Wax Content Research Articles

Origin and hydrocarbon source of the Ordovician high wax content oil in Southern Slope Zone of Dongying Depression

Exploration has inevitably extended into deep layers with ever-increasing exploration for oil and gas. Oils from Ordovician burial hill are recently discovered from Ordovician burial hill in the south slope of Dongying Depression, Bohai Bay basin, and the oils are characterized by high content of waxy alkanes with a low concentration of biomarker and sulphur content. Several types of oils also existed in the south slope of Dongying depression, such as biodegraded oil, normal oils in Shahejie Formation and high wax oils in Kongdian Formation. Forty-three oil samples and twenty-three source rock samples are finely analysed by inclusion analysis, monomer hydrocarbon isotope analysis and absolute content of biomarkers. On the basis of isotope compositions, biomarkers and integrating the physical properties of the hydrocarbons including densities and PVT relationships, it can be speculated that the oils from Ordovician buried hill and Kongdian Formation have the same source, obviously different from the overlying oils from Shahejie Formation. Combined with maturity parameters, biomarkers, and inclusions analysis, it is speculated that the oils are a secondary hydrocarbon accumulation from the mixing of earlier formed oil and a late formed gas, and the oils of Ordovician and Kongdian bear a typical features of deep Es4 source rocks. Aquatic organism, higher plants and bacteria are the source of the waxy oil, and the gas invasion in geological history should be responsible for the formation of the high waxy oils. This study is helpful for unravelling hydrocarbons accumulation mechanisms and deep petroleum resources evaluation in this area. Besides, the research process in this paper can also be applied to other basins to explore for high wax oil reservoirs.

Rapid and simultaneous determination of physical and chemical properties of asphalt by ATR-FTIR spectroscopy combined with a novel calibration-free method

Determining wax content, softening point, and penetration of asphalt products by traditional methods is too time-consuming to meet the instant need in practice. Although infrared spectroscopy combined with multivariate calibration may realize rapid determination of asphalt, its modeling and maintenance are very labor-intensive and challenging. In this paper, a novel method combining attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) with a fast algorithm of spectrum representation (SR) was proposed to rapidly and expediently determine the properties. The proposed method achieves calibration-free, effectively overcoming the drawback of the modeling methods. The feasibility of the new method was demonstrated using 431 asphalt samples produced by different kinds of crude oil. The root mean standard error of prediction (RMSEP) of wax content, softening point, and penetration by SR method are 0.14%, 0.55 °C and 4.71 (0.1 mm), respectively. Each of them is below the reproducibility of corresponding standard test method. Moreover, the new method is compared with other two commonly used methods, partial least squares regression (PLS) and local modeling by densification (LMD), in detail. The results show that the new method not only can solve the disadvantages of PLS modeling effectively, but also is remarkably superior to LMD method, in repeatability and speed, and robustness for predicting the sample in the region with lower density and unreasonable distribution of the samples in data bank.

Effects of shear rate and time on deposit composition in the cold flow regime under laminar flow conditions

The effects of shear rate and time on solid deposition and deposit composition, from wax–solvent mixtures in the cold flow regime under laminar flow conditions, were investigated experimentally using a cold finger apparatus. The deposition experiments were conducted with a 10 mass% multicomponent wax–solvent mixture at different agitation speeds, with a coolant temperature of WAT–12 °C, at a wax–solvent mixture temperature of WAT–6 °C, and for different deposition times. The experimental results indicated that the deposit mass increased with a decrease in the agitation speed (Re), or the shear rate, and an increase in the deposition time (t). The predictions from a transient model based on the moving boundary formulation agreed with these results. The wax content and carbon number distribution of deposit samples varied with Re and t. The deposit ‘aging’ behaviour was modeled successfully using a previously developed approach, based on the shear-induced deformation of a cubical cage, causing a partial squeezing out of the liquid phase from the deposit, in which the deformation angle (β) of the tilted cubical cage depends on Re and t. A correlation was developed for the effects of Re and t on deposit composition in the cold flow regime under laminar flow conditions. The results of this study further confirm that the deposition process is described very well by heat-transfer considerations and the ‘aging’ of deposit is modeled satisfactorily by considering the effect of shear stress during its formation and growth.

Investigations of temperature and dilution effect on rheological properties of waxy crude oil

The purpose of the paper is to study the effect of temperature and hydrocarbon solvent addition on thixotropy of waxy crude oil. Oil is a complex multicomponent hydrocarbon system. There are many interactions between wax and asphaltene, wax and aromatics, asphaltene and resins in original oil. For example, the dispersion of asphaltenes is known to be influenced by resins. The resins are adsorbed onto the surface of the asphaltenes, whereby the asphaltenes are not aggregated. Wax is adsorbed by fine asphaltene particles and wax appearance temperature (WAT) observed at low temperature (formed wax crystals too small to be detected by measuring system). The authors of the paper have studied the separate effect of two solvents (kerosene and diesel fuel), wax concentration and impurities (kaolinite) on WAT to understand how all these factors affect WAT in wax-bearing solutions individually. Wax-bearing solutions in wax concentration range from 10 to 60% by weight were investigated by the visual and rheological methods under atmospheric pressure. It is shown that the diesel-based solutions have higher WAT than the kerosene-based solutions. Studies have shown that the increase in wax concentration in solution leads to an increase in WAT. The paper describes that the addition of impurities (kaolinite) to the solutions resulted in an increase in WAT. Besides, it is shown that WAT obtained by rheological method is higher on average of 1 °C than WAT obtained by visual method. The authors suggested that under constant other conditions (pressure, resin and asphaltenes content, etc.) an increase in wax content in oil and the content of impurities will lead to an increase in WAT. The scientific basis for this conclusion is that, in the future we can, adding or removing from solution hydrocarbon components, with certain assumptions, simulate the properties of oil. In particular, this will allow us to study separate interactions between the wax and asphaltene, wax and aromatics, and wax and naphtha compounds, and abstract away from other factors. The waxy crude oil production in the Samara region is complicated by impurities entrainment and non-Newtonian properties of oil. The investigations of waxy crude oil were provided with light scattering method (in near infrared region), microscopy under high pressure with the grain size analysis (visual) and a rheological method. We obtained the unique «viscosity superanomaly» discovered by Vinogradov and Malkin (Rheol Acta 5(3):188–193, 1966) at low temperatures and shear stress by rheological method under atmospheric pressure. The area of the hysteresis loop on the flow curve increases as the temperature decreases, which is caused by the formation of the lattice by wax. We have also shown that the use of solvent and the increase in temperature allow to reduce «viscosity superanomaly». Simultaneous use of light scattering and microscopy under high-pressure methods allows increasing in accuracy of measuring. For waxy crude oil, there will also be a difference between rheological and visual methods of WAT measuring, as these methods have different sensitivity limits. Besides, the study showed that addition of N2 and CO2 to oil leads to decrease in WAT. However, it is necessary to provide a number of additional studies before gas injection projects in the field. For example, it is shown that CO2 injection leads to asphaltenes precipitation in oil by many scientists. Novelty of the paper consists in investigation of rheological properties of waxy crude oil of the Samara and the effect of nonhydrocarbon gases on WAT. In this study, unique flow curves of oil of the Samara region were obtained.

Experimental Investigation of the Rheology and Crystal Morphology of Model Waxy Oils under Gelling Conditions

The influence of six experimental variables (cooling rate, weight fraction of linear wax, weight fraction of branched wax, shear rate during cooling, final cooling temperature, and aging time) on the yield stress of gelled waxy oils was simultaneously investigated using an experimental design. Rheological tests were performed with systems comprising spindle oil and a blend of paraffin waxes. The waxes were characterized by differential scanning calorimetry, gas chromatography–flame ionization detection, Fourier transform infrared and 13C NMR spectroscopy, and X-ray diffraction, pointing to predominantly linear- and branched-type wax. Also, wax crystal morphology was assessed through polarized light microscopy. Cooling rate, wax content, shear rate during cooling, final cooling temperature, and aging time were the variables analyzed. The obtained results disclosed the relative importance of these variables on the viscoelastic properties of the gelled oils. Multiple linear regression was used to propose a m...

Silicon accumulation in rice plant aboveground biomass affects leaf carbon quality

Silicon is known to be able to substitute carbon in plant biomass, especially in cellulose, lignin and phenols. However, a more comprehensive picture regarding the effect of silicon accumulation on plant carbon quality (cellulose, lignin, phenol, wax, lipids, and free organic acids content) with regard to potential decomposability is still missing. Two different rice varieties (French brown and red rice cultivars) were cultivated under five different soil silicon availabilities. After maturity we harvested the plants and analyzed them regarding carbon quality by FTIR spectroscopy and regarding plant silicon concentrations. Silicon accumulation was found to be dependent on silicon availability and on the specific rice cultivar. The lowering of carbon compounds content by silicon was found not to be restricted to cellulose, lignin and phenol. Silicon accumulation was able to decrease other carbon compounds such as fat, wax, lipids, and free organic acids, too. Consequently, silicon is important for the carbon quality of silicon accumulating plants. Furthermore, silicon accumulation in plants is interfering with a large range of different carbon compounds potentially altering the leaf economic spectra, decomposability, and thus potentially interfering with the whole performance of ecosystems dominated by silicon accumulating plant species.

Gravimetric and Spectrophotometric Determination of Surface Wax Content in Maize Kernels

There are several methods available to determine wax content in maize kernel. These methods are based on gravimetric, spectrophotometric, and chromatographic analyses. This study aims to determine the surface wax content on maize kernel with different reference methods and develop NIR (Near Infrared Reflectance Spectroscopy) calibration models based on those reference methods. In this study, samples from 250 different maize genotypes were used. Surface wax content in the samples was determined by gravimetric and UV-Spectrophotometric methods. The results of each reference method were used to develop NIR prediction models for surface wax content in kernel samples. Our results suggest that there is a medium-level correlation (r=0.708) between the data obtained from spectrophotometric and gravimetric methods. Also, significant differences were observed between the wax content obtained from reference methods. It has been found that the NIR calibration model (RMSE =4.381, R2 =0.143, r =0,378, RPD =1.08) based on the gravimetric method had lower estimation power than the NIR calibration model (RMSEC =7.257, R2 =0.221, r =0.471, RPD =1.34) based on the UV spectroscopic method. Keywords: Near Infrared Spectroscopy, Biochemical test, Zea mays, Regression DOI: 10.7176/JSTR/5-9-11

Application of a Dual-Solvent Method in Separating Paraffin from a Shale Oil: A Combined Experimental and DFT Study

An effective dual-solvent (DS) extraction combined with recrystallization was designed for refined paraffin (RP) separation from a shale oil (SO). The content of wax enriched with acetonitrile (AN)/petroleum ether is higher than that with other DSs. The maximum recovery of RP is 22.1 wt % obtained by regulating the DS/SO ratio, extraction time (ET), and extraction times (ETs). The corresponding total relative content of oil obtained by controlling solvent polarity during the recrystallization is 1.9% based on the analysis with a gas chromatograph/mass spectrometer. Long-chain n-alkanes are predominant in RPs, which is consistent with Fourier transform infrared analysis. In addition, the mechanisms for synergic DS extraction were revealed by quantum chemistry calculation with density functional theory, i.e., C–H···π and X–H···Y bonds exist between AN and selected model compounds according to the analyses of electrostatic potential and average local ionization energy. The low boiling point and immiscibility...

Influence of operating temperatures on long-duration wax deposition in flow lines

Operating temperatures have major impacts on wax deposition. Although significant research efforts have been expended on this topic, no satisfactory agreement has been achieved in the available literature. In the present work, we conducted cold-flow flow-loop wax deposition experiments using a waxy condensate with 9.5% wax content to investigate the influence of operating temperatures on wax deposition. To achieve a closer representation of field operation, we varied the oil temperature while keeping the initial wall temperature constant and conducted the tests up to 72 h. It was observed that the deposit forms more slowly but contains higher wax content as the difference between oil temperature and wall temperature increases, and these trends hold at both 48 and 72 h. Moreover, we calculated the diffusive mass flux at different operating conditions using the prevailing theory of molecular diffusion and found that the predicted trends are opposite to experimental observations. These results, along with findings from recent publications, collectively suggest that the long-standing modeling approach based on molecular diffusion is insufficient to completely describe wax deposition phenomenon, and that wax deposit morphology and other deposition mechanisms deserve further attention to close this knowledge gap.

The R2R3 MYB transcription factor MdMYB30 modulates plant resistance against pathogens by regulating cuticular wax biosynthesis

BackgroundThe MYB transcription factor family is one of the largest transcriptional factor families in plants and plays a multifaceted role in plant growth and development. However, MYB transcription factors involved in pathogen resistance in apple remain poorly understood.ResultsWe identified a new MYB family member from apple, and named it MdMYB30. MdMYB30 was localized to the nucleus, and was highly expressed in young apple leaves. Transcription of MdMYB30 was induced by abiotic stressors, such as polyethylene glycol and abscisic acid. Scanning electron microscopy and gas chromatograph–mass spectrometry analyses demonstrated that ectopically expressing MdMYB30 in Arabidopsis changed the wax content, the number of wax crystals, and the transcription of wax-related genes. MdMYB30 bound to the MdKCS1 promoter to activate its expression and regulate wax biosynthesis. MdMYB30 also contributed to plant surface properties and increased resistance to the bacterial strain Pst DC3000. Furthermore, a virus-based transformation in apple fruits and transgenic apple calli demonstrated that MdMYB30 increased resistance to Botryosphaeria dothidea. Our findings suggest that MdMYB30 plays a vital role in the accumulation of cuticular wax and enhances disease resistance in apple.ConclusionsMdMYB30 bound to the MdKCS1 gene promoter to activate its transcription and regulate cuticular wax content and composition, which influenced the surface properties and expression of pathogenesis-related genes to resistance against pathogens. MdMYB30 appears to be a crucial element in the formation of the plant cuticle and confers apple with a tolerance to pathogens.

Preparation and characterization of waste papers based composites and their applications in leather industries

In this work, the utilization of waste paper in the preparation of cellulous-based composite is described, with latex as a binder. Paraffin wax and acrylic woven fibers were also used at various weight ratios to get the best mechanical and physical properties. The results were compared with the performance the Dixon, regularly used material in shoes manufacturing. The following tests were performed: compression resistance, density, water absorption, shrinkage, and moisture content. Manual method was employed in the preparation of test specimens in addition to laboratory forging machine for finishing of the specimens. Results of compression test (Modulus of elasticity, compressive strength, resistance to crushing) of the Specimens that contain pulp paper and reinforced with latex and acrylic fibers and low content of paraffin wax showed the highest resistance to compression, The increase of additives contents within the mix resulted in an increase in density. To mimic the real application conditions of the insole, the specimens were subjected to water absorption test by irrigation for 2 hours. The best specimen compositions for the water resistance test are those with high (5-10%) wax content due to the fact that the wax is a water repellent material. The shrinkage is another important parameter for the use of the composite in shoe industry. Result of shrinkage and humidity of all specimens show comparable results to commercially available and Dixon are also very close to the requirements of the specification of leather industry. However, in comparison with the available carton and dixon, our specimens contain from weight fraction (50g) waste pulp, (20g) latex, (4g) paraffin wax, (0.7g) acrylic fibers, proved comparable performance.

Experimental and numerical study on direct electrical heating for plug removal of subsea waxy crude pipelines

Subsea pipeline of waxy crude oil may face a high risk of the wax plug during shut down or pigging. Direct Electrical Heating (DEH) technology is expected to be an efficient and convenient way to melt the wax plug in the subsea pipeline. An industrial-scale experimental facility with a test tube of 10-in. diameter and a power supply of 0–1350 A is set up, and then several sets of experiments are carried out. Simultaneously, the melting process of the wax plug is simulated by FLUENT software. The numerical model is validated from the aspects of liquid fraction and solid patterns. The melting rate and temperature of the wax plug with different wax content and current are analyzed, and the temperature of the pipe wall is considered for the sake of pipeline integrity. Furthermore, to avoid secondary solidification, the recooling process of the wax plug and pipe wall is also discussed. Finally, the effects of the “Maximum Allowable Temperature”, “Maximum Safe Power”, “Effective Liquid Fraction” and “Applicable Heating Time” on economic evaluation are investigated, and the correlations are developed between the above factors and common pipe diameters (6–32-in.), which shows heating with maximum safe power is also the most economical method in engineering.

A novel heterogeneous wax deposit structure triggered by polyethylene vinyl acetate (EVA) wax inhibitors

Polyethylene vinyl acetate (EVA) has been widely investigated and employed as polymeric wax inhibitor (PWI). In this paper, the wax deposition characteristics of synthetic oils with different concentrations of EVA PWI were investigated. The obtained surface and bottom wax deposits were analyzed through differential scanning calorimeter (DSC), polarizing microscope, Fourier transform-infrared spectroscopy (FT-IR) and high-temperature gas chromatography (HTGC). It is found that the EVA PWI could obviously decrease the wax deposition rate and accelerate the aging of wax deposits. Adding the EVA PWI can trigger a novel heterogeneous wax deposit structure, in which the wax appearance temperature and wax content increases continuously from the bottom to the surface layer. Compared to the bottom wax deposit, the surface wax deposit has higher concentrations of both EVA and high carbon number wax molecules (Cn > C25). The formation mechanism of the novel heterogeneous wax deposit structure was explained from two aspects. Firstly, the wax crystal morphology of surface layer is significantly changed from needlelike to diamond-like due to higher temperature and the accumulation of EVA and high carbon number wax molecules in the surface wax deposit, therefore, higher solid wax content is needed for the building of a continuous three-dimensional network structure to resist shearing of pipe flow. Secondly, the lower temperature and larger aspect ratio of wax crystals in the bottom wax deposit are adverse for the diffusion of wax molecules into the bottom wax deposit, thus the aging rate of bottom wax deposit is lower than that of surface layer.

Development of drought‐tolerant breeding lines derived from Helianthus annuus × H. argophyllus interspecific crosses

AbstractHelianthus argophyllus is a wild species known as “silver sunflower”, which possesses several traits, including morphological traits that increase drought tolerance. Therefore, introgressions between chosen cultivated lines and two H. argophyllus accessions were made, and segregating generations were established. Important agronomic traits including single heading, high pollen fertility, silver canopy (indicating more cuticular wax), and content of cuticular waxes and oil were selected over six segregating generations. The resulting F6 lines showed introgression of water saving traits, as they had lower excise leaf water loss, with comparable yield to standard checks. However, these F6 lines were late maturing and showed poor flowering synchronization between the cultivated and introgressed lines. Introgressed line “D‐22” was particularly promising as a breeding line, with superior agronomic and drought resistance traits. This line had the potential to be used as an inbred parental line for introgression of drought resistance traits into elite sunflower germplasm. Combining ability analysis of the introgressed lines further showed their potential for heterosis breeding or to be used as parental lines in breeding programme.

Natural Cellulosic Fiber from Coccinia Indica Stem for Polymer Composites: Extraction and Characterization

ABSTRACT This study mainly focuses on the possibility of using Coccinia Indica (CI) fiber as reinforcement in structural polymer composite materials because of its lightweight and eco-friendly nature. Fibers were extracted from the dried stems by combing process using metal teeth brush. The thermo-physico-mechanical properties, chemical compositions, and morphological structures of CI fiber were analyzed in detail. A higher percentage of cellulose content in CI fiber and the lesser amount of skimpy lignin, hemicellulose, ash, and wax content were confirmed through chemical analysis. The functional groups with their corresponding peaks were depicted through FTIR analysis. XRD studies divulge that the CI fiber contains crystallinity index (CrI) of 53.03% and crystallite size (L) of 5.81 nm. SEM revealed that the fiber possesses cylindrical morphology with multi-cellular structure. The presence of parenchyma and chlorenchyma tissues in the cell wall of CI fiber was also confirmed, which helps for better adhesion and mechanical properties to the composite. TGA study reveals that the major degradation of CI fiber occurs at a temperature range of 204.16°C to 376.3°C. The tensile strength of cellulose-based CI fiber is comparable with the other conventional fibers and it is well enough for its usage as reinforcing material in composite manufacturing.

Characterization of raw and alkali treated new natural cellulosic fibres extracted from the aerial roots of banyan tree

The objective of this investigation is to check the suitability novel cellulosic fibre extracted from the aerial roots of Banyan tree (ARBFs) as reinforcement in fibre reinforced plastics. The Fundamental properties of ARBFs such as density, tensile strength, chemical composition, crystallinity index, crystalline size, thermal stability, maximum degradation temperature and surface roughness were studied. The chemical analysis results revealed that after the alkalization cellulose content was improved while hemi-cellulose, lignin and wax content were demised. The enhancement in the crystallinity index (76.35% from 72.47%) and crystalline size (7.74 nm from 6.28 nm) of alkali treated ARBFs were evidenced by the X-ray diffraction analysis. Thermal analysis results confirmed that maximum degradation temperature (368 °C) and kinetic activation energy (75.45 kJ/mol) of alkali treated ARBFs had increased from 358 °C and 72.65 kJ/mol respectively. The results of scanning electron microscopic and atomic force microscopic analysis exhibited that impurities and wax on the outer surface of the ARBFs were removed after the alkali treatment. All the above finding concluded that ARBFs is the appropriate material to use as a reinforcement in fibre reinforced plastics.

Developmental changes in the composition of leaf cuticular wax of banana influenced by wax biosynthesis gene expression: a case study in Musa acuminata and Musa balbisiana

The composition of the cuticular wax varies from species to species as well as the developmental stage of the organ. In the present study, the variation in the pattern of accumulation of C28 and > C28 chain length of the cuticular wax compounds in the two contrasting Musa species for wax content has been examined—Musa balbisiana ‘Bee heekela’ (BB genome) (with high wax content) and Musa acuminata ssp. Burmannicoides Colla—‘Calcutta-4’ (AA genome) (with low wax content). These two species are the progenitors for the modern cultivated banana. Using GC–MS analysis, 40 different cuticular wax compounds from five different leaf developmental stages in these two musa species were identified. Around tenfold higher accumulation of C28 length compounds was found in ‘Calcutta-4’ as compared to that of ‘Bee hee kela’. In case of ‘Bee hee kela’, > C28 length compounds were in large proportion compared to C28 length wax compounds. The qPCR analysis was carried out for the gene CUT1/CER6/KCS6 which are involved in the fatty acid elongation step of cuticular wax biosynthesis. A higher expression in the 2nd (young), 4th and 6th (old) fully expanded leaves of high wax genotype ‘Bee hee kela’ with 1.57083, 9.71512, and 1.44963 fold change, whereas a lower expression of 0.9151, 4.8785, and 1.2321 fold change in low wax genotype ‘Calcutta-4’, respectively, was observed. A negative relationship between the gene expression and C28 wax compounds’ accumulation was observed, indicating the importance of the expression of CUT1/CER6/KCS6 gene for elongation of C28 to > C28 cuticular wax compounds. The current study suggest that CUT1/CER6/KCS6 from ‘Bee heekela’ would be a good contributor for higher cuticular wax with higher > C28 compounds, thus, finally, contributing for higher leaf water retention capacity their by conferring drought tolerance helping in the future banana improvement programs.

Influence of Heavy Organics Composition on Wax Properties and Flow Behavior of Waxy Crude Oils

Paraffinic crude oils are desirable because of their high content of saturated hydrocarbons but may present handling challenges due to crystallization of high molecular weight paraffin at low temperatures. The prediction of wax properties and behavior of waxy crude oil is important in order to adopt appropriate mitigative measures to forestall flow assurance problems associated with wax crystallization and deposition. Accurate predictive models are limited mainly by the sheer complexity of crude oil composition. Result of analysis of saturates, aromatics, resins and asphaltene content of crude oils (SARA) has been used as a simple tool to predict and interpret crude oil properties and behavior but has been found inadequate in predicting wax instability. In this paper, we report on the use of SARA analysis and paraffin distribution data to interpret the wax properties and flow behavior of Niger-Delta crude oils. The crude oil properties determined include wax content, asphaltene and resin content by gravimetry, pour point, wax appearance temperature by cross-polarized microscopy and paraffin carbon number distribution of whole oil and wax precipitate by GC-FID. Asphaltene and resin content were found to influence the oil pour point, while saturates content, paraffin carbon number of crystallizing waxes and wax content control its low-temperature flow properties.

Differences in quantity and composition of leaf particulate matter and morphological structures in three evergreen trees and their association in Harbin, China

Urban trees have been assumed to effectively clean air particulate matter (PM), while the inter-species differences are not yet well defined, especially the PM chemical composition. In this study, PM from leaf surface and wax layer of 3 evergreen tree species (Juniper: Juniperus rigida; Black pine: Pinus tabuliformis var. mukdeais; Spruce: Picea koraiensis) were used for finding differences in PM adsorption and its compositional traits (characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectrum and Inductively coupled plasma-optical emission spectrometry). Possible improvement in PM removal was also evaluated by a detail whole city tree census and different scenarios of species adjustment data. We found that: 1) the amount of PM on juniper leaves was 5.73 g m−2, 2–2.5-fold higher than black pine and spruce (p < 0.05). Of them, 38.73%, 38.22%, and 23.11% were in the wax layer. 2) Compared with the explicit interspecies differences in PM quantity, more complex interspecies difference showed different patterns for different compositional traits. In general, leaf surface PM had higher O, Si, Al, Fe, N, Pb, Cu, Ni, Cr, and Cd, while the wax PM had higher C and Na contents (p < 0.05). 3) Association ordination found that the smaller leaf size, lower leaf water content, higher leaf area per unit mass, higher wax content, and larger stomatal openness aligned with the more PM adsorption by leaf, together with the higher amounts of CO stretching, O, Si, Al, N, heavy metals of Pb, Cu, Ni, Cr, and Cd in PM. 4) Compared with the other 2 species, increase of juniper percentage in urban forests is more effective for maximizing PM removal from air, accompanying more heavy metal removal but less crystalized minerals in PM. Our findings highlight that proper species configuration in urban afforestation could maximize the air PM removal capacity.

Wax Inhibitor Screening by Differential Scanning Calorimeter for High Wax Content Crude Oil

In order to investigate the wax inhibition performance of various inhibitors different scanning calorimetric (DSC), a powerful and quickly technique having no request of sample pretreatment, has been used for investigation the thermal characteristics of the wax remover. According to the parameters such as wax appearance temperature (WAT), content of wax and rheology, it is found that the best wax removing rate can be reached to 457mg/L•h under 40°C with 150mg/L surfactant combination (fatty alcohol polyoxyethylene ether + calcium petroleum sulfonate + mixed alcohol).