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Article ; Online: CFD simulation of CVD reactors in the CH3SiCl3(MTS)/H2 system using a two-step MTS decomposition and one-step SiC growth models

Tatsuya Ogawa / Kazui Fukumoto / Hiroshi Machida / Koyo Norinaga

Heliyon, Vol 9, Iss 4, Pp e15061- (2023)

2023

Abstract: In this study, we report on a computational fluid dynamics (CFD) simulation of the chemical vapor deposition reactor of silicon carbide (SiC) in the methyltrichlorosilane (MTS, CH3SiCl3)/H2 system. The formation of SiC thin film is controlled by various ... ...

Abstract	In this study, we report on a computational fluid dynamics (CFD) simulation of the chemical vapor deposition reactor of silicon carbide (SiC) in the methyltrichlorosilane (MTS, CH3SiCl3)/H2 system. The formation of SiC thin film is controlled by various process parameters, such as temperature and pressure. In this study, we propose a reaction mechanism of MTS decomposition to SiC growth on a substrate surface for CVD reactors in the CH3SiCl3(MTS)/H2 system. The reaction mechanism has two gas-phase pyrolysis reactions and one SiC film formation reaction. However, we individually build and validate MTS decomposition and SiC growth models to reduce uncertainty. An in-house version of reactingFoam, a reactive flow solver within OpenFOAM v2006, was used as the simulation tool. Our model accurately reproduced MTS decomposition for T = 1100–1350 K and [H2]/[MTS] = 2.65–14 at p = 101,325 Pa. Then, the MTS decomposition model was coupled with the SiC growth model, and the coupled model was applied to the SiC deposition data. The model could reproduce multiple datasets through validation studies.
Keywords	CVD ; MTS ; SiC ; CFD ; OpenFOAM ; Science (General) ; Q1-390 ; Social sciences (General) ; H1-99
Subject code	660
Language	English
Publishing date	2023-04-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Effects of HZSM-5 on volatile products obtained from the fast pyrolysis of lignin and model compounds

Yang, Huamei / Haijun Wang / Ji Li / Koyo Norinaga / Wenyou Zhu

Fuel processing technology. 2018 Dec. 01, v. 181

2018

Abstract: 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 ... ...

Abstract	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.
Keywords	aromatic hydrocarbons ; carbon monoxide ; catalytic activity ; catechol ; gas chromatography ; gases ; guaiacol ; lignin ; models ; phenol ; pyrolysis
Language	English
Dates of publication	2018-1201
Size	p. 207-214.
Publishing place	Elsevier B.V.
Document type	Article
ZDB-ID	1483666-x
ISSN	0378-3820
ISSN	0378-3820
DOI	10.1016/j.fuproc.2018.09.022
Database	NAL-Catalogue (AGRICOLA)

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Article: Experimental investigation of thermal decomposition of dihydroxybenzene isomers: Catechol, hydroquinone, and resorcinol

Yang, Huamei / Jun-ichiro Hayashi / Koyo Norinaga / Shinji Kudo / Yuki Furutani

Journal of analytical and applied pyrolysis. 2016 July, v. 120

2016

Abstract: In this study, dihydroxybenzene isomers such as catechol, resorcinol, and hydroquinone were used as models of volatiles from solid fuels to better elucidate the mechanism of the thermochemical conversion of solid fuels. These isomers were pyrolyzed in a ... ...

Abstract	In this study, dihydroxybenzene isomers such as catechol, resorcinol, and hydroquinone were used as models of volatiles from solid fuels to better elucidate the mechanism of the thermochemical conversion of solid fuels. These isomers were pyrolyzed in a two-stage tubular reactor with a residence time up to 3.6s and temperature ranging from 650 to 950Â°C. In total, 51 products were identified by online gas chromatography. The product distribution from the pyrolysis of the three isomers was quite different. p-Benzoquinone was the primary product obtained from the pyrolysis of hydroquinone, while o-benzoquinone and m-benzoquinone were not detected from the pyrolysis of catechol and resorcinol, respectively. CO was the major final product formed from catechol, resorcinol, and hydroquinone, with maximum yields of 27.3wt%, 19.4wt%, and 20.0wt%, respectively, whereas CO2 (15.5wt%) generated from resorcinol was significantly higher than those generated from hydroquinone (1.0wt%) and catechol (0.8wt%) at 950Â°C and 0.3s. Considering the mass selectivity of C1âC5 light hydrocarbons, the possible reaction pathways leading to CO and CO2 were analyzed to describe the pyrolysis of catechol, resorcinol, and hydroquinone. Catechol mainly afforded CO and C4 hydrocarbons by H-migration and ring-opening reactions. Hydroquinone mainly generated CO, C2, and C4 hydrocarbons, with the initial step being the formation of p-benzoquinone. During the pyrolysis of resorcinol, competition reactions occurred for the formation of CO and CO2 with the production of C1âC5 hydrocarbons at a nearly equal mass selectivity. Compared with catechol and hydroquinone, resorcinol produced significantly more C5 hydrocarbons, which suggested the intramolecular combination of aldehyde radical and ketone radical for explaining the large amount of CO2 formed from the pyrolysis of resorcinol.
Keywords	aldehydes ; benzoquinones ; carbon dioxide ; carbon dioxide production ; carbon monoxide ; catechol ; fuels ; gas chromatography ; hydrocarbons ; hydroquinone ; isomers ; models ; pyrolysis ; resorcinol ; temperature
Language	English
Dates of publication	2016-07
Size	p. 321-329.
Publishing place	Elsevier B.V.
Document type	Article
ISSN	0165-2370
DOI	10.1016/j.jaap.2016.05.019
Database	NAL-Catalogue (AGRICOLA)

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Article: Characteristic Properties of Lignite To Be Converted to High-Strength Coke by Hot Briquetting and Carbonization

Kudo, Shinji / Aska Mori / Gentaro Hayashi / Jun-ichiro Hayashi / Koyo Norinaga / Noriyuki Okuyama / Takuya Yoshida

Energy & fuels. 2017 Nov. 15, v. 32, no. 4

2017

Abstract: 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 ... ...

Abstract	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.
Keywords	carbon ; carbonization ; chemical structure ; elemental composition ; equations ; feedstocks ; lignite ; nuclear magnetic resonance spectroscopy ; prediction ; shrinkage ; stable isotopes ; tensile strength
Language	English
Dates of publication	2017-1115
Size	p. 4364-4371.
Publishing place	American Chemical Society
Document type	Article
ZDB-ID	1483539-3
ISSN	1520-5029 ; 0887-0624
ISSN (online)	1520-5029
ISSN	0887-0624
DOI	10.1021/acs.energyfuels.7b03155
Database	NAL-Catalogue (AGRICOLA)

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Article: CO2 Gasification of Sugar Cane Bagasse: Quantitative Understanding of Kinetics and Catalytic Roles of Inherent Metallic Species

Zahara, Zayda Faizah / Arief Budiman / Daniyanto / Jun-ichiro Hayashi / Koyo Norinaga / Shinji Kudo / U. P. M. Ashik

Energy & fuels. 2017 Nov. 29, v. 32, no. 4

2017

Abstract: A total of 18 chars from the pyrolysis of six trios of sugar cane bagasses (SCBs; original, water-washed, and acid-washed) were gasified with CO2 at 900 °C, aiming at a quantitative description of the rate of gasification catalyzed by inherent metallic ... ...

Abstract	A total of 18 chars from the pyrolysis of six trios of sugar cane bagasses (SCBs; original, water-washed, and acid-washed) were gasified with CO2 at 900 °C, aiming at a quantitative description of the rate of gasification catalyzed by inherent metallic species and a correlation of the catalytic activity and its change during the gasification with the metallic species composition. The measured kinetics was described quantitatively over a range of char conversion, 0–0.999, by a model that assumed progress in parallel of the catalytic gasification and non-catalytic gasification, together with the presence of a catalytic precursor and three to four types of catalysts having different activities and deactivation characteristics. A series of regression analyses was scrutinized and reached expression of initial catalytic activity as a linear function of Na, K, Ca, Fe, and Si concentrations in the char with a correlation factor (r2) of >0.98. The catalyst precursor contributed fully by water-soluble Na, K, and Ca. Si was responsible for the catalyst deactivation during the pyrolysis but not during the gasification. The chars produced from original SCBs followed a linear relationship between the initial catalytic deactivation rate and initial activity (r2 > 0.99), while such a linear relationship was not valid for those formed from the water-washed SCBs. This was explained mainly by more rapid deactivation of the Fe catalyst in the chars from water-washed SCBs than that in the chars formed from the original SCBs. Na and K in char from the original SCBs, originating from the water-soluble SCBs, chemically interacted with the Fe catalyst, slowing its deactivation.
Keywords	calcium ; carbon dioxide ; catalysts ; catalytic activity ; fuels ; gasification ; iron ; models ; potassium ; pyrolysis ; regression analysis ; silicon ; sodium ; species diversity ; sugarcane bagasse ; water solubility
Language	English
Dates of publication	2017-1129
Size	p. 4255-4268.
Publishing place	American Chemical Society
Document type	Article
ZDB-ID	1483539-3
ISSN	1520-5029 ; 0887-0624
ISSN (online)	1520-5029
ISSN	0887-0624
DOI	10.1021/acs.energyfuels.7b03147
Database	NAL-Catalogue (AGRICOLA)

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Article: In-situ reforming of the volatiles from fast pyrolysis of ligno-cellulosic biomass over zeolite catalysts for aromatic compound production

Uemura, Kazuhiro / Hisahiro Einaga / Jun-ichiro Hayashi / Koyo Norinaga / Shinji Kudo / Srinivas Appari

Fuel Processing Technology. 2015 Aug., v. 136

2015

Abstract: Characteristics of in-situ catalytic reforming of the products derived from fast pyrolysis of biomass were studied with an originally designed analytical pyrolysis technique. The volatile products derived from ligno-cellulosic biomass as well as ... ...

Abstract	Characteristics of in-situ catalytic reforming of the products derived from fast pyrolysis of biomass were studied with an originally designed analytical pyrolysis technique. The volatile products derived from ligno-cellulosic biomass as well as cellulose, xylan, and lignin were converted using a two-stage tubular reactor at 550Â°C over various zeolite catalysts with different acidities and pore structures. HZSM-5 exhibited the best performance for converting the cedar derived volatiles to arenes, which mainly composed of benzene, toluene, and naphthalene with a selectivity of 26% on carbon basis. The HZSM-5 had a little effect in increasing the yields of the arenes for xylan and lignin, while it had a significant effect for cellulose, showing that more than 30% of carbon in cellulose was converted into arenes. A reaction pathway analysis for reforming of volatiles suggested that alkyne and diene such as acetylene, propyne, and cyclopentadiene are the important precursors of the major aromatic hydrocarbon products such as benzene, toluene, and naphthalene. The formations of those intermediates were also confirmed experimentally in an early stage of the in-situ reforming.
Keywords	acetylene ; benzene ; biomass ; carbon ; catalysts ; cellulose ; lignin ; naphthalene ; pyrolysis ; toluene ; xylan ; zeolites
Language	English
Dates of publication	2015-08
Size	p. 73-78.
Publishing place	Elsevier B.V.
Document type	Article
ZDB-ID	1483666-x
ISSN	0378-3820
ISSN	0378-3820
DOI	10.1016/j.fuproc.2014.10.002
Database	NAL-Catalogue (AGRICOLA)

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Article ; Online: Sulfonate Ionic Liquid as a Stable and Active Catalyst for Levoglucosenone Production from Saccharides via Catalytic Pyrolysis

Jun-ichiro Hayashi / Zhenwei Zhou / Koyo Norinaga / Kento Yamasaki / Shinji Kudo

Catalysts, Vol 3, Iss 4, Pp 757-

2013 Volume 773

Abstract: In this study, various types of ionic liquids (ILs) were examined for catalytic activity in the pyrolysis of cellulose for the production of levoglucosenone, which is a valuable and versatile compound for the synthesis of a variety of novel compounds. ... ...

Abstract	In this study, various types of ionic liquids (ILs) were examined for catalytic activity in the pyrolysis of cellulose for the production of levoglucosenone, which is a valuable and versatile compound for the synthesis of a variety of novel compounds. Cellulose was simply mixed with the ILs and subjected for the pyrolysis, typically at 300 °C, to produce volatile products, including levoglucosenone, separated from the ILs phase. The type of IL anion significantly affected the catalysis, and the use of ILs bearing sulfonate anion resulted in distinguished yields of levoglucosenone and IL recoveries for the reutilization. Detailed thermogravimetric analysis and discussion on properties of ILs revealed the active and thermally stable nature of the sulfonate ILs. Catalytic pyrolysis with those ILs was applied to the conversion of other saccharides composed of glucose molecules, resulting in a preferential formation of levoglucosenone but at low yields as compared to that from cellulose.
Keywords	ionic liquid ; cellulose ; pyrolysis ; catalysis ; levoglucosenone ; Chemical technology ; TP1-1185 ; Chemistry ; QD1-999
Subject code	660
Language	English
Publishing date	2013-09-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article: Kinetic modeling of non-catalytic partial oxidation of nascent volatiles derived from fast pyrolysis of woody biomass with detailed chemistry

Thimthong, Narumon / Jun-ichiro Hayashi / Keita Iwanaga / Koyo Norinaga / Ryota Tanaka / Shinji Kudo / Srinivas Appari / Tetsuya Shoji

Fuel Processing Technology. 2015 June, v. 134

2015

Abstract: The gas-phase partial oxidation (POx) of nascent volatiles (NV) derived from the fast pyrolysis of cedar sawdust at 700 and 800Â°C was studied both numerically and experimentally. A detailed chemical kinetic model (DCKM) was applied to simulate the POx ... ...

Abstract	The gas-phase partial oxidation (POx) of nascent volatiles (NV) derived from the fast pyrolysis of cedar sawdust at 700 and 800Â°C was studied both numerically and experimentally. A detailed chemical kinetic model (DCKM) was applied to simulate the POx in a two-stage reactor: the first stage was designed for fast biomass pyrolysis and the second effected the POx of the NV. Analytical pyrolysis experiments were also conducted to approximate the molecular composition of the NV, which is required input for computations using DCKM. The DCKM was modified by an empirical kinetic model for the decomposition of an ill-defined portion of the NV. The kinetic model coupled with a plug-flow reactor model reproduced the observed trends in the product yields with respect to both temperature and oxygen-to-fuel ratio, for not only the major products, but also minor products such as aromatic hydrocarbons which are typically found in the refractory post-gasification tar.
Keywords	aromatic hydrocarbons ; biomass ; gases ; kinetics ; models ; oxidation ; pyrolysis ; sawdust ; temperature
Language	English
Dates of publication	2015-06
Size	p. 159-167.
Publishing place	Elsevier B.V.
Document type	Article
ZDB-ID	1483666-x
ISSN	0378-3820
ISSN	0378-3820
DOI	10.1016/j.fuproc.2015.01.029
Database	NAL-Catalogue (AGRICOLA)

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Article: An approach for on-line analysis of multi-component volatiles from coal pyrolysis with Li+-attachment ionization mass spectrometry

Zhang, Lu / Jun-ichiro Hayashi / Kazuhiro Uemura / Keita Iwanaga / Kenji Furuya / Koyo Norinaga / Li-Xin Zhang / Shi-Chao Qi / Shinji Kudo

Fuel processing technology. 2017 Apr., v. 158

2017

Abstract: Ion-attachment mass spectrometry (IAMS) is a technique used for measuring easily ionized organic compounds in a non-fragmenting mode by softly attaching a Li+ or another type of alkaline ion to the gaseous molecule. In this study, a prototype device for ... ...

Abstract	Ion-attachment mass spectrometry (IAMS) is a technique used for measuring easily ionized organic compounds in a non-fragmenting mode by softly attaching a Li+ or another type of alkaline ion to the gaseous molecule. In this study, a prototype device for Li+ IAMS is developed for real-time quantitative monitoring of the vapor produced from thermochemical conversion of coal. Simulated tar vapor containing a suite of aromatics and the real vapor produced from the pyrolysis of coal are monitored by IAMS with a Li+ source. It is confirmed that both the simulated and real vapors are ionized without undergoing fragmentation and the sensitivities of these detected aromatic molecules are similar to one another. In addition, when the feeding rate of the coal sample is changed from 0.5 to 1.0g/min, the peak intensities increase nearly twice as much. These results show the possibility of applying IAMS to the quantitatively monitoring of coal-derived volatiles.
Keywords	aromatic compounds ; coal ; ionization ; mass spectrometry ; monitoring ; pyrolysis ; vapors
Language	English
Dates of publication	2017-04
Size	p. 141-145.
Publishing place	Elsevier B.V.
Document type	Article
ZDB-ID	1483666-x
ISSN	0378-3820
ISSN	0378-3820
DOI	10.1016/j.fuproc.2016.12.001
Database	NAL-Catalogue (AGRICOLA)

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Article: Modeling of gas/particle flow in coal conversion with a drop tube reactor using a lumped kinetic model accounting volatilesâchar interaction

Li, Cheng-Yi / An-Ni Huang / Hsiu-Po Kuo / Jun-ichiro Hayashi / Koyo Norinaga / Li-Xin Zhang / Shinji Kudo / Srinivas Appari

Fuel Processing Technology. 2015 Oct., v. 138

2015

Abstract: Coal conversion including reforming of nascent tar over the char surface in a drop tube reactor (DTR) was studied both experimentally and numerically. Victorian brown coal and char prepared from the same coal were co-fed into an atmospheric DTR. The ... ...

Abstract	Coal conversion including reforming of nascent tar over the char surface in a drop tube reactor (DTR) was studied both experimentally and numerically. Victorian brown coal and char prepared from the same coal were co-fed into an atmospheric DTR. The effects of reaction temperature (973â1173K), solid hold-up (8.31Ã10â6â2.50Ã10â4), residence time (0â4.6s for gas; 0â0.78s for solid particles), and steam partial pressure (0â0.05MPa) on the conversion characteristics were investigated. A 4-lump kinetic model consisting of tar, gases, char, and soot with 6 global reactions was developed based on the experimental results. The lumped kinetic model was integrated with a computational fluid dynamics (CFD) simulation using an EulerianâEulerian approach for mixed phase flow to simulate the coal conversion experiments in the DTR. The CFD results for product distribution during coal conversion in the DTR showed reasonable agreement with the experimental results. The CFD approach presented is suitable for use in designing and optimizing a pyrolyzer for a triple-bed combined circulating fluidized-bed coal gasifier, consisting of a downer (pyrolyzer), a bubbling fluidized bed (gasifier), and a riser (combustor).
Keywords	coal ; fluid mechanics ; fluidized beds ; gases ; kinetics ; models ; soot ; temperature
Language	English
Dates of publication	2015-10
Size	p. 588-594.
Publishing place	Elsevier B.V.
Document type	Article
ZDB-ID	1483666-x
ISSN	0378-3820
ISSN	0378-3820
DOI	10.1016/j.fuproc.2015.06.043
Database	NAL-Catalogue (AGRICOLA)

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