Volatile Product Distribution Research Articles

Temperature Programmed Pyrolysis and Supercritical Extraction of Turkish Lignites

The aim of this study was to determine product evolution rate and volatile product distribution with the capillary gas chromatographic detection during temperature programmed pyrolysis of some Turkish lignites. The pyrolysis examinations conducted under non-isothermal conditions at a low heating rate of 2 K/min up to 550°C can show that the typical volatile product evolution begins at about 350°C and reaches its maximum value at approximately 440°C. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified as a carbon number. n-Paraffins up to about C30 were observed among the products and these were accompanied by smaller but significant amounts of 1-olefins. Supercritical toluene extraction was also performed on the lignite samples and the conversion degree and the extract yield results were compared with the results of pyrolysis.

Effect of acid catalysts on scrap tyre pyrolysis under fast heating conditions

A study has been carried out on the effect of acid catalysts prepared based on HZSM-5, HY and HBeta zeolites on the distribution of volatile products (gas, non-aromatic C 5–C 10 fraction, aromatic C 10 − and tar), in the pyrolysis of tyre material carried out in a fast heating microreactor. The results have been compared with those of thermal pyrolysis. The strategies of using the catalyst in situ and reforming the volatiles generated in thermal pyrolysis have also been compared. The use of a catalyst in situ lowers the pyrolysis temperature by 50 K (to 723 K) and produces a significant increase in the yield of gases and light aromatic C 10 − , at the expense of a decrease in the yield of non-aromatic C 10 − . The yield of tar increases only slightly. The shape selectivity of each zeolite has a significant effect and, consequently, HY zeolite leads to the formation of heavier structures that make up the tar and to aromatic C 10 − , which is favoured by hydrogen transfer capacity. HZSM-5 is more efficient for the formation of gases, although it contributes only to decreasing the molecular weight of aromatic C 10 − fraction. HBeta zeolite catalyst has an intermediate behaviour. Reforming pyrolysis volatiles at 723 K using a HZSM-5 zeolite catalyst efficiently increases (from 2 to 20 wt%) the yield of gases, with a high yield of ethene and propene. The yields of BTX fraction are also very high (around 11.5 wt%).

Fast Pyrolysis of Şırnak Asphaltite (Turkey) and Characterization of Pyrolysis Products

Fast pyrolysis of Şırnak Asphaltite (SASP) was investigated to determine yield and distribution of volatile products at different temperatures. A special sampling technique was used for collecting organic products formed at different time intervals and pyrolysis temperatures. The fast pyrolysis products were analyzed by capillary gas chromatography. The total product evolution rate was determined for a time range with 10 minutes at each pyrolysis run. n-Paraffin and 1-olefin in aliphatic fraction of pyrolysis products were classified by their carbon number. The evolution of volatile hydrocarbons increased with increasing temperature. The conversion of organic carbon to aliphatic hydrocarbons was found to be 5.9, 8.5, 12.9, 21.2, and 26.6 wt% at 450°C, 500°C, 550°C, 600°C, and 650°C, respectively.

Classification of volatile products evolved at fast co-pyrolysis of Goynuk oil shale with low density polyethylene

Fast co-pyrolysis of Goynuk oil shale (GOS) with low density polyethylene (LDPE) was investigated. The aim of the research was to determine the distribution of volatile products and conversion of blends at different temperatures and time intervals. Pyrolysis of oil shale, LDPE and co-pyrolysis of oil shale-LDPE blend of the total carbon ratio of 1:1 were performed by using the fast pyrolysis method in an isothermal pyrolysis reactor. Volatile organic products eluted from the reactor were collected at different temperatures and time intervals by using a special sampling technique. Fast pyrolysis products were analyzed by capillary gas chromatography. In the aliphatic fraction of pyrolysis products, n-paraffins and 1-olefins were classified by their carbon number. The effect of co-pyrolysis on conversion of total organic carbon into volatile products was identified by determination of the experimental and the hypothetical mean values. Possible synergetic effect was investigated by comparing the results on fast pyrolysis of GOS and LDPE. The effect of co-processing of GOS with LDPE was determined by calculating the difference between experimental and hypothetical mean value of conversion of total organic carbon into volatile products. The experimental conversion of the blend to volatile hydrocarbons was found to be lower than hypothetical mean value of conversion at co-pyrolysis, and thus, no synergetic effect was observed.

CLASSIFICATION OF VOLATILE PRODUCTS EVOLVED AT FAST CO-PYROLYSIS OF GÖYNÜK OIL SHALE WITH LOW DENSITY POLYETHYLENE

Fast co-pyrolysis of Goynuk oil shale (GOS) with low density polyethylene (LDPE) was investigated. The aim of the research was to determine the distribution of volatile products and conversion of blends at different temperatures and time intervals. Pyrolysis of oil shale, LDPE and co-pyrolysis of oil shale-LDPE blend of the total carbon ratio of 1:1 were performed by using the fast pyrolysis method in an isothermal pyrolysis reactor. Volatile organic products eluted from the reactor were collected at different temperatures and time intervals by using a special sampling technique. Fast pyrolysis products were analyzed by capillary gas chromatography. In the aliphatic fraction of pyrolysis products, n-paraffins and 1-olefins were classified by their carbon number. The effect of co-pyrolysis on conversion of total organic carbon into volatile products was identified by determination of the experimental and the hypothetical mean values. Possible synergetic effect was investigated by comparing the results on fast pyrolysis of GOS and LDPE. The effect of co-processing of GOS with LDPE was determined by calculating the difference between experimental and hypothetical mean value of conversion of total organic carbon into volatile products. The experimental conversion of the blend to volatile hydrocarbons was found to be lower than hypothetical mean value of conversion at co-pyrolysis, and thus, no synergetic effect was observed.

Secondary Organic Aerosol Production from Terpene Ozonolysis. 2. Effect of NOx Concentration

We report secondary organic aerosol (SOA) yields from the ozonolysis of alpha-pinene in the presence of NO and NO2. Experimental conditions are characterized by the [VOC]0/ [NOx]0 ratio (ppbC/ppb), which varies from approximately 1 to approximately 300. SOA yield is constant for [VOC]0/[NOx]0 > approximately 15 and decreases dramatically (by more than a factor of 4) as [VOC]0/[NOx]0 decreases. Aerosol production is completely suppressed in the presence of NO for [VOC]0/[NOx]0 < or = 4.5. Fouriertransform IR analysis of filter samples reveals that nitrate-containing species contribute significantly to the total aerosol mass at low [VOC]0/[NOx]0. Yield reduction is a result of the formation of a more volatile product distribution as [VOC]0/[NOx]0 decreases; we propose that the change in the product distribution is driven by changes in the gas-phase chemistry as NOx concentration increases. We also present two-product model parameters to describe aerosol production from the alpha-pinene/0/NOx system under both high- and low-NOx conditions.

Secondary Organic Aerosol Production from Terpene Ozonolysis. 1. Effect of UV Radiation

We report secondary organic aerosol (SOA) yields from the ozonolysis of alpha-pinene under both dark and UV-illuminated conditions. Exposure to UV light reduces SOA yield by 20-40%, with a maximum reduction in yield coinciding with a minimum in the amount of terpene consumed (15-30 ppb). The data are consistent with a constant absolute reduction in the yield of approximately 0.03. Gas chromatography mass spectrometry analysis of filter samples indicates that the major products found in alpha-pinene SOA include organic acids (e.g., pinic acid), keto acids (e.g., pinonic acid), and hydroxy keto acids (e.g., 10-hydroxypinonic acid). Analysis of filter-based results suggests that yield reduction is a result of the formation of a more volatile product distribution when experiments are conducted in the presence of UV light. These results implythat previous "dark bag" experiments may overestimate SOA generation from monoterpenes and also that SOA generation in the atmosphere may depend significantly on actinic flux.

CLASSIFICATION OF ALIPHATIC HYDROCARBONS FORMED AT TEMPERATURE-PROGRAMMED CO-PYROLYSIS OF TURKISH OIL SHALES OF KEROGEN TYPES I AND II

Temperature-programmed co-pyrolysis of Goynuk and Beypazari oil shales was investigated with the aim to determine volatile product distribution and product evolution rate of co-processing. A series co-pyrolysis operation was performed using three total carbon ratios. A fixed-bed reactor was used to pyrolyse small samples of oil shale mixtures under an inert gas (argon) flow. A special sampling technique was used for collecting organic products formed at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by their carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The effect of co-processing was determined comparing the results with the data of their separate pyrolysis. The effect of oil shale kerogen type on co-pyrolysis operation was also investigated. Conversion into volatile hydrocarbons was found to lower with increasing Beypazari oil shale share in the mixture while the amounts of C1–C15 hydrocarbons and coke to increase in the presence of this oil shale.

Co-pyrolysis of Göynük-oil shale and Şırnak-asphaltite from Turkey and analysis of co-pyrolysis products by capillary GC total stream sampling technique ☆

Temperature-programmed co-pyrolysis of Göynük-oil shale (GOS) with Şırnak-asphaltite (ASP) from Turkey was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of co-processing of GOS with ASP. A series co-pyrolysis operation was performed with GOS and ASP using a 1/2, 1/1, 2/1 total carbon ratio of GOS to ASP. A fixed-bed reactor was used to pyrolyse small sample of GOS and ASP mixture under an inert gas flow (Argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified as a carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of GOS and ASP. The effect of co-processing of GOS with ASP was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products.

Effect of α-, γ-, and δ-tocopherol on the distribution of volatile secondary oxidation products in fish oil

The relative ability of α-, γ- and δ-tocopherol (TOH) to influence the distribution of volatile secondary oxidation products in fish oil was studied, with particular emphasis on oxidation products expected to be important for adverse flavour formation. Purified fish oil samples with 100 ppm or 1000 ppm of the different tocopherols were analysed by dynamic headspace analysis of the volatiles formed after 2, 5 and 8 d of storage at 30 °C. The tocopherol type and concentration affected not only the overall formation of volatile secondary oxidation products, but also the composition of this group of oxidation products. Principal component analysis of the data obtained suggested that high tocopherol hydrogen-donating power, i.e. a high tocopherol concentration or the use of αTOH as opposed to γTOH or δTOH, directs the formation of hydrocarbons, unsaturated carbonyl compounds of relatively high molecular weight, as well as the formation of cis,trans isomers of unsaturated aldehydes. Although an active inhibitor of overall volatile formation, aTOH at a high concentration thus appears to direct the formation of the more flavour-potent aldehydes, such as those linking the carbonyl group with ethylenic conjugated unsaturation.

Classification of volatile products evolved from temperature-programmed pyrolysis of Soma-Lignite and Şırnak-Asphaltite from Turkey

Temperature-programmed pyrolysis of Soma-Lignite and Şırnak-Asphaltite were investigated. The aim of this research was to determine the volatile product distribution and product evolution rate during pyrolysis of lignite and asphaltite as a function of temperature and time. A fixed-bed reactor was used to pyrolyze small sample of lignite and asphaltite under an inert gas flow (argon). A special sampling technique was used for collecting organic products released from the reactor at different temperature and time intervals. The pyrolysis products were analyzed by both capillary gas chromatography (GC) and GC–mass spectroscopy (GC–MS) coupling. The temperature at which product evolution rate is the highest proved to be ∼430 °C both for lignite and asphaltite in pyrolysis operation. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by carbon number. The hydrocarbons produced by pyrolysis of lignite and asphaltite contained 32.4 and 30.1 wt.% of n-paraffins, respectively, at the maximum product release temperature. 1-Olefins produced by pyrolysis of lignite and asphaltite were determined and found as 10.2 and 16.6 wt.% of the pyrolytic oil, respectively. In addition, the performance of the experimental apparatus was investigated by establishing a carbon balance, and the degree of recovery of total organic carbon of the samples as aliphatic hydrocarbons and in solid residue was determined. Conversion into volatile hydrocarbons was found to be lower but the amount of carbon in solid residue was higher for lignite than for asphaltite pyrolysis.

CO-PYROLYSIS OF TURKISH SOMA LIGNITE AND ŞIRNAK ASPHALTITE. ANALYSIS OF CO-PYROLYSIS PRODUCTS BY CAPILLARY GAS CHROMATOGRAPHY TOTAL STREAM SAMPLING TECHNIQUE

Temperature-programmed co-pyrolysis of Turkish Soma lignites and Sornak asphaltite was investigated with the aim to determine the volatile product distribution and product evolution rate of co-processing. A series co-pyrolysis operation was performed using three total carbon ratios of lignite to ashpaltite. A fixed-bed reactor was used to pyrolyse small samples of mixtures under an inert gas (argon) flow. A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified by their carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The effect of Soma lignites and Sornak asphaltite co-processing was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products.

Temperature-programmed co-pyrolysis of Turkish lignite with polypropylene

Temperature-programmed co-pyrolysis of Soma-lignites form Turkey with polypropylene (PP) was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of co-processing of Soma-lignites with PP. A series co-pyrolysis operation was performed with lignites and PP using a 1:3, 1:1, 3:1 total carbon ratio of lignites to plastic. A fixed bed reactor was used to pyrolyse small sample of lignites and PP mixture under an inert gas flow (argon). A special sampling technique was used for collecting organic products released from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of co-pyrolysis products were classified by a carbon number. In addition, the performance of the experimental apparatus was investigated by establishing a carbon balance, and the degree of recovery of total organic carbon of the samples as aliphatic hydrocarbons and in solid residue was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of lignites and PP. The effect of co-processing of lignites with PP was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. Conversion into volatile hydrocarbons was found higher with increasing PP ratio in lignites–PP system while C 16+ hydrocarbons and the amount of coke deposit were lower in the presence of PP.

Classification of volatile products evolved during temperature-programmed co-pyrolysis of low-density polyethylene (LDPE) with polypropylene (PP)

Temperature programmed co-pyrolysis of low-density polyethylene (LDPE) with polypropylene (PP) was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of co-processing of LDPE with PP. A series co-pyrolysis operation was performed with LDPE and PP using a 1:3, 1:1, 3:1 total carbon ratio of LDPE to PP. A fixed bed reactor was used to pyrolyse small sample of LDPE and PP mixture under an inert gas flow (argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-paraffins and 1-olefins in aliphatic fraction of co-pyrolysis products were classified as a carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of LDPE and PP. The effect of co-processing of LDPE with PP was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. Conversion into volatile hydrocarbons was found to be higher, with the increasing PP ratio in the co-pyrolysis operation.

Thermal degradation of polystyrene

Thermal degradation of plastic wastes offers the possibility of recovering energy and useful chemicals. Polyethylene and polypropylene pyrolysis have been discussed already in previous works (E. Ranzi, M. Dente, T. Faravelli, G. Bozzano, S. Fabini, R. Nava, V. Cozzani, L. Tognotti, J. Anal. Appl. Pyrol., 40–41 (1997) 305–319 and T. Faravelli, G. Bozzano, C. Scassa, M. Perego, S. Fabini, E. Ranzi, M. Dente, J. Anal. Appl. Pyrol., 52 (1999) 87–103). This paper aims to develop a detailed kinetic model of polystyrene thermal degradation. The predictions of overall rates of degradation and volatile product distribution are compared with experimental results obtained by different authors at different pressure and temperature conditions. In order to reduce the computing times required by the numerical integration of the kinetic model, a flexible lumping procedure has also been introduced.

Supramolecular origins of product selectivity for methanol-to-olefin catalysis on HSAPO-34.

Ethylene selectivity in methanol-to-olefin (MTO) catalysis is related to the number of methyl groups on benzene rings trapped in the nanocages of the preferred catalyst HSAPO-34. By correlating the time evolutions of the catalysts' 13C NMR spectra and the volatile product distribution following abrupt cessation of methanol flow, we discovered that (in the absence of other adsorbates) propene is favored by methylbenzenes with four to six methyl groups but ethylene is predominant from those with two or three methyl groups. We substantially increased ethylene selectivity by operating at lower methanol partial pressures or higher temperatures, either of which reduces the steady-state average methyl substitution. As a step toward a kinetic analysis of the MTO reaction on HSAPO-34, we treated each nanocage with a methylbenzene molecule as a supramolecule capable of unimolecular dissociation into ethylene or propene and a less highly substituted methylbenzene. Addition of a water molecule to a nanocage containing a methylbenzene produces a distinct supramolecule with unique properties. Indeed, co-feeding water with methanol significantly increased the average number of methyl groups per ring at steady state relative to identical conditions without additional water, and also increased ethylene selectivity, apparently through transition state shape selectivity.

Classification of Volatile Products Evolved from the Temperature-Programmed Co-Pyrolysis of Turkish Oil Shales with Atactic Polypropylene (APP)

Temperature-programmed co-pyrolysis of Turkish oil shales with atactic polypropylene (APP) was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of co-processing of oil shale with APP. A series co-pyrolysis operation was performed with oil shale and APP using a 1:3, 1:1, 3:1 total carbon ratio of oil shale to plastic. A fixed bed reactor was used to pyrolyze a small sample of an oil shale and APP mixture under an inert gas flow (argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fractions of pyrolysis products were classified as a carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of oil shale1,2 and APP. The effect of co-processing of oil shale with APP was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. The effect of kerogen type of oil shale on co-pyrolysis operation was also investigated. Conversion into volatile hydrocarbons was found higher with an increasing APP ratio in the oil shale−APP systems while C16+ hydrocarbons and the amount of coke deposit were lower in the presence of APP.

Inclusion of the effects of polydispersity and volatility on the random chain scission statistical analysis for polymer degradation

The statistical product distribution for a linear polydisperse polymer of finite molecular weight was included into the statistical analysis for a system undergoing random chain scission showing the effect of volatilization of species other than monomer. Two sets of equations were derived. One set is for the nonvolatile fraction; the other is for the volatile fraction. Within each set there are three equations, one for the number of polymer molecules, the second for the molar (or number) fraction, and the third for the weight fraction of polymer molecules containing a specific number of repeat units. As degradation proceeds the polydispersity index should converge to a value of 1 rather than 2, which has been reported previously. The expected effects of polydispersity, number-average degree of polymerization, and volatility were treated individually, and we determined that the molecular weight of a polymer has no theoretical influence on the product distribution. As for the effect of volatility, we determined that only the volatile product distribution would change.

Classification of volatile products evolved during temperature-programmed co-pyrolysis of Turkish oil shales with low density polyethylene

Temperature programmed co-pyrolysis of Turkish oil shales with LDPE was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of coprocessing of oil shale with LDPE. A series co-pyrolysis operation was performed with oil shale and LDPE using a 1:3, 1:1, 3:1 total carbon ratio of oil shale to plastic. A fixed bed reactor was used to pyrolyse small sample of oil shale and LDPE mixture under an inert gas flow (Argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products were classified as a carbon number. In addition, the recovery of total organic carbon as a organic volatile products was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of oil shale1,2 and LDPE. The effect of coprocessing of oil shale with LDPE was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. The effect of kerogen type of oil shale on co-pyrolysis operation was also investigated. Conversion into volatile hydrocarbons was found lower with increasing LDPE ratio in oil shale-LDPE system while C16+ hydrocarbons and the amount of coke deposit were higher in the presence of LDPE.

95/05747 Demand for gasoline in Kuwait. An empirical analysis using cointegration techniques

Temperature programmed co-pyrolysis of low-density polyethylene (LDPE) with polypropylene (PP) was investigated. The aim of this research was to determine the volatile product distribution and product evolution rate of co-processing of LDPE with PP. A series co-pyrolysis operation was performed with LDPE and PP using a 1:3, 1:1, 3:1 total carbon ratio of LDPE to PP. A fixed bed reactor was used to pyrolyse small sample of LDPE and PP mixture under an inert gas flow (argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analyzed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-paraffins and 1-olefins in aliphatic fraction of co-pyrolysis products were classified as a carbon number. In addition, the recovery of total organic carbon as an organic volatile product was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of LDPE and PP. The effect of co-processing of LDPE with PP was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. Conversion into volatile hydrocarbons was found to be higher, with the increasing PP ratio in the co-pyrolysis operation.