Design Group

1
Design Group

• Vincent Piepiora
• Suzanne Rapp
• Pablo Celestino

2
Synthesis to covert syngas to EtOH and HA
3
Synthesis to convert syngas to EtOH and HA

• Main Processes Intermediary process Catalysts
  for
• Direct Synthesis Methanol synthesis Direct
  synthesis
• F-T synthesis F-T synthesis
• Methanol Homologation Methanol homologation
• ENSOL process ENSOL process
•  
• Focus on
• MoS2-based catalyst
• F-T synthesis/Direct synthesis

4
Catalysts

• Homogenous
• More selective to EtOH
• Expensive
• Separation and recirculation is difficult

• Heterogeneous
• Suitaible for continuos process
• Low yield and selectivity to EtOH

5
Heterogeneous

• Noble metals-based
• Primarily supported by Rh catalyst
• Expensive and limited amount

• Non-noble metals-based
• Used in MeOH synthesis, F-T synthesis and Direct
  synthesis
• Produce mixture of C1-C6 alcohols
• High selectivity toward MeOH and isobutOH
• Little selectivity toward EtOH

6
Alkali promoters

• They play a significant role in activity,
  selectivity toward HA and lifetime of the
  catalysts.
• Addition of alkali promoters increase the higher
  alcohol production in the order of LiltNaltKltCsgtRb
• Helps to suppress the formation of HC
• Catlayst doping with a small amount of alkali
  usually increases the reaction rate.
• F-T synthesis catalyst and MoS2-based catalyst
• - optimum alkali loading of 10 wt and 20 wt
  respectively to achieve a max selectivity for
  EtOH and HA.

7
MoS2-based catalyst- Pos. compared to other
catalysts

• Sulphur resistant
• Less severe coke deposition
• - even with a syngas having a low H2/CO ratio
• Favours the formation of linear alcohols with a
  high selectivity to EtOH
• Less sensitive to CO2 in the syngas stream
  compared to other alcohol synthesis catalysts
• Requires a sulphur content (H2S) of 50-100ppm

8
MoS2-based catalyst

• Without alkali-doping primarily CH4 in product.
• With alkali-doping the selectivity will be
  shifted toward alcohols.
• Ni promoted MoS2-based catalyst decreases the
  MeOH selectivity and increases the selectivity
  toward C2 higher alcohols, especially EtOH.
• - HC formation, due to Ni addition, could be
  suppressed by modifying the catalyst with La.

9
MoS2-based catalyst
10
Ecalene HAS process
11
Direct synthesis of syngas to EtOH and HA

• 2CO(g) 4H2(g) gt CH3CH2OH(g) H2O(g)
• Water-gas shift reaction
• CO(g) H2O(g) gt CO2(g) H2(g)
• Side reactions, formation of
• - CH4
• - C2-C5 alkanes and olefins
• - ketones, aldehydes, esters and acetic acid
• Methanation reaction
• CO(g) 3H2(g) gt CH4(g) H2O(g)

12
BIOMASS Composition
  Composition () Composition () Composition () Composition () Composition ()
  C H N O Ash in dry subst
Forest Wood (Finnish) 52.0 6.2 0.41 41.4 1.33
Forest Wood (Swedish) 53.2 6.0 0.94 39.8 4.05
Chips 52.1 6.1 0.30 41.4 0.60
Peat 57.0 5.8 0.95 36.0 0.75
13
Gasifier

• Accept 3/16 particule size
• Fluidized Bed (10MW) Entrained
  Flow(100MW)

14
Cleaner

• Inorganic Cleaner
• Dust Cleaner
• Hydrosulfur Cleaner (Mo and Co Catalyst)

15
Fischer-Tropsch process
16
Fischer-Tropsch Catalyst
17
Fischer-Tropsch Catalyst
18
Fischer-Tropsch Catalyst

• High pressure, 573K and low reaction time

19
Fischer-Tropsch Catalyst

• Questions, What do we do with HC gas and MeOH?

20
(No Transcript)
21
Reactor Election

• Syngas to Alcohol ? highly exothermic
• reaction
• High Temperature
• Steam process generation
• Heat transfer limitations in catalyst ? Hotspots

CATALYST DEACTIVATION
22
Single Fixed Bed Reactor

• Simple design and easy to scale-up
• Heat transfer limitations
• Use of jacket with counter-current water
• steam production
• Importance of catalyst deactivation
• it has to be taken in account for the design

23
Two-Step Fixed Bed Reactor

• Due to thermodinamics and kinetics
• Low T favours methanol production
• High T favours C-C bonding (HA production)
• Use of fixed bed reactor with 2 steps
• Use of special catalysts
• Cu based catalyst for low T (325C)
• Zn-chromite catalyst for high T (405C)

24
(No Transcript)
25
Slurry Reactor

• Uses up to 50 wt catalyst dispersed in inert
  hydrocarbon oil
• Catalyst is pulverized in small particles
• Heat and mass transfer limitations minimized

26
Slurry Reactor

• Advantages
• Low heat and mass limitations
• Excellent heat removal ? Good T control
• Efficient conversion of heat into steam
• Lower abrasion compared to fluidized reactor
• Capability of mixing different catalysts
• Disadvantages
• Much longer residence time ? more consecutive
  reactions

27
Recirculating Unreacted Species

• After the reactor, the hot gas stream can be
  cooled down in a condenser
• Gas stream H2, CO, CO2, CH4
• Liquid stream MeOH, EtOH, HA, water, byproducts
• Gas stream ? different options
• Combustion electricity or steam process
• Recirculation to the reactor or the digester

28
Recirculating Unreacted Species

• Liquid stream
• Simple distillation to separate methanol
• MeOH intermediate specie for HA production
• can be recycled to the reactor to increase
• alcohol yield
• Complete conversion of MeOH into EtOH
• after 7-8 cycles in the FT reactor

29
Alcohol Separation

• Liquid stream
• Contains EtOH, HA, water and byproducts
• We want a fuel ? water has to be separated
• Problem azeotrope bewteen EtOH and water
• difficulties for distillation
• Availability of different techniques
• Azeotropic distillation, solvent extraction,
  molecular sieve, membrane technology, etc.

30
Questions?