5-7 OCTOBERISFR2011

101

TOLEDO (SPAIN)

FUEL PRODUCTION BY RAPID HYDROPYROLYSIS OF POLYMERIC MATERIALS
H. Yasuda1, T. Kamo1, O. Yamada1, M. Kaiho1, K. Kawasaki2 and H. Nakagome2
1 National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, JAPAN 305-8569
2 Graduate School & Faculty of Engineering, Chiba University, Chiba, JAPAN 263-8522

e-mail:yasuda-hajime@aist.go.jp

Abstract
Rapid pyrolysis and rapid hydropyrolysis are used as parts of hydrogasification. Hydrogasification has been developed toproduce methane (SNG) directly from coal. Reaction conditions of hydrogasification are at around 1000K and 7MPa,expected products are methane and BTX. Only coal had been thought to use for hydrogasification process, co-feed ofwaste plastics with coal was considered to diversify feedstock. We had studied the hydrogasification of polyethylene (PE)and coal/PE mixture. Hydrogasification of coal/PE mixture was carried out and the methane yield was compared to theyield from hydrogasification of coal and PE respectively. In conclusion, the synergistic effect on methane yield was foundby sample mixing. The mixing effect of coal/PP was similar to that in coal/PE mixture. Rapid hydropyrolysis of biomass tar
and epoxy oligomers' model compounds was also carried out. Difference in the mixing effect which depended on thesamples was discussed. The mixing effect was found by using some mixture of the model compounds, but was not foundfor some other mixtures. The effect was smaller than that of the coal/PE mixture.

Keywords: rapid hydropyrolysis, coal, plastics, biomass, mixture

1. Introduction
In the study of co-hydrogasification of coal/plastic mixture,
we had found the synergistic effect for the increase inmethane production [1]. The effect was investigated byvarious conditions of experimental research. Rapid
pyrolysis and rapid hydropyrolysis of polymeric materials
and their model compounds were carried out. In thispaper, several R&D work for fuel production weredescribed, the experimental results were discussed andwere summarized. Difference in the synergistic effect
was found among the several mixture systems containing
each two components and the factor of the effect wasdiscussed.

2. Co-hydrogasification of coal/plastics
Hydrogasification has been developed to produce
methane (SNG) directly from coal. Hydrogasification
reaction mainly consists of rapid pyrolysis and rapidhydropyrolysis which is reaction with hydrogen. Methane
is a main component of natural gas. Demand for natural
gas is increasing because of its high environmental
acceptability. There are a couple of ways to produce
SNG, one is a direct method such as hydrogasificationand the other is an indirect method through synthesis ofCO/H2 produced by gasification. Theoretical energy
efficiency for direct method is higher than that for indirect
method.
Only coal had been thought to use for hydrogasification
process, co-feed of waste plastics with coal wasconsidered to diversify feedstock in Japan. We hadstudied the hydrogasification of polyethylene (PE) andcoal/PE mixture [1]. Hydrogasification of coal/PE mixture

interiores libro.indd 101

was carried out and the methane yield was compared tothe yield from hydrogasification of coal and PE
respectively. Reaction conditions of hydrogasification
were at around 1073K and 7MPa. The value wascalculated from the results obtained from coal and PE,
respectively, to estimate the methane yield from themixture assumes no mutual influence. The experimental
result of methane yield from the mixture was obviously
greater than the value calculated, especially for the short
reaction time of 2–3s. It suggests that a significant
synergistic effect was present in co-hydrogasification ofcoal/PE. Enthalpy generated by hydrogasification of PE
is larger than the heat required to compensate for theendothermic process caused by the pyrolysis of coal.
Enhanced reactions caused by the exothermic process
may result in the synergistic effect. In recent study, it wassuggest that not only coal reaction but also PE reaction
seemed to be enhanced [2]. Polypropylene was alsoused as sample for co-hydrogasification. As a result, themixing effect in coal/PP for methane production was
similar to that in coal/PE mixture. Moreover, positiveeffect for increase in methane production was also foundin the hydrogen partial pressure of 0.9MPa. Therefore,
the synergistic effect was observed in coal/plastics cohydrogasification for several kinds of plastics and forwide range of hydrogen pressure.

3. Production of Fuel from wood biomass
waste containing synthetic polymer
A new process, consistent with the several processcomponents, had proposed to produce a fuel from wood
wastes mixed with synthetic polymer materials such as

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6th International Symposium on Feedstock Recycling of Polymeric Materials

plastics or adhesives [3]. The process components are
as follows:
Pyrolysis - Wood wastes mixed with synthetic polymers
pyrolyzed and degradated to lower molecular weight
products at mild conditions.
Hydrogen production - The solid residue produced fromthe pyrolysis reactor is converted to hydrogen undercoexistence of water and the sodium compound.
Cracking/reforming - The liquid heavy compounds, tar,produced from the pyrolysis reactor is cracked andreformed by hydrogen to light hydrocarbons. The lighthydrocarbons would mainly be methane, ethane, andbenzene. Elements such as nitrogen and chlorine could
be separated as valuable materials such as ammonia
and hydrogen chlorides.
In the cracking/reforming process component, rapidhydropyrolysis is adopted and raw materials are mixturesof various sorts of hydrocarbons. For rapidhydropyrolysis of such mixtures, similar effect to synergy
in co-hydrogasification of coal/plastics was thought to beexpected. Model compounds, paraffin, naphthalene andphenol as biomass tar were used to examine the mixing
effect [4]. As a result, the increase in product yield on
reaction with mixing were observed for phenol/paraffin
mixture even the change was smaller than that in cohydrogasification of coal/plastics. For the mixture ofphenol/naphthalene, the mixing effect was negative. The
reason why the mixing effect is to be occurred seems
that exothermic reaction promotes endothermic reaction
in a short time.

4. Rapid pyrolysis of oligomers' modelcompounds from resin and biomass tar
To recover useful materials from glass-fiber composite
epoxy boards, such as those found in end-of-lifeelectronic equipment, we have proposed a new processthat involves liquefying the epoxy resin under mild
conditions using heavy tar derived from pyrolysis ofwoody biomass [5]. In this process, liquefied and partiallypyrolyzed epoxy resin oligomers along with the heavy tar
are reformed to lighter materials. These lighter materials
can then be used as the circulation solvent for theproposed process or as feedstock for fuel or chemicals.
As a experimental study, we reformed model compounds
in a pressurized hydrogen atmosphere. The mixture ofphenol and bisphenol-A was used. As a result, theexperimental methane yield from the mixture was smaller
than the calculated yield [6, 7]. These phenomena aredifferent than those observed for hydropyrolysis of a
mixture of phenol/paraffin (section 3) and forhydrogasification of a mixture of coal/plastics (section 2)[1, 4]. These studies suggested that the enthalpy fromparaffin or PE hydrogenation, which is an exothermic
reaction, promoted the endothermic reaction of phenol orcoal, respectively. Form the deviations in temperatureduring rapid hydropyrolysis of phenol, bisphenol-A, andtheir mixture, an endothermic reaction dominated for all
samples in the early stage of the reaction. Therefore, it
seems consistent that the methane yield from the mixture

interiores libro.indd 102of phenol and bisphenol-A was not increased by mixing,
but rather decreased as a result of this endothermic
process.

5. Conclusions
Rapid pyrolysis and rapid hydropyrolysis of coal, plastics,
biomass tar and epoxy oligomers' model compounds
were carried out. Useful fuel could be produced fromvarious kind of polymeric materials by rapid pyrolysis andrapid hydropyrolysis. Difference in the mixing effectwhich depended on the samples was discussed. The
synergistic mixing effect was found by using somemixture, but was not found for some other mixtures. The
synergistic effect for methane production by cohydrogasification of mixture was present when theenthalpy generated by rapid hydropyrolysis of one
component is larger than the heat required by thepyrolysis of the other component. The effect may not bepresented or be negative when the both components ofthe mixture show similar phenomena of endothermic
pyrolysis processes.

References[1] H. Yasuda, O. Yamada, A. Zhang, K. Nakano, and M.
Kaiho. Hydrogasification of coal and polyethylene mixture.
Fuel 83 (2004), 2251-2254.
[2] K. Kawasaki, H. Yasuda, S. Sajima, O. Yamada, M.
Kaiho and H. Nakagome. In: Proc. Int. Symp. onFeedstock Recycling of Polymeric Materials, Toledo,Spain, 5-7 October 2011.
[3] H. Yasuda, T. Kamo, and H. Nakagome. In: Proc. Int.
Symp. on Feedstock Recycling of Plastics and Other
Innovative Techniques, pp. 137-144, Jeju, Korea, 23-27
September 2007.
[4] H. Yasuda, S. Sajima, T. Kamo, and H. Nakagome.
In: Proc. 10th Japan-China Symp. on Coal and C1
Chemistry, P-19, Tsukubak, Japan, 26-29 July 2009.
[5] T. Kamo, Y. Liu, N. Akaishi, M. Adachi, and H.
Yasuda. In: Proc. Int. Symp. on Feedstock andMechanical Recycling of Polymeric Materials, pp. 186192, Chengdu, China, 11-14 October 2009.
[6] H. Yasuda,T. Kamo,M. Adachi, S. Sajima, and H.
Nakagome. In: Proc. Int. Symp. on Feedstock andMechanical Recycling of Polymeric Materials, pp. 199204, Chengdu, China, 11-14 October 2009.
[7] H. Yasuda,T. Kamo,M. Adachi, S. Sajima, and H.
Nakagome. Rapid hydropyrolysis of model compounds
for epoxy resin oligomers and biomass tar. J MaterCycles Waste Manag 12 (2010), 123-127.

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