• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.676-685
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• 2016

This study investigated the conversion of oil products from polystyrene by using dispersed Co and Mo catalyst on reaction time and concentration change for knowledging on characteristics at low temperature (425, 450 and $475^{\circ}C$) pyrolysis and reaction time(20~80 min, 15 min interval) in a batch reactor. It will be showed the conditions for optimum pyrolysis at reaction temperature $450^{\circ}C$ and the reaction time 35min, and the main components of the converted liquid oil were styrene and benzene derivatives by GC/MS. The oil products formed during pyrolysis were classified into gas, gasoline, kero, diesel and heavy oil according to the domestic specification of petroleum products. The pyrolysis conversion rate was showed as Co catalyst > Mo catalyst > Thermal in all reaction time at reaction temperature $450^{\circ}C$. The yields rate of gas, kerosine, diesel were the most hight at Mo Catalyst, gasoline was at thermal and heavy oil was at Co catalyst. The conversion rate and yields of the pyrolysis products were the most height when Co catalyst ratio was 100%.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.975-984
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• 2018

Fast pyrolysis bio-oil has unfavorable properties that restrict its use in many applications. Among the main issues are high acidity, instability, and water and oxygen content, which give rise to corrosiveness, polymerization during storage, and a low heating value. Esterification and azeotropic water removal can improve all of these properties. A 500 g of Quercus mongollica which grounded 0.8~1.4 mm was processed into bio-oil via fast pyrolysis for 2 seconds at $550^{\circ}C$. The esterification consists of treating pyrolysis oil with a high boiling alcohol like n-butanol at $70^{\circ}C$ under reduced pressure (100 hPa). All products are analyzed for water mass fraction, viscosity, higher heating value, pH, FT-IR and GC/MS. The water mass fraction can be reduced by 91.4 % (from 31.5 % to below 2.7 %), the viscosity by 65.8 % (from 36.5 to 12.5 cP) and the higher heating value can be increased by 96.8 % (from 3,918 to 7,712 kcal/kg), the pH by 1.3 (from 2.7 to 4.0). FT-IR and GC/MS analysis indicated that labile acids, aldehydes, ketones and lower alcohols were transformed to stable target products. Using this approach, the water content of the pyrolysis oil is reduced significantly. These improvements should allow the utilization of upgraded pyrolysis liquids in standard boilers and as fuel in CHP (Combined heat and power) plants.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.31-39
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• 2005

This study was conducted to evaluate the characterization of the pyrolysis products of propylene glycol(PG) and glycerine alone and together with tobacco. The weight change of the samples during the pyrolysis was measured by a thermal analyzer(STD-2960). The pyrolysis products were determined by GC/MS after pyrolysis using a curie-point pyrolyzer(CPP, $220^{\circ}C,\;420^{\circ}C,\;650^{\circ}C,\;and\;920^{\circ}C$) and a double-shot pyrolyzer(DSP, $220^{\circ}C,\;420^{\circ}C,\;650^{\circ}C,\;and\;800^{\circ}C$), respectively. The pyrolysis products from tobacco with and without the addition of PG($2\%$) and glycerine($2\%$ were assayed for its pyrolytic behavior. The results showed that a dramatic change in weight of PG and glycerine was observed at $175^{\circ}C\;and\;249^{\circ}C$, respectively. PG and glycerine showed different patterns for their pyrolysis products according to the method of pyrolysis. Namely, the change rate in pyrolysis with DSP was much higher than that of CPP at above $650^{\circ}C$. The major pyrolysis products of PG were propene, acetaldehyde, propanal, and acetol; the major pyrolysis products of glycerine were 2-propenal, 2-propenol, acetol, and acetic acid. In the pyrolysis experiments of tobacco added PG and glycerine, the pyrolysis products of PG and glycerine weren't detected additionally, except for diethyleneglycol diacetate. From these results, it can be concluded that the PG and glycerine added to tobacco would not be expected to pyrolyse extensively during smoking.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.12-19
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• 2006

Rice straw is one or the main renewable energy sources in Korea. Bio-oil is produced from rice straw with a lab-scale equipment mainly with a fluidized bed and a char removal system. It was investigated how the reaction temperature affected the production of bio-oil and the efficiency of a char removal system. To elucidate how the temperature depended on the production of bio-oil, experiments were conducted at $466^{\circ}C,\;504^{\circ}C\;and\;579^{\circ}C$, respectively. The mass balance was established in each experiment, and the produced gas and oil were analyzed with the aid of GCs and a GC-MS system. The char removal system is composed of a cyclone and a hot filter. Tn the experiments, we observed that the production of bio-oil was decreased with temperature, and the bio-oil contained very useful chemicals.

• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.35-41
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• 2001

Lignin model compounds I-lV were pyrolyzed at 315$^{\circ}C$. The mixture compounds pyrolized were analyzed by GC-MS spectrometry. The results were summarized as follows : 1. From the pyrolysis of lignin model compound I and II, 0.45mo1 of guaiacol, 0.5mol of dimethoxyphenol(DMP), and 0.12 and 0.23mo1 of dimethoxyacetonphenone(DMAP) were produced respectively. 2. In the pyrolysis of lignin model compound III and IV, 0.26mol of guaiacol, 0.30mo1 of DMP, and 0.09 and 0.15mo1 of trimethoxyaretonphenone(TMAP) were produced respectively 3. Pyrolysis mechanism of lignin model compounds are dehydrated at first, and $\beta$-04 linkage cleavaged, and then guaiacol, DMP, DMAP and TMAP were produced. The above results show that lignin model compound I and II produce more aromatic compounds than lignin model compound III and IV. This is reason that veratryl unit structures may pyrolize easier than trimethoxyphenol unit structures. The closer research is proceeding.

• Journal of the Korean Wood Science and Technology
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• v.47 no.4
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• pp.442-450
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• 2019

Despite its potential as a renewable source for fuels and chemicals, lignin valorization still faces technical challenges in many aspects. Overcoming such challenges associated with the chemical recalcitrance of lignin can provide many opportunities to innovate existing and emerging biorefineries. In this work, we leveraged a biomass genetic engineering technology to produce phenolic aldehyde-rich lignin structure via downregulation of cinnamyl alcohol dehydrogenase (CAD). The structurally altered lignin obtained from the Arabidopsis thaliana CAD mutant was pyrolyzed to understand the effect of structural alteration on thermal behavior of lignin. The pyrolysis was conducted at 400 and $500^{\circ}C$ using an analytical pyrolyzer connected with GC/MS and the products were systematically analyzed. The results indicate that aldehyde-rich lignin undergoes fragmentation reaction during pyrolysis forming a considerable amount of C6 units. Also, it was speculated that highly reactive phenolic aldehydes facilitate secondary repolymerization reaction as described by the lower yield of overall phenolic compounds compared to wild type (WT) lignin. Quantum mechanical calculation clearly shows the higher electrophilicity of transgenic lignin than that of WT, which could promote both fragmentation and recondensation reactions. This work provides mechanistic insights toward biomass genetic engineering and its application to the pyrolysis allowing to establish sustainable biorefinery in the future.

• Asian Journal of Atmospheric Environment
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• v.6 no.1
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• pp.53-66
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• 2012

A comparison of analytical approaches for Levoglucosan ($C_6H_{10}O_5$, commonly formed from the pyrolysis of carbohydrates such as cellulose) and used for a molecular marker in biomass burning is made between the four different analytical systems. 1) Spectrothermography technique as the evaluation of thermograms of carbon using Elemental Carbon & Organic Carbon Analyzer, 2) mass spectrometry technique using Gas Chromatography/mass spectrometer (GC/MS), 3) Aerosol Mass Spectrometer (AMS) for the identification of the particle size distribution and chemical composition, and 4) two dimensional Gas Chromatography with Time of Flight mass spectrometry (GC${\times}$GC-TOFMS) for defining the signature of Levoglucosan in terms of chemical analytical process. First, a Spectrothermography, which is defined as the graphical representation of the carbon, can be measured as a function of temperature during the thermal separation process and spectrothermographic analysis. GC/MS can detect mass fragment ions of Levoglucosan characterized by its base peak at m/z 60, 73 in mass fragment-grams by methylation and m/z 217, 204 by trimethylsilylderivatives (TMS-derivatives). AMS can be used to analyze the base peak at m/z 60.021, 73.029 in mass fragment-grams with a multiple-peak Gaussian curve fit algorithm. In the analysis of TMS derivatives by GC${\times}$GC-TOFMS, it can detect m/z 73 as the base ion for the identification of Levoglucosan. It can also observe m/z 217 and 204 with existence of m/z 333. Although the ratios of m/z 217 and m/z 204 to the base ion (m/z 73) in the mass spectrum of GC${\times}$GC-TOFMS lower than those of GC/MS, Levoglucosan can be separated and characterized from D (-) +Ribose in the mixture of sugar compounds. At last, the environmental significance of Levoglucosan will be discussed with respect to the health effect to offer important opportunities for clinical and potential epidemiological research for reducing incidence of cardiovascular and respiratory diseases.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.135-140
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• 1998

The constituents of deposits on paper machine and holes/spots in paper have been analyzed by a combination of analytical techniques, such as FTIR, Py-GC-MS, and EDS. FTIR spectroscopy was used prior to Py-GC-MS and EDS analysis, as a preliminary analysis. The analysis of organic components was carried out with a pyrolysis unit connected to a GC-MS, and inorganic components in ash were analyzed by SEM equipped with an EDS analyzer after pyrolysis at $590^{\circ}C$. The deposits on the dryer section were complex pitch, which was the mixture of the organic components of fatty acid ester and starch, and the inorganic components of talc, clay, and calcium carbonate. The complex pitch was estimated to come from the coated broke. We knew the deposits on the metering rod of sym-sizer were associated with the interaction of unstable alkyl keten dimer(AKD) and $CaCO_3$. The compositions of holes or spots varied considerably and were associated with chemical interaction within the system. The holes, spots, and blotches in the finished paper were PE and PP from pulp sources, complex pitch that were caused by the interaction of the different additives in the system, polymer such as flexible PVC that was used for the prop of palette, and hot melt as adhesives that came from the inadequate handling of broke. In addition, we identified that poly(caprolactam) which is used for forming fabrics or press felts, could be mixed with the raw materials by accident and results in streaks on coating.

• Journal of the Korean Society of Tobacco Science
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• v.26 no.2 s.52
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• pp.141-151
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• 2004

This study was conducted to evaluate the characterization of the pyrolysis products of tobacco constituents such as cellulose, lignin and tobacco additives. The pyrolysis condition was designed to simulate the pyrolysis/distillation zone$(200\~600^{\circ}C)$ and combustion zone$(700\~950^{\circ}C)$of burning com in the smoking cigarette. The pyrolysis products were determined by GC/MS after pyrolysis using Double-Shot pyrolyzer. In the case of cellulose and lignin, the number of pyrolysis product in the condition that simulate the pyrolysis/distillation zone was much more than the combustion zone simulating one. The major products of cellulose were levoglucosan, furfural, and 1, 6-anhydro-$\beta$-D-glucofuranose and that of lignin were phenol, 2-methoxy phenol, and 1, 2-dimethoxy benzene. In the case of tobacco additives such as 2, 6-dimethyl pyrazine, maltol, and piperonal, the pyrolysis products of these additives were evaporated from the pyrolyszer at least $96\%$ intactly. These results indicate that tobacco constituents such as cellulose and lignin were thermally degraded at the pyrolysis/distillation zone and thoroughly broke down at the combustion zone, but tobacco additives were intactly evaporated from burning com of smoking cigarette.

• Journal of the Korean Chemical Society
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• v.41 no.10
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• pp.524-534
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• 1997

Analysis of additives in cured rubber is often a difficult task for analytical chemists because of a wide variety of complex components. Conventional analyses of additives and rubbers have been done in multistep, off-line processes with large sample size and extensive sample preparations. The coumarone-indene resin, resorcinol-formaldehyde resin, and prevulcanization inhibitor have been characterized by their pyrolysis pathways and mass spectra of characteristic pyrolyzates. Pyrolysis Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used in the identification of additives without any sample pretreatment. This result shows that several organic additives in cured rubber can be directly analyzed.