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1. Comprehensive characterization of hydrothermal liquefaction products obtained from woody biomass under various alkali catalyst concentrations

Author:
Choi, In-Gyu,   et al.   ; Hwang, Hyewon; Lee, Jae Hoon; Choi, Joon Weon;     Show all 4 Authors
Source:
Environmental technology 2019 v.40 no.13 pp. 1657-1667
ISSN:
1479-487X
Subject:
Larix; Quercus; biofuels; biomass; catalysts; catechol; heat; hot water treatment; hydrochars; hydrolysis; hydroquinone; hydrothermal liquefaction; lignin; lignocellulose; oils; organic carbon; potassium; potassium carbonate; quinones; solvents; water solubility
Abstract:
... Hydrothermal liquefaction (HTL) of lignocellulosic biomass has been widely investigated for the production of renewable and alternative bio-crude oil. In this study, catalytic hydrothermal processing of two biomasses (larch and Mongolian oak) was performed using different K₂CO₃ concentrations (0, 0.1, 0.5, 1.0 wt% of solvent) to improve fuel yield and properties. HTL oil, hydrochar, water-soluble ...
DOI:
10.1080/09593330.2018.1427799

2. Simultaneous production of glucose, furfural, and ethanol organosolv lignin for total utilization of high recalcitrant biomass by organosolv pretreatment

Author:
Choi, In-Gyu,   et al.   ; Choi, June-Ho; Jang, Soo-Kyeong; Kim, Jong-Hwa; Park, Se-Yeong; Kim, Jong-Chan; Jeong, Hanseob; Kim, Ho-Yong;     Show all 8 Authors
Source:
Renewable energy 2019 v.130 pp. 952-960
ISSN:
0960-1481
Subject:
biomass; biorefining; economics; ethanol; furfural; glucose; hydrolysates; lignin; lignocellulose; liquids; renewable energy sources; sulfuric acid
Abstract:
... The main purpose of this study was simultaneous production of glucose, ethanol organosolv lignin (EOL), and furfural for total utilization of lignocellulosic biomass to improve economics of biorefinery. The glucose production (37.1 g, under conditions of 160 °C with 1% sulfuric acid) was significantly increased after organosolv pretreatment, dissolving 11.4 g of the initial hemicellulose-derived s ...
DOI:
10.1016/j.renene.2018.05.052

3. Photodegradation of Natural Wood Veneer and Studies on Its Color Stabilization for Automotive Interior Materials

Author:
Choi, In-Gyu,   et al.   ; Park, Se-Yeong; Hong, Chang-Young; Kim, Seon-Hong; Choi, June-Ho; Kwon, Ohkyung; Lee, Hyo-Jin;     Show all 7 Authors
Source:
Journal of wood chemistry and technology 2018 v.38 no.4 pp. 301-312
ISSN:
1532-2319
Subject:
chemical treatment; color; hydrogen peroxide; lignin; photolysis; photostability; sodium hypochlorite; ultraviolet radiation; wood veneer
Abstract:
... The aim of this study was to investigate the color and chemical changes of natural wood veneers after ultraviolet (UV) exposure for automotive interior materials. To control the photodegradation, chemical treatments with hydrogen peroxide (H₂O₂) and sodium hypochlorite (NaClO) solution were applied to the veneer under different concentration conditions. The veneers treated with H₂O₂ showed strong ...
DOI:
10.1080/02773813.2018.1488872

4. Investigation of conditions for dilute acid pretreatment for improving xylose solubilization and glucose production by supercritical water hydrolysis from Quercus mongolica

Author:
Choi, In-Gyu,   et al.   ; Jang, Soo-Kyeong; Kim, Jong-Hwa; Jeong, Hanseob; Choi, June-Ho; Lee, Soo-Min;     Show all 6 Authors
Source:
Renewable energy 2018 v.117 pp. 150-156
ISSN:
0960-1481
Subject:
Quercus mongolica; autoclaves; corrosion; feedstocks; glucose; hydrolysis; liquids; renewable energy sources; response surface methodology; solubilization; sulfuric acid; xylose
Abstract:
... The objective of this study was to prepare a feedstock, which xylose should be highly solubilized and most of the glucose remained in the solid fraction, for supercritical water hydrolysis (SCWH). Response surface methodology (RSM) with two independent variables (reaction time and sulfuric acid concentration) was adopted to find suitable conditions for pretreatment using a simple apparatus an auto ...
DOI:
10.1016/j.renene.2017.10.015

5. Sequential solvent fractionation of lignin for selective production of monoaromatics by Ru catalyzed ethanolysis

Author:
Choi, In-Gyu,   et al.   ; Kim, Jae-Young; Park, Shin Young; Lee, Jae Hoon; Choi, Joon Weon;     Show all 5 Authors
Source:
RSC advances 2017 v.7 no.84 pp. 53117-53125
ISSN:
2046-2069
Subject:
acetone; depolymerization; dioxane; ethanol; ethanolysis; ethyl acetate; fractionation; lignin; methanol; molecular weight; phenols; solubility; solvents
Abstract:
... The purpose of this study was to investigate the impact of lignin structure, especially its average molecular weight (Mw) on the distribution of catalytically depolymerized products. Soda lignin (SL) was sequentially fractionated by organic solvents (ethyl acetate: F1, methanol: F2, acetone: F3, dioxane/water: F4, and insoluble fraction: F5). The Mw of SL, F1, F2, F3, and F4 were 2800, 1120, 2860, ...
DOI:
10.1039/c7ra11541e

6. Evaluation of hydrodeoxygenation reactivity of pyrolysis bio-oil with various Ni-based catalysts for improvement of fuel properties

Author:
Choi, In-Gyu,   et al.   ; Oh, Shinyoung; Choi, Hang Seok; Choi, Joon Weon;     Show all 4 Authors
Source:
RSC advances 2017 v.7 no.25 pp. 15116-15126
ISSN:
2046-2069
Subject:
acetic acid; acidity; carbon; catalysts; energy efficiency; furfural; hydrogen; liquids; nickel; oils; oxygen; porous media; pyrolysis oils; surface area; vanillin; viscosity; water content
Abstract:
... Three Ni-based catalysts were prepared for hydrodeoxygenation (HDO) of bio-oil with three different support materials (active carbon, SBA-15 and Al-SBA-15) and their catalytic effects were tested with crude bio-oil at 300 °C and under 3 MPa H₂ pressure for 60 min. After the HDO reaction, gas, liquid phase (light oil and heavy oil) and char were obtained as the primary products. Heavy oil was produ ...
DOI:
10.1039/c7ra01166k

7. Evaluation of correlation between glucan conversion and degree of delignification depending on pretreatment strategies using Jabon Merah

Author:
Choi, In-Gyu,   et al.   ; Jang, Soo-Kyeong; Jeong, Hanseob; Kim, Ho-Yong; Choi, June-Ho; Kim, Jong-Hwa; Koo, Bon-Wook;     Show all 7 Authors
Source:
Bioresource technology 2017 v.236 pp. 111-118
ISSN:
0960-8524
Subject:
acid treatment; cellulose; chemical composition; crystal structure; delignification; enzymatic hydrolysis; hemicellulose; hot water treatment; hydrolysates; lignin; peracetic acid
Abstract:
... The main purpose of this study was to investigate the glucan conversion rate after enzymatic hydrolysis depending on the treatment methods and conditions with changes in the chemical composition of treated solid fraction of Jabon Merah. The glucan conversion rate (17.4%) was not significantly improved after liquid hot water treatment (1st step) even though most of the hemicellulose was dissolved i ...
DOI:
10.1016/j.biortech.2017.03.154

8. Catalytic effects of magnesium on the characteristics of fast pyrolysis products – Bio-oil, bio-char, and non-condensed pyrolytic gas fractions

Author:
Choi, In-Gyu,   et al.   ; Hwang, Hyewon; Oh, Shinyoung; Choi, Joon Weon;     Show all 4 Authors
Source:
Journal of analytical and applied pyrolysis 2015 v.113 pp. 27-34
ISSN:
0165-2370
Subject:
Liriodendron tulipifera; aromatic hydrocarbons; biochar; biofuels; elemental composition; gas chromatography-mass spectrometry; magnesium; magnesium chloride; molecular weight; pyrolysis; viscosity; water content
Abstract:
... Fast pyrolysis of yellow poplar impregnated with different concentrations of MgCl2 was carried out at 450, 500, and 550°C to investigate the effects of magnesium on the characteristics of the pyrolytic products. Analysis of the physicochemical properties of bio-oil, bio-char, and non-condensed pyrolytic compounds was carried out accordingly. The results indicate that the yield of char as well as s ...
DOI:
10.1016/j.jaap.2014.09.028

9. Solvent effects on improvement of fuel properties during hydrodeoxygenation process of bio-oil in the presence of Pt/C

Author:
Choi, In-Gyu,   et al.   ; Oh, Shinyoung; Kim, Ung-Jin; Choi, Joon Weon;     Show all 4 Authors
Source:
Energy 2016 v.113 pp. 116-123
ISSN:
0360-5442
Subject:
acetone; acidity; biofuels; carbon; catalysts; ethanol; oils; oxygen; solvents; viscosity; water content
Abstract:
... Bio-oil was subjected to hydrodeoxygenation (HDO) reactions with polar protic (ethanol), polar aprotic (acetone), and nonpolar (ether) solvents in the presence of Pt/C catalyst. Mass balances (gas, light oil, heavy oil and char) of products were influenced by the solvent used. Subjecting the oil to HDO yielded improvement in the following heavy oil properties: water content, heating value, viscosi ...
DOI:
10.1016/j.energy.2016.07.027

10. Influence of K and Mg Concentration on the Storage Stability of Bio-Oil

Author:
Choi, In-Gyu,   et al.   ; Hwang, Hyewon; Lee, Jae-Hoon; Moon, Jaegwan; Kim, Ung-Jin; Choi, Joon Weon;     Show all 6 Authors
Source:
ACS sustainable chemistry 2016 v.4 no.8 pp. 4346-4353
ISSN:
2168-0485
Subject:
Liriodendron tulipifera; acid value; aldehydes; biofuels; biomass; elemental composition; ketones; leaching; magnesium; molecular weight; oils; potassium; storage quality; storage time; temperature; viscosity; water content
Abstract:
... In this study, the storage stability of bio-oil was investigated for periods of 1, 2, 4, and 8 weeks at a temperature of 23 °C. Four kinds of bio-oil from biomass with different inorganic content controlled by impregnation process, i.e., yellow poplar (YP), demineralized YP (D-YP), K-impregnated YP (K-YP), and Mg-impregnated YP (Mg-YP), were subjected to aging. During aging, the elemental composit ...
DOI:
10.1021/acssuschemeng.6b00895

11. Changes of major chemical components in larch wood through combined treatment of drying and heat treatment using superheated steam

Author:
Choi, In-Gyu,   et al.   ; Park, Yonggun; Jang, Soo-Kyeong; Park, Jun-Ho; Yang, Sang-Yun; Chung, Hyunwoo; Han, Yeonjung; Chang, Yoon-Seong; Yeo, Hwanmyeong;     Show all 9 Authors
Source:
Journal of wood science 2017 v.63 no.6 pp. 635-643
ISSN:
1435-0211
Subject:
acetic acid; arabinans; atmospheric pressure; cellulose; condensates; drying; furfural; heat treatment; high performance liquid chromatography; lignin; liquids; lumber; steam; sugars; wood; xylan
Abstract:
... The effects of the combined treatment of drying and heat treatment using superheated steam (SHS) were studied relative to the changes of the major chemical components in larch wood. The green lumber was dried and heat-treated in SHS conditions of 250 °C and 0.5 MPa for 18 h, and the relative percentage contents of sugars, lignin, and extractives were investigated and compared with the relative per ...
DOI:
10.1007/s10086-017-1657-9

12. Levulinic acid production by two-step acid-catalyzed treatment of Quercus mongolica using dilute sulfuric acid

Author:
Choi, In-Gyu,   et al.   ; Jeong, Hanseob; Jang, Soo-Kyeong; Hong, Chang-Young; Kim, Seon-Hong; Lee, Su-Yeon; Lee, Soo Min; Choi, Joon Weon;     Show all 8 Authors
Source:
Bioresource technology 2017 v.225 pp. 183-190
ISSN:
0960-8524
Subject:
Quercus mongolica; biomass; hydrolysates; levulinic acid; liquids; sugars; sulfuric acid; temperature
Abstract:
... The objectives of this research were to produce a levulinic acid by two-step acid-catalyzed treatment of Quercus mongolica and to investigate the effect of treatment parameter (reaction temperature range: 100–230°C; sulfuric acid (SA) concentration range: 0–2%) on the levulinic acid yield. After 1st step acid-catalyzed treatment, most of the hemicellulosic C5 sugars (15.6gg/100gbiomass) were relea ...
DOI:
10.1016/j.biortech.2016.11.063

13. Degradation and polymerization of monolignols by Abortiporus biennis, and induction of its degradation with a reducing agent

Author:
Choi, In-Gyu,   et al.   ; Hong, Chang-Young; Park, Se-Yeong; Kim, Seon-Hong; Lee, Su-Yeon; Choi, Won-Sil;     Show all 6 Authors
Source:
The journal of microbiology 2016 v.54 no.10 pp. 675-685
ISSN:
1225-8873
Subject:
ascorbic acid; coniferyl alcohol; culture media; enzymes; free radicals; lignin; molecular weight; oxidation; polymerization; reducing agents; sinapyl alcohol; vanillin
Abstract:
... This study was carried out to better understand the characteristic modification mechanisms of monolignols by enzyme system of Abortiporus biennis and to induce the degradation of monolignols. Degradation and polymerization of monolignols were simultaneously induced by A. biennis. Whole cells of A. biennis degraded coniferyl alcohol to vanillin and coniferyl aldehyde, and degraded sinapyl alcohol t ...
DOI:
10.1007/s12275-016-6158-9

14. Improvement of lignin oil properties by combination of organic solvents and formic acid during supercritical depolymerization

Author:
Choi, In-Gyu,   et al.   ; Park, Se-Yeong; Hong, Chang-Young; Jeong, Han-Seob; Lee, Su-Yeon; Choi, Joon Weon;     Show all 6 Authors
Source:
Journal of analytical and applied pyrolysis 2016 v.121 pp. 113-120
ISSN:
0165-2370
Subject:
Liriodendron tulipifera; biofuels; carbon; depolymerization; ethanol; formic acid; gas chromatography-mass spectrometry; gel chromatography; hardwood; hydrogen; isopropyl alcohol; lignin; methanol; molecular weight; oils; oxygen; p-cresol; pyrolysis; solvents
Abstract:
... Supercritical treatment of ethanol organosolv lignin was conducted to produce lignin-derived bio-oil. The reaction was performed at 350°C for 40min with 3MPa hydrogen gas pressure. To improve the yield of lignin oil and inhibit repolymerization during supercritical treatment, formic acid was added to the solvent. The effect of formic acid was examined by gas chromatography mass spectrometry (GC/MS ...
DOI:
10.1016/j.jaap.2016.07.011

15. Effect of ethanol organosolv pretreatment factors on enzymatic digestibility and ethanol organosolv lignin structure from Liriodendron tulipifera in specific combined severity factors

Author:
Choi, In-Gyu,   et al.   ; Jang, Soo-Kyeong; Kim, Ho-Yong; Jeong, Han-Seob; Kim, Jae-Young; Yeo, Hwanmyeong;     Show all 6 Authors
Source:
Renewable energy 2016 v.87 pp. 599-606
ISSN:
0960-1481
Subject:
Liriodendron tulipifera; biomass; catalysts; enzymatic hydrolysis; ethanol; gel chromatography; hydrolysates; lignin; lignocellulose; oxidation; pH; renewable energy sources; temperature
Abstract:
... In this study, various ethanol organosolv pretreatment factors including reaction temperature, time, and concentration of acid catalyst were evaluated for effective decomposition of lignocellulosic biomass. The different pretreatment conditions had the same combined severity factor (1.16). With an increase in reaction temperature and pH, the water-insoluble residue recovery and amount of lignin in ...
DOI:
10.1016/j.renene.2015.10.045

16. Transcriptomic analysis of the white rot fungus Polyporus brumalis provides insight into sesquiterpene biosynthesis

Author:
Choi, In-Gyu,   et al.   ; Lee, Su-Yeon; Kim, Myungkil; Kim, Seon-Hong; Hong, Chang-Young; Ryu, Sun-Hwa;     Show all 6 Authors
Source:
Microbiological research 2016 v.182 pp. 141-149
ISSN:
0944-5013
Subject:
Polyporus; biochemical pathways; biosynthesis; enzymes; gene expression; gene expression regulation; germacrene; high-throughput nucleotide sequencing; mycelium; phosphates; transcriptomics; unigenes; white-rot fungi; wood
Abstract:
... Object of this study was to identify genes and enzymes that are involved in sesquiterpene biosynthesis in the wood rotting fungus, Polyporus brumalis. Sesquiterpenes, β-eudesmane and β-eudesmol, were produced by the mycelium of P. brumalis cultured in modified medium. However, theses final products were not observed when the fungus was grown in potato dextrose medium. We used next generation seque ...
DOI:
10.1016/j.micres.2015.10.008

17. Biotransformation of (-)-α-pinene and geraniol to α-terpineol and p-menthane-3,8-diol by the white rot fungus, Polyporus brumalis

Author:
Choi, In-Gyu,   et al.   ; Lee, Su-Yeon; Kim, Seon-Hong; Hong, Chang-Young; Park, Se-Yeong;     Show all 5 Authors
Source:
The journal of microbiology 2015 v.53 no.7 pp. 462-467
ISSN:
1225-8873
Subject:
Polyporus; alpha-pinene; alpha-terpineol; bioactive properties; biocatalysts; biotransformation; fungi; geraniol; metabolites; mycelium
Abstract:
... In this study, the monoterpenes, α-pinene and geraniol, were biotransformed to synthesize monoterpene alcohol compounds. Polyporus brumalis which is classified as a white rot fungus was used as a biocatalyst. Consequently α-terpineol was synthesized from α-pinene by P. brumalis mycelium, after three days. Moreover, another substrate, the acyclic monoterpenoids geraniol was transformed into the cyc ...
DOI:
10.1007/s12275-015-5081-9

18. Study on the hydrodeoxygenative upgrading of crude bio-oil produced from woody biomass by fast pyrolysis

Author:
Choi, In-Gyu,   et al.   ; Kim, Tae-Seung; Oh, Shinyoung; Kim, Jae-Young; Choi, Joon Weon;     Show all 5 Authors
Source:
Energy 2014 v.68 pp. 437-443
ISSN:
0360-5442
Subject:
Liriodendron tulipifera; autoclaves; biofuels; biomass; catalysts; hydrogen; liquids; oils; pyrolysis; temperature; water content; wood
Abstract:
... Crude bio-oil produced from fast pyrolysis of yellow poplar wood was subjected to HDO (hydrodeoxygenation) for the purpose of reducing water content as well as increasing heating value. HDO was performed in an autoclave reactor at three different reaction factors: temperature (250–370 °C), reaction time (40–120 min), and Pd/C catalyst loading (0–6 wt%) under hydrogen atmosphere. After completion o ...
DOI:
10.1016/j.energy.2014.03.004

19. Optimization of enzymatic hydrolysis conditions for extraction of pectin from rapeseed cake (Brassica napus L.) using commercial enzymes

Author:
Choi, In-Gyu,   et al.   ; Jeong, Han-Seob; Kim, Ho-Yong; Ahn, Sye Hee; Oh, Sei Chang; Yang, In;     Show all 6 Authors
Source:
Food chemistry 2014 v.157 pp. 332-338
ISSN:
0308-8146
Subject:
Brassica napus; enzymatic hydrolysis; ethanol; hydrolysis; isopropyl alcohol; pectins; rapeseed cake; reducing sugars; subtilisin
Abstract:
... The aims of this study were to extract pectin from rapeseed cake (RSC) by enzymatic hydrolysis using commercial enzymes (Celluclast and Alcalase) and to investigate the effects of different reaction conditions, such as enzymatic hydrolysis time, enzyme–RSC ratio, and Celluclast–Alcalase ratio, on the degradation of RSC and pectin yield. RSC was treated using a combined extraction process that cons ...
DOI:
10.1016/j.foodchem.2014.02.040

20. Fast pyrolysis of potassium impregnated poplar wood and characterization of its influence on the formation as well as properties of pyrolytic products

Author:
Choi, In-Gyu,   et al.   ; Hwang, Hyewon; Oh, Shinyoung; Cho, Tae-Su; Choi, Joon Weon;     Show all 5 Authors
Source:
Bioresource technology 2013 v.150 pp. 359-366
ISSN:
0960-8524
Subject:
aromatic hydrocarbons; biomass; gas chromatography; mass spectrometry; pH; phenols; potassium; pyrolysis; temperature; viscosity; water content; wood
Abstract:
... TGA results indicated that the maximum decomposition temperature of the biomass decreased from 373.9 to 359.0°C with increasing potassium concentration. For fast pyrolysis, char yield of potassium impregnated biomass doubled regardless of pyrolysis temperature compared to demineralized one. The presence of potassium also affected bio-oil properties. Water content increased from 14.4 to 19.7wt% and ...
DOI:
10.1016/j.biortech.2013.09.132
PubMed:
24185037