Obtencion of 1,2 and 1,3-PDO from glycerol - IQ

The dwindling supply and exponential growth in the
demand of fossil fuels have motivated researchers t
o explore alternative resources and technologies for
fuels and chemicals. The utilization of the relatively
large amounts of glycerol side product (10wt.%)
formed in bio-diesel manufacture is a major factor in
the overall cost effectiveness of the process .
Therefore, use of this glycerol as a renewable
feedstock to produce value added chemicals is
crucial to biorefinery economics.
Descrition (or glycerin, glycerine) (C3H8O3) : is
a simple polyol compound.
Descrition (C3H8O2): It is a colorless, nearly odorless,
clear, viscous liquid with a faintly sweet taste, hygrosc
opic and miscible with water, acetone, and chloroform.
Ways of obtaining:by catalytic hydrogenolysis
Industry interest: industrial solvent, antifreeze, deicing
agent and approved additive in food, cosmetic and ph
armaceutical industries
Descrition (CH2(CH2OH)2): This three-carbon diol is a
colorless viscous liquid that is miscible with water.
Ways of obtaining: by bacterial fermentation
Industry interest: Plastics based on this monomer exhi
bit better product properties and higher light stability th
an those produced by 1,2-propanediol, butanediol or e
thylene glycol. 1,3-Propanediol can also be used as a
polyglycol-type lubricant and as a solvent.
In this assignment, 1,2-PDO has been obtained with
two hydrogenlysis methots. We are going to discuss
the best aspects of each one
The catalyst in this experiment is an admixture of
5 wt.% Pt/Al2O3 and 5 wt.% Ru/ Al2O3 .
The Pt/Al2O3 was chosen to promote the aqueous
phase reforming of glycerol to hydrogen , whereas
Ru/Al2O3 was chosen to facilitate the hydrogenoly
sis of glycerol by in situ hydrogen generated .
It is demonstrate that the admixture catalyst outpe
rformed the individual catalysts with respect to
1,2-PDO selectivity and yield under without added
hydrogen condition.
 The yield of 1,2-PDO was also higher with the
admixture catalyst when compared to the externall
y added hydrogen condition.
The results with 5% Ru/A
l2O3 and 5% Pt/Al2O3 ad
mixture combinations an
d the monometallic cataly
sts on glycerol hydrogen
olysis in absence of exter
nally added hydrogen at
493 K are compared in
these graphs.
Glycerol is converted into hydroxyacetone (reaction
intermediate) through the dehydration, followed by
the hydrogenation into 1,2-propanediol, with a yield
over 96%.
In this process, the dehydration needs relatively
high reaction temperatures, whereas the hydrogenat
ion favors low temperatures and high hydrogen
The main catalyst is Cu/Al2O3, it doesn’t present
deactivation until 200ºC and whit that, it would be
obtained the best yields and selectivity
The best temperatures for this process are betwee
n 170 and 200ºC
The production of 1,3 – PDO has been carried out us
ing two bacterias: Clostridium butyricum and Klebsie
lla pneumoniae
The experiment includes fermentations in batch
culture, fed-batch culture and continuous culture.
This experiments were carried out in shake flasks
and a fixed-bed bioreactor.
Results showed that the NaCS/PDMDAAC
microcapsule has desirable properties such as
biomass enrichment in the microcapsule ,
enhanced substrate tolerance and stable activity
of cells respect of the no encapsulated cells.
Maximum concentration of 1,3-propanediol (55–60
g/L) was obtained in batch and fedbatch cultures .
Continuous culture has the advantage of relatively
high productivities ,however, its 1,3-propanediol
concentration is not high enough to reduce the
load of downstream separation.
Also, there has been growing interest in a more e
conomical route that utilizes glucose as a lower-co
st feedstock.
The great difference of this bacteria is that it present
s a strong tolerance at the inhibitory effect of the 1,3propanediol and glycerol, even at high concentration
s of this substance at the chemostat.
It means that 1,3-PDO can be carried out with pure
or industrial glycerol. A great advantage for the
In this assignment we have studied the production of 1,3PDO with batch, single-step and two-stage continuous
The medium yield for glycol is 55%, in single-step
continuous, large quantities of 1,3-PDO have been
obtained with low concentrations of glycerol, however if t
he flow increases, the concentration decreases of 1,3 PDO.
having a second stage could be mainly used to further in
crease the product concentration and to completely use t
he residual glycerol.

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