PARTⅣ BIOMASS DEGRADATIONEFFECT OF PRESSURE OR HYDROGEN ON RAPIDPYROLYSIS OF OLIGOMERS' MODEL COMPOUNDSFROM RESIN AND BIOMASS TARHajime Yasuda*,1 Tohru Kamo,1 Mariko Adachi, 2Satoshi Sajima, 2 Hideki Nakagome2
1National Institute of Advanced Industrial Science andTechnology (AIST), Tsukuba 305-8569, Japan.
2Graduate School & Faculty of Engineering, Chiba University,
Chiba 263-8522, Japan.
E-mail: yasuda-hajime@aist.go.jp
Abstract: Effect of reaction conditions such as hydrogen partial pressure on rapidhydropyrolysis of oligomers’ model compounds was discussed. Supposed oligomers werepartially pyrolyzed epoxy resin with biomass tar as solvent for the resin. Bisphenol-A andphenol were mainly used as model compounds in this study. Major products were benzene,
methane, and phenol by rapid pyrolysis of Bisphenol-A at 973K and 1073K. Toluene wasrelatively minor products. More phenol produced at 973K than at 1073K. Yield of methane,
which is final product by hydropyrolysis, increased with partial pressure of hydrogen. On theother hand, benzene and phenol was estimated to be behaved intermediate products.
1. IntroductionIn order to recover the useful materials from glass fiber composite epoxy board such as
end-of-life electronic equipments, a new process with solubilizing the epoxy resin under amild condition by using the heavy tar derived from wood biomass was proposed [1]. In theprocess, solubilized and partially pyrolyzed epoxy resin with heavy biomass tar will assumed
to be then reformed to lighter materials, which will be used as the circulation solvent of theprocess or as feedstocks. In this study, model compounds for oligomers both from epoxy resinand from biomass tar were used. Experimental study of model compounds reforming wascarried out in hydrogen atmosphere. Product distributions of rapid hydropyrolysis were shown.
The effects of reaction temperature and hydrogen partial pressure on the product yield werediscussed.
2. Experimental
A unique batch reactor was used for rapid hydropyrolysis experiment which wasdescribed previously [2]. Briefly, the reactor was mainly composed of three parts, sample- 199 -The 5th ISFR (October 11-14, 2009, Chengdu, China)
feeder, reaction chamber and gas reservoir. Prior to reaction, the sample was loaded in thesample tube and was kept at room temperature. The reaction chamber filled with gas forreaction atmosphere under the condition where the reaction pressure was preheated to thereaction temperature and the sample tube was driven into preheated chamber just before thereaction started. The reaction was started with sample to be blown into the reaction chamberfrom the sample tube with a small amount of gas. The gas for blowing was same as reaction
atmosphere which set at a slightly higher pressure than that in the chamber. After a prescribedreaction time, the gas phase of the product was moved instantaneously to the gas reservoir
which was previously evacuated. Liquid phase products were captured by filter and werecorrected by washing or extracting with tetrahydrofuran (THF) as a THF solution. The
composition of the products was analyzed with GC-TCD, GC-FID and GC-MS. Reaction
experiment was carried out at 1073K, 973K under 0MPa (100% N2), 0.9Mpa (N2/H2 mixed
gas with ratio of 70:30 at total pressure of 3.0MPa), 3.0MPa (100% H2), 7.0MPa (100% H2)
of hydrogen partial pressure. The reaction time was 80 seconds. As for model compounds,bisphenol-A and phenol were mainly used. The amount of samples for each experiment was0.5g. Mixture of phenol and bisphenol-A was also used with the amount of 0.25g each.

3. Results and Discussion
3.1 Major Products from each model compound
Major products from both phenol and bisphenol-A by rapid hydropyrolysis experimentwere methane, benzene, and less amount of ethane. Significant amounts of phenol and toluene
were also produced depending on the reaction conditions. Product distribution as carbon
conversion of three major compounds, methane, benzene, and ethane, from phenol withvarying hydrogen partial pressure at 1073K is shown in Fig.1. C2Hx refers to C2 hydrocarbons
including ethane and ethylene, most of C2Hx was ethane. Benzene produced much in thelower hydrogen partial pressure, methane produced large amount in the higher partial pressure.
Methane increase linearly with partial pressure, benzene increase from 0.9MPa to 3.0MPa
following by decreasing to 7.0MPa with convex upward. It is assumed that phenol mainly
degraded to form benzene by deoxygenation in the lower partial pressure of hydrogen,methane was formed from benzene in the higher partial pressure. It is concluded that benzene
behaved as an intermediate product which would further convert to methane, as final
hydropyrolysis product, with more hydrogen. Product distribution of three major compounds
from bisphenol-A with varying hydrogen partial pressure at 1073K is shown in Fig. 2. Overall
trend of the change in product distribution with hydrogen partial pressure was similar to thatfrom phenol as shown in Fig.1. Yield of methane and benzene from bisphenol-A were almost
same level in the lower region of hydrogen partial pressure under 3.0MPa, which differedslightly to the case of phenol with larger amount of benzene production than methane.

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100Carbon conversion (%)

80
604020002468

Hydrogen partial pressure (MPa)Fig. 1 Carbon conversion to major products by rapid hydropyrolysis at 1073K from phenol.
●: CH4,■: C2Hx,▲: C6H63.2 Sample mixing effect on methane yield

Carbon conversion (%)

10080604020002468Hydrogen partial pressure (MPa)Fig. 2 Carbon conversion to major products by rapidhydropyrolysis at 1073K from bisphenol-A.
●: CH4,■: C2Hx,▲: C6H6

Carbon conversion (%)

10080604020002468Hydrogen partial pressure (MPa)Fig. 3 Carbon conversion to methane by rapid hydropy-rolysis at 1073K from phenol andbisphenol-A mixture. ●: mixture experiment, - - -: estimated- 201 -

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Carbon conversion to methane from mixture of phenol and bisphenol-A at 1073K areshown in Fig. 3. The values were calculated from the results obtained from phenol andbisphenol-A respectively to estimate the methane yield from the mixture, assuming no mutual
influences. The original data from them respectively have been plotted in Fig. 1 and 2. The
calculated values are shown with a broken line in Fig. 3. The plotted solid line was obtained
from experiment results of mixture. The methane yield from the mixture experiments seemed
to be smaller than the values calculated. These phenomena are different from the observationin the mixture of phenol and paraffin hydropyrolysis [3] and observation also in the mixtureof coal and polyethylene (PE) hydrogasifi-cation [4]. It was suggested that the enthalpy fromhydrogenation of paraffin or PE, which is exothermic reaction, enhanced the endothermic stepof reaction of phenol or coal. This implication of reaction mechanism was supported byobservation of tempera-ture profile inside the reaction chamber. Deviations of the temperatureduring rapid hydropyrolysis of phenol, bisphenol-A, and their mixture for the 80 seconds
period are shown in Fig. 4. For all samples, the temperature dropped at the beginning of thereaction. It took about 10 seconds for the temperature to come back to the initial stage. This
indicates that an endothermic reaction dominates for all samples in the early stage of thereaction. It seems consistent that the methane yield from the mixture of phenol andbisphenol-A was not increased by mixing, but rather decreased as a result.

Temperature change (K)100500-50-20

02040Reaction time (s)6080Fig. 4 Temperature change during rapid hydropyrolysis at1073K of phenol ( ), bisphenol-A ( ), and their mixture ( ).
●○●3.3 Selectivity of phenol as a product from bisphenol-AIn the proposed process, epoxy tar oligomers will assumed to be reformed to feedstocks.
Both phenol and toluene, which were produced from bisphenol-A as model compound ofepoxy tar depending on the reaction conditions, are valuable chemicals. Carbon conversion tophenol, as a product, and toluene from bisphenol-A at 1073K are shown in Fig. 5. Bothconversions to phenol and toluene seemed to have relative maximum with varying hydrogen- 202 -PARTⅣ BIOMASS DEGRADATION
partial pressure. Especially, phenol showed to have relative maximum clearly at 3.0MPa ofhydrogen partial pressure, but only less than 3%. Carbon conversion to phenol and toluene
from bisphenol-A at 973K are shown in Fig. 6. Both conversions showed to have relative
maximum at 0.9MPa. More phenol was produced at 973K than at 1073K, comparing the Fig.
5 and Fig.6. However, toluene was produced about the same level at 973K and at 1073K.
Phenol was one digit larger than toluene at 973K, which was about double as maximum ratioat 1073K. It means that there was selectivity to obtain phenol. The selectivity was higher at973K than at 1073K. As shown in Fig. 2, benzene performed as an intermediate product.
Phenol and toluene are also seems intermediate products and they may then convert tomethane through benzene. Although it was shown the highest yield of phenol frombisphenol-A at 973K and 0.9MPa in the conditions which were chosen, more phenol could beobtained in higher selectivity by optimizing the reaction conditions.

Carbon conversion (%)

2015105002468Hydrogen partial pressure (MPa)Fig. 5 Carbon conversion to products by rapid hydro-pyrolysis
at 1073K from bisphenol-A mixture. ◆: phenol, ■: toluene

Carbon conversion (%)

2015105002468

Hydrogen partial pressure (MPa)Fig. 6 Carbon conversion to products by rapid hydro-pyrolysis
at 973K from bisphenol-A mixture.◆: phenol, ■: toluene- 203 -

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4. Conclusions
Experimental study of model compounds rapid pyrolysis was carried out in hydrogen
atmosphere at 1073K and 973K. Phenol and bisphenol-A as model compounds for oligomers
both from epoxy resin and from biomass tar were used. Product distributions of rapidhydropyrolysis were shown. The effects of reaction temperature and hydrogen partial pressure
on the product yield were discussed. Major products were benzene, methane, and phenol from
Bisphenol-A. Toluene was relatively minor products. More phenol produced at 973K than at
1073K. Yield of methane, which is final product by hydropyrolysis, increased with partialpressure of hydrogen. On the other hand, benzene and phenol was estimated to be behaved
intermediate products. It was suggested that phenol could be obtained in high selectivity fromtar, by optimizing the reaction conditions.
References[1] T. Kamo, Y. Liu, N. Akaishi, M. Adachi, H. Yasuda Proc. the 5th ISFR, Chengdu, China
2009.
[2] H. Yasuda, T. Kamo, M. Kaiho, H. Nakagome Proc. the 4th ISFR, Jeju, Korea, 2007, 137.
[3] S. Sajima, H. Yasuda, T. Kamo, H. Nakagome Proc. the 5th ISFR, Chengdu, China, 2009.
[4] H. Yasuda, O. Yamada, A. Zhang, K. Nakano, M. Kaiho Fuel 2004, 83, 2251.

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