GAS PRODUCTION BY STEAM GASIFICATION OF POLYPROPYLENE/BIOMASSWASTE COMPOSITES IN A DUAL-BED REACTOR
Md. Azhar Uddin*1, Taichi Watanabe1, Yoshiei Kato1,Elena Parparita2, Cornelia Vasile2, Jale Yanik3
1 Department of Energy and Materials, Okayama University, Okayama, Japan.
2 Petru Poni Institute of Macro Molecular Chemistry, Iasi, Romania.
3 Department Of Chemistry, EGE University, Izmir, Turkey

e-mail: alazhar@cc.okayama-u.ac.jp; phone & fax: +81-86-251-8897

Abstract
Polypropylene/biomass waste composites were tested by steam gasification in a dual-bed microreactor in a two-stage
process for the production of fuel gases. Gasification experiments were carried out at different gasification temperatures, inabsence and presence of Fe2O3/CeO2 catalysts. The gases produced during the process were mainly H2, CO, CO2, CH4 andsome higher hydrocarbons.
Keywords: polypropylene, biomass composites, gasification.

1. Introduction
Many developed countries are dealing with serious
sustainability problems, especially concerning energy
needs and waste handling. Plastic wastes are of great
importance due to the increase of their production inrecent years and waste plastics are also valuable sourceof materials and energy when utilized properly. Biomass
has lately attracted considerable attention as a source ofclean fuel and energy. Gasification is a technology forconverting carbonaceous materials such as coal,biomass, and waste plastics into gaseous fuel. Studies
on co-gasification of plastic with other materials like coalor biomass have been reported that the gaseous
products with high hydrogen content can be obtained bysteam gasification [1]. However, the gasification
efficiency depends on the operating conditions, reactor
types and the use of reaction promoting materials suchas catalysts. The goal of this work is to study the steam
gasification of polypropylene/biomass wastes composites
in a dual bed reactor in presence and absence of catalyst
in order to investigate the effectiveness of catalyst in theproduction of fuel gases.

2. Materials and Methods
The biomass and plastics samples studied in this work
were Brassica rapa (BR), Eucalyptus globulus (EG),Energy grass (EnG), Pine cones (PC) and polypropylene(PP). The composites containing polypropylene (PP) 70wt % and biomass 30 wt % were obtained by melt
blending at 175 °C in the chamber of a Brabender mixer.
The steam gasification experiments of the samples werecarried out in a dual bed quartz reactor with top bed
temperature at 200-850 °C (programmed: 3 °C/min) andthe bottom bed temperature at 700 °C. In a typical run,
0.04g of sample was placed in the top section on aquartz wool bed and the desired amount (0.065ml) of
10% Fe2O3/90%CeO2 catalyst was placed on the bottomquartz wool bed. Gasification experiments were carriedout in absence and presence of catalyst at 700 °C and750 °C. Fig. 1 shows the scheme of the steam
gasification experiment.

N2watervaporizer
Inlet gas: 30% H2O-N2(20cc/min)
Sample bed: 200? ? 850? (3? /min)Catalyst bed: setting constant temp.
Samplingbags

GC II

Samplebed.

p850?
me
T

Furnace200?

FurnaceTime.

pme
T

Catalyst bed
TimeGC I
Ice trap

Fig.1 Diagram of steam gasification set up

3. Results and discussion
Figure 1 and 2 shows the amount of gases produced
during steam gasification of PP, BR, EG, EnG, PC,PP/BR, PP/EG, PP/EnG and PP/PC composites at700°C in the bottom bed temperature without catalysts(a) and with catalyst (b). During steam gasification of thePP and biomass samples, CO, CO2, C1-C4 hydro carbons
and hydrogen were produced as gaseous products.
Degradation of PP produces mainly H2, CH4 and C2-C4,
while the biomass BR, EG, EnG and PC produces mainly
H2, CO and CO2. The use of 10% Fe2O3/90%CeO2

7th International Symposium on Feedstock Recycling of Polymeric Materials (7th ISFR 2013)
New Delhi, India, 23-26 October 2013catalyst in the steam gasification of biomass, plastics andbiomass/plastic composites resulted in the increase inproduction of gaseous products indicating that thecatalyst accelerated the gasification rate. Particularly theproduction of H2 and CO2 increased significantly which
could be attributed to the effect of catalyst in water gas
shift reaction of CO (CO + H2O  H2 + CO2).
70

H2el 60pm
asg50/cc,s 40
ag
fo
tsn30
uo
20m
alato10T

COCH4CO2C2-C470
H2lep60m
as50/gcc,s 40
ag
fo
tn30
uomal 20atoT10COCH4CO2C2-C40Fig. 2 Effect of catalyst on the production of gaseous
products at 700 °C for the steam gasification of biomass
and biomass/PP composites

0Fig. 1 Thermal steam gasification of PP, biomass andPP/biomass composites

Moreover, the synergistic effect of combining plastics
with biomass was also observed since the amount of H2
production increased in the case of PP/biomass
composites compared to the added contribution ofproduction of H2 from the individual components (Table1). This synergistic effect may be resulted from theinteraction of the degradation products of the plastics andbiomass gasification.

Table 1. Synergistic effect of biomass and PP gasification at 700°C
Amount of gas production (cc)
PP/BR

PP/EG

PP/EnG

PP/PC

Calc.aExp.b

Calc.aExp.b

Calc.aExp.b

Calc.aExp.b

49.53

5.16

42.94
4.63

44.59

5.09

43.65
4.81

52.59

5.59

40.07
5.01

41

CO

43.59
4.65

5.63

CH4

5.78

7.86

5.83

8.95

5.67

6.25

5.70

4.99

CO2

16.52

16.82

15.67

12.50

16.28

14.31

17.17

12.9

10.58
13.44
12.49
12.74
12.8
12.76
12.70
a Calculated by adding the contribution of gasification products of individual components.
b Obtained from co-gasification of PP/biomass composites.

11.94

H2C2-C4References
1. F. Pinto, C. Franco, R. N. André, M. Miranda,
I. Gulyurtlu and I. Cabrita. Fuel 81 (2002) 291-297.

7th International Symposium on Feedstock Recycling of Polymeric Materials (7th ISFR 2013)
New Delhi, India, 23-26 October 2013