The document discusses the production of levulinic acid (LA) from biomass, emphasizing its advantages over conventional methods such as higher efficiency and lower costs. Experimental results reveal optimal conditions for LA yield from fructose, including a reaction time of 30 minutes, temperature of 140 °C, and pH of 0.5, with microwave reactors demonstrating superior performance compared to batch reactors. Key findings indicate that fructose yields the highest LA, while glucose and cellulose are less effective due to additional processing challenges.

1. I N T E R N AT I O N A L CO N F E R E N C E O N E N G I N E E R I N G T E C H N O LO G I E S
( N O V E M B E R 1 7 - 1 9 , 2 0 2 2 KO N YA / T U R K E Y )
1
Levulinic acid production by catalytic decomposition of fructose,
glucose and cellulose
Chingiz NASIRLI1
, Nihal CENGİZ1*
, Levent BALLİCE1
1
Ege University, İZMİR/Turkey nasirli93@hotmail.com
1
Ege University, İZMİR/Turkey nihal.cengiz@ege.edu.tr
1
Ege University, İZMİR/Turkey levent.ballice@ege.edu.tr

2. 2
PRODUCTION OF VALUABLE CHEMICALS FROM BIOMASS
Simplified reaction scheme for the conversion of lignocellulosic biomass

3. Levulinic Acid
 Levulinic acid (LA) is an important chemical produced from bio-
based resources.
 Levulinic acid (LA) was listed among one of the top value-added
chemicals by the U.S. Department of Energy and has also been
identified as a promising sustainable material for the synthesis of
other important chemicals.
3

4.  Levulinic acid (LA) has several important applications. Levulinic esters (LE),
which is obtained through esterification of LA is applicable as oxygenated fuel.
4

5. Production methods of LA
• Conventional
• Bio-based
5

6. Conventional Production
In this process; LA manufatured from maleic anhydride or
furfuryl alcohol. It has some disadvantages such as:
 Low production efficiency
 High amount of raw material requirement
 Complexity of production process
 Production cost
6

7.  Bio-based Production,
 Raw material is biomass and process is easier in comparing to
conventional one.
 It has high production efficiency and yield, low equipment and
production cost.
 Disadvatage is the separation and purification of the product
stream.
7

8.  Bio-based Production,
 Raw material is biomass and process is easier in comparing to
conventional one.
 It has high production efficiency and yield, low equipment and
production cost.
 Disadvatage is the separation and purification of the product
stream.
8

9. 3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 9
The conversion of Jerusalem artichoke to LA and by-products

10. Subcritical water
 Water represents a promising reaction medium for the decomposition of
biomass.
 Biomass that contains large fractions of water may be directly utilized
without energy-intensive pretreatment and converted into fuel
precursors and platform chemicals.
1 0

11. Subcritical water
 Subcritical Water is water
that is held by pressure at a
temperature higher than its
natural boiling point of 100°C
(this could be anything up to
its critical temperature of
374°C).
1 1

12. EXPERIMENTAL SET-UP
1 2

13. Experimental procedure
1st step
Desired amount of
biomass sample and
solvent were placed
into autoclave.
4th step
After reaching the set
temperature value, held
at this temperature for
2h.
2nd step
The inside of the
reactor was swept by an
inert gas stream
(nitrogen) to remove
air.
5th (final) steps
At the end of the experiment, the reactor was cooled
to ambient temperature in a short period of time.
Suspended particles in liquid solution is separeted
helping by a filter.
3rd step
The reactor was placed into
the heater
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 1 3

14. EVALUATION OF THE
RESULTS
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 1 4

15. Investigated parameters;
 The substrate type, reaction temperautre and time,
pH level of the homogeneous acid catalyst, type of
the reactor system
 Type and concentration of the catalyst, type of the
feedstock and the process specifications change
the optimum temperature to reach maximum
yields
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 1 5

16. Effect of reaction time on product concentration with 1.54 g of fructose and 20 mL of
water at reaction temperature of 180°C with H2
SO4
at pH of 0.5 in batch reactor system.
Feed Fructose
Reaction time (min) 10 20 30 40
LA yield
(%mol)
42.9 43.0 41.4 38.7
LA
(g/kg fructose)
276 277 267 249
Formic acid
(g/kg fructose)
83 81 74 81
Acetic acid
(g/kg fructose)
- - - -
5-HMF
(g/kg fructose)
- - - -
TOC (mg/L) 4710 4687 4635 4652
The highest yield was obtained at duration of
20 min with the feedstock of fructose at 180
°C of reaction temperature and was added
H2SO4 as catalyst.
In accordance with the literature,
decomposition was almost completed within
the first 30 min.
The yield of LA reached at the end of the 30
min was 41.4 % mole, after it started to
decrease. This shows that the produced LA
was decomposed to other by-products.

17. Effect of reaction temperature on product concentration with 1.54 g of fructose and 20
mL of water at reaction time of 30 min with H2SO4 at pH of 0.5 in batch reactor system.
Feed Fructose
Temperature (°C) 120 140 160 180
LA yield
(%mol)
42.2 47.0 42.8 41.4
LA
(g/kg fructose)
272 303 276 267
Formic acid
(g/kg fructose)
104 121 99 74
Acetic acid
(g/kg fructose)
- - - -
5-HMF
(g/kg fructose)
1.95 0.65 - -
TOC (mg/L) 4640 4772 4640 4635
The highest yields for LA was 47 % mole at
140 °C and the amount of FA was also the
highest at this temperature.
HMF was determined as very low at lower
temperatures and above 140 °C, it was not
detected.
These results suggest that a higher
temperature favors LA formation. The
reaction temperature may be milder
relative to the required temperature with
acidic catalysts.

18. Effect of pH on product concentration with 1.54 g of fructose and 20 mL of water at
reaction time of 30 min and temperature of 140 °C with H2SO4 at difererent acidity levels
of the reaction medium.
Feed Fructose
pH 0.5 1 1.5
LA (g/kg
fructose)
303 242 62
LA yield (%mol) 47 38 10
Formic Acid
(g/kg fructose) 121 106 41
Acetic Acid
(g/kg fructose) - - 7
5-HMF (g/kg
fructose)
0.65 9.22 183
TOC (mg/L) 4772 4635 4737
The increment in the yield of LA is dramatic
between at pH 1.5 and pH 1.0, that is almost
28 %. HMF amount is 183 g/kg fructose,
while LA is only 62 g/kg fructose.
Elevated pH levels favors HMF formation
stable and HMF does not converted to LA.
In this study, the most effective parameter
was found as acid catalyst concentration in
fructose decomposition. Catalysts have a
very important effect on the formation HMF
and LA from glucose/fructose.

19. 1 9
Feed Fructose Glucose Cellulose
LA yield (%mol) 47 22 20
LA
(g/kg model
compound)
303 143 131
Formic Acid
(g/kg model
compound)
121 67 60
Acetic Acid
(g/kg model
compound)
- - -
5-HMF
(g/kg model
compound)
1 13 9
TOC (mg/L) 4772 4885 4930
Effect of model compound type on LA yield and TOC of aqueous product with 1.54 g
of fructose and 20 mL of water, H2SO4 at pH of 0.5 at reaction time of 30 min and
temperature of 140 °C with in batch reactor system
Eq.1
• Fructose converted to HMF through a dehydration
reaction results in a higher yield of HMF.
Rehdydration reaction of HMF in the presence of
acid catalyst produce equimolar LA and FA.
• The yield of LA from fructose is significantly higher
than the yields with glucose and cellulose.
• The amount of the produced FA is also lower from
glucose and cellulose like LA, while HMF amounts
are very low for all substrates. HMF degradation is
very fast comparing to LA decomposition to other
byproducts.

20. 3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 2 0
Effect of model compound type on LA yield and TOC of aqueous product with 0.6 g of model
compound and 3 mL of water at reaction time of 30 min and temperature of 140 °C with H2SO4
at pH of 0.5 in in microwave reactor system.
Feed Fructose Glucose Cellulose
LA
(g/kg model
compound)
341 108 91
LA yield
(%mol)
53 17 14
Formic Acid
(g/kg model
compound)
161 64 54
Acetic Acid
(g/kg model
compound)
- - -
5-HMF
(g/kg model
compound)
2 10 9
TOC (mg/L) 16335 17262 17658
The main differences of the autoclave batch
reactors and microwave reactors are the fast
heating and cooling, homogeneous heat
distribution and efficient control of
heating/cooling.
The reaction efficiency and the product yield is
higher in microwave reactor. LA yield obtained
with fructose as substrate is 47 % mole in batch
reactor system while 53 % in microwave reactor.
Efficient heating provides energy saving and
reduces the cost. MW reactors has
advantageous of fast cooling while in batch
autoclaves it takes a long time to cool down to
room temperature that is necessary for and the
discharging and cleaning steps of the
experiment.

21. Figure 2. Effect of model compound type on product
concentration with 1.54 g of fructose and 20 mL of
water at reaction time of 30 min and temperature of 140
°C with H2SO4 at pH of 0.5 in microwave reactor
system.
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 2 1
Fructose Glucose Cellulose
0
50
100
150
200
250
300
350
400
450 LA
Formic Acid
5-HMF
Type of the model compound
Product
concentration
[g/kg
model
compound]
Fructose Glucose Cellulose
0
100
200
300
400
500
600
LA
Formic Acid
5-HMF
Type of the model compound
Product
concentration
[g/kg
model
compound]
Figure 1. Effect of model compound type on product
concentration with 1.54 g of fructose and 20 mL of water
at reaction time of 30 min and temperature of 140 °C
with H2SO4 at pH of 0.5 in batch reactor system.
Batch versus Microwave reactor system

22. CONCLUSIONS
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 2 2

23.  The highest yields of LA and HMF were reached with fructose as
substrate, while yields are significantly lower when cellulose and glucose
are used as substrate. Main reason of this is the hydrolysis of cellulose
and isomerization reaction of glucose to fructose requires additional
effort and the conditions should be appropriate.
 Hydrolysis step includes the cleavage of the β-1,4-glycosidic bonds of
cellulose and isomerization of fructose/ glucose is needed for higher
HMF production.
 The most appropriate reaction conditions are determined as 30 min, 140
°C, pH = 0.5, with H2SO4 as catalyst and fructose as substrate. Highest
LA yield is obtained as 53 % mole in MW reactor at these conditions.
3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 2 3

24. 3 / 1 / 2 0 X X S A M PL E F O OT E R T E X T 2 4
 Higher temperature and lower pH levels enhances LA formation
while the longer reaction time does not promote LA yields. As
reaction proceeds fructose was polymerized to soluble byproducts
and therefore yield of desired products has decreased.
 In the case of 5-HMF production is desired to maximize, higher pH
should be preferred at mild reaction conditions.
 Microwave reactor is more effective than the autoclave reactor
due to higher yields of LA, easy control of the heating and cooling
system, short reaction time, minimized side products, etc.