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In this study, new results of comparative research on autothermal reforming(ATR) of biofuels (hydrodeoxygenated biodiesel and long- stored biodiesel) over composite RhSC catalysts (0.24 wt.% Rh supported on structured Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl carrier) were obtained. The impact of fuel chemical composition on the catalyst performance was discussed. Hydrodeoxygenated biodiesel mainly consisted of heptadecane, other normal alkanes and small amounts of alkenes together with a portion of unreacted fatty acid ethers. RhSC exhibited syngas productivity of about 2.5 m3Lcat−1 h−1 (STP) at complete conversion of hydrodeoxygenated biodiesel without considerable by-products formation, at molar ratios O2/C = 0.54, H2O/C = 3, T =750 °C and GHSV =5000 h−1. The catalyst exhibited stable operation and no coke formation for at least 90 h on stream. Biodiesel after nine years storage, which was used in this study, contained methyl esters of saturated and unsaturated fatty acids and a large proportion of polymeric compounds. It was successfully demonstrated that even this aged biodiesel can be converted to synthesis gas over the developed Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl structured catalyst. Further optimization of the catalyst and reaction conditions (higher temperature, lower GHSV, catalyst doping by promoters) is required for reaching efficient reforming of the aged biodiesel. Nevertheless, it was demonstrated that biodiesel and hydrodeoxygenated biodiesel, which combine high energy density and renewability, were very attractive biofuels for fuel cell-based power unit applications.

The background of this study is to provide the importance of hydrocarbon seepage information that can assist in conducting a petroleum system study, the existence of seepages on the earth's surface scattered in the Barru area has never been studied in detail. Through the analysis of geological structure analysis and hydrocarbon geochemical analysis, it has provided initial information about the presence of seepage in this region. Based on the structural pattern, the seepage position appears at the lithological contact between the Barru tectonic block and the carbonate sedimentary rock of the Tonasa Formation and is also controlled by the Northwest-Southeast (NW-SE) trending direction of structural lineament. Meanwhile, seepage in Ralla, Watu, and Ullo is controlled by the Northwest-Southeast (NW-SE) trending direction of structural lineament and is placed on the sedimentary rock of the carbonate rocks of Tonasa Formation. The results of the gas chromatography and mass spectrometry (GC-MS) determination also give different indications, namely: three locations show indications of hydrocarbon seepage with the composition of the aromatic hydrocarbons benzenediol (C 8 H 10 OS) , ethanone (C 7 H 8 O 3 ) and benzenetriol (C 6 H 6 O 3 ) , two locations are including in gas seepage which is characterized by the content of ethanol (C 2 H 6 O) and phenol (C6H6O). The presence of alkane compounds (heptadecane, octadecane, and nanodecane) indicates hydrocarbon potential in Ralla Area.

This study is part of a project devoted to determining the scent of all the orchid species present in Basilicata. All the analyses were performed by using the solid-phase microextraction technique coupled with gas chromatography-mass spectrometry. The scent of eight species belonging to the Orchis genus was investigated. In the case of O. anthropophora, caryophyllene, tetradecanal and hexadecanal were the main components of the aroma, in O. purpurea, 3,5-dimethoxytoluene and elemicin were found, in O. italica, caryophyllene and 4-(3-hydroxy-2-methoxyphenyl)butan-2-one were found, in O. pauciflora, linalool and 1,4-dimethoxybenzene were found, in O. mascula, linalool was found, in O. quadripunctata, penta- and heptadecane were found, in O. provincialis, β-farnesene and farnesal were found, and in O. pallens, curcumene was the main product.

The concise synthesis of dysifragilones A and B and dysidavarones has been accomplished for the first time in a divergent way from a common intermediate. The synthetic route features an intramolecular reductive Heck reaction to construct the 6/5/6/6/-tetracycle of dysifragilones A and B and an intramolecular palladium-catalyzed α-arylation of a sterically hindered ketone to forge the tetracyclo[7.7.1.02,7.010,15]heptadecane core structure of dysidavarone C. The late-stage introduction of amino and ethoxy groups is effective.

The strong electrostatic adsorption (SEA) technique was used to prepare palladium catalysts on a graphene support to convert stearic acid to diesel-like hydrocarbon via a deoxygenation process. The pH shifts of graphene were determined, and the point of zero charge (PZC) was obtained at pH = 4.6. With a moderately low PZC, the cation Pd precursor (i.e., [Pd(NH3)4]2+—palladium tetraammine—PdTA) was preferred. In the adsorbed conditions, PdTA and the graphene surface attained the strongest electrostatic adsorption at pH = 12 and had the maximum metal surface density around 0.6 μmol/m2. The Pd loading of 5 wt% catalysts was controlled by the initial concentration of PdTA. The Pd particle size distribution was considerably uniform and had a diameter around 2–3 nm according to transmission electron microscopy (TEM). The ring pattern from electron diffraction (ED) and the spectra from X-ray diffraction (XRD) verified that the Pd metal had a face-centered cubic (fcc) crystal structure. The deoxygenation reaction was carried out and reached 99% conversion of stearic acid using 5 wt% Pd/graphene catalysts with mass of 0.6 g. The main product was straight chain hydrocarbon called heptadecane (C17H36), suggesting a decarboxylation pathway. Moreover, the diesel-like hydrocarbon (C16–C21) attained a maximum selectivity at 85.4%.

Volatile organic compounds (VOCs) comprise a wide range of compounds with low molecular weight that are released from seaweeds as secondary metabolites. Therefore, the aim of this work was to evaluate the profile of VOCs from six sub-Antarctic macroalgae by means of gas chromatography–mass spectrometry. Results indicated that the studied seaweeds contained approximately 40 different compounds found as aldehydes, ketones, hydrocarbons and alcohols, for instance. For brown macroalgae, hexanal was found in greater amounts (12.87–29.46%) followed by 2-pentylfuran (5.52–11.61%) and pentadecane (4.29–10.28%), while red seaweeds were mainly composed of heptadecane (27.79–85.12%), hexanal (1.78–11.62%) and benzaldehyde (1.36–2.87%). Further evaluation using principal component analysis showed that distinct compositions of VOCs could differentiate brown and red seaweeds. Therefore, sub-Antarctic macroalgae had their VOCs elucidated for the first time assisting in the efforts for understanding their biochemical constitution as well as supporting in further potential pharmacological and biotechnological applications.

The present study focused on the nematicidal activities of bio-molecules extracted from mushrooms against M. incognita. The experimental results revealed that the highest hatching inhibition and the juvenile mortality were recorded with the ethyl acetate fraction of cell-free culture (CFC) filtrate of Ganoderma lucidum followed by Lentinus edodes. At 1000 ppm concentration, the bio-active molecules of G. lucidum exhibited the maximum inhibition of egg hatching (92.6%) and juvenile mortality (93.2%) of M. incognita at 72 hours of incubation. GC –MS analysis of G. lucidum revealed the presence of 23 compounds viz. ., Octadecane,3-ethyl-5-(2-ethyl butyl), Decane, Undecane, 3,7-dimethyl-, Dihydroartemisinin, Benzaldehyde, 3,4-dimethyl-, Heptadecane, 2,6,10,15-tetramethyl-, 2,4-Di-tert-butyl-phenol, 1-Propanamine, Pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-,1,2-Benzenedicarboxylic acid, butyl octyl ester, n-Hexadecanoic acid, Dibutyl phthalate, 2,2,4-Trimethyl-3-(3,8,12,16-tetramethylheptadeca-3,7,11,15-tetraenyl)-cyclohexanol, Methyl stearate, Cyclohexane, Octadecanoic acid, Deoxyspergualin, Methyl glycocholate, 3TMS derivative, 1,25-dihydroxyvitamin D3, TMS derivative, Spirost-8-en-11-one, 3-hydroxy-, 1H-Indene, 1-hexadecyl-2,3-dihydro- and Bis(2-Ethylhexyl) phthalate. Among these, 2, 4-Di-tert-butyl-phenol, n-Hexadecanoic acid and Dibutyl phthalate might have been responsible for antinemic activity.

Biofuels have generated considerable interest as a direct substituent for fossil fuels due to the energy crisis and greenhouse effect. In this article, bifunctional Pt–Mo catalyst supported on activated carbon (AC) was fabricated for in situ hydrogenation of methyl stearate to alkanes using small amounts of formic acid (FA) as a hydrogen source. A total yield of 75.3% is obtained under 290 °C for 2 h with a small FA/methyl stearate mole ratio of 3.9. Prolonging the reaction time to 6 h results in a total yield of 100%. The experimental and characterization results indicate that the strong interaction of β-Mo2C and Pt over Pt–Mo/AC catalysts give rise to excellent catalytic performance and that Pt active sites are responsible for FA dehydrogenation and decarbonylation of methyl stearate to heptadecane and Pt-doped β-Mo2C active sites catalyzing hydrodeoxygenation of methyl stearate to octadenane. This catalyst is stable during three recycles and is versatile for various feedstocks.

The corrosion response of mild steel in 0.5 M H2SO4 acid solution in the presence of Moringer oliefera (MO) leaf extract was investigated using gravimetric, electrochemical, and DFT techniques. Gravimetric results indicate that MO exhibits a high inhibition value up to 93.0% when the concentration was 1.5 g/L. Inhibition value in general increased with an increase in concentration of the extracts but decreased with prolonged exposure time and temperature. Analysis of polarization curves indicated that MO extract acted as mixed-type inhibitors. The adsorption process of MO on a mild steel surface in the acid solution fitted the Langmuir isotherm. GC/MS analysis of MO extract revealed the presence of more than 29 active constituents including 9,12-Octadecadienoic acid (Z, Z) methyl ester (28.55%); n-Hexadecanoic acid (11.24%); 9,12,15-Octadecatrienoic acid methyl ester (9.31%), Benzeneacetonitrile, 4-hydroxy-(6.32%), 2-Furancarboxaldehyde,5-(hydroxymethyl)-(5.6%), Heptadecane (4.85%). Quantum chemical calculations were applied on some of the identified constituents to assess their adsorbability on the mild steel surface and the result revealed remarkable high interaction energies.

This study aimed to investigate the insecticidal activity and toxicity durability of Plantago major seed (PMS) extract loaded nanoliposomes against Tribolium castaneum. The major constituents of PMS extract were determined by GC–MS: benzene dicarboxylic acid (23.49%), dodecane (9.17%), 1-ethynylcyclopentanol (7.36%), heptadecane (6.47%) and cyclohexanol (4.56%). The Characterization of Plantago major seed extract loaded nanoliposomes was investigated by SEM, DLS, ζ-potential, FTIR, and encapsulation efficiency. The mean particle size distribution of PMS nanoliposomes is 50 ± 1.8 nm with PDI 0.41 ± 0.014. The ζ-potential of PMS extract loaded nanoliposomes was equal to − 27.23 ± 5.31 mV. The encapsulation efficiency of nanoliposomes containing PMS extract was 96%. PMS extract loaded nanoliposomes have a spherical shape. FTIR reveals interactions of the PMS extract in nanoliposome structures with phospholipid groups. To determine the insecticidal potential of Plantago major seed extract nanoliposomes were impregnated with concentration (10, 25, 40, 65, 80, and 100 mg/ml). During fumigant testing, the LC50 of the Plantago major seed extract was 39.30 mg/ml against Tribolium castaneum adults after 72 h of exposure time. The requirement decreased to 35.50 mg/ml after the nanoencapsulation of plant extract for 72 h of exposure of time. The mortality percentage of Tribolium castaneum by PMS extract and PMS extract loaded nanoliposomes (V: 100 mg/ml) for 60 days after the production of samples 16.25% and 62.50%., respectively. The release percentage of Plantago major seed extracts loaded nanoliposomes was 54% after 24 h. The conclusions of this study indicate that nano-encapsulated Plantago major seed extracts have good effects on the pest, and can be an effective alternative to synthetic pesticides. Graphic abstract Plantago major seed (PMS) extract loaded nanoliposomes have a good insecticidal effect on Tribolium castaneum.

Fatty acids (FAs) and volatile organic compounds (VOCs) are among bioactive substances produced by macroalgae, which have important reported biological activities. The aim of this work was to determine the diversity of FAs and VOCs in brown, green, and red Antarctic macroalgae. Results showed that seaweeds contained 13 to 25 FAs with a predominance of palmitic, oleic, linoleic, and eicosapentaenoic acids. Concerning VOCs, 28 to 55 distinct compounds could be detected, distributed among aldehydes, hydrocarbons, furan derivatives, and ketones, for instance. Generally, hexanal (5.83%–25.51%), heptadecane (0.92%–49.84%) and 2-pentylfuran (3.02%–12.57%) were found in considerable amounts in the analyzed specimens. It is worth noting that, to the best of our knowledge, this was the first time that Antarctic macroalgae had their VOCs elucidated. Therefore, Antarctic seaweeds were composed of several VOCs and FAs which could assist in the elucidation of secondary metabolites from these organisms.

International audience; Plastics generally play a very important role in a plethora of industries, fields and our everyday lives. In spite of their cheapness, availability and important contributions to lives, they however, pose a serious threat to the environment due to their mostly non-biodegradable nature. Recycling into useful products can reduce the amount of plastic waste. Thermal degradation (Pyrolysis) of plastics is becoming an increasingly important recycling method for the conversion of plastic materials into valuable chemicals and oil products. In this work, waste Polyethylene terephthalate (PET) water bottles were thermally converted into useful gaseous and liquid products. A simple pyrolysis reactor system has been used for the conversions with the liquid product yield of 65 % at a temperature range of 400°C to 550°C. The chemical analysis of the pyrolytic oil showed the presence of functional groups such as alkanes, alkenes, alcohols, ethers, carboxylic acids, esters, and phenyl ring substitution bands. The main constituents were 1-Tetradecene, 1-Pentadecene, Cetene, Hexadecane, 1-Heptadecene, Heptadecane, Octadecane, Nonadecane, Eicosane, Tetratetracontane, 1-Undecene, 1-Decene). The results are promising and can be maximized by additional techniques such as hydrogenation and hydrodeoxygenation to obtain value-added products.

The SPME-GC-MS analysis of the aroma components of Serapias cordigera, Serapias cordigera subsp. lucana, Serapias vomeracea, Serapias lingua, and Serapias parviflora were reported. The relevant components of the scent of Serapias cordigera were α-amorphene, ethyl oleate, heneicosane, heptadecane, 2-heptadecanone, ethyl elaidate, pentadecane, octadecane, farnesylacetaldehyde, nonadecane, and ethyl stearate. Serapias cordigera subsp. lucana gave α-amorphene, pentadecane, propyl undecanoate, heptadecane, ethyl elaidate and oleate, ethyl stearate, and 8-heptadecene. Serapias vomeracea showed pentadecane, 5-nonadecene, 1-nonadecene, 3-heptadecene, benzyl benzoate, 2-undecanone, and octadecane. Serapias lingua showed the presence of heptadecane, 3-heptadecene, isopropyl myristate, pentadecane, nonadecane, isopropyl palmitate, octadecane, and benzyl benzoate. Serapias parviflora gave pentadecane, pentadecene, hexadecane, heptadecane, nonadecane, and ethyl elaidate.

Deoxygenation of fatty acids into liquid hydrocarbons is an efficient method of producing second-generation biofuels from biomass. Herein, we report efficient upgrading of stearic acid into a long-chain hydrocarbon at relatively low reaction temperature (140–220 °C) over a commercial Ru/C catalyst. The conversion process is predominantly through the hydrodecarboxylation pathway and not hydrodeoxygenation since heptadecane and not octadecane is found as the main product with the detection of CO2 in the gaseous products. The effects of process parameters including the solvent type (hexane, dodecane, isopropanol, water, and solvent-free), solvent volume, hydrogen pressure, catalyst loading, mass of feedstock, reaction temperature and reaction time on the conversion of stearic acid were systematically studied and optimized and the reusability of the catalyst was also studied. Hexane is found to be the most suitable solvent for the catalytic system. Under the optimized reaction conditions, 100% stearic acid conversion can be achieved at even 160 °C alongside a 90.1% yield of heptadecane. The apparent activation energy of the hydrodecarboxylation process over the commercial Ru/C catalyst was calculated to be 58.6 kJ mol−1. Notably, the reusability potential of the Ru/C catalyst is slightly limited by the accumulation of carbon deposits across multiple usage cycles.

Orchids are rich treasure troves of various important phytomolecules. Among the various medicinal orchids, Ansellia africana stands out prominently in the preparing of various herbal medicines due to its high therapeutic importance. The nodal explants of A. africana were sampled from asymbiotically germinated seedlings on basal Murashige and Skoog (MS) medium and were micropropagated in MS medium supplemented with 3% sucrose and 10 µM meta topolin (mT) + 5 µM naphthalene acetic acid (NAA) +15 µM indole butyric acid (IBA) + 30 µM phloroglucinol (PG). In the present study, the essential oil was extracted by hydrodistillation and the oleoresins by the solvent extraction method from the micropropagated A. africana. The essential oil and the oleoresins were analysed by Gas Chromatography (GC) and GC/MS (Mass spectrometry). A total of 84 compounds were identified. The most predominant components among them were linoleic acid (18.42%), l-ascorbyl 2,6-dipalmitate (11.50%), linolenic acid (10.98%) and p-cresol (9.99%) in the essential oil, and eicosane (26.34%), n-butyl acetate (21.13%), heptadecane (16.48%) and 2-pentanone, 4-hydroxy-4-methyl (11.13%) were detected in the acetone extract, heptadecane (9.40%), heneicosane (9.45%), eicosane (6.40%), n-butyl acetate (14.34%) and styrene (22.20%) were identified and quantified in the ethyl acetate extract. The cytotoxic activity of essential oil and oleoresins of micropropagated A. africana was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay on Vero cells compared to the standard drug doxorubicin chloride. The present research contains primary information about the therapeutic utility of the essential oil and oleoresins of A. africana with a promising future research potential of qualitative and quantitative improvement through synchronised use of biotechnological techniques.

Two novel phloroglucinol-terpenoid adducts (1 and 2), featuring a rare 2,2,4-trimethyl-cinnamyl-β-triketone unit, were isolated from the buds of Cleistocalyx operculatus. Their structures with absolute configurations were established by spectroscopic analyses, single-crystal X-ray diffraction, and quantum chemical calculations. Structurally, compound 1 represents a new carbon skeleton possessing a densely functionalized tricyclo[11.3.1.03;8]heptadecane bridged ring system with an unusual bridgehead enol. Compounds 1 and 2 exhibited significant in vitro antiviral activities against respiratory syncytial virus (RSV).

BACKGROUND: Oils derived from plants, animal fats, and algae contain both saturated and unsaturated fatty acids. These fatty acids can be converted into liquid fuels and chemicals in the presence of active solid catalysts. RESULTS: Nickel‐based catalysts were supported on mordenite via ion exchange synthesis and evaluated for the deoxygenation of stearic acid to diesel fuels. By tuning the synthesis pH, loadings of over 20 wt% Ni were obtained. Catalysts synthesized at pH 8.5 displayed the highest Ni loading and the highest activity for the decarboxylation/decarbonylation of stearic acid under inert nitrogen gas atmospheres, yielding 47% heptadecane. Characterization included scanning transmission electron microscopy‐energy‐dispersive spectroscopy (STEM‐EDS), X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), inductively coupled plasma atomic emission spectroscopy (ICP‐AES), N₂ physisorption and thermogravimetric analysis (TGA), providing new insights into the recyclability of the catalyst. The observed loss of catalytic activity upon recycling was attributed to the agglomeration of Ni nanoparticles and the accumulation of carbonaceous coke. CONCLUSION: This work demonstrates that Ni‐based catalysts supported on mordenite zeolite can effectively convert stearic acid into heptadecane. Yields to heptadecane were as high as 47%. Mechanistically, the reaction proceeds by decarboxylation and decarbonylation pathways. © 2019 Society of Chemical Industry

Periconiastone A (1), an ergosterol with an unprecedented pentacyclo[8.7.0.01,5.02,14.010,15]heptadecane system, was isolated from Periconia sp. TJ403-rc01. Its structure was assigned by extensive spectroscopic analyses and quantum-chemical 13C NMR and ECD calculations. A vinylogous α-ketol rearrangement and an aldol condensation reaction during biosynthesis were proposed as key steps for the formation of 1. Compound 1 showed antibacterial activity against Gram-positive S. aureus and E. faecalis with MIC values of 4 and 32 μg/mL, respectively.

Aliphatic hydrocarbons in the surface ocean are derived from phytoplankton and oil, but the coexistence and cycling of these two sources is not well-defined. Moreover, phytoplankton and oil can cre...

Selective production of octadecane through the hydrodeoxygenation of oleic acid in hexane containing pressurized CO2, a green reaction media, using a mesocellular foam (MCF) supported Fe-Pd-Ni/MCF catalyst was demonstrated in this study. In addition to hexane containing pressurized CO2 playing a key role in directing the hydrotreatment of oleic acid towards hydrodeoxygenation over decarboxylation/decarbonylation, the use of MCF as the support helped achieve higher selectivity for octadecane, the major hydrodeoxygenation product while at the same time completely negating heptadecane, the decarboxylation/decarbonylation product. Negligible diffusion resistance aided by the 3-dimensional cage like structure and large pore opening of MCF, plus a better dispersion of the catalyst were identified as major reasons for enhancement of octadecane yield. An octadecane yield of 93% at 4 h was achieved through an optimization of temperature to 278 °C and a H2 pressure to 40 bars, while the CO2 pressure was kept constant at 20 bars. The activation energy for the hydrodeoxygenation of stearic acid to octadecane was observed to be a 43.6% reduction over the existing literature. An increased spillover of H2 onto the surface of Fe nanoparticles, triggered by an increased sticking capability of H2 on Pd-Ni alloy patches formed on the top Fe nanoparticles, was proposed as the major reason for this acceleration. The proposed catalyst could not only avoid production of undesired decarbonized product heptadecane but also reduce energy requirement to achieve higher yield over reported data due to the lowering of temperature and time, indicating its superiority.

Nonvariant equilibrium points in diphenyl oxide–n-heptadecane and biphenyl–diphenyl oxide–n-heptadecane systems are calculated according to Schroeder–Le Chatelier’s method. The experimental studies of the binary and ternary eutectic systems by DSC method are planned using the calculated data. The melting points and compositions of binary and ternary eutectics are determined. Calculated and experimental data are compared. Densities and flash points in open cup are measured.

Pt/C has a good performance for decarboxylation of oleic acid, but its catalytic stability needs further improvement. In this work, metal oxide films with controllable thicknesses were synthesized using atomic layer deposition to protect the Pt in the Pt/C to increase its catalytic stability. Compared to Pt/C, which showed only a 17% yield of heptadecane at the fourth catalytic cycle, the Pt/C deposited with porous Al2O3 films after high-temperature calcination showed improved catalytic stability that still obtained a 41% yield of heptadecane at the fourth catalytic cycle. These findings are important for improving the stability of noble metal–based catalysts and reducing the cost of industrial biofuel production.

Interactions between water and hydrocarbons play a significant role in chemical, physical, and biological processes. Here, we present a set of force-field (FF) parameters that define the interactions between coarse-grained (CG) hydrocarbon models ( An , Y. J. Phys. Chem. B , 2018 , 122 , 7143 - 7153 ) and one-site water model ( Bejagam , K. K. J. Phys. Chem. B , 2018 , 122 , 1958 - 1971 ) developed in our recent work. The nonbonded FF interactions between various hydrocarbon beads and the water beads are represented by the 12-6 Lennard-Jones potential. The FF parameters were optimized to reproduce the experimentally measured Gibbs hydration free energies of selected hydrocarbon models (decane and hexadecane with 2:1 mapping scheme and nonane and pentadecane with 3:1 mapping scheme) and the interfacial tensions of decane and nonane models at 300 K. The predicted values of Gibbs hydration free energies of CG decane, hexadecane, nonane, and pentadecane models by the optimized FF parameters were within 8, 12, 11, and 4% of their corresponding experimental values, respectively. These new optimized FF parameters were transferable when used to calculate the Gibbs hydration free energies of different hydrocarbons ranging from pentane to heptadecane at 300 K (minimum error ∼0.5%, and maximum error ∼40.8%). Furthermore, the interfacial tensions of the CG hydrocarbon models calculated by using these new FF parameters showed good agreement with their corresponding experimental values at 300 K. Homogeneous mixtures of CG water and hydrocarbon models were able to exhibit the phase segregation during 1 μs. These new nonbonded interaction parameters were expected to be utilized in modeling the interactions between water and polymer backbones represented with hydrocarbon beads.

The liquid-liquid coexistence curves in a temperature range of about 10 K from the upper consolute critical temperature for binary solutions of {dimethyl carbonate + pentadecane} and {dimethyl carbonate + heptadecane} have been precisely measured. The upper consolute mole fraction xc of n-alkane and the upper consolute temperature Tc were determined to be xc = 0.210, Tc = 312.234 K for {dimethyl carbonate + pentadecane} and xc = 0.183, Tc = 320.496 K for {dimethyl carbonate + heptadecane}, respectively. From the data collected in the near critical point, the critical exponent β was deduced and shown to be consistent well with its theoretical value for the 3-D Ising universality class. The dependences of critical properties on the chain length of n-alkane for a series of {dimethyl carbonate + n-alkane} binary solutions were investigated. Furthermore, it was found that the asymmetric behaviors of the coexistence curve could be well described by the complete scaling theory. The contribution of the heat capacity related term to the asymmetric behaviors of the coexistence curves was discussed.

Highly active Zn–Al composite oxides were synthesized via a hydrothermal process followed by thermal treatment and were used as supports to prepare Ni-based hydrogenation catalysts for catalytic deoxygenation of oleic acid, stearic acid, and 1-octadecanol. The results showed that increasing the temperature of hydrothermal synthesis changed the morphology of the Zn–Al composite oxides from sheet-like structures to spheroidal structures. High hydrothermal synthesis temperatures enhanced the interaction between Zn and Al atoms, resulting in more ZnAl2O4 spinel phase. This phase not only improved the chemical stability of the support but also supplied strong basic sites which efficiently inhibited the formation of by-products and increased the yield of heptadecane in the catalytic deoxygenation of oleic acid. Stearic acid and 1-octadecanol could be readily transformed to alkanes in the presence of metallic Ni and ZnAl2O4 phase. Decarbonylation of the octadecanal intermediate and dehydrogenation of 1-octadecanol were key reaction pathways to produce heptadecane, in which decarbonylation was catalyzed by metallic Ni, while the dehydrogenation was attributed to synergistic catalysis between metallic Ni and the strong basic sites of the support. Individual metallic Ni only catalyzed the cleavage of C–H bonds but did not affect the O–H bond of 1-octadecanol.

Larval Diaphania indica (Saunders) (Lepidoptera: Crambidae) cause complete defoliation of Trichosanthes anguina L. and reduce crop yield in India. Females lay eggs on the leaf surface, and therefore leaf surface waxes are potentially involved in host selection. Alkanes and free fatty acids are the major constituents of leaf surface waxes, so a study was conducted to determine whether these wax constituents from three T. anguina cultivars (MNSR-1, Baruipur Long, and Polo No.1) could act as short-range attractants and oviposition stimulants in D. indica females. Twenty n-alkanes from n-C14 to n-C36 and 13 free fatty acids from C12:0 to C21:0 were detected in the leaf surface waxes of these cultivars. Heptadecane and stearic acid were predominant among n-alkanes and free fatty acids, respectively, in these cultivars. Females showed attraction towards one leaf equivalent surface wax of each of these cultivars against solvent controls (petroleum ether) in Y-tube olfactometer bioassays. A synthetic blend of heptadecane, eicosane, hexacosane, and stearic acid, a synthetic blend of hexacosane and stearic acid, and a synthetic blend of pentadecane and stearic acid comparable to amounts present in one leaf equivalent surface wax of MNSR-1, Baruipur Long, and Polo No.1, respectively, were short-range attractants and oviposition stimulants in D. indica. Female egg laying responses were similar to each of these blends, providing information that could be used to developing baited traps in integrated pest management (IPM) programs.

Solid-liquid phase change materials (PCMs) have been preferred for solar passive thermal energy storage (TES) applications. However, low thermal conductivity and leakage issue of molten PCMs considerably restrain their TES potential. In this framework, n-Heptadecane (HD) as a solid-liquid PCM was incorporated with carbonized lemon peel (CLP) for development of a novel leak-proof composite PCM. Chemical compatibility between the constituents of the leak-proof composite PCM was examined by using FTIR spectroscopy and XRD diffraction analyses. The DSC results revealed that the developed leak-proof CLP/HD composite PCM had a melting temperature of 19.79 °C and LHS capacity of 141.8 J/g. The composite PCM exposed venerable thermal degradation stability after a 1000-cycling heating-cooling process. Thermal conductivity of the CLP/HD composite PCM (0.46 W/m.K at 10 °C) was measured as approximately 77% higher than that of pristine HD (0.26 W/m.K at 10 °C). © 2021 Elsevier B.V.

In this study, we describe a proof-of-concept investigation of the potential and limitations of employing channel occlusion for sample preparation in untargeted analysis in petroleomics. A middle petroleum distillate composed of fatty acid methyl esters (FAME) and a complex mixture of linear, branched, and cyclic hydrocarbons were selected as the model samples for this investigation. A microfluidic device was engineered to overcome the limitations of channel occlusion, resulting in a quick and robust method for sample preparation. The 3D-printed device using fused deposition modelling (FDM) allowed the combination of a 13-h multi-step sample handling protocol into a 2-min single-step procedure, which is also automation-friendly. Such developments were also evaluated using the analytical eco-scale to guide the development of a green analytical method. The relative standard deviation decreased 2-fold with method miniaturization. The efficiency of n-alkane removal was extended from tridecane (n-C13) to heptadecane (n-C17), compared to original method (n-C16 to n-C17). The analytical performance of the method was investigated for untargeted analysis. The tool used to probe the intra- and inter-class variance was multi-way principal component analysis (MPCA). MPCA modelling revealed that both methods generated equivalent chemical information, highlighting the benefits of reliable and reproducible sample preparation methods, especially for untargeted analysis. Such awareness is critical to avoid the generation of misleading results in fields that heavily rely on untargeted analysis and fingerprinting, such as petroleomics.

To obtain high thermal performance composite phase change materials (PCMs), various other supporting materials have been utilized to encapsulate organic PCMs. In this study, four carbon materials (biochar, activated carbon, carbon nanotubes, and expanded graphite) were introduced to support heptadecane. The composite PCMs were designed using vacuum impregnation techniques. The structural stability, chemical compatibility, thermal stability, and thermal energy storage capacity of the as-prepared materials were systematically characterized using differential scanning calorimetry, Fourier-transform infrared spectroscopy, etc. Among the supporting materials, expanded graphite had a high PCM content of 94.5%, whereas it was low for biochar-supported PCM (25.7%). Meanwhile, the latent heat storage capacity ranged from 53.3 J/g to 195.9 J/g. It was observed that the intermolecular interactions between the PCM and supporting materials and the surface functionality of the encapsulating agents play a leading role in the thermal performance of the composite PCMs. Furthermore, pore structures such as specific surface area, total pore volume, and pore size distribution have a combined effect on the crystallinity of heptadecane in the composite PCMs. The study will provide insight into developing and designing carbon-based composite PCMs for heat-storage purposes.

The paper investigates the effect of thermo‑optic switching resulting from the hybrid combination of a tapered optical fiber (TOF) with alkanes doped with nanoparticles of zinc sulfide doped with manganese (ZnS:Mn NP). Presented measurements focused on controlling losses in an optical fiber by modification of a TOF cladding by the alkanes used, characterized by phase change. Temperature changes cause power transmission changes creating a switcher or a sensor working in an ON‑OFF mode. Phase change temperatures and changes in the refractive index of the alkane used directly affected power switching. Alkanes were doped with ZnS:Mn NPs to change the hysteresis observed between ON‑OFF modes in pure alkanes. The addition of nanoparticles (NPs) reduces the difference between phase changes due to improved thermal conductivity and introduces extra nucleating agents. Results are presented in the wide optical range of 550&ndash, 1200 nm. In this investigation, hexadecane and heptadecane were a new cladding for TOF. The higher alkanes were doped with ZnS: Mn NPs in an alkane volume of 1 wt.% and 5 wt.%. The thermo‑optic effect can be applied to manufacture a thermo‑optic switcher or a temperature threshold sensor.

Trichlorobiphenyl (TCB) is a persistent toxic organic compound and exerts more hydrophilicity than other polychlorinated biphenyl (PCB) compounds. PCBs have been used on large scale in transformer oil. To observe the strong ozone oxidation effect on the degradation of TCB in aqueous medium, synthetic wastewater was prepared from transformer oil with TCB. Microbubbles ozonation of TCB was done in order to completely oxidize it. A batch treatment system was used for 60 min in glass column with a diffuser at the bottom to convert ozone gas into microbubbles. GCMS analyzed TCB and other toxic compounds before and after the treatment. TCB was reduced to below detection limit during the first 20 min of ozonation. Ethylbenzene and 1-chloroheptacosine were identified after 10 and 20 min, the concentrations of these compounds increased to 1.45 and 3.9 mg/L after 60 min. Alkane with chlorine containing compounds were identified more than any other compounds. The alkanes compounds with chlorine, such as tetradecane 1-chloro, hexadecane 1-chloro, heptadecane 1-chloro, octadecane 1-chloro and nonadecane 1-chloro were found during 60 min of ozonation. Chemical oxygen demand (COD) in the wastewater reduced from 700 to 390 mg/L. Small increase in pH was observed from 7.7 to 8.3. In this study it was concluded that TCB and other pollutants in transformer oil were degraded with ozone dose, 0.05 g/min L in the shortest period of 60 min., Environmental chemistry; Environmental engineering; Environmental hazard; Environmental pollution; Environmental toxicology; PCBs; Trichlorobiphenyl; Degradation; Ozonation; Diffuser; Oxidation and wastewater

The hydrocarbon pattern in the floral scent of Yucca species was found to comprise a group of unbranched, mid-chain alkanes, alkenes, and an alkadiene. In Y. reverchonii, highly dominant (Z)-8-heptadecene is accompanied by (6Z,9Z)-6,9-heptadecadiene and heptadecane as minor components and by traces of other saturated and unsaturated hydrocarbons with similar chain length. Some of these volatiles proved to be perceived by the antennae of Tegeticula cassandra (pollinating seed-eater of Yucca) and Prodoxus decipiens (herbivore on Yucca). The possible biosynthesis of the compounds is discussed.

Acidic hydrolysis process of wet microalgae is a worthy technique to reduce the processes and energy of the production. To aim the alternative fuel as a biofuel feedstock from wet microalgae, the Spirulina platensis containing high moisture, 88–95 wt%, was representative in this research. Microalgae cell disruption by acidic hydrolysis was investigated using various concentrations of sulfuric acid with the hydrolysis temperature in the range of 25–100 °C and hydrolysis time in the range of 30–120 min. The acid-hydrolyzed lipid was extracted from the mixture by solvent extraction using n-hexane. The maximum lipid concentration from acidic hydrolysis was 17.15 wt% that obtained at hydrolysis temperature of 100 °C for 60 min and then extracted with 700 mL of hexane for 30 min. The physical and chemical analyses of the lipid and microalgae solid residue were examined. According to the research results, the higher heating values of hydrolyzed lipid were found in the range of 32–40 MJ/kg and their main chemical components were hexadecane, heptadecane, and palmitic acid. The boiling point ranges of the hydrolyzed lipid were mainly indicated in the fractions of light and heavy gas oils which may be generated in term of biofuel feedstock for automobile fuels.

Decarboxylation of fatty acids using sub or supercritical water is a renewable pathway for producing fuel range hydrocarbons with high selectivity without an added external source of H2. Activated carbon (AC) has been shown as an effective catalyst for decarboxylation of fatty acids to fuels but it has limited life and an unknown surface chemistry for this catalysis. This study investigates the stability (time on stream) and surface chemistry of AC for the decarboxylation of oleic acid in a bench scale continuous reactor system at 400 °C, 2 h of space time and water to oleic acid ratio of 4:1. AC was found to be effective until 30 h time on stream (out of 45 h), providing 91% degree of decarboxylation constantly. The degree of decarboxylation declined afterwards, dropping from 91 to 50% after 45 h time on stream due to deactivation. The thermal regeneration of deactivated AC was examined using potassium hydroxide (KOH) treatment at 750 °C which helped to regain the physical and catalytic properties of AC. The degree of decarboxylation of oleic acid using fresh and regenerated AC were 91% and 87%, respectively. On the other hand, the selectivity of heptadecane obtained using fresh and regenerated activated carbon was 89.3% and 81.2%, respectively. Decarboxylated liquid products using fresh and regenerated activated carbon gave a similar density and HHV’s as commercial fuels, showing the utility of this approach.

In this work, a series of ZrO2-supported Cu, Ni and bimetallic Cu-Ni catalysts were synthesized and evaluated for their activity and stability in the in situ hydrogenation and decarboxylation of oleic acid using methanol as a hydrogen donor. High-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM), energy dispersive X-ray spectroscopy (EDS-mapping), X-ray diffraction (XRD) and temperature programmed reduction (TPR) characterizations revealed that the as-synthesized Cu-Ni/ZrO2 was a Cu-Ni alloy that was highly dispersed on mixed m-ZrO2 and t-ZrO2. The bimetallic Cu-Ni/ZrO2 nanostructures not only exhibited better catalytic activity for the conversion of oleic acid compared to monometallic Cu/ZrO2 and Ni/ZrO2 catalysts but also demonstrated good reuse performance. The formation of the Cu-Ni alloy facilitated the decarboxylation reaction and inhibited the cracking reaction, leading to enhanced catalytic performance. The good stability of Cu-Ni/ZrO2 was primarily due to the good hydrothermal stability of the ZrO2 support.

Two new triazaspiro tetracycles have been synthesized, the compounds have been characterized using spectroscopy, microanalysis and single crystal X-ray diffractometry. The single crystal X-ray crystallography of 4-methyl-8 I ,10 I ,17 I -triazaspiro[cyclohexane-1,9 I -teracyclo[8.7.0 2,7 .0 11,16 ]heptadecane]-1 I (17),2 I (7 I ),3 I ,5 I ,11 I ,13 I ,15 I -heptaene (compound I ) has been discussed. The DFT computed bond angles have been obtained for both compounds and contrasted with experimental results for compound I . The atoms that make up the frontier orbitals which contribute to the reactivity of the compounds have been discussed.

Diunsaturated linoleic acid was deoxygenated in H2, CO2, and N2 atmospheres over 0.3 wt % Pt/ZIF-67/Zeolite 5A bead catalysts. Nearly complete conversion was observed in H2 and N2 atmospheres (≥95%...

The mirage of bioactive compounds in essential oil (EO) has raised its prospects as an alternative to synthetic chemicals preservatives. The yields of the hydro-distilled EO from the leaf and stem-bark of Adansonia digitata were: 0.302% and 0.403%; while identified compounds were: 23 and 40 respectively. The principal chemical constituents of the EO were: hydrocarbons, alkene alcohol, cyclic ketonic ether, terpenoids, amides, esters. Tetramethyl-2-hexadecen-1-ol (26.31%), 8-dimethyl-2-(1-methylethenyl) (8.20%), Tetracosan (6.54%), Heptacosane (5.81%) and Tetratetracontane (5.59%) were dominant compounds in the leaves EO. While, the major compounds of the stem-bark EO were: Octadecane (9.30%), Cyclopentane (8.81%), 1-Octadecanesulphonyl chloride (8.73%), Heptadecane (8.50%), Eicosane (8.34%), and Tetracosan (7.12%). The antimicrobial activity of the EO against post-harvest decay of tomato fruits stored at room temperature (27±2 °C) indicated significant (P

Ni/AC (nickel on active carbon) catalysts with different Ni loadings were synthesized and studied for the decarboxylation and aromatization of oleic acid in the absence of H2 or hydrogen donors. Without the use of hydrogen source, the whole deoxygenation process became more economical. Moreover, oleic acid can be saturated using the H2 derived from the production of aromatics, which were also considered as the critical component in aviation biofuels. The structure and properties of the catalysts were investigated using X-ray diffraction, transmission electron microscopy, and temperature-programmed desorption of CH3COOH and CO. The experimental and characterization results revealed that 30% Ni/AC had a higher adsorption capacity of CH3COOH among the other Ni/AC catalysts and highly dispersed and small Ni particles, providing a heptadecane yield of 40.7%. It also contained 13.8% aromatics, which fulfills the requirement of aviation fuels. This Ni/AC catalyst showed good stability even after being reused thrice.

A novel extraction technique is proposed in which the Multiple Headspace Extraction (MHE) approach is used in conjunction with Headspace Sorptive Extraction (HSSE) and Gas Chromatography-Mass Spectrometry (GC–MS) detection. The extraction method was developed to determine volatile compounds in macroalgae. Optimization of the extraction parameters was carried out using design of experiments to identify factors that affect the extraction: extraction time, temperature, twister length and amount of sample. The results of the optimization led to an extraction of 2 g of sample using a 20 mm Twister® at 66 °C for 180 min. The progression constants (β) were calculated for 43 volatile compounds, 29 of which could be quantified using the method. Linearity was attained with a determination coefficient higher than 0.99 for all studied compounds. Inter-day and inter-twister precisions ranged from 0.22% to 19.01% and from 0.69% to 14.76% respectively, and values below 10% were obtained for the majority of compounds. LOD and LOQ values ranged from the values obtained for diethyl succinate (0.012 μg/L and 0.088 μg/L, respectively) and those obtained for dimethyl sulfide (5.544 μg/L and 40.286 μg/L, respectively). However, for the majority of compounds values obtained were below 1 μg/L (LOD) and 5 μg/L (LOQ). Compounds such as ethyl acetate, hexanal, heptadecane, 2-hexenal, 6-methyl-5-hepten-2-one, dimethyl sulfide, benzyl alcohol, beta ionone, or beta cyclocitral, among others were correctly determined in three species of macroalgae: Ulva sp., Gracillaria sp. and Enteromorpha sp.

Fatty acids are considered as a renewable feedstock for the production of high value products such as fuel-range hydrocarbons. Decarboxylation can produce high quality fuels from fatty acids, although either high pressure or additional hydrogen is required. This study investigated a low pressure (