研究者詳細 - 則永　行庸

Effects of HZSM-5 on volatile products obtained from the fast pyrolysis of lignin and model compounds 査読有り

Yang, HM; Norinaga, K; Li, J; Zhu, WY; Wang, HJ

FUEL PROCESSING TECHNOLOGY 181 巻頁： 207 - 214 2018年12月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel Processing Technology

This study aimed to experimentally investigate the effect of HZSM-5 on the distribution of volatile products, especially carbon monoxide (CO), C1–C5 hydrocarbons and aromatic hydrocarbons (AHs) during catalytic pyrolysis of lignin and lignin model compounds. Catechol was pyrolyzed using a two-stage tubular reactor (TS-TR) connected to a gas chromatography system over HZSM-5 at 550–950 °C. Forty-three products, including four inorganic gases, twenty C1–C5 hydrocarbons, and nine AHs were quantified using three GC-columns. Results indicated that HZSM-5 accelerated the catechol conversion with a large amount of CO and AHs produced. C1–C5 hydrocarbons were formed during non-catalytic pyrolysis of model compounds, and consumed quickly during HZSM-5 catalytic pyrolysis of catechol. Catalytic pyrolysis of phenol, guaiacol and syringol was carried out at 650 °C in the TS-TR over HZSM-5. HZSM-5 obviously promoted the conversion of lignin model compounds, and largely increased the yield of volatile products especially CO and AHs. Three lignin samples were also catalytically pyrolyzed over HZSM-5 in the TS-TR at 650 °C. HZSM-5 increased the yield of C2-C3 hydrocarbons and AHs, and reduced the yield of oxygenated compounds. HZSM-5 could promote the formation of AHs (lower than 10 wt%) during lignin pyrolysis, but not as obviously as during model compounds pyrolysis (higher than 19 wt%). High yields of char and tar would account for the low catalytic efficiency of HZSM-5 during lignin pyrolysis.

DOI： 10.1016/j.fuproc.2018.09.022

Prediction of hot coke oven gas reforming by LES coupled with the extended flamelet/progress variable approach 査読有り

Yu P., Norinaga K., Watanabe H., Kitagawa T.

Fuel 231 巻頁： 234 - 243 2018年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Fuel

Large-eddy simulation (LES) coupled with the extended flamelet/progress variable approach (EFPV) has been performed to predict characteristics of reacting flows in a bench-scale hot coke oven gas (HCOG) reformer. In order to investigate the capability of capturing effects of operating conditions, simulations were carried out in two different cases in which the coke oven gas temperature and oxygen ratio were altered. Results showed that the LES coupled with the EFPV performed very well in terms of predicting temperature distribution as well as the temperature variation trend between the two cases. In addition, major species such as H2, CO, CO2, H2O and CH4, as well as minor species like benzene and some typical polycyclic aromatic hydrocarbons (PAH) were analyzed to illustrate their activities and dominant chemical events. With regards to the composition of the dry reformed gas, comparisons were made between the experimental data and the numerical simulation results, and reasonable results have been obtained. It has been confirmed that the general feature of the reacting flows in the HCOG reformer can be precisely captured by the present LES.

DOI： 10.1016/j.fuel.2018.05.104

Characteristic Properties of Lignite to Be Converted to High-Strength Coke by Hot Briquetting and Carbonization 査読有り

Kudo S., Mori A., Hayashi G., Yoshida T., Okuyama N., Norinaga K., Hayashi J.I.

Energy and Fuels 32 巻 ( 4 ) 頁： 4364 - 4371 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Energy and Fuels

A sequence of hot briquetting and carbonization (HBC) is a promising technology for the production of coke with a high mechanical strength from lignite, but factors affecting the coke strength have not yet been fully understood. The HBC cokes prepared from 12 lignites in this study showed diverse tensile strength (e.g., from 0.2 to 31.2 MPa in the preparation at 200 °C and 112 MPa for hot briquetting and 1000 °C for carbonization), and the coke strengths could not be explained by differences in commonly used structural properties of the parent lignites, such as elemental composition and contents of volatile matter/fixed carbon and ash. In this study, two methods were proposed for correlating the coke strength with the lignite properties, which employed the chemical structure analyzed by solid-state 13C nuclear magnetic resonance or the volumetric shrinkage during carbonization. A stronger coke was obtained from lignite that contained more aliphatic carbons (less aromatic carbons) or shrank more considerably. These characteristics contributed to intensified compaction of lignite in the briquetting and suppression of the formation of large pores, which are a cause of coke fracture. Two empirical equations, predicting the coke strength from the parameters of lignite properties, were established to be criteria for selection of lignite as HBC coke feedstock, although further investigation with more experimental data would be necessary for the validation.

DOI： 10.1021/acs.energyfuels.7b03155

Computational Study on the Thermal Decomposition of Phenol-Type Monolignols 査読有り

Furutani Y., Dohara Y., Kudo S., Hayashi J.I., Norinaga K.

International Journal of Chemical Kinetics 50 巻 ( 4 ) 頁： 304 - 316 2018年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Journal of Chemical Kinetics

A detailed chemical kinetic model has been developed to theoretically predict the pyrolysis behavior of phenol-type monolignol compounds (1-(4-hydroxyphenyl)prop-2-en-1-one, HPP; p-coumaryl alcohol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, HHPP; 1-(4-hydroxyphenyl)propane-1,3-diol, HPPD) released from the primary heterogeneous pyrolysis of lignin. The possible thermal decomposition pathways involving unimolecular decomposition, H-addition, and H-abstraction by H and CH3 radicals were investigated by comparing the activation energies calculated at the M06–2X/6–311++G(d,p) level of theory. The results indicated that all phenol-type monolignol compounds convert to phenol by side-chain cleavage. p-Coumaryl alcohol decomposes into phenol via the formation of 4-vinylphenol, whereas HPP, HHPP, and HPPD decompose into phenol via the formation of 4-hydroxybenzaldehyde. The pyrolytic pathways focusing on the reactivity of the hydroxyl group in HPP and producing cyclopentadiene (cyc-C5H6) were also investigated. The transition state theory (TST) rate constants for all the proposed elementary reaction channels were calculated at the high-pressure limit in the temperature range of 300–1500 K. The kinetic analysis predicted the two favorable unimolecular decomposition pathways in HPP: the one is the dominant channel below 1000 K to produce cyc-C5H6, and the other is above 1000 K to yield phenol (C6H5OH).

DOI： 10.1002/kin.21164