Wax Removal Research Articles

Optimizing the low-temperature performance of high-wax-content crude oil with emulsion-based wax inhibitors: Mechanisms and efficacy.

Wax deposition in constant-temperature transportation of waxy oil with high pour points poses a significant challenge for the oil industry. The demand for efficient methods to solve wax deposition has gained attention. To elucidate the impact of emulsion-based wax inhibitors on the performance of crude oils with varying wax content at low temperatures, experiments, rheological analyses, and microscopic analyses were conducted to study their pour point regulation, low-temperature flow improvement, wax prevention effectiveness, and wax crystallization behavior. The results indicate that emulsion-based wax inhibitors significantly reduce the pour point of crude oil, especially for high-wax-content oil, while for low-wax-content oil, the pour point only decreased by 3°C. By penetrating and dispersing wax crystals, the inhibitor reduced the viscosity of crude oil at low temperatures, enhancing its flowability. At 28°C, crude oil transitioned from a shear-thinning non-Newtonian fluid to a Newtonian fluid at wax inhibitor dosages of 500-750ppm. At 1000ppm, the wax prevention rate for high-wax-content oil reached 87.5%, but the effect plateaued beyond this concentration. Additionally, the wax prevention and removal mechanism of the emulsion-based wax inhibitors is discussed. This study confirms that emulsion-based wax inhibitors significantly enhance the low-temperature processability of crude oil, offering a viable strategy for the conveyance and refinement in cold climates.

Research on wax removal and prevention technology of White Wolf City oil well

Abstract Oil well wax removal technology is an important subject in the process of oil field exploitation. This paper analyzes the mechanism and characteristics of wax formation in oil Wells by measuring the amount of wax in crude oil in Baiwolcheng oil area. When the waxy component, which usually exists in liquid form, is accompanied by crude oil from underground to the ground, the waxy crystal precipitates and deposits in the inner wall of oil pipe due to the gradual decrease of the temperature of crude oil. The phenomenon of paraffin formation, paraffin formation process and paraffin formation law of oil well are studied, and chemical paraffin removal and anti-wax technology is determined as the main research object, evaluation and optimization of paraffin removal and anti-wax agent, and determination of dosage concentration and dosage.

Development of a microbial dewaxing agent using three spore forming bacteria

Microbial enhanced oil recovery (MEOR) is a cost effective and efficient method for recovering residual oil. However, the presence of wax (paraffin) in residual oil can substantially reduce the efficiency of MEOR. Therefore, microbial dewaxing is a critical process in MEOR. In this study, a bacterial dewaxing agent of three spore-forming bacteria was developed. Among these bacteria, Bacillus subtilis GZ6 produced the biosurfactant surfactin. Replacing the promoter of the surfactin synthase gene cluster (srfA), increased the titer of surfactin in this strain from 0.33 g/L to 2.32 g/L. The genetically modified strain produced oil spreading rings with diameters increasing from 3.5 ± 0.1 to 4.1 ± 0.2 cm. The LadA F10L/N133R mutant was created by engineering an alkane monooxygenase (LadA) using site-directed mutagenesis in the Escherichia coli host. Compared to the wild-type enzyme, the resulting mutant exhibited an 11.7-fold increase in catalytic efficiency toward the substrate octadecane. When the mutant (pIMPpladA2mu) was expressed in Geobacillus stearothermophilus GZ178 cells, it exhibited a 2.0-fold increase in octadecane-degrading activity. Cultures of the two modified strains (B. subtilis GZ6 (pg3srfA) and G. stearothermophilus GZ178 (pIMPpladA2mu)) were mixed with the culture of Geobacillus thermodenitrificans GZ156 at a ratio of 5:80:15. The resulting composition increased the rate of wax removal by 35% compared to the composition composed of three native strains. This study successfully developed a multi-strain bacterial agent with enhanced oil wax removal capabilities by genetically engineering two bacterial strains.

Cellulose nanocrystals isolated from sugarcane bagasse using the formic/peroxyformic acid process: Structural, chemical, and thermal properties

Sugarcane bagasse (SCB) is a renewable biomass source for cellulose extraction. In the pretreatment, SCB is processed to break down the cellulose-lignin-hemicellulose matrix and isolate components. This work proposes a formic/peroxyformic acid process for extracting cellulose nanocrystals (CNCs) from SCB. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and solid-state 13C nuclear magnetic resonance (ss- 13C NMR) were employed to evidence the removal of wax, hemicellulose, and lignin from the raw SCB. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) were used for analyzing crystallinity, morphology, and thermal properties. SEM results showed that after lignin removal, the size of purified cellulose fibrils decreased significantly, and the structure of cellulose microfibers became smoother and more apparent. After acid hydrolysis of bleached cellulose microfibers, XRD analysis showed CNCs had the highest crystallinity (70.8 %). In TEM images, rod-like structures of CNCs were measured to be 23 ± 2.7 nm wide and 610 ± 18 nm long. The eco-friendly formic/peroxyformic acid procedure with a chlorine-free bleaching stage produced a white, cellulose-rich solid powder of CNCs.

Micromorphological and Chemical Characterization of Drimys winteri Leaf Surfaces: The Secondary Alcohols Forming Epicuticular Wax Crystals Are Accompanied by Alkanediol, Alkanetriol and Ketol Derivatives.

The cuticle is a hydrophobic coating of most aerial plant surfaces crucial for limiting non-stomatal water loss. Plant cuticles consist of the lipid polyester cutin and associated waxes with compositions varying widely between plant species and organs. Here, we aimed to provide a comparative analysis of the dark-glossy adaxial and pale-glaucous abaxial sides of Drimys winteri (Winteraceae) leaves. Scanning electron microscopy showed nanotubular wax crystals lining the entire abaxial side of the leaf (including stomatal pores), while the adaxial side had patches of mixed platelet/tubule crystals and smooth areas between them. Consecutive treatments for wax removal and cutin depolymerization revealed that the waxes were deposited on a cutin network with micron-scale cavities across the entire abaxial surface including the stomata pores, and on a microscopically smooth cutin surface on the adaxial side of the leaf. Gas chromatography coupled to mass spectrometry and flame ionization detection showed that the wax mixtures on both sides of the leaf were complex mixtures of very-long-chain compounds dominated by the secondary alcohol nonacosan-10-ol and alkanediols with one hydroxyl on C-10. It is therefore very likely that the characteristic tubular wax crystals of both leaf sides are formed by these alcohols and diols. Further secondary alcohols and alkanediols, as well as ketols and alkanetriols with one functional group on C-10, were identified based on mass spectral fragmentation patterns. The similarities between all these mid-chain-functionalized compounds suggest that they are derived from nonacosan-10-ol via regio-specific hydroxylation reactions, likely catalyzed by three P450-dependent monooxygenases with different regio-specificities.

Integrated treatment of wax and scale removal in old wells of the Tanjung Field

The majority of oil wells in the Tanjung Field are old wells with reservoir characterized by low pressure and temperature, as well as high water production. The characteristic of oil in the Tanjung Field has a relatively high wax content of 17.61%. This condition has led to several wells in the Tanjung Field experiencing issues with the simultaneous formation of wax and scale deposits within the wellbore equipment. The simultaneous occurrence of wax and scale can significantly impact the production rate. Therefore, addressing this production issue efficiently requires a method known as wax scale removal (WSR). WSR can effectively tackle the problem of wax and scale deposits occurring simultaneously in production equipment. In this method, a solvent for dissolving wax deposits and an acid for dissolving scale are injected together using the huff and puff technique.

Optimization and Application of Wax Removal Technology for Fixed Tubing String in Offshore Wells

This study focuses on the selection and application of wax removal techniques tailored for fixed tubing columns in offshore wells that have been obstructed by wax deposits. Initially, the paper delves into the importance of well decommissioning and examines prevalent decommissioning techniques, outlining their respective advantages and limitations. Subsequently, three distinct unblocking technologies are proposed, tailored to address different causes and scenarios of well clogging: physical plugging removal technology, chemical treatment technology, and mechanical unblocking technology. Each technology is thoroughly analyzed, discussing their applicable scopes, operational procedures, equipment and anticipated effectiveness in removing blockages. To validate the feasibility and practicality of these proposed unblocking methods, an actual offshore well case study is conducted. The results demonstrate that thermal nitrogen wax removal technology emerges as the most effective approach, necessitating further optimization of its application. The paper then details the oil-filed implementation of this technology, including methods for generating hot nitrogen and its subsequent application. Following the implementation, significant improvements in wax removal and unblocking are observed, attesting to the technology's effectiveness. The findings of this study offer valuable insights and practical guidance for addressing wax blockage issues in fixed tubing columns of offshore oil wells. By providing a comprehensive analysis of different unblocking techniques and their application in oil-filed, this paper contributes to enhancing the efficiency and reliability of offshore oil production operations.

An increased wax load on the leaves of goji plants (Lycium barbarum) results in increased resistance to powdery mildew

Abstract Background Goji (Lycium barbarum) is an important economic crop that is widely cultivated in Northwest China and is known as superfood. Goji plants are often affected by powdery mildew (Arthrocladiella mougeotii) in the field, resulting in considerable reduction in production and serious economic losses. The long-term reliance on agricultural chemicals to control powdery mildew not only leads to environmental pollution, but also causes excessive residues to accumulate in fruits, endangering human health. The plant epicuticular wax is the first physical barrier between land plants and the atmospheric environment, and plays an important role in the interactions of plants with pathogenic microorganisms. However, the relationship between epicuticular wax and powdery mildew resistance in goji plants is not well understood. Results The leaf epicuticular wax crystals of ‘Ningqi I’ goji were dense and small, and the wax load was 121.74 μg/cm2, which was 3.36 times greater than that of ‘Huangguo’ goji. The ratio of alcohol components in ‘Ningqi I’ goji was 121.18% greater than that in ‘Huangguo’ goji. The incidence rate and disease index of ‘Ningqi I’ goji inoculated with powdery mildew were significantly lower than those inoculated ‘Huangguo’ goji, showing high resistance and moderate susceptibility, respectively. After mechanical wax removal, the disease indices of the two goji varieties increased significantly, indicating extreme susceptibility. Seventeen differential expression genes showing significantly greater expression in ‘Ningqi’ goji leaves than in ‘Huangguo’ goji leaves were enriched in genes involved in fatty acid elongation and the wax biosynthesis pathway. The FAR activity and relative expression levels of LbaFAR and LbaWSD1 in ‘Ningqi I’ goji were significantly greater than those in ‘Huangguo’ goji. The relative expression levels of these genes significantly increased in the overexpression tobacco lines FAR-OE and WSD1-OE, and the wax load were augmented by 46.10% and 22.23%, respectively. Conclusions The increased expression of the LbaFAR and LbaWSD1 genes in ‘Ningqi I’ leaves led to increased FAR and WSD1 activity, increasing the wax load and alcohol content of the epicuticular of leaves, and improving leaf glossiness, resulting in strengthened resistance to powdery mildew. Therefore, the production of leaf epicuticular wax mediated by the LbaFAR and LbaWSD1 genes could be the main reason for the difference in powdery mildew resistance between the two goji varieties, which can provide a theoretical basis for the selection of resistant varieties to control goji powdery mildew. Graphical Abstract

Thermal removal mechanism of paraffin deposits: Impact of flowrate on removal efficiency

Active heating is increasingly explored as a cost-effective strategy for managing wax deposition in production flowlines. While these methods are commonplace throughout the industry to maintain or raise the temperature of the production fluid above the wax appearance temperature (WAT), there are no clear guidelines for wax removal using active heating. In this study, a novel dynamic microscopic visualization technique is used to observe the effects of the flow regime on the removal process. At high enough temperatures, 50.6 °C and 43.3 °C, 100% removal is observed in both turbulent and laminar cases. A removal temperature of 37.0 °C resulted in 72.5% removal under turbulent conditions, and 97% removal under laminar conditions. No reduction in thickness was observed in either case when removing at a temperature of 30.6 °C. Turbulent conditions were also shown to significantly increase the heating time required before detachment compared to laminar conditions at the same removal temperature. The turbulent experiments required 2.7 times as long for detachment to occur when removal temperatures were raised to 43.3 °C, and 4.6 times as long when temperatures were raised to 37.0 °C. Turbulent conditions are also shown to require higher temperatures to trigger the removal process, likely due to the harder deposits formed at higher flow rates. This analysis sheds light on the impact flow regime and deposit properties have on the removal process. The results obtained in this study enhance the understanding of the impact of flow on thermal removal and this knowledge is necessary for accurate removal modeling.

Evaluation of Fermented Plant Extracts as Bioinsecticides in Controlling Phenacoccus solenopsis Colonies on Hibiscus rosa-sinensis under Laboratory Conditions

The mealybug, Phenacoccus solenopsis, is a serious pest of Hibiscus rosa-sinensis. The waxy coating on its body may hinder pesticide penetration, and the extensive use of pesticides is risky to humans and the environment. Considering these drawbacks, fermented plant extracts (FPEs) were explored for their potential use in controlling this pest in a more user and environmentally-friendly manner. FPEs derived from eleven plant materials were evaluated against P. solenopsis for their insecticidal activity, mealybug wax removal potential and phytotoxicity effect on H. rosa-sinensis. Five concentrations of FPE [5, 10, 15, 20, and 25% (w/v)] were prepared. Among the 11 FPEs, FPE derived from ficus, kaffir lime, and turmeric were effective in suppressing P. solenopsis with lethal concentration at 50% (LC50 value) less than 20% concentration. Although ficus FPE was the top performer in the insecticidal assay, it induced medium to very high levels of leaf damage after being treated with 15–25% concentration at 24 and 72 hr post-treatment. A low level of leaf damage was observed in treatment with turmeric and kaffir lime FPEs at 72 hr post-treatment. FPEs could remove wax from the body of P. solenopsis with no significant difference among them. In conclusion, the FPE of ficus, kaffir lime, and turmeric showed promising insecticidal effects against P. solenopsis.

Study on optimized culture of microbial strains and their ability in wax removal and viscosity reduction of paraffin-based crude oil

High-viscosity paraffin-based crude oil is prone to wax deposition at low temperatures, hindering development and transportation efficiency while posing safety risks. Microbial technology offers a safe, eco-friendly, and economically viable solution. In this study, strain B-1 is isolated and cultivated optimally using statistical multifactorial synergistic optimization. Species identification reveals strain B-1 to be a new Gram-positive aerobic bacterium. After optimization, strain B-1′s growth activity increases by 11.5 %. Lipopeptide surfactants produced by strain B-1 reduce wax content and viscosity of the crude oil by 37.29 % and 23 %, respectively. It also shows a significant impact on long carbon chain heavy component hydrocarbon substrates, degrading C17-C40 hydrocarbons by 37.93 % on average. Moreover, strain B-1 transforms aggregated wax crystals into dispersed microcrystals, improving flowability. These findings offer a promising solution for enhancing reservoir development efficiency and ensuring pipeline transportation safety.

Study of Extraction, Treatment and Characterization of Pineapple Leaves Fibers as Potential Utility in Textile Industry

Extraction, treatment and characterization of pineapple leaves fibres was achieved. The study revealed that water retting is the best way to extract fibers as it is easily controlable which reduces the chance of reducing the strength of fibres. Also,it was observed that dried pineapple leaves fibres take longer time to ret compare to fresh leaves.The fibers were treated using NaOH for scouring while bleaching was carried out using H2O2. The treatment of fibers was conducted to get rid of fat, wax and other impurities as well as undesired colors bonded to fibers that could not be removed through water retting. The best scouring concentration of NaOH was found to be 1.25 % while the best bleaching concentration of H2O2 was found to be 10 %. More so, FTIR was carried out for both treated and untreated fibers and it was shown that wax, fat and other impurities can be removed by fibres’ scouring and bleaching. This was further confirmed by the use of Soxhlet to extract ethanol-benzene extract from both treated and untreated fibres, where untreated fibres showed a considerable weight loss while the treated fibers did not show any weight loss. Thereafter, mercerization was carried out and it was found out that the best mercerization concentration for pineapple leaves fibres is NaOH is 10%. Furthermore, the quantitative analysis of pineapple leaves fibers revealed that the fibers have, ethanol-benzene extractives of 2.6 %, pectin content of 1.53%, Lignin content of 12%, cellulose content of 79% and ash content of 2.15 %. The fibers showed a water, oil and vapor absorption of 82%,32 % and 29% respectively. Also, the thermal analysis showed that the degradation temperature is 400 0C while the fibers started to display thermal instability at 350 0C. Moreover, SEM and XRD analysis showed that the treatment of fibres participated in removal of wax and oil as well as other gummy materials, which also is in line with FTIR results obtained. Keywords: Extraction, Pineapple Leaves Fibers, Scouring, Bleaching, Mercerization, Characterization, Textile

Extraction, Treatment and Characterization of Banana Pseudo-Stem Fibers as Potential Utility in Textile Industry

Extraction, treatment and characterization of banana pseudo stem fibres was achieved. The study revealed that water retting is the best way to extract fibers, however the gummy materials bending fibres together must be weakened by boiling the fibres rich material prior to retting where the fibres were able to be extracted at 14th day of retting. The fibers were treated using NaOH for scouring while bleaching was carried out using H2O2. The treatment of fibers was conducted to get rid of fat, wax and other impurities as well as undesired colors bonded to fibers that could not be removed through water retting. The best scouring concentration of NaOH was found to be 17.5 % while the best bleaching concentration of H2O2 was found to be 2 %. More so, FTIR was carried out for both treated and untreated fibers and it was shown that wax, fat and other impurities can be removed by fibres’ scouring and bleaching. This was further confirmed by the use of Soxhlet to extract ethanol-benzene extract from both treated and untreated fibres, where untreated fibres showed a considerable weight loss while the treated fibers did not show any weight loss. Thereafter, mercerization was carried out and it was found out that the best mercerization concentration of NaOH is 15%. Furthermore, the quantitative analysis of the banana pseudo-stem fibers revealed that the fibers have, ethanol-benzene extractives of 4.2 %, pectin content of 3.07%, Lignin content of 18%, cellulose content of 68.3% and ash content of 4.2 %. The fibers showed a water, oil and vapor absorption of 71%,59 % and 8% respectively. Also, the thermal analysis showed that the degradation temperature is 370 0C while the fibers started to display thermal instability at 290 0C. Moreover, SEM and XRD analysis showed that the treatment of fibres participated in removal of wax and oil as well as other gummy materials, which also is in line with FTIR results obtained. Keywords: Extraction, Banana Pseudo-stem Fibers, Scouring, Bleaching, Mercerization, Characterization, Textile

A comparative study on the efficacy of over-the-counter wax solvents versus distilled water for managing ear cerumen

Abstract Background: Ear wax, or cerumen, is a naturally occurring hydrophobic waxy substance frequently encountered in otorhinolaryngology practices. Despite the abundance of water- and oil-based ceruminolytic agents available nowadays, there remains a lack of consensus regarding the preferred agent type, composition, or ideal treatment duration. Aims and Objectives: The study aimed to assess the efficacy of using distilled water as a wax-softening agent for ear wax removal and determine its advantages compared to over-the-counter (OTC) ceruminolytics. Materials and Methods: This double-masked, randomized prospective cohort study enrolled 236 patients seeking treatment for ear wax-related concerns at the Ear, Nose, Throat outpatient department. The cohort exclusively consisted of cases involving right ear wax, which were then randomly allocated into two groups: group A received distilled water ear drops, whereas group B received OTC ceruminolytic ear drops containing a combination of paradichlorobenzene with turpentine oil, benzocaine, and chlorbutol. Evaluation of patients took place pre- and post-intervention, focusing on three key parameters: the total duration required for ear suctioning, any additional instrumentation employed, and the occurrence of pre-procedure and post-procedure complications. Results: Out of the total 118 participants in the study, they were randomly distributed with 67 males and 51 females in group A and 63 males and 55 females in group B. During the pre-intervention complication assessment, nine subjects in group A reported ear blockage, whereas four subjects in group B did so. Additionally, two subjects in group A complained of pain, whereas none in group B did. Furthermore, five subjects in group A developed otitis externa, compared with three in group B. The average time required for ear suctioning to visualize the tympanic membrane was 9.24 ± 2.50 min in group A and 9.68 ± 2.18 min in group B. During the intervention, nine subjects in group A experienced pain during wax removal, whereas only six patients in Group B reported pain. After the interventions, five patients in group A complained of increased ear pain compared with seven in group B. Mild post-interventional pain was managed with an as-needed dosage of nonsteroidal anti-inflammatory drugs Statistically significant differences were observed in the study parameters between the subjects of the two groups. Conclusion: This study confirms that distilled water can serve as a viable method for dispersing wax, proving its efficacy comparable with commercially available OTC ceruminolytics.

Effect of Mercerization on the Crystallographic, Macromolecular, and Thermal Properties of Plantain Fibers for Fiber Reinforced Composite

In this research, natural fibers (NF) were obtained from plantain pseudo stem. The extracted plantain fibers (PF) were modified by mercerization under diverse conditions in terms of treatment time and concentration. The crystallographic structures and macromolecular properties, and surface extracted PF were all influenced by the modification process. Improvements in thermal properties were observed along with increases in the crystallite size, and degree of crystallinity as revealed by x-ray diffraction (XRD) analysis. FTIR spectroscopy confirmed partial removal of wax, lignin, and hemicellulose. Bulk density was also observed to change under treatment conditions, while Scanning electron microscope (SEM) imagery demonstrates how the treatment altered the surface of the PF. A considerable change in the macromolecular and structural characteristics of plantain fiber was observed under optimum treatment conditions.

Pemanfaatan Limbah Pucuk Tebu sebagai Sumber Selulosa Bahan Baku Plastik Biodegradable

Plastic waste continues to be a significant environmental issue due to the extended degradation period it requires. Bioplastics represent an innovation in the conventional plastic cycle, being made from natural materials such as agricultural waste containing cellulose. The objective of this research is to determine the influence of adding cellulose from sugarcane tops in the production of biodegradable plastic. The research method begins with the extraction of cellulose from sugarcane tops, including preparation stages, wax removal, bleaching, hemicellulose removal, and delignification. Sugarcane top cellulose is utilized as a raw material for bioplastic. Cellulose with concentrations of 0%, 10%, 30%, and 50% by weight is processed together with a mixture of water and tapioca, to which chitosan and glycerol are subsequently added. Observation parameters for the bioplastic include functional group characterization and mechanical tests, encompassing transparency, tensile strength, elongation, density, thickness, water absorption, and biodegradability. The research results indicate that the characterization of functional groups using FTIR produces spectra of O-H, C-H, C=C, C-O, indicating the constituent components of cellulose, glycerol, and chitosan. Meanwhile, based on the mechanical tests, the 50% sugarcane top bioplastic is the most favorable, with transparency value of 89% transmittance, tensile strength of 39.2 MPa, elongation percentage of 17.32%, density of 0.8444 g/cm3, thickness of 0.276 mm, water absorption of 98.36%, and biodegradability over 4 days. Based on the mechanical tests, the produced bioplastic holds potential for food packaging material.

Larvae of Cryptolaemus montrouzieri(Coleoptera: Coccinellidae) Prioritize Secretion of Protective Wax Over Daily Consumption and Growth.

In holometabolous insects, the immature or larval stage is characterized by a high rate of food consumption. The nutrients obtained from which are directed towards the maintenance of metabolism, growth, pupation, and metamorphosis. However, when resources are scarce, the lack thereof can affect the growth rate and compromise the metamorphosis and formation of adults. Do increased energy expenditures yield outcomes similar to those resulting from restricted food intake during the larval stage? We hypothesized that removing the wax layer from the larvae of the ladybird Cryptolaemus montrouzieri Mulsant, 1850 would result in increased energy expenditure, which can compromise both larval growth and adult size. We compared the development time, feeding rate, and adult size of larvae with an intact wax layer, and those with constantly removed wax layers. We found that the production of the wax layer was continuous. Unlike the waxed larvae, the larvae of C. montrouzieri extended their development time in response to energy depletion through wax removal. The total number of mealybugs consumed by waxless larvae was higher than the total number consumed by waxed larvae; however, the daily consumption of waxless larvae was lower than that of waxed larvae. Furthermore, the adults of waxless larvae were smaller than those whose larvae had intact wax layers. This suggests that the cost associated with wax layer secretion is a pivotal factor in larval growth. Removing this layer does not get compensated by increased larval feeding or extended development time.

The cuticular wax on sorghum straw influenced soil microbial diversity and straw degradation in soil

The cuticular waxes cover living plant surface but the ecological significance of cuticular wax in crop straw returning to soil remains uncertain. This study focused on sorghum straw to investigate the bioactivity of cuticular waxes in the soil system. The surface of sorghum leaf, sheath and stem organs was covered with epicuticular wax crystals, which present a dull and glaucous wax layer. The leaf surface with wax exhibited an average contact angle of 83°, while after the wax removal the contact angle decreased to 53° on average, showing hydrophobic surface on the sorghum leaf. In total, six wax classes were identified across all organs, including aldehydes, alkanes, fatty acids, primary alcohols, sterols, and minor triterpenoids. The total wax coverage on leaves was 1.5 μg·cm−2, which was significantly lower than that on sheaths (20.6 μg·cm−2) and stems (6.3 μg·cm−2). The wax addition increased the proportions of Actinobacteria and Firmicutes by 24.42 % and 78.02 %, whereas decreased Proteobacteria and Acidobacteria by 16.32 % and 23.16 % on day 14 under higher wax rate. The microbial communities inhabiting returned straw surfaces also differed significantly between wax-retrained and wax-removed straw, as well as among leaf, stem, and sheath components, and at various decomposition stages. Wax addition increased soil microbial biomass carbon and nitrogen by 56.76 % and 25.60 % at higher rate, and soil enzyme activities (i.e., soil urease, soil acid phosphatase activity, soil sucrase activity). Wax removal significantly increased the decomposition rate of dry matter by 24.28 % and crude fiber by 27.22 % on day 154. These findings demonstrate that plant cuticular waxes maintain their bioactivities after entering the soil, which broadens our knowledge of the roles of plant cuticular waxes in ecosystems. Therefore, selecting efficient wax-degrading microorganisms would accelerate the nutrient cycling of crops in soil system.

Enhanced microwave assisted pyrolysis of waste rice straw through lipid extraction with supercritical carbon dioxide.

A combination of supercritical carbon dioxide (scCO2) extraction and microwave-assisted pyrolysis (MAP) have been investigated for the valorisation of waste rice straw. ScCO2 extraction of rice straw led to a 0.7% dry weight yield of lipophilic molecules, at elevated temperatures of 65 °C and pressures of 400 bar. Lipid compositions (fatty acids, fatty alcohol, fatty aldehydes, steroid ketones, phytosterols, n-alkanes and wax esters) of the waxes obtained by scCO2 were comparable to those obtained Soxhlet extraction using the potentially toxic solvent n-hexane. ScCO2 extraction positively influenced the pyrolysis heating rate, with a rate of 420 K min-1 for particles of 500-2000 μm, compared to 240 K min-1 for the same particle size of untreated straw. Particle size significantly affected cellulose decomposition and the distribution of pyrolysis products (gaseous, liquid and char), highlighting the importance of selecting an adequate physical pre-treatment. TG and DTG of the original rice straw and resulting biochar produced indicated that cellulose was completely decomposed during the MAP. While a rapid pressure change occurred at ∼120 °C (size > 2000 μm) and ∼130 °C (size 500-2000 μm) during MAP and was associated with the production of incondensable gas during cellulose decomposition, this takes place at significantly lower temperatures than those observed with conventional pyrolysis, 320 °C. Wax removal by scCO2 influences the dielectric properties of the straw, enhancing microwave absorption with rapid heating rates and elevated final pyrolysis temperatures, illustrating the benefits of combining these sustainable technologies within a holistic rice straw biorefinery.

Analysis of Wax Formation Mechanism and Anti Wax Effect of Oil Well Tubing in a Certain Oilfield

During the production process of oil wells, wax deposition is caused by factors such as temperature reduction and dissolved gas precipitation. Severe wax deposition in oil wells can cause tubing blockage, leading to a decrease in oil well production and even stopping production due to wax blockage, affecting normal oil well production. Therefore, wax deposition can have a serious impact on the wellbore and even oilfield production. This article takes a certain oilfield block as an example to analyze the mechanism of wax deposition in oil wells and compares the effectiveness of commonly used wax removal and prevention measures such as different hot washing processes, adding wax removers, running acoustic viscosity reduction and wax prevention devices along with the oil pipe, and hot washing packers for sealing wells. The results show that superconducting hot washing, adding wax remover, and using acoustic wave viscosity reducing and wax preventing devices can effectively slow down wax deposition in oil wells. The use of hot washing packers effectively solves the problem of long-term inability to hot wash sealed wells, and it is recommended to promote their use.