acetone-butanol-ethanol (abe) production from cassava … wan.pdf · acetone-butanol-ethanol (abe)...
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Acetone-butanol-ethanol (ABE) Production from
Cassava by a Fermentation-pervaporation Coupled
Process
Yinhua Wan
Institute of Process Engineering
Chinese Academy of Sciences
Email:[email protected]
Pacific Rim Summit on Industrial Biotechnology and Bioenergy
December 7-9, 2014, San Diego, California
Butyl aldehyde,
Butanic acid
Butyl acrylate
(solvent)
Dibutyl phthalate
Aliphatic dibutyl diester
(Plasticizer)
Butadiene
Butyl acetate
(solvent)
Butyl amine
Butanol — An Important Platform Chemicals
Butanol
Polybutadiene rubber,
Styrene-Butadiene rubber
In 2007, annual consumption
> 400,000 tons in China
In 2007, annual consumption
>1,300,000 tons in China
In 2007, annual consumption
> 900,000 tons in China
In 2007, annual consumption
> 800,000 tons in China
Butanol — A Promising Biofuel with Huge Market
Gasoline Butanol
Ethanol
MethanolCalorific
value
Btu/gallon
11
4,0
00
11
0,0
00
84
,00
0
64
,00
0
Octane
number 96
94
92
91
weak hydrophility, low corrosion, easy to pipe
mixing with gasoline at random proportion
oxygen content similar to MTBE
Butanol-fuelled car driving 10,000 miles,
DOE, 2005
Gasoline Butanol Ethanol Methanol
Bottleneck in Industrial Fermentation—
Products Toxicity and Inhibition
Low productivity
Titer: normally <20 g/L
Volume productivity:
~0.35 g/Lh
High energy consumption
Steam: 13 tons/ton ABE
Large amount of wastewater
50 tons wasterwater / ton ABE
Comparison of in-situ Product Recovery Technologies
Stripping Adsorption Extraction Pervaporation
Capacity Moderate Low High Moderate
Selectivity Low Low High Moderate
Fouling Low High Moderate Low
Energy required
（MJ/kg ABE）21 33 14 9
Operational simplicity High Low Low High
Groot et al., Process
Biochemistry 27 (1992) 61-75
Engineering Strategy : Developing Fermentation-in
situ Separation Coupled Process
PV module
Condenser
Water bath
Storage tank
Pump
Vacuum
pump
Permeate
Schematic of fermentation-pervaporation process
Fermentor
Advantages: Key techniques:
Fermentation-pervaporation Coupled Process
Low product inhibition High fermentation productivity Low separation energy consumption Low wastewater production
Development of PV membrane with high performance
Optimization of the coupled process
Module development & fouling control
Pervaporation membrane materials
Example
Polymeric materialsPDMS (α=30-45)、PTMSP(α=52-75)
Inorganic materials Silicalite-1 (α=80-125)
Hybrid materialsSilicalite-1 filled PDMS (α= 50-111)
Membrane Materials and Membrane Performance
Problem
Silicalite flocculation in membrane
Decreasing the membrane selectivity
Decreasing the membrane strength when
the silicalite loading was over 60%.
Our solution
Modify the outer surface of the silicalite to
improve the affinity between silicalite and polymer matrix
Problem and Solution in Preparation of Hybrid
Membrane
Conventional hybrid PV membrane
New hybrid PV membrane
+ —Si—CH=CH2 silicalite
OH
OHOH
HO
HO
HO
OH
OH
OCH2CH3
OCH2CH3
CH3CH2O
1. Hydrolysis of the ethoxy groups
2. Condensation
a. with the silanol groups of silicalite
b. between adjacent silane molecules
silicalite
O
OH
O
O
O
O
O
OH
Si
O
CH
OCH2CH3
CH2
Si
OCH2CH3
CH CH2CH3CH2O
Si
OCH2CH3
OCH2CH3
CH2 CH
Si
OCH2CH3
CHH3CH2CO
CH2
Si
H3CH2CO
OCH2CH3
CH2 CH
Si
OCH2CH3
CH CH2CH3CH2O
Si
OCH2CH3
H3CH2CO
CH2 CH
Unmodified silicalite-1 VTES(vinyltriethoxysilane)
Silane modified silicalite-1
Surface Modification of Silicalite-1 Particles
Contact angles:
38.1°(unmodified)
143.7°(modified)
Cross-linking Reaction of PDMS and Modified Silicalite-1
silicalite
O
OH
O
O
O
O
O
OH
Si
O
CH
OCH2CH3
CH2
Si
OCH2CH3
CH CH2CH3CH2O
Si
OCH2CH3
OCH2CH3
CH2 CH
Si
OCH2CH3
CHH3CH2CO
CH2
Si
H3CH2CO
OCH2CH3
CH2 CH
Si
OCH2CH3
CH CH2CH3CH2O
Si
OCH2CH3
H3CH2CO
CH2 CH
+ +
Prepolymer(RTV615A) Crosslinker (RTV615B)
Silane-modified silicalite-1
Si
O
CH3
H3C
Si
CH3
H3CO
SiCH3
n
CH2
CH2
HC
H3C
Si O
CH3
CH3
Si
CH3
CH3
O Si
CH3m
CH2
CH3
Si O
CH3
CH3
silicalite
O
OHO
O
O
O
O
OH
Si
O
CH
OCH2CH3
CH2
Si
H3CH2CO CH2
CH3CH2O
Si
OCH2CH3
OCH2CH3
CH2 CH
Si
OCH2CH3
H2C
H3CH2COSi
H3CH2CO
OCH2CH3
CH2
Si
OCH2CH3
H2CCH3CH2O
Si
OCH2CH3
H3CH2CO
CH2
Si
OH3C
CH3
Si
CH3
H3CO
Si
CH3
CH2
CH2
CH2
CH
CH3
Si O
CH3
CH3
Si
CH3
CH3
O Si
CH3m
CH3
CH2
Si O
CH3
CH3
CH2 Si O
CH3
CH3
Si
CH3
CH3
O Si
CH3
CH2
CH3
Si O
CH3
CH3
H3C Si O
CH3
CH3
Si
CH3
CH3
O Si
CH3m
CH3
CH2
Si O
H2C
CH3
Si O
CH3
CH3
Si
CH3
CH3
OSi
CH3
CH2CH2 CH
H3C
Si
O
CH3H3C
Si CH3H3C
O
Si CH3
CH2
CH2
CH
H3C
Si
O
CH3
H3C
SiCH3
H3CO
Si CH3
H2C
CH2
CH
H3C
CH3 Si O
CH3
CH3
Si
CH3
CH3
O Si
CH3
CH3
CH2
Si O
H2C
CH3
CH2Pt-catalyst
Crosslinked polymer network
0 2 4 6 8 10 120
200
400
600
800
Flu
x (
g/m
2.h
)
Butanol concentration (g/L)
butanol flux
water flux
total flux
y=16.84x
R2=0.999
2 4 6 8 10 120
10
20
30
40
50
Sep
ara
tio
n f
acto
r
Butanol concentration (g/L)
Butanol separation factor
0
100
200
300
400
500
Bu
tan
ol
con
cen
trati
on
in
per
mea
te (
g/L
)
Butanol concentration in permeate
Effect of butanol concentration on flux and separation factor using butanol/water
model solutions at 37℃. (a) flux and (b) separation factor.
a b
Evaluation of Silicalite-1 PDMS/PAN Composite
PV Membrane
Membrane module Fermentation-Pervaporation System
Experimental Setup for the Coupled Process
CharacteristicsStrains
ATCC 824 DP 217
Fermentation time (h) 72 60
Acetone (g/L) 3.04±0.18 3.74±0.01
Butanol (g/L) 5.67±0.05 9.53±0.03
Ethanol (g/L) 0.55±0.14 2.33±0.18
Total solvent (g/L) 9.26±0.35 15.60±0.24
Batch ABE Fermentation from Cassava by C.
Acetobutylicum ATCC 824 and DP217
Inhibition of Butanol
7 g/L-13 g/L Butanol results
in a 50 % inhibition of growth.
S. Y. Lee, J. H. Park, S. H.
Jang, et al, Biotechnol.
Bioeng., 101(2008)209 – 228
Effect of butanol on ABE production by C.
acetobutylicum
The butanol inhibition
concentration: >5g/L
0 2 4 6 8 10
8
9
10
11
12
13
14
15
Butanol added concentration /g/L
AB
E c
on
ce
ntr
atio
n in
ferm
en
tatio
n /
g/L
(a) OD620, glucose concentrations and pH, (b) solvent and acid concentrations.
ABE Batch Culture with Optimized Medium
Medium: 70 g/L cassava power + 2.17 g/L CSP + 0.01 g/L FeSO4•7H2O
Initial pH: 6.81
The culture produced 20.14 g/L total solvent
Acid concentration was above 1 g/L
ABE Production in Batch Fermentations using
Cassava with PV
PV operation started at the 16th hour when butanol concentration was 4.3 g/L
More ABE was produced (21.78 g/L ABE, i.e., 7.36 g/L acetone + 12.95 g/L
butanol + 1.47 g/L ethanol)
Acid concentration was less than 1.0 g/L
Higher productivity, higher yield, shorter fermentation time (42 h)
Performance of the Membrane in Batch
Fermentation-PV Coupled Process
The performance of the membrane was very stable in terms of the
flux and separation factor
Continuous ABE Production by Fermentations-
PV Coupled Process
□Glucose; ■ Total solvent concentration; ▲ Acetone; ▼ Ethanol; ● Butanol;
▶ Acetic acid; ◀ Butyric acid
Glucose: 20-30 g/L
ABE: ~ 7.5 g/L
Butanol: ~ 4.5 g/L
Acetone: ~1.8 g/L
Ethanol: ~ 1.2 g/L
Permeate Concentration in Continuous ABE
Fermentations-PV Coupled Process
■ Total solvent ▲ Acetone; ▼ Ethanol; ● Butanolb
Membrane Performance in Continuous ABE
Production by the Coupled Process
■ Total flux; Separation factor for △ Acetone ▽ Ethanol and ○ Butanol
Average flux:
557 g/m2•h
Separation factor:
39.4 for acetone
31.2 for butanol
8.4 for ethanol
Process
Solvent Glucose
utilization rate
(g/Lh)Productivity
(g/Lh)
Yield
(g/g)
Batch-PV 0.49 0.35 1.26
Continuous
Coupling0.76 0.38 2.02
Batch 0.42 0.33 1.00
Summary of Solvent Production by Fermentation
with and without Pervaporation
In ABE fermentation from cassava, it is technically feasible
to eliminate the product inhibition by the fermentation-
pervaporation coupled process. ABE could be effectively
concentrated in the permeate.
With the coupled process, the ABE yield could be increased,
therefore, substrate can be utilized more efficiently.
Developing PV membranes with higher selectivity and
higher flux and optimizing the integrated process would
further promote the economic and technical feasibility of the
process.
Summary
Acknowledgements
Dr Jing Li
Associate Professor Xiangrong Chen
Associate Professor Yi Su
Associate Professor Benkun Qi
National Natural Science Foundation of China
(Grant No. 21176239)
National High-Tech R & D Program (Grant No.
2012AA03A607)
Thank You !