高密度、低十六烷值柴油加氢改质生产优质清洁柴油工艺研究

以高密度、低十六烷值柴油为原料进行加氧改质研究,结果表明:在压力10.0～12.0 MPa、空速0.7～1.0 h-1、氢油比700～1 000及一定的温度条件下,柴油馏分质量收率较高,其十六烷值提高19.5～25.5个单位,密度大幅度降低,其它指标均有不同程度的改善,可作优质清洁柴油的调和组分.副产品石脑油馏分芳潜高,硫、氮含量低,是优质的重整原料.     

Neural network prediction of cetane number and density of diesel fuel from its chemical composition determined by LC and GC-MS

Neural networks were used to correlate and predict the cetane number and the density of diesel fuel from its chemical composition. Cetane number (CN) and density were correlated with 12 hydrocarbon groups in diesel fuel determined by liquid chromatography (LC) and gas chromatography-mass spectrometry (GC-MS). In total, 69 diesel fuels were available for this study: 48 diesel fuels were included in the training data set and 21 in the test data set. Various neural network architectures were trained using the training data set, and the accuracy of the model obtained was examined by using the test data set. For correlating both CN and density in this study, the best neural network architecture was a general regression neural network (GRNN). With the test data set, the mean absolute errors were 1.23 (CN) and 0.002 g/cm³ for the CN and density, respectively. Predictive equations for CN and density of diesel fuel from its chemical composition were also developed with a standard multiple linear regression method. The comparison of the neural network method with the multiple linear regression method, using this data set, revealed that for complex nonlinear problems such as the correlation of the CN with the hydrocarbon type characterization, the neural network approach could provide a better model. However, for a simpler correlation problem like the density of a diesel fuel, which is approximated well by the sum of the contributions of individual components, the predictive equations produced by multiple linear regression and neural network methods gave similar results.     

影响催化裂化柴油十六烷值的因素与MCI技术

对影响催化裂化柴油十六烷值的因素进行了工艺研究,结果表明,用加氢精制的方法不能大幅度提高柴油的十六烷值,而高压脱芳在工业生产上也受到限制,中国石化抚顺石油化工研究院(FRIPP)开发的MCI技术很好的解决了这一矛盾,为清洁燃料的生产开避了广阔前景.     

Thermal Evaluation of Diesel/Hydrogen Peroxide Fuel Blend

Thermal properties of fossil fuel are the key fundamental characteristics, which can distinguish any compound as a potential fuel. The performance of diesel fuel blend along with stability and solubility parameter designs are evaluated. The results from the experimental study indicate that the increase in hydrogen peroxide (H₂O₂) amount enhances the cetane number of diesel fuel blend significantly. However, the calorific value decreases as compared to pure diesel fuel. All values performed well according to the ASTM D‐975 diesel testing method. The thermodynamics of the prepared fuel blends also revealed that substantial solubility and diesel/H₂O₂ blend stability are provided even at lower temperatures. Such blends can be used as a feasible replacement of pure diesel fuel.     

Key properties and blending strategies of hydrotreated vegetable oil as biofuel for diesel engines

Hydrotreating catalysis is becoming a promising alternative to transesterification for the production of biofuels derived from vegetable oils. They have potential advantages with respect to both biodiesel fuels and petroleum-derived diesel fuels in terms of production costs, engine emissions and adaptability to current engine designs, but they have also some limitations which may restrict their capability to replace diesel fuels. Those fuel properties considered the most restrictive ones were measured on different blends of HVO (selected among the variety of names given to these fuels) with a winter ultra low sulfur diesel fuel (in 10, 20, 25, 30, 35, 40, 45, 50, 55, and 75 vol.%) in order to propose some blending strategies to optimize engine performance and emissions, to protect the engine components and to keep the vehicle operability. The results obtained show that the main restrictions are imposed by lubricity and cetane number, and, in case of cold regions, also by cold flow properties. A compromise between lubricity and derived cetane number would lead to a recommendation for low or medium HVO concentrations, and blends with concentrations above 50% would not be recommended. Density and viscosity would not impose direct blending restrictions, although the reductions in density could provide some economic savings and some flexibility to refineries. The loss of heating value per unit volume (and consequently the expected increase in fuel consumption) would be lower than 3% in blends up to 50% in volume. Finally, the sooting tendency of the blends is sharply reduced, indicating lower engine PM emissions and reduced need for regeneration of diesel particulate filters.     

Accurate Prediction of Kinematic Viscosity of Biodiesels and their Blends with Diesel Fuels

Viscosity of mixtures of biodiesels (admixtures) and mixtures of biodiesel/diesel (blends) is a important parameter for determining their combustion behavior. There is no universal and general model for prediction of viscosity of these systems at different conditions. Hence, developing simple, accurate, and general models for prediction of viscosity of these systems is of great importance. In this work, three computer-based models named multilayer perceptron neural network (MLP-NN), radial basis function optimized by particle swarm optimization (PSO-RBF), and adaptive neuro fuzzy inference system optimized by hybrid approach (Hybrid-ANFIS) were developed for prediction of viscosity of blends and admixtures. A number of 966 experimental data covering wide ranges of influencing parameters were utilized to develop the models. The accuracy of predictions of the developed models was examined by using different statistical quality measure approaches as well as comparing their results with the predictions of literature models. Results showed that the developed models present accurate predictions and are superior to the literature models. The predictions of PSO-RBF model were also better than Hybrid-ANFIS and MLP-NN models.     

An analysis for effect of cetane number on exhaust emissions from engine with the neural network

Decoupling cetane number from the other compositions and properties of diesel fuel, the individual effect of cetane number on the exhaust emissions from an engine may be researched. This paper has presented a back-propagation neural network model predicting the exhaust emissions from an engine with the inputs of total cetane number, base cetane number and cetane improver, total cetane number and nitrogen content in the diesel fuel; as well as the output of the exhaust emissions of hydrocarbon (HC), carbon oxide (CO), particulate matter (PM) and nitrogen oxide (NO_x). An optimal design has been completed for the number of hidden layers, the number of hidden neurons, the activation function, and the goal errors, along with the initial weights and biases in the back-propagation neural network model. HC, CO, PM and NO_x have been predicted with the model, the effects of cetane improver and nitrogen content on them have also been analyzed, and better results have been achieved.     

提高催化裂化柴油十六烷值技术探讨及应用

随着柴油质量标准的不断升级,催化裂化柴油因十六烷值低、芳烃含量高等特点,加工难度日趋增大。研究学者针对提高催化裂化柴油十六烷值开发出加氢改质、加氢转化、加氢处理-催化裂化组合、加氢裂化掺炼催化柴油等技术,各类技术在产品结构、产品质量、改造难度等方面各具特色。炼油企业可根据自身的需求选择适宜的技术,以实现柴油质量升级。某企业在应用了加氢裂化掺炼催化柴油技术、加氢处理-催化裂化组合技术后,柴油十六烷值有所提升,车用柴油比例由60%提升至94%,在每月加工1万t外购催化柴油的情况下,车用柴油比例仍维持80%以上。     

Novel mesoporous aluminosilicate supported palladium-rhodium catalysts for diesel upgrading: II. Catalytic activity and improvement of industrial diesel feedstocks

Bimetallic PdRh catalysts (molar ratio Pd/Rh = 1 and 2) were prepared by impregnation of a mesoporous aluminosilicate (molar ratio Si/Al = 10 and 20). These materials are destined to be used in industrial processes aiming to improve diesel quality by hydrogenation and ring-opening of aromatic components. The four catalysts were examined for their activity in hydrogenation of naphthalene and tetralin model feedstocks, at 6 MPa, including in the presence of sulfur containing compounds. The capacity of one of these catalysts to improve the quality of hydrogenated industrial light cycle oil containing ≤50 wt ppm of sulfur was evaluated in a pilot plant. In these industrial conditions, the catalyst has a higher catalytic activity at lower temperature than a reference state of-the-art catalyst, giving a seven-point improvement of the cetane number at 280–300 °C and with formation of less than 10% of non-selective cracking products.     

Diesel Oil Degradation Potential of a Bacterium Inhabiting Petroleum Hydrocarbon Contaminated Surface Waters and Characterization of Its Emulsification Ability

Degradation of poorly water soluble hydrocarbons, like n‐alkanes and polycyclic aromatic hydrocarbons are challenged by some bacteria through emulsification of hydrocarbons by producing biosurfactants. In diesel oil bioremediation, diesel oil degrading and surfactant producing bacteria are used to eliminate these pollutants from contaminated waters. Therefore, identifying and characterizing bacteria capable of producing surfactant and degrading diesel oil are pivotal. In this study, bacteria isolated from hydrocarbon contaminated river water were screened for their potential to degrade diesel oil. Primary selection was carried out by using conventional enrichment culture technique, emulsification index measurement, gravimetric and gas chromatographic analyses of diesel oil degradation. A bacterium with 60 % emulsification index and 92 % diesel oil degradation ability in 14 days was identified as Acinetobacter haemolyticus Zn01 by 16S rRNA sequencing. A. haemolyticus Zn01 was shown to harbor both catabolic genes alkB and C23O effective in diesel oil degradation. The biosurfactant of the bacterium was also characterized in terms of surface tension, zeta potential, Fourier transform infrared spectroscopy and scanning electron microscopy. Being able to emulsify and degrade diesel oil, A. haemolyticus Zn01 seems to have high potential for the elimination of diesel oil from polluted waters.     

Dynamic Analysis of the Removal of Fatty Acid from a Pet Surface Using a Quartz Crystal Microbalance

A quartz crystal microbalance (QCM) was used to study the removal of stearic acid from poly(ethylene terephthalate) (PET) substrate in aqueous alkali and surfactant solutions. The PET substrate was prepared on a QCM gold electrode by spin‐coating; its properties were examined by scanning electron microscopy, X‐ray photoelectron spectroscopy, and water contact angle measurements. As a result, the QCM electrode was found to be completely covered with a smooth PET film. To investigate the effect of soil deposition state on its removal, stearic acid (an oily soil model) was deposited onto the PET substrate with the Langmuir–Blodgett (LB) technique or by spraying. The QCM frequency was recorded during the removal of stearic acid from the PET substrate in aqueous solutions. In NaOH solution, stearic acid deposited by the LB method was more rapidly removed than when deposited by the spraying method. However, the LB films of stearic acid were difficult to be removed in surfactant solutions. With respect to removal behavior of spray‐deposited stearic acid in surfactant solutions, the results determined by the QCM method were compared with those from microscopic image analysis. The removal efficiencies in the sodium dodecyl sulfate solution were in good agreement between the two methods. However, in the alkyl ethoxylate solution, the removal efficiencies obtained by the QCM method were larger than those from microscopic image analysis. These experimental results were explained by the removal mechanism of stearic acid by the alkali and surfactant solutions.     

几种食用油中不饱和脂肪酸和皂化值的测定研究

以茶籽油、玉米油、橄榄油、芝麻油、花生油为原料,利用容量分析方法测定其不饱和脂肪酸含量及皂化值.经碘酊法测定,这5种食油用的不饱和脂肪酸含量(以碘值衡量)最高的为茶籽油,达95.46g·(100g)-1,碘值最低的为花生油54.67g·( 100g)-1.这5种植物油碘值由大至小依次为:茶籽油＞玉米油＞橄榄油＞芝麻油＞...     

Anticancer Potential of Small-Molecule Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase

Recently fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) inhibitors have been in the limelight due to their anticancer potential. Both FAAH and MAGL are the endocannabinoid degrading enzymes that hydrolyze several endogenous ligands, mainly anandamide (AEA) and 2-arachidonic glycerol (2-AG), which regulate various pathophysiological conditions in the body such as emotion, cognition, energy balance, pain sensation, neuroinflammation, and cancer cell proliferation. FAAH and MAGL inhibitors block the metabolism of AEA and 2-AG, increase endogenous levels of fatty acid amides, and exert various therapeutic effects including chronic pain, metabolic disorders, psychoses, nausea and vomiting, depression, and anxiety disorders. FAAH and MAGL are primarily neurotherapeutic targets, but their contribution to various types of carcinomas are significant. Inhibitors of these enzymes either alone or as multitarget agents, or with supra-additive effects show the potential effect in ovarian, breast, prostate, and colorectal cancers. Besides highlighting the role of FAAH and MAGL in cancer progression, this review provides an update on the anticancer capabilities of known and newly discovered FAAH and MAGL inhibitors and also provides further directions to develop FAAH and MAGL inhibitors as new candidates for cancer therapy.     

Recent Advances in Inhibitors of Bacterial Fatty Acid Synthesis Type II (FASII) System Enzymes as Potential Antibacterial Agents

Bacterial infections are a constant and serious threat to human health. With the increase of multidrug resistance of clinically pathogenic bacteria, common antibiotic therapies have been less effective. Fatty acid synthesis type II (FASII) system enzymes are essential for bacterial membrane lipid biosynthesis and represent increasingly promising targets for the discovery of antibacterial agents with new mechanisms of action. This review highlights recent advances in inhibitors of bacterial FASII as potential antibacterial agents, paying special attention to the activities, mechanisms, and structure–activity relationships of those inhibitors that mainly target β‐ketoacyl‐ACP synthase, β‐ketoacyl‐ACP reductase, β‐hydroxyacyl‐ACP dehydratase, and enoyl‐ACP reductase. Although inhibitors with low nanomolar and selective activity against various bacterial FASII have entered clinical trials, further research is needed to expand upon both available and yet unknown scaffolds to identify new FASII inhibitors that may have antibacterial potential, particularly against resistant bacterial strains.     

Potential of Unconventional Seed Oils and Fats from West African Trees: A Review of Fatty Acid Composition and Perspectives

Seed oils sourced from West Africa are generally not well-characterized, but likely to have an untapped potential. This review aims to make an overview of fatty acid (FA) composition of unconventional seed oils from semi-arid West African trees and evaluate potential for new and enhanced uses and for improving local livelihoods and biodiversity conservation. A total of 111 studies on FA composition were found, covering 31 species. Only 69 of the studies (62%) were included in the review, as 38% had unreliable or incomplete results. There was a clear link between taxonomic kinship and FA composition. Over 20 potentially interesting and underexploited oils were found, including oils with properties similar to palm oil, olive oil, coconut oil, shea butter, and cotton seed oil. About half of the oils have promising potential for cosmetics. One third of the oils were relatively saturated, indicating properties for structuring food and heat resistance. Most of the species had multiple uses and oil production could be profitable in co-production with other non-timber forest products. Furthermore, establishment of sustainable oil production and domestication of oil trees could promote biodiversity conservation. Enhanced oil production in semi-arid West Africa is promising, but several practical constraints remain to be overcome.     

铜与硝酸反应的绿色化设计

化学实验教学实现绿色化思想的关键有两点:一是挥发有害物质的化学反应在完全密封状态下进行;二是实验产物的无害化处理.利用U型管巧妙设计,可使铜与浓、稀硝酸反应的毒气实验在密闭环保中进行,同时达到了绿色化尾气处理利用NO与浓HNO3反应,可证明铜与浓硝酸反应为什么生成的是NO2而不是NO,从事实上为学生纠错提供了有力判据.     

Simultaneous Catalytic Removal of Nitrogen Oxides and Soot from Diesel Exhaust Gas over Potassium Modified Iron Oxide

Iron oxide modified by potassium, i.e. Fe_1.9K_0.1O₃, exhibits high catalytic performance for the simultaneous conversion of soot and NO_x into CO₂ and N₂. The present study shows that long‐time treatment of the catalyst leads to a drastic decrease in the activity, whereas even the aged catalyst maintains considerable activity. On the other hand, long‐time treatment causes selective N₂ formation, i.e. no more formation of the byproduct N₂O. This alteration of catalytic performance is likely due to agglomeration of the promoter potassium being present at the surface of catalyst. Detailed experiments were carried out with a more realistic diesel model exhaust gas to confirm that Fe_1.9K_0.1O₃ is a suitable catalyst for the simultaneous removal of soot and NO_x between 350 and 480 °C. It was assumed that (CO) intermediates, formed by the catalytic reaction of NO_x and oxygen with the soot surface, are the reactive species in NO_x‐soot conversion.     

Melting Points and Viscosities of Fatty Acid Esters that are Potential Targets for Engineered Oilseed

Our previous isolation of branched-chain fatty acid (BCFA) methyl esters from lanolin was improved and scaled up. Also, oleate esters of isopropanol, oleyl alcohol and normal alcohols of 1–12 carbons chain lengths were prepared. Esters were made by interesterification with sodium alcoholates and by esterification with Candida antarctica lipase. It proved easier to obtain pure esters by the enzymatic synthesis. Melting points and viscosities over the range of 0–70 °C were determined in order to better identify potential lubricant targets that might be produced by genetically modified oilseed crops. Isopropyl and butyl oleate have melting points of −33 and −32 °C, respectively and viscosities that range from ~17 cp (0 °C) to ~2.5 cp (70 °C). They should have suitable stability for lubricants. BCFA esters had viscosities similar to their straight chain analogs. Viscosities increased with alcohol chain length and decreased with temperature. The dependence of viscosity on temperature was fit with an equation based on Erying’s rate equation. Some esters with branched acid or branched alcohol moieties, and some oleate esters might be utilized as biolubricants or biofuels on the basis of their melting points and viscosities.     

Structural Analyses of Hydrated Crystals in Mixed Green Surfactant Systems: α‐Sulfonated Fatty Acid Methyl Ester Salt and Fatty Acid Soap Mixtures

α‐Sulfonated fatty acid methyl ester salts (MES), synthesized from renewable plant resources, are an example of green surfactants used in eco‐friendly washing detergents because of their excellent detergent properties, biodegradability, and enzyme stability. Although various physicochemical properties of MES crystals and micelles have been studied, mixed systems composed of MES and other surfactants have not been well studied. We investigated the crystalline structures of hydrated solids in mixed systems containing MES and soaps, which have been utilized as detergents, using small‐ and wide‐angle X‐ray scattering (SWAXS), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy techniques. The minimum dissolution temperature, determined by visual observation, of a 4:1 M ratio of the sodium salt of α‐sulfonated palmitic acid methyl ester (C₁₆MES‐Na) and sodium palmitate (C₁₆‐Na), is indicative of a eutectic mixture. SWAXS measurements reveal that C₁₆MES‐Na and C₁₆‐Na crystals are formed separately in this system. Eutectic mixtures were also observed for the C₁₆MES‐Na/C₁₆MES‐K (α‐sulfonated palmitic acid methyl ester potassium salt) system and in the C₁₆MES‐K/C₁₆‐Na system. Furthermore, in addition to C₁₆MES‐K and C₁₆‐Na crystals, C₁₆MES‐Na crystals were also formed in the C₁₆MES‐K/C₁₆‐Na system, through counterion exchange during crystallization.