生物柴油对柴油机排放影响的研究综述

介绍生物柴油与普通0#石化柴油的理化特性,分析生物柴油对柴油机常规排放物的影响,提出改善生物柴油排放性的措施,为进一步开展生物柴油的应用研究提供一定的研究基础。     

发展我国生物柴油产业的探讨

生物柴油来源于动植物油脂等可再生资源。作为矿物柴油的替代燃料，生物柴油具有空气污染物排放少、润滑性好、生物降解完全等优点，但生物柴油的成本高是制约其发展的瓶颈。结合我国具体国情，从原料（油料作物、油料林木果实、油藻和食用废油等）的综合利用，生物柴油的加工技术（酸碱催化、酶催化、无催化和副产高品质甘油的酯交换工艺），以及高附加值的后续产品（润滑添加剂、特种溶剂、表面活性剂等）的开发利用等方面，阐述了生物柴油作为环境友好的替代燃料和大宗有机化工原料的可行性。指出必须开发符合我国国情的生物柴油专有技术，才能使生物柴油产业成为真正具有竞争力的新兴产业。     

我国生物柴油企业发展瓶颈和对策

在能源和生态双重危机下,世界上许多国家正大力开发生物柴油技术并推进其产业化进程,生物柴油产业近些年得到了快速的发展。本文分析我国生物柴油在发展中遇到政策支持力度不够、市场,原料、成本等问题,并提出解决瓶颈相应的对策。     

固定化酶催化酯交换反应制备生物柴油的研究现状及展望

生物柴油是以动植物油脂为原料合成的可再生能源,可作为石油、柴油的替代品或部分替代燃料。脂肪酶法制备生物柴油具有反应条件温和、醇用量小、甘油易回收和无废物产生等特点。综述了脂肪酶的固定化、不同载体固定的脂肪酶催化合成及其操作条件(酰基受体、有机溶剂、含水量、温度),并对酶促酯交换反应合成生物柴油的发展前景进行了展望。     

我国生物柴油产业发展的探讨

介绍了美国、欧盟等和我国生物柴油产业发展的最新进展,包括产能、标准和政策等。从原料供应和生产经济性角度分析了我国生物柴油产业发展面临的困境,并建议采用废弃油脂作为起点,推动我国生物柴油产业发展,特别是要用生物柴油(脂肪酸甲酯)和甘油来生产高附加值的化工产品,大幅度提高利润。     

精制棕榈油制备生物柴油的实验研究

以精制棕榈油为原料,与无水乙醇进行酯交换反应制取生物柴油。探讨了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响,采用正交实验优化合成条件确定了最佳合成条件及影响反应的关键因素,并运用气相色谱-质谱技术分析了产物的结构和组成,运用核磁共振技术对主要成分进行了结构确定。结果表明该生物柴油符合《柴油机燃料调和用生物柴油国家标准》(GB/T20828-2007),接近美国和德国的生物柴油标准,基本符合《轻柴油》(GB252-2000),适于中小规模及大规模生产应用。     

声酶法合成生物柴油的比较研究

以玉米油、乙醇和Lipozyme TL IM脂肪酶为主要原料,研究了声酶法合成生物柴油不同因素的影响,并与静态、摇床作用下酶法合成生物柴油进行了比较,结果表明,随着乙醇量、反应温度或溶剂石油醚加入量的增大,生物柴油的产率均先增大后降低,随着酶添加量增大、反应时间的延长,生物柴油产率相应增大。适宜的反应条件为:油醇摩尔比1:1、反应温度60℃、酶添加量10%、溶剂加入量(mL)与玉米油质量(g)比为1:1、声酶法合成反应时间3h。超声波辐射显著提高了生物柴油的产率,在相同反应温度下,超声波辐射使生物柴油产率比静态条件下的产率提高了27%-33%,比摇床作用下的产率提高了6%-15%。超声波作用没有改变酶的最适反应温度。     

生物柴油及应用

综述了生物柴油的发展历史和西方主要国家对生物柴油的研究和生产现状及有关的政策。讨论了各种生物柴油的制备方法及生物柴油应用的主要问题。对我国生物柴油的研究与开发提出了一些看法。     

精制棕榈油制备生物柴油的实验研究

以精制棕榈油为原料，与无水乙醇进行酯交换反应制取生物柴油。探讨了反应物配比、催化剂用量、温度、反应时间等因素对产物产率的影响，采用正交实验优化合成条件确定了最佳合成条件及影响反应的关键因素，并运用气相色谱一质谱技术分析了产物的结构和组成，运用核磁共振技术对主要成分进行了结构确定。结果表明该生物柴油符合《柴油机燃料调和用...     

活性炭负载酸性离子液体催化制备生物柴油

以活性炭(AC)负载酸性离子液体[Hmim-BS][HSO4]制备的[Hmim-BS][HSO4]/AC为催化剂,以大豆油和甲醇为原料,通过酯交换反应生成生物柴油。考察了离子液体负载量、催化剂用量、反应时间、反应温度以及醇油摩尔比等因素对生物柴油收率的影响。研究结果表明:在催化剂负载量为30%,催化剂用量为大豆油质量的7.5%,140℃下反应5h,生物柴油收率超过92%。重复使用4次后,生物柴油收率仍可达到83%左右,表现出良好的催化性能。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.