look past the boundaries of their own sector
and gained a whole new perspective.
ACHEMA 2018 focal topic “Biotech for
Chemistry” puts the spotlight on the fact
that biotechnology and chemistry are
growing together. The congress program
features presentations about novel
processes and products while the exhibition
shows equipment of every scale for both
biotechnological and chemical techniques.
ACHEMA TREND REPORT