Bio-oil Synthesis from Organic Wastes P. R. Christensen1, A. J. Mørup1, M. Glasius1, B. B. Iversen1

1Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus C

Conclusion » ZrO2 has no catalytic effect

in HTL of biomass.

» The reactor wall has a neg-lible catalytic effect in HTL of biomass.

Elemental CompositionZrO2 does not affect the CHNOS content or the heating value.

The reactor wall does not affect the CHNOS content or the heating value.

Figure 3: CHNOS elemental analysis and higher heat-ing value (HHV) of DDGS and bio-oil samples.

15

20

25

30

35

40

0

20

40

60

80

DDGS K2CO3GoldZrO2

K2CO3Gold

K2CO3ZrO2

K2CO3

Hig

her H

ea

ting V

alue

[MJ/kg

]

Ele

me

nta

l Co

nte

nt [w

t%]

Process Parameters

C

H

N

O

S

HHV

21.2 22.2 23.3 23.8

1.8 2.2 2.6 2.5

0

5

10

15

20

25

30

K2CO3GoldZrO2

K2CO3Gold

K2CO3ZrO2

K2CO3

Yie

ld [

wt%

]

Process Parameters

Oil yield Solid residue

Oil yieldNo effect on oil yield or solid residue from ZrO2.

Negligible effect from reactor material on oil yield and solid residue.

Figure 2: The oil and solid residue yield.

Ash & Char contentCombustion of bio-oil produces higher amounts of ash and char when com-pared to North Sea oil. The higher char content in K2CO3+ZrO2 arises from change in the chemical com-position.

Figure 4: The char and ash content of the bio-oil.

0

4

8

12

16

20

NorthSea oil

K2CO3GoldZrO2

K2CO3Gold

K2CO3ZrO2

K2CO3

Cha

r co

nte

nt [

wt%

]

Process Parameter

Char content

Ash Content

0

0.04

0.08

0.12

0.16

0.20

Ash co

ntent [w

t%]

ExperimentalThe bio-oil was synthesized using a stop-flow reactor.

Interference effects from the steel-based reactor material avoided by using a 24 carat gold liner and catalyst bed.

Figure 1: (a) Unsealed reactor with gold liner and catalyst bed inserted. (b) Side-view of the gold liner. (c) Gold catalyst bed containing m-ZrO2 pellets.

DDGS biomass

a b

c

Sample Phenols

(%)

Ketones

(%)

Nitrogenated aliphatics

(%)

Nitrogenated aromatics

(%)

Aliphatics

(%)

Fatty acids

(%)

Other

(%)

Total

(%)K2CO3 5.9 7.2 22.7 11.0 4.2 20.4 2.6 74.1

K2CO3+ ZrO2 9.3 8.6 23.2 8.7 1.1 8.7 10.2 69.8K2CO3+ Gold 4.8 9.0 26.1 10.0 4.8 18.7 3.4 76.8

K2CO3+ Gold + ZrO2 5.8 5.0 26.8 15.7 5.6 17.8 4.1 80.8

Chemical CompositionThe bio-oil mainly consists of long chained nitrogenated aliphatics and fatty acids.

The K2CO3 + ZrO2 bio-oil has a higher phe-nol content and a lower aliphatic content. This is suggested to cause the higher char content observed for this bio-oil.

No effect on the chemical composition from the reactor wall is observed (Table 1).

Table 1. Chemical composition of bio-oil. Values are given in percentages of the total peak area.

Biomass slurry HTL Product

20 wt% DDGS2 wt% K2CO3

78 wt% H2OHTL Process

IntroductionHydrothermal Liquefaction (HTL): » 2. genration biofuel process. » Converts wet biomass into bio-oil. » Operates at 300-400°C and 200-

300 bar. » Water is used as reaction medium.

AIM: Investigate the catalytic effect of a nanocrystalline ZrO2 catalyst and the reactor material in HTL.