The dwindling supply and exponential growth in the demand of fossil fuels have motivated researchers...
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- Slide 1
- Slide 2
- 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.
- Slide 3
- Descrition (or glycerin, glycerine) (C3H8O3) : is a simple
polyol compound.
- Slide 4
- Descrition (C 3 H 8 O 2 ): It is a colorless, nearly odorless,
clear, viscous liquid with a faintly sweet taste, hygrosc opic and
miscible with water, acetone, and chloroform.hygrosc
opicmisciblewateracetonechloroform Ways of obtaining:by catalytic
hydrogenolysis Industry interest: industrial solvent, antifreeze,
deicing agent and approved additive in food, cosmetic and ph
armaceutical industries
- Slide 5
- Descrition (CH 2 (CH 2 OH) 2 ): This three-carbon diol is a
colorless viscous liquid that is miscible with water.diolmiscible
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.
- Slide 6
- In this assignment, 1,2-PDO has been obtained with two
hydrogenlysis methots. We are going to discuss the best aspects of
each one
- Slide 7
- The catalyst in this experiment is an admixture of 5 wt.%
Pt/Al2O3 and 5 wt.% Ru/ Al 2 O 3. The Pt/Al 2 O 3 was chosen to
promote the aqueous phase reforming of glycerol to hydrogen,
whereas Ru/Al 2 O 3 was chosen to facilitate the hydrogenoly sis of
glycerol by in situ hydrogen generated.
- Slide 8
- 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.
- Slide 9
- The results with 5% Ru/A l 2 O 3 and 5% Pt/Al 2 O 3 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.
- Slide 10
- 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 concentration.
- Slide 11
- The main catalyst is Cu/Al 2 O 3, it doesnt present
deactivation until 200C and whit that, it would be obtained the
best yields and selectivity The best temperatures for this process
are betwee n 170 and 200C
- Slide 12
- The production of 1,3 PDO has been carried out us ing two
bacterias: Clostridium butyricum and Klebsie lla pneumoniae
- Slide 13
- 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.
- Slide 14
- Maximum concentration of 1,3-propanediol (5560 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.
- Slide 15
- The great difference of this bacteria is that it present s a
strong tolerance at the inhibitory effect of the 1,3- propanediol
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 industry.
- Slide 16
- In this assignment we have studied the production of 1,3- PDO
with batch, single-step and two-stage continuous cultures. 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.