Adsorptive desulfurization of thiophene from the model fuels onto graphite oxide/metal-organic framework composites

The composites of a copper-based metal-organic framework (HKUST-1) in the presence of graphite oxide (GO) were synthesized via a solvothermal method to remove thiophene (TP). The prepared GO/HKUST-1 composites were characterization by N₂ adsorption-desorption, XRD, SEM. The desulfurization performance of TP from the model fuels by GO/HKUST-1 with different content of GO was investigated. Most importantly, under the optimum adsorptive conditions, the composite material 1.75%GO/HKUST-1 exhibited excellent adsorption capacity of 60.67 mg/g, which was attributed to the highest surface area and porosity.     

Fabrication of oxygen-defective tungsten oxide nanorods for deep oxidative desulfurization of fuel

Owing to the increasingly serious environmental issues caused by the sulfur burnt in fuel, desulfurization has become an important topic. In this work, an amphiphilic oxygen-defective tungsten oxide was synthesized by a colloidal chemistry method. The amphiphilic property and oxygen defects were well characterized, and the structure of the oxygen-defective tungsten oxide catalyst was investigated. In addition, the catalyst was employed in oxidative desulfurization system of fuel, and deep desulfurization was achieved. It was found that the very high oxidative desulfurization performance of oxygen-defective tungsten oxide catalyst resulted from both the amphiphilic property and oxygen defects. This work can provide a strategy for preparation of highly active metal oxide catalysts with oxygen defects in oxidative desulfurization reaction of fuel.     

常减压蒸馏装置减压塔顶含硫不凝气的喷射增压脱硫技术

介绍了一种应用于减压塔顶等低压富含硫化氢气体的增压脱硫工艺技术。该技术直接采用液体脱硫剂为驱动介质,通过液体喷射方式将减压塔顶低压富含硫化氢气体(或其它低压气体)增压,经与一定浓度的液体脱硫剂充分混合,气体中的硫化氢则与脱硫剂完全反应,从而实现包括减顶气在内的低压含硫气体的增压及高效深度脱除硫化氢气体的目的。通过大型工业装置应用表明,该技术可在深度脱除硫化氢的同时有效改善低压气体的压力使用条件,为加热炉提供环保型气体燃料,有效降低加热炉烟气中二氧化硫含量,工业应用表明可使减顶燃料气硫质量分数小于0.25%,在减压炉用燃料油含硫量不大于1%时,排放烟气的SO2质量浓度可不大于850 mg/m3,满足排放要求。与传统的采用压缩机将低压气体增压后进行塔式低压吸收脱硫工艺相比,减少了压缩机投资和维护费用,具有工艺流程简单、占地小、节省投资、容易操作和维护及增压和脱硫效率高的优点。     

An optimization of process parameters for deep desulfurization of model fuel by ZSM-5/ZnO photocatalyst using response surface method

One of the major factors that causes air pollution are sulfur oxides) SO_x) that exiting from vehicles exhaust by combustion of fossil fuel. Although hydrodesulfurization method has always been the option in oil refineries to reduce sulfur contents, but it is almost impossible to meet stringent new environmental regulation by this method. The Achilles heel of the conventional method is weakness in removing aromatic sulfur recalcitrant compounds. In the present research, photocatalytic oxidative desulfurization (PhOD) based on the ZSM-5/ZnO catalyst is developed. n-Decane as the model fuel and benzothiophene (BT) and dibenzothiophene (DBT) as the sulfur compounds are used. Then by the response surface method the optimum conditions were developed. The result indicates that catalyst with 6%wt Zn/ZnO, 45 min reaction time, UV power of 32 watts and catalyst to fuel ratio of 2 gr/L is able to remove BT and DBT with efficiency of 86.1% and 74.0%, respectively.     

微波法制备AgCeY吸附剂及其脱硫性能的研究

采用微波辅助法成功制备了AgCeY吸附剂,采用XRD,BET,XPS和Py-FTIR等技术对吸附剂进行了表征,并对吸附剂的制备条件,平衡等温吸附,动力学和热力学进行了研究。研究表明：在微波辐射时间20 min,微波功率400 W,微波温度70 °C条件下制备的AgCeY吸附剂具有最佳的吸附脱硫性能。微波法制备的AgCeY吸附剂比传统的液相离子交换法制备的AgCeY具有更高的路易斯酸度,并且其脱硫能力有了显著提高。噻吩（TP）和苯并噻吩（BT）在AgCeY吸附剂上的吸附过程可用Langmuir模型来描述,动力学模型可用伪一级模、伪二级模型和Langmuir模型来描述。TP和BT在AgCeY吸附剂上的吸附过程是传质控制的,并且是一个自发放热过程。     

Extension of gas adsorption models to liquid diesel fuel desulfurization: Validity and predictability

Desulfurization of diesel fuel is simulated in a fixed-bed adsorption column. Researchers have paid less attention to models that describe and predict liquid phase adsorption. Hence, the ability of five widely used models which were originally developed for gas adsorption (Zhang–Cheng, Clark, Thomas, Bohart–Adams, and Wolborska) to simulate and predict the fuel desulfurization breakthrough curve is investigated. Afterward, the best model is chosen to predict the breakthrough curve in different flow rates and bed depths. An industrial scale-up with a real refinery flow rate using the appropriate model has been done. The results are in good agreement with the reported ones.     

Applications of guar gum and its derivatives in petroleum industry: A review

Green chemistry approach is growing rapidly and the replacement of petroleum derived materials with bio-based materials is greatly enhanced for environmental and health concerns. Polymers from renewable natural resources have attracted an increasing amount of attention over the last three decades, predominantly due to two main reasons: firstly environmental concerns, and secondly the realization that our petroleum resources are finite. Natural polymers are available in large quantities from different renewable sources, while synthetic polymers are produced from non-renewable petroleum resources. They include proteins and polysaccharides. Among the most important polysaccharides is Guar gum which has been extensively used in a wide range of applications due to its unique properties. The objective of this review is to focus the light on Guar Gum and its derivatives. The chemical structure, sources, chemical modification, physical properties (mechanical properties and thermal stability), and some potential industrial applications are reviewed and discussed.     

Investigation of emulsion and effect on emission in CI engine by using diesel and bio-diesel fuel: A review

The exhaust of diesel engine is a main significant air pollution source which affects the environment and human life. A number of researchers have contributed their valuable efforts from each and every perspective to reduce air pollution. In the present work in-depth analysis is done on the recent investigation which is carried out in the field of alternative Fuels. The study examines the result of several aspects of emulsion stability and also investigated variables such as type of surfactant, mixing speed, mixing time and various additives and its effect on emission. Higher mixing speed with less water percentage increases emulsion stability. The objective of this paper is to highlight the analysis on W/D emulsion fuel, emulsion fuel stability and effect of W/D fuel on combustion, performance and emission characteristic. The results disclose an enhancement in engine performance and reduction of harmful emission for various additives compared to diesel.     

Liquid fuel resources and prospects for ligno-cellulosic ethanol: An Egyptian case study

Fossil fuels (oil, natural gas and coal) presently represent about 90% of the world’s total commercial primary energy demand. Yet, they are depletable sources of energy. Growth in the production of easily accessible oil, the main source of high energy liquid transportation fuels, will not match the projected rate of demand growth, especially in developing countries. In the transport sector, today, the only alternative to non-sustainable fossil fuels is biofuels that are produced from biomass, a stored environmentally neutral solar energy. These fuels are compatible with current vehicles and blendable with conventional fuels. Moreover, they share the long-established distribution infrastructure with little, if any, modification of equipment. The main biofuels presently in commercial production are bioethanol and biodiesel. Industrial countries started production of the 1st generation bioethanol and biodiesel from food products (grains and edible oil) since a few decades and these fuels are currently available at petrol stations. Second generation bioethanol from ligno-cellulosic materials is on the research, pilot and/or demonstration stage. This paper discusses the current situation regarding liquid fuels in Egypt which are experiencing imbalance between total production and demand for gasoline and diesel fuels. The quantified need for nonconventional sources is presented. Based on a thorough assessment of current and prospective generated agriculture residues as distributed over the political areas, mapping of the number and capacity of plants to be installed for production of bioethanol from available residues namely rice straw, sugar cane residues and cotton stalks has been developed. Annual capacities of 3000, 10,000 and 20,000 tons ethanol/year until year 2021 have been proposed. Capital and operating requirements and economic indicators have been estimated. It has been concluded that at current price of ethanol of about $0.6/kg, the simple rate of return on investments is about 2.8%, 11% and 16% for the 3000, 10,000 and 20,000 tons annual capacity ethanol respectively.     

A review of Listeria monocytogenes: An update on outbreaks,virulence, dose-response,ecology, and risk assessments

Improved control measures starting in the 1990s have greatly reduced the prevalence of L. monocytogenes in many food categories, particularly in meats and meat products. However, the rate of listeriosis has remained constant during the last decade and the more severe, systemic (invasive) form of listeriosis is now recognized as occurring more frequently in small outbreaks than previously recognized. This review addresses the recent advances in epidemiology and virulence, in growth and modelling, and insights from the risk assessments. Recognition of recent outbreaks from food vehicles not traditionally associated with L. monocytogenes (celery, cantaloupe, mung bean sprouts, stone fruits, caramel apples and ice cream) was facilitated by PFGE and, increasingly, whole genome sequencing. The Key Events framework, an understanding of the key individual biochemical steps from ingestion to infection, provides a structure for relating new knowledge on strain variability, mutations, and host susceptibility to the probability of illness. Guidance for determination of the growth/no growth potential of a food has been issued by several regulatory authorities and the risk assessments indicate that prevention of growth remains a principle control element. The recognition of biofilm formation and the possible existence of dormant, non-dividing persister cells will require additional attention. The recent outbreaks underscored the individual characteristics of specific foods (melons vs all fruit; microenvironments in the caramel apples) and raised questions about the current understanding of infectivity of lower doses and the susceptibility of specific individuals. Advances have been made in these areas, but further research is clearly necessary to control this pathogen.     

阴离子型酸液胶凝剂的研制

介绍了制备阴离子型高分子量聚合物胶乳的技术路线和合成工艺,评价了合成产品的性能。用AMPS作阴离子单体,通过与一至两种非离子单体反乳液共聚反应,制得了固相含量高、分子量高、在酸液中能速溶的阴离子型高分子量聚合物胶凝剂。该产品具有耐热酸水解、耐热稀释、抗剪切、抗盐降解性能。     

Advances in biofilm control for food and beverage industry using organo-silane technology: A review

Cell adhesion can be a potential problem as well as a valuable tool for microbiological engineering. It can lead to biofouling, contamination of product and corrosion. On the other hand, cell adhesion is purposely employed in fermenters and bioreactors to influence reactor performance. This paper presents an overview of organo-functional silanes – their chemistry, properties, use, and the main laboratory experiments that can be of interest to the food and beverage industry. The purpose is to introduce and explore possibilities for using organo-silane combinations to enhance or reduce microbial adhesion.     

Multi-walled carbon nanotubes-based magnetic solid-phase extraction for the determination of zearalenone and its derivatives in maize by ultra-high performance liquid chromatography-tandem mass spectrometry

A simple and rapid magnetic solid-phase extraction (M-SPE) procedure using multi-walled carbon nanotube-magnetic nanoparticles (MWCNT-MNPs) as sorbents was established for purification of zearalenone (ZEA), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL) and β-zearalanol (β-ZAL) in maize. The main parameters affecting the clean-up efficiency were thoroughly investigated, and high purification efficiencies for all analytes were obtained. The resulting MWCNT-MNP-ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was validated for maize samples. The matrix effects were greatly minimized using the M-SPE approach, with signal suppression/enhancement values decreased from 69.9–127.6% to 92.1–103.8%. Consequently, complex matrix-matched calibration curves were not necessary and the calibrations constructed in acetonitrile could be applied for accurate quantification of the targeted mycotoxins in real samples. The average recoveries ranged from 75.8 to 104.1% and the inter- and intra-day precision values expressed as RSDs, were all lower than 14%. Limits of detection and quantification were in the range of 0.03–0.04 and 0.07–0.10 μg/kg, respectively. The analytical performance of the developed method was also successfully evaluated with maize samples, and this method was proved to be a powerful tool for monitoring ZEA and its derivatives in maize.     

深层背斜圈闭中泥岩盖层完整性评价方法及其应用——以四川盆地川中地区震旦系气藏为例

深层致密泥岩盖层由于成岩程度高、脆性强,易发生脆性破裂并造成盖层泄漏,因此,盖层的完整性评价十分关键.泥岩盖层的变形特征主要受泥岩密度和围压控制,随着埋深增大,泥岩会经历塑性—脆性—塑性的复杂转变,但在沉积盆地埋深范围内总体以发育脆性变形为主.深层泥岩盖层在抬升过程中由于脆性增强,更易发生脆性破裂.在同样的抬升背景下,...     

低渗透砂岩储层成岩相测井识别方法及其地质意义——以鄂尔多斯盆地姬塬地区长8段储层为例

在对鄂尔多斯盆地姬塬地区长8段储层绿泥石衬边弱溶蚀成岩相、不稳定组分溶蚀成岩相、压实致密成岩相、高岭石充填成岩相和碳酸盐胶结成岩相常规测井响应特征进行分析的基础上,提出利用中子测井、密度测井以及中子-密度视石灰岩孔隙度差,辅助以自然伽马和电阻率测井曲线,连续定量识别储层成岩相的方法,并建立了相应的储层成岩相测井识别图版。利用该图版对黄36井测井资料进行了处理,通过与薄片鉴定结果的对比,验证了图版的准确性。利用成岩相识别结果,划分储集层的类型和产能级别：绿泥石衬边弱溶蚀成岩相储层是姬塬地区最有利储层,对应的含油级别划定为A级;不稳定组分溶蚀成岩相储层是第二类储层,对应含油级别划定为B级;含碳酸盐胶结成岩相夹层的储层产油能力最弱,是第三类储层,对应的含油级别划定为C级。