Energetics of cellulose and cyclodextrin glycosidic bond cleavage

2017 ◽  
Vol 2 (2) ◽  
pp. 201-214 ◽  
Author(s):  
Cheng Zhu ◽  
Christoph Krumm ◽  
Gregory G. Facas ◽  
Matthew Neurock ◽  
Paul J. Dauenhauer
Keyword(s):  
High Temperature ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Bond Cleavage ◽  
Thermochemical Conversion ◽  
Lignocellulosic Materials ◽  
Renewable Chemicals ◽  
Volatile Organic ◽  
Glycosidic Bond Cleavage ◽  
Long Chain

Thermochemical conversion of lignocellulosic materials for production of biofuels and renewable chemicals utilizes high temperature to thermally decompose long-chain cellulose to volatile organic compounds.

scholarly journals Volatile Organic Compounds of Kaffir Lime (Citrus hystrix DC.) Leaves Fractions and their Potency as Traditional Medicine

2017 ◽  
Vol 14 (4) ◽  
pp. 1235-1250 ◽  
Author(s):  
Elsa Dilla Dertyasasa ◽  
Woro Anindito Sri Tunjung
Keyword(s):  
Fatty Acids ◽  
Volatile Organic Compounds ◽  
Ethyl Acetate ◽  
Traditional Medicine ◽  
Volatile Compounds ◽  
Organic Compounds ◽  
Fatty Alcohols ◽  
Crude Extracts ◽  
Volatile Organic ◽  
Long Chain

ABSTRACT: Previous studies have reported that a number of organic compounds are present in kaffir lime (Citrus hystrix DC.) leaf extracts. Further research is needed to purify these compounds and determine which are biologically active. The objective of this study is to identify the volatile organic compounds of kaffir lime leaf crude extracts and fractions and to study their bioactivity. Fractionation was performed by the double maceration method, using hexane as the second solvent. TLC was performed to analyze the qualitative separation, whereas the individual constituents were detected using GC-MS. Our results showed that chloroform and ethyl acetate crude extracts contained various volatile organic compounds such as fatty acids, fatty alcohols, prenol lipids, sterol lipids, terpenoids and long chain alkanes. Fractionation separated these compounds into non-hexane fractions, which contained less volatile compounds, and hexane fractions. The volatile compounds of non-hexane fractions were identified to be long chain alkanes, meanwhile the hexane fractions contained terpenoids, fatty acids, fatty alcohols, prenol lipids and sterol lipids. Palmitic acid and terpenoids, such as citronellyl propionate, nerolidol, citronella and caryophyllene oxide were found to be the most dominant bioactive compounds in chloroform and ethyl acetate crude extract and their hexane fractions, which were reported to possess cytotoxicity against cancer cells. Meanwhile in non-hexane fractions, long chain alkanes such as triacontane and hentriacontane were found to be the most dominant bioactive compound which also possessed cytotoxic effect. In conclusion, fractionation using the double maceration method yielded different volatile organic compounds composition with different biological activities. The crude extracts and fractions of kaffir lime leaves were potential to be developed as a traditional medicine for cancer treatment.

Grey System Theoretical Analysis on the Influence of Volatile Organic Compounds Emission from Asphalt on its Performance

2013 ◽  
Vol 753-755 ◽  
pp. 481-485
Author(s):  
Hong Hua Zhang ◽  
Shao Peng Wu ◽  
Ling Pang ◽  
Kim Jenkins ◽  
Man Yu ◽  
...  
Keyword(s):  
System Theory ◽  
High Temperature ◽  
Volatile Organic Compounds ◽  
Physical Properties ◽  
Organic Compounds ◽  
Grey System Theory ◽  
Grey System ◽  
Voc Emission ◽  
Volatile Organic ◽  
Light Components

Light components in the asphalt can volatilize under the circumstances of high temperature or long-term service process, leading to the deteriorating of the asphalt pavement. This paper tried to discuss the influences of volatile organic compounds (VOC) emission from the asphalt on physical properties in the high temperature (at 180) by grey system theory. Both Heat and Vacuum environment were monitored as the emission conditions and the emission temperature was 180°C, physical properties of asphalt, released and unreleased were analyzed. Basic tests, including mass change, chemical compositions, penetration and soften point, were used to compare the influences of VOC emission on the asphalts performances. Meanwhile, grey system theory was used to investigate the sequent performances influenced by VOC emission. Results show that physical properties and four generic components of the asphalts are affected obviously in these two emission conditions, and the oxygen may promote VOC emission from the asphalt. In additional, the greatest factor associating with VOC emission is light components in the asphalt.

Analysis on Health Risk of Volatile Organic Compounds of Smoked Bamboo Biomaterial by TD-GC-MS

2011 ◽  
Vol 467-469 ◽  
pp. 1697-1701 ◽  
Author(s):  
Wan Xi Peng ◽  
Qiu Xue ◽  
Feng Juan Wu ◽  
Xu Zhang ◽  
Zhong Feng Zhang
Keyword(s):  
Acetic Acid ◽  
High Temperature ◽  
Volatile Organic Compounds ◽  
Health Risk ◽  
Organic Compounds ◽  
Human Settlements ◽  
Potential Health ◽  
Potential Health Risk ◽  
Volatile Organic

Smoked bamboo, which was made by bamboo in high temperature smoke, is a new indoors materials. In order to evaluate its potential health risk to human settlements, the volatile organic compounds of smoked bamboo biomaterial were adsorbed and determined by TD-GC-MS. And the main constituents of volatiles at 60°С were cyclononasiloxane, octadecamethyl-(35.14%), acetic acid(23.27%), cyclotrisiloxane, hexamethyl- (9.53%), bicyclo[4.4.0]dec-1-ene,2-isoprop yl-5-methyl-9-methylene-(7.56%), silane, 1,4-phenylenebis[trimethyl(4.32%), 1,3-benzodioxole, 5-(2-propenyl)- (3.47%), cedrol(2.75%), etc. (2) The main constituents of volatiles at 130°С were acetic acid(43.78%), 2,5-furandione, dihydro-3- methylene-(16.57%), 1,3-benzodioxole, 5-(1-propenyl)-,(z)-(6.75%), octasiloxane, 1,1,3,3,5,5,7,7,9,9, 11,11,13, 13,15,15- hexadecamethyl -(4.09%), bicyclo[2.2.1]heptan-2-one, 1,7,7- trimethyl-, (1s)- (3.21%), etc. Generally, the smoked bamboo biomaterial was safe under 60-130°С.

Volatile Organic Compounds emitted during High-temperature Alfalfa Drying

2006 ◽  
Vol 94 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Ajay Dalai ◽  
Greg Schoenau ◽  
Dharani Das ◽  
Phani Adapa
Keyword(s):  
High Temperature ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Volatile Organic

Analysis of the Volatile Organic Compounds (VOCs) during the Regeneration of Post-Consumed Poly(Ethylene Terephthalate) Using HS-GC-MS Method

2019 ◽  
Vol 944 ◽  
pp. 1208-1214
Author(s):  
Shan Shan Liu ◽  
Ji Yue Hu ◽  
Dan Qin ◽  
Ling Ling Gao ◽  
Ye Chen ◽  
...  
Keyword(s):  
High Temperature ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Raw Materials ◽  
Recycled Pet ◽  
Voc Emissions ◽  
Volatile Organic ◽  
Manufacturing Techniques ◽  
Poly Ethylene ◽  
Heat Preservation

VOCs emissions from recycled PET are recognized as one of the major causes of poor healthy condition. Much attention has been increasingly focused on VOCs produced from regenerated PET for their significance in ecological safety. These emissions may be strongly influenced by the raw materials and manufacturing techniques of the recycled PET. However, there is very little published information regarding this issue. The purpose of this study was to examine VOCs releasing from reprocessed productions when exposed to high temperature or other extreme conditions.In this study, we determined and compared VOCs emissions from samples after different manufacturing stages such as PET popcorn, dried PET popcorn, screw melts, undrawed fibers and drawed fibers, including their species and content. To simulate the VOC emissions of samples processed with the high temperature in longer time during screw melting, we investigated VOCs from screw melts utilizing Thermo Gravimetric-Mass Spectrometry (TG-MS) with 90 min in 280°C . We found that: (1) The optimisation of the equilibration procedure for volatile organic compounds was performed and the optimal equilibration conditions were determined to be 30 min at 120°C ; (2) Seven individual VOCs were identified: considerable VOC content changes during the manufacturing process; and the drying was tremendously helpful in reducing the VOC emissions from PET popcorn; formaldehyde, acetaldehyde and TVOC were reduced by 24%, 58% and 50%, respectively after drying; while acetaldehyde, benzene, benzaldehyde and TVOC increased dramatically after screw melting; (3) The VOCs were released at the initial stage of heat preservation (about 5 min) and VOCs content came to the maximum which indicated the almost immediate thermal degradation in screw melting.

JUSTIFICATION OF MAXIMUM (ONE-TIME) ALLOWABLE CONCENTRATION OF VOLATILE ORGANIC COMPOUNDS, EMERGING DURING THE HIGH TEMPERATURE TREATMENT OF WOOD IN CHIPBOARD PRODUCTION, IN THE AMBIENT AIR

2017 ◽  
pp. 42-47 ◽  
Author(s):  
O. V. Budarina ◽  
M. A. Pinigin ◽  
L. A. Fedotova ◽  
Z. F. Sabirova ◽  
Z. V. Shipulina
Keyword(s):  
High Temperature ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Experimental Studies ◽  
Ambient Air ◽  
High Temperature Treatment ◽  
Residential Areas ◽  
Atmospheric Air ◽  
Volatile Organic ◽  
High Temperature Processing

Results of experimental studies are reported on the substantiation of the maximum single permissible concentration (MAC maximum single) of volatile organic compounds, formed during a high temperature processing of wood in chipboard production (based on tererpene hydrocarbons), in the atmospheric air of residential areas at the level of 0.05 mg/m3. The magnitude was established on the basis of olfacto-odorimetry taking into account new approaches to the determination of «obsessive» odor thresholds as a limiting criterion for the MAC maximum single justification in accordance with the international practice of setting odor limits and our home experience gained in the standardization of odorous substances in the ambient air. The selection of priority substances for the control of the designed value (α-pinene, β-pinene, 3-carene, limonene, camphene) was based on the analysis results of the composition of releases from a high temperature processing of wood and atmospheric air in the enterprise location area.

Investigation of Volatile Organic Compounds from the Manufacturing Process of Recycled PET Fibers Using TGA-DTA/MS Technique

2019 ◽  
Vol 944 ◽  
pp. 1221-1225
Author(s):  
Ji Yue Hu ◽  
Ye Chen ◽  
Shan Shan Liu ◽  
Fu You Ke ◽  
Ling Ling Gao ◽  
...  
Keyword(s):  
High Temperature ◽  
Volatile Organic Compounds ◽  
Thermal Degradation ◽  
Thermal Oxidation ◽  
Organic Compounds ◽  
Manufacturing Process ◽  
Melt Spinning ◽  
Recycling Process ◽  
Volatile Organic ◽  
Pet Fibers

Recycling is promising to dispose the wasted Poly (ethylene terephthalate) (PET) fibers currently. However, high temperature and oxygen in the recycling process may accelerate the degradation of PET and residual dyes, resulting in the volatile organic compounds (VOCs) emissions, which will do serious harm to the environment and human health. Exploring the source of VOCs is significant to remove VOCs and keep products safety. This study was carried out to investigate the influence of high temperature on the release of four VOCs (formaldehyde (CH2O), acetaldehyde (C2H4O), benzene (C6H6) and toluene (C7H8)) during the recycling process of PET fibers, utilizing thermogravimetric analysis and differential thermal analysis coupled with mass spectrometric (TGA-DTA/MS). The atmospheres and heating conditions of esterification, polycondensation and melt spinning were simulated by TGA with various atmospheres and programmed heating processes (heating from 50 °C to 240 °C in Ar, 280 °C in Ar and 280 °C in air, respectively, and then maintaining for 30min). Bis (2-hydroxyethyl) terephthalate (BHET) (esterification product) and virgin PET (VPET) were used to explore the thermal degradation of PET. White PET popcorn, black PET popcorn and dyes were used to explore the effect of dyes on the release of VOCs. The results indicated that: (1) Aldehydes including formaldehyde and acetaldehyde are generated during the manufacturing process of PET, mainly due to its thermal oxidation;(2) Aromatic compounds including benzene and toluene are originated from the disperse dyes. So the degree of dye removing has a great influence on the production safety; (3) Thermal oxidation causes more VOCs than nonoxidative thermal degradation. So in the stages of melt spinning and slightly alcoholysis, usually in O2 containing atmosphere, devolatilization should be developed further.

Influence of VOC Emission on Asphalt Components

2014 ◽  
Vol 599 ◽  
pp. 178-181 ◽  
Author(s):  
Hong Hua Zhang ◽  
Pei Qiang Cui ◽  
Liu Jing Zi Qiu ◽  
Shao Peng Wu
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Volatile Organic Compounds ◽  
Low Temperature ◽  
Organic Compounds ◽  
Chemical Components ◽  
Chemical Compositions ◽  
Voc Emission ◽  
Volatile Organic ◽  
Different Temperatures

Volatile organic compounds (VOC) emission from different asphalts not only causes the change in the performances of the bitumen, but also its chemical compositions. This paper carried out four-component analysis to study the influence of VOC emission from different asphalts on bitumens chemical compositions under different conditions. Results show that four-component of asphalts from different places is different. Also as the time of VOC emission increases, the total contents of resins and asphaltenes increase, but the total contents of saturates and aromatics decrease. VOC emission under different temperatures also has a great impact on the asphalt chemical components; Saturates and aromatics decrease in high temperature is larger than in low temperature, and there exists big differences in the asphalt surface layer and the internal of chemical components.

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