Comparative analysis of pyrolysis oils and its subfractions under different atmospheric conditions

In this paper comparative analysis of bio-oils and their subfraction from static, sweeping gas and steam pyrolysis of apricot pulp, a food industry waste, was investigated. Experimental studies were conducted in a well-swept fixed-bed reactor with a heating rate of 5 °C min^{− 1}, to a final pyrolysis temperature of 550 °C. The oil yield which was 22.4% at the static atmosphere reached to the value of 23.2% in the sweeping gas atmosphere by using 100 cm³ min^{− 1} N₂ flow rate. The yield of liquid product in steam pyrolysis was higher (27.2%) than the static and inert gas atmosphere.The elemental analyses of the pyrolysis oils were determined, and the chemical compositions of the oils were investigated using chromatographic and spectroscopic techniques. The liquid products were fractionated into pentane solubles and insolubles (asphaltenes). Pentane solubles were then solvent fractionated into pentane, toluene, and methanol subfractions by fractionated column chromatograpy. The aliphatic subfractions of the oils were then analysed by capillary column gas–liquid chromatography and GC/MS. For further structural analysis, the pyrolysis oils' aliphatic, aromatic and polar subfractions were conducted using FTIR and ¹H NMR spectra.     

Removal of pentane and styrene mixtures from waste gases by a trickle‐bed air biofilter

The biofilter process is a relatively new technology that has been proven to be more cost‐effective than traditional technologies for treating many kinds of volatile organic compounds (VOCs) from waste gases. Pentane and styrene mixtures are commonly encountered in the manufacture of polymers such as polystyrene. This research attempts to employ a trickle‐bed air biofilter (TBAB) for treating such mixtures under different influent carbon loadings. In the pseudo‐steady‐state conditions, the elimination capacities of pentane and styrene increased but the removal efficiencies decreased with increased influent carbon loading. The removal efficiencies of styrene were higher than those of pentane, indicating that styrene is a preferred substrate and the differences were enhanced at a high carbon loading. Removal efficiencies of more than 80% were achieved with influent carbon loadings of pentane and styrene below 25 and 68 gm^?3 h^?1, respectively. The TBAB appears to be efficient for controlling VOC emissions with low pentane and medium styrene loadings, and the effectiveness could be maintained over 140 days of laboratory operation. © 2001 Society of Chemical Industry     

Die Photochlorierung des Pentans

The Chlorination of Pentane The kinetics of the chlorination of pentane were studied and the concentration course of the mono- and dichlorpentanes calculated with the aid of an analog-computer. The relative reactivities of different C H-bonds were determined from the rate constants. The structure of the diastereomeres formed is discussed.     

Effect of vitamin E on pentane exhaled by rats treated with methyl ethyl ketone peroxide

One useful method to monitor in vivo lipid peroxidation is the measurement of volatile hydrocarbons, mainly pentane and ethane, that derive from unsaturated fatty acid hydroperoxides. Vitamin E, the biological antioxidant, inhibits lipid peroxidation and the production of pentane and ethane. The rates of pentane production by male Sprague-Dawley rats fed a diet that contained 10% vitamin E-stripped corn oil and 0, 1, 3, 5 or 10 IU dl-α-tocopherol acetate/kg were monitored over a 12-wk period. During the eleventh and twelfth weeks, the rats were injected intraperitoneally with 3.3 and 13 mg of methyl ethyl ketone peroxide (MEKP)/kg body wt, respectively. Pentane production was then measured at intervals over a 50-min period, and the total amount of pentane produced over this time interval was estimated. An asymptotic function was found to describe the relationship between exhaled pentane and the low levels of dietary vitamin E that were fed to the rats. As measured by pentane production, rats had a higher minimal vitamin E requirement after they were treated with the potent peroxidation initiator MEKP than they did prior to treatment. The level of pentane exhaled by rats injected with 13 mg MEKP/kg body wt was significantly correlated with kidney and spleen tocopherol levels.     

The role of lipid peroxidation during chronic and acute exposure to ethanol as determined by pentane expiration in the rat

Weanling rats were fed one of 3 diets containing 0, 11 or 200 international units (IU) dl-α-tocopherol acetate/kg diet for 4 weeks. Following this period, the drinking water was replaced with an 18% solution of ethanol (v/v). An isocaloric D-glucose solution was substituted for the drinking water of a control group of rats fed the vitamin-E-deficient diet for 4 weeks. The 4 treatment groups were maintained on the diet and drinking regimen for 20 weeks. Basal levels of expired pentane were determined at weeks 0, 1, 3, 5, 7 and 9. Chronic ethanol consumption did not influence basal pentane production during the 9-week treatment. Basal levels of expired pentane were affected by dietary vitamin E. Rats supplemented with vitamin E had basal pentane levels less than one-half of the level of rats fed a vitamin-E-deficient diet (p<0.001). After 14 weeks of treatment, the 2 groups of rats fed a vitamin-E-deficient diet were administered p.o. an acute dose of 6 g of ethanol/kg body wt. Pentane expired above basal levels during the following 4-hr period correlated with the amount of hepatic triglycerides determined at the conclusion of the experiment. The etiology of ethanol toxicity is a complex and multifactorial system made up to many biological variables that influence lipid peroxidation. The appropriate choices of experimental designs and methods are important in examining the role of lipid peroxidation.     

Effects of dietary vitamin E,selenium, and polyunsaturated fats on in vivo lipid peroxidation in the rat as measured by pentane production

Starting at 21 days of age, groups of six rats each were fed a basal Torula yeast diet supplemented with 0,4% L-methionine and varying amounts of vitamin E as dl-alpha tocopherol acetate, selenium as sodium selenite, and with either 10% stripped corn oil, stripped lard, or coconut oil. By 7 wk, pentane production by rats fed a corn oil diet deficient in both vitamin E and selenium was twice that by rats fed 0.1 or 1 mg of selenium per kg of the same basal diet. Blood glutathione peroxidase activity after 7 wk was proportional to the logarithm of dietary selenium. Groups of rats fed the vitamin E- and selenium-deficient diets with lard or coconut oil had one-half the pentane production of rats fed the vitamin E- and selenium-deficient corn oil diets. The plasma level of linoleic plus arachidonic acid was 1.8 times greater on a wt % basis in rats fed corn oil than in rats fed lard or coconut oil as the fat source. Pentane production by rats fed 40 i.u. dl-alpha tocopherol acetate per kg of the selenium-deficient corn oil diet was one-sixth of that by rats fed the same diet without vitamin E; the plasma of the rats fed the vitamin E-supplemented corn oil diet had a level of vitamin E that was about six times greater than that of the rats fed the vitamin E-deficient corn oil diet.     

Pentane production by peanut lipoxygenase

Pentane and hexanal were the major volatile end-products of a peanut lipoxygenase and linoleic acid model system and were produced by both crude and purified enzyme preparations. The enzyme system did not require an anerobic condition for the production of pentane and hexanal, thus distinguishing it from other reported systems. A 122-fold purification of the enzyme was achieved.     

Viscosity of coal-derived liquids

A coal-derived liquid was separated into toluene insolubles, asphaltene and pentane soluble oil by conventional solvent analysis. The asphaltene was separated further into an acid-neutral and a basic component by a previously reported procedure from our laboratory. The viscosities of liquids reconstituted from toluene insolubles, asphaltenes, acid-neutral asphaltene or basic asphaltene in the pentane soluble oil were determined. The logarithm of the viscosity ratio is a linear function of concentration for each of the solutes. On a weight basis, the toluene insolubles produce about twice the viscosity as the asphaltenes. The viscosity of mixtures of acid-neutral and basic asphaltene in pentane soluble oil is greater than either component determined separately, presumably due to complex formation. The variation of the reduced specific viscosity with concentration indicates that aggregation of the asphaltene and toluene insoluble fractions plays a significant role in the viscosity of coal-derived liquids.     

Monitoring of headspace volatiles in milk‐cereal‐based liquid infant foods during storage

The effect of storage (time and temperature) on the evolution of pentanal, hexanal, heptanal and pentane as volatile lipid oxidation products in two liquid ready‐to‐eat milk‐cereal‐based infant foods was studied. An SPME‐GC method was used to this effect. Samples were stored for 9 months at 25, 30 and 37 °C and tested eight times during this period. Freshly produced infant foods contained pentanal, hexanal and heptanal (mean values: 10.71, 71.5 and 1.2 µg/kg, respectively), which decreased during the first 3 months of storage, although from the fourth month onwards no significant differences among storage times were found. Aldehyde content was inversely proportional to storage temperature. Pentane content was directly proportional to storage temperature and increased (19.9 µg/kg at zero time) over all months of storage up to 43.1 µg/kg.     

Mating stimulant of the pine weevilHylobius abietis (L.)

Factors eliciting copulatory behavior in mature maleHylobius abietis were studied in the laboratory. Dead female weevils were sexually attractive, while dead mature males and pentane-extracted female weevils were not. The sexual attractiveness of dead females declined with time after death. Pentane extracts of whole female weevils or of the anterior or posterior parts of their bodies elicited a copulatory response when applied to decoys. In contrast, extracts of hindgut or frass were inactive. Juvenile males were sexually attractive for about four weeks, after which their attractiveness gradually declined. The results indicate that the mating stimulant is present on the body surface of female and juvenile male weevils, and it can be extracted with pentane.     

Volatile hydrocarbon and carbonyl products of lipid peroxidation: A comparison of pentane,ethane, hexanal,and acetone as in vivo indices

A study was undertaken to determine whether respiratory hexanal and acetone as well as pentane and ethane could be measured as potential indices of lipid peroxidation in vivo. The tests of induction of lipid peroxidation in rats included injection of iron-dextran and the vitamin E deficiency status. Injection of 460 mg of iron/100 g body wt over a 28-day period increased pentane and ethane production 4- and 6-fold, respectively. Hexanal production was increased 7-fold after injection of 60 mg of iron/100 g body wt, and then it fell back to the preinjection level in spite of continued injection of iron-dextran. Acetone production was lower in iron-injected rats than in controls, and it was ca. 10-fold higher in fasted vitamin E-deficient rats than in vitamin E-supplemented rats, being ca 48 and 5 nmol/100 g/min, respectively. It was observed that halomethane injection did not increase hexanal production, while acetone and pentane production were increased. Pentane and hexanal, but not acetone, were found to arise from decomposition of linoleic acid hydroperoxide in vitro. It was concluded that hydrocarbon gases are better indices of lipid peroxidation than hexanal, which is enzymatically metabolized, and acetone, the production of which is dominated by factors such as altered carbohydrate metabolism.     

Extraction of soybeans with four hydrocarbon solvents

Soybean flakes were extracted in glass extraction apparatus with four hydrocarbon solvents: hexane, isohexane, pentane, and isopentane. The amount of extracted oil was determined at 10 min intervals for 60 min. The extraction rates of the solvents increased in the following order: isopentane, pentane, isohexane, and hexane. Quality and fatty acid composition of the oils extracted by the four solvents showed no significant differences.     

A coupled technology to produce high-purity normal and isomeric pentane with reforming topped oil

This paper investigates a coupled technology to produce the high-purity normal and isomeric pentane from reforming topped oil. The coupled technology is adsorption after rectification technology, which is better than the traditional one in product purity and energy consumption. The purity of the n-pentane and the iso-pentane obtained from the coupled technology are both higher than 99%, and the quality of pentane foamer obtained from blending the n-pentane with the pentane oil meets the Q/SHZL 0005-1999 standard.     

Untersuchungen des Reaktionsverlaufes und der Produkte der säurekatalysierten Reaktion von Phenolen mit Holzöl, 2. Vergleichende untersuchungen an verschiedenen phenolen

In this paper the acid-catalysed reaction between phenols and tung oil is investigated for 4 different phenols (phenol, o-, m- and p-cresol). This reaction is important for the production of modified resins for electrical insulating laminates. In particular by means of ¹³C-NMR- and IR-method it is proved that phenols are C-alkylated by tung oil in the manner of a Friedel-Crafts-reaction exceptionally. The reaction positions at the phenols are determined. Further, the rates of the reaction of phenol with the eleostearic acid esters are compared for the four different phenols.     

Thermo‐physical properties of n‐pentane/bitumen and n‐hexane/bitumen mixture systems

The gravity drainage as a result of viscosity reduction is the main governing mechanism of the solvent‐aided thermal bitumen recovery processes. Therefore, the density and viscosity of the diluted or heated bitumen are essential to predict the oil production rate. In this paper, we report thermo‐physical properties of n‐pentane/bitumen and n‐hexane/bitumen mixtures. The density and viscosity of Athabasca bitumen diluted with n‐pentane and n‐hexane were measured at different temperatures (30 to 190 °C), pressures (2 to 8 MPa), and solvent mass fractions (0.05 to 0.5). Various correlations and mixing rules proposed in the literature were examined to calculate the density and viscosity of the diluted bitumen. This study proposes appropriate mixing rules and generalized parameters for predicting the density and viscosity of solvent‐bitumen systems. Our findings will find applications in the design and simulation of heavy oil and bitumen solvent‐aided thermal recovery processes.     

超临界沥青喷雾造粒中的戊烷闪蒸CFD模拟

重油梯级分离技术作为重油轻质化的新工艺,它通过耦合渣油萃取和沥青喷雾造粒过程,有效的简化重油处理的工艺流程,减少设备成本。在此工艺流程中,处于超临界状态的戊烷的闪蒸速率对沥青造粒质量起到了关键作用。根据其减压过程中的质量和热量传递机理,改进了戊烷闪蒸的经验模型,并将其植入到CFD软件FLUENT中,使其能较为准确的预测闪蒸雾化的非平衡热力学过程。同时对气液戊烷和沥青的三相闪蒸流动过程进行了数值模拟,结果显示喷嘴结构是控制闪蒸速率的关键,直接影响了沥青造粒的质量;此外沥青相的加入为戊烷的相变过程提供了更多能量,提高了戊烷在喷嘴内的汽化率。     

A study of some equation‐of‐state parameters of poly(methylhydrosiloxane‐co‐dimethylsiloxane) with some solvents by gas chromatography

Trace amount of methyl acetate, ethyl acetate, tert‐butyl acetate, pentane, hexane, and heptane were passed through the chromatographic column loaded with poly(methylhydrosiloxane‐co‐dimethylsiloxane) coated on Chromosorb W. The retention diagrams of the solvents on the copolymer were plotted by means of specific retention volumes at temperatures between 40 and 80°C by inverse gas chromatography technique. In this study, some thermodynamic interaction parameters such as Flory–Huggins polymer–solvent interaction parameter, equation‐of‐state polymer–solvent interaction parameter, effective exchange energy parameter, and weight fraction activity coefficients at infinite dilution of the solvent were determined. Then, the exchange enthalpy parameter and entropy parameter were determined by using a relation for the enthalpy interaction parameter of the equation‐of‐state theory, which is arranged for the inverse gas chromatography conditions. Later, the partial molar heat of sorption and the partial molar heat of mixing were obtained. The solubility parameter of this copolymer was determined as 6.64 (cal/cm³)^1/2 at room temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1627–1631, 2007     

Über die Möglichkeiten der Raffination von Sonnenblumenöl mittels Molekulardestillation

The Possibilities of Refining Sunflower Oil with Molecular Distillation The experiment on the deacidification of sunflower oil with molecular distillation was extended to the total refining of the oil. The elimination curve of cold pressed oil is determined, the region of deacidification found out, the distillates and the residues, obtained after distillation, analysed and also the vitamine-E contents of the same are examined. The possibility of refining the cold pressed oil by repeated distillations in a small laboratory apparatus as well as in a semi-industrial plant was studied. The sunflower oil can be refined by molecular distillation in a one step process even at 40° to 50° C. At this temperature, the acid value of the oil remains under 1 and the peroxide value under 10.     

Solubility and demixing of polyethylene in supercritical binary fluid mixtures: Carbon dioxide–cyclohexane,carbon dioxide–toluene,carbon dioxide–pentane

Solubility of polyethylene in three different supercritical binary solvent systems—carbon dioxide–cyclohexane, carbon dioxide–toluene, and carbon dioxide–pentane—have been studied. Solvent compositions that lead to complete dissolution at pressures below 70 MPa have been identified. Demixing pressures have been determined for a range of polymer concentrations at temperatures up to 200°C. It is shown that the behavior of the solutions depends strongly on the fluid composition. In the composition ranges studied, solutions in cyclohexane–carbon dioxide mixtures were found to show lower critical solution temperature (LCST) behavior. It is found that the behavior of solutions in carbon dioxide–toluene and carbon dioxide–pentane mixtures shifts from upper critical solution temperature (UCST) to LCST with increasing toluene or pentane content. © 1993 John Wiley & Sons, Inc.     

Generation of protonic acid sites from pentane on the surfaces of Pt/SO42−-ZrO2 and Zn/H-ZSM5 evidenced by IR study of adsorbed pyridine

Pyridinium ion was formed from pyridine, which had been bound to Lewis acid sites on Pt/SO₄^2?-ZrO₂ and Zn/H-ZSM5 by contact with pentane vapor. Protonic acid sites were generated on these surfaces by contact with pentane. The protonic acid sites generated in the presence of pentane were eliminated when pentane was removed from gas phase. The generation of the protonic acid sites occurred above 350 K for Pt/SO₄^2?-ZrO₂ and above room temperature for Zn/H-ZSM5.