二甲醚的燃料特性与生产方法

论述了二甲醚替代石油液化气,替代柴油的燃料特性;从燃料毒性、燃料替代对象、适用发动机、尾气中甲醛含量等方面对比了甲醇燃料和二甲醚燃料的共同特点和不同优势;介绍了四川天一科技股份有限公司开发的甲醇气相法生产二甲醚的工艺特点、设备优势和生产应用情况.     

二甲醚市场前景浅析

文章简要阐述了目前目际国内二甲醚市场的现状，预测了二甲醚作为民用燃料和汽车代用燃料的市场需求及市场竞争能力。     

车载二甲醚重整制氢技术的研究进展

二甲醚是一种清洁燃料,有望取代传统汽车燃料以达到高效能低排放的目的。研究表明,在发动机中添加一定量氢气可有效提高二甲醚的燃烧性能,车载二甲醚重整制氢技术的研究迫在眉睫。本文总结和评述了二甲醚重整制氢技术的研究进展,包括二甲醚重整制氢的方法以及重整催化剂等,并简要分析了各种二甲醚重整方法应用于车载重整器的可能性,指出催化剂的新型制备方法与等离子体重整技术是今后二甲醚车载制氢的主要方向。     

二甲醚作为LPG和柴油替代品问题探讨

针对二甲醚在替代LPG和柴油的实际运用过程中,存在不能长时间稳定供气燃烧、不能稳定向发动机供应燃料、生产成本高等问题,从二甲醚的特性、生产工艺、市场三方面进行了阐述和探讨,并提出了初步解决问题的办法和设想。     

二甲醚自动定量装车系统设计实施

介绍二甲醚自动定量装车系统的设计、实施和应用。二甲醚是一种新兴的基本化工原料．具有良好的易压缩、冷凝、汽化特性,在制药、燃料、农药等工业中有许多独特的用途。随着石油资源的紧缺及价格上涨．清洁环保理念的深入．作为柴油替代资源的清洁燃料——二甲醚得到大力推广．并逐渐进人了民用燃料市场和汽车燃料市场。     

甲醇气相脱水制二甲醚新技术

0 前言 二甲醚是一种含氧化合物，溶于水、在大气对流层中可降解，是环境友好介质。二甲醚可用于气雾剂、制冷剂、化工原料。二甲醚可做燃料，具有与液化气相类似的性质，而且燃烧完全、热效率高、无黑烟。近年来，由于石油制品的连年涨价，作为洁净环保燃料的二甲醚引起了社会各界的重视。特别是煤基二甲醚生产成本低，与石油液化气有较大差价，使得二甲醚全面替代石油液化气做为民用、工业用燃料成为可能。国内外多家研究机构也正在进行以二甲醚为燃料的汽车发动机研究乃至行车试验，由于二甲醚十六烷值高、燃烧尾气污染物少，是被业内人士看好的车用柴油的替代品。因此，二甲醚做燃料的市场前景十分广阔。同时，生产二甲醚也是当甲醇市场供大于求时甲醇生产企业的一条产业出路。[第一段]     

汽车代用燃料的开发

为减少对不可再生石油能源的过度开采和环境污染 ,用于汽车的许多种代用燃料已经被开发出来 ,主要有压缩天然气、液化石油气、醇燃料、合成燃料、二甲醚、生物柴油、氢及燃料电池等。压缩天然气和液化石油气是较好的代用燃料 ,将会被大量应用 ;醇燃料是清洁燃料 ,但当要避免甲醇的毒性问题时 ,乙醇可代替 ;合成燃料有两种 ,一种是合成气经费 托反应制取液体燃料 ,另一种是通过煤液化反应制取 ;二甲醚和氢制备方法较成熟 ,均是清洁燃料 ,适用不同的发动机 ;生物柴油以天然植物油为原料 ,有环保和润滑特性 ,但高粘度影响了它的应用 ;燃料电池…     

甲醇气相催化脱水制二甲醚新技术

1前言 二甲醚是一种含氧化合物，溶于水，在大气对流层中可降解，是环境友好介质。二甲醚可用作气雾剂、制冷剂、化工原料。二甲醚可做燃料，具有与液化石油气相类似的性质，而且燃烧完全、热效率高、无黑烟。近年来，由于石油制品的连年涨价，作为洁净环保燃料的二甲醚引起了社会各界的重视。特别是煤基二甲醚生产成本低，与液化石油气有较大差价，使得二甲醚全面替代液化石油气作为民用、工业用燃料成为可能。国内外多家研究机构也正在进行以二甲醚为燃料的汽车发动机研究乃至行车试验，由于二甲醚十六烷值高、燃烧尾气污染物少，是被业内人士看好的车用柴油的替代品。因此，二甲醚做燃料的市场前景十分广阔。同时，生产二甲醚也是当甲醇市场供大于求时甲醇生产企业的一条产业出路。     

二甲醚生产技术的新进展

1 引言 二甲醚是近年来开发的重要有机化工产品,用途十分广泛。其中80％用作气雾剂,作为良好的溶剂、冷冻剂、萃取剂等,在化妆品、医药、染料、农药等行业也得到广泛应用。二甲醚还以其高十六烷值、对环境污染小的特性,成为潜在的汽车燃料和民用燃料。     

二甲醚的生产现状及发展前景

二甲醚是我国值得重点发展的清洁燃料,文章分析了二甲醚代替柴油作为汽车燃料、代替民用液化石油气的可行性,并对二甲醚的生产工艺如两步法、一步法、二氧化碳及生物质直接合成二甲醚等进行评述,认为一步法工艺比较适合我国国情,适用于化肥厂和甲醇厂生产二甲醚。     

二甲醚燃气使用方法

二甲醚是由天然气、煤炭衍生生产的新型清洁燃料,本文阐述了二甲醚的物性和用途、作为民用燃料、工业燃料、汽车燃料及化工应用的方法。     

二甲醚的应用及下游产品开发

综述了二甲醚的性质、制备方法、应用和下游产品的开发利用。二甲醚是氯氟烃的替代品,用它可以开发一系列高附加值产品,例如碳酸二甲酯、醋酸、醋酐、甲醛等;可作为石油液化气的替代品,还可以作为清洁燃料用于机车、民用和热电厂等;同时它也可以作为氢源,开发二甲醚燃料电池。附参考文献38篇。     

Investigation on the fuel spray and emission reduction characteristics for dimethyl ether (DME) fueled multi-cylinder diesel engine with common-rail injection system

The aim of this study is to investigate the effects of dimethyl ether (DME) fuel on the engine performance and the exhaust emission reduction characteristics in a DME fueled four-cylinder diesel engine with a common rail injection system, as well as an injection characteristics and a spray behavior. The injection rate meter and the spray visualization system are utilized for the analysis of the injection characteristics and the spray behavior. Also, the modified four-cylinder diesel engine with 1.6 liter engine size is used for the investigation of the engine performance and the exhaust emission reduction characteristics of DME fuel.Based on the experimental investigation, it revealed that the injection quantity of DME fuel was larger than that of the ultra low sulfur diesel (ULSD) due to the high return fuel pressure at the same injection pressure and energizing duration. In this case, the injection quantity of DME fuel is increased by extension of real injection duration due to return fuel pressure.In combustion characteristics, the peak combustion pressure and the ignition delay of DME fuel are higher and faster than those of ULSD, respectively. The NO_x emission of DME fuel shows slightly higher than that of ULSD at the same engine load condition, and the soot emission of DME fuel is nearly zero level. The oxygenated component and volatility of DME resulted in HC and CO emissions that were lower than those of diesel.     

二甲醚火焰传播速度的实验测定

二甲醚被誉为21世纪的绿色燃料，是目前理想的内燃机与民用替代燃料．为了获得二甲醚应用的重要基础参数——火焰传播速度，在定容球弹法、本生火焰法和平面火焰法作出比较分析后，采用本生火焰法实验测定了二甲醚火焰的传播速度．得出了二甲醚火焰传播速度与一次空气系数的关系曲线，并且在一次空气系数约为0．85处，二甲醚火焰传播速度的峰值为0．48m／s．     

Fuelling of a compression ignition engine on ethanol with DME as ignition promoter: Effect of injector configuration

The effect of injector configuration on the combustion and emissions of a compression ignition engine, fuelled on ethanol as the main fuel and dimethyl ether as ignition promoter, were investigated. Baseline constant speed tests were initially performed on diesel fuel using the recommended three-hole configuration. The tests were repeated with the recommended three-hole injector and then with a four-hole injector with ethanol as the main fuel. All other aspects of the engine remained unmodified. The four-hole injector resulted in the combustion of ethanol occurring closer to top dead centre, producing marginally more power and higher fuel conversion efficiency. In the case of the four-hole injector, emissions of both THC and NO_X were found to be lower than those produced by the three-hole injector. They were, however, in both cases lower than levels achieved with diesel fuelling.     

Experimental and analytical study on the spray characteristics of dimethyl ether (DME) and diesel fuels within a common-rail injection system in a diesel engine

This paper investigates the effect of injection parameters on the characteristics of dimethyl ether (DME) as an alternative fuel in a diesel engine with experimental and analytical models based on empirical equations. In order to study macroscopic and microscopic characteristics of DME fuel, this work focuses on the atomization characteristics of DME and compares experimental and predicted results for spray development obtained by empirical models for diesel and DME fuel. Detailed comparisons of spray tip penetration from three different empirical correlations and from visualization experiments of diesel and DME fuels were conducted under various fuel injection conditions. In comparison with the results of different empirical equations for measured spray tip penetration, the experimental results of this study provide good agreement with the calculation results based on empirical equations, except during the earliest stage of the injected spray sequence. The results of atomization characteristics indicate that DME showed better spray characteristics than conventional diesel fuel. Also, the fuel injection delay and maximum injection rate of DME fuel are shorter and lower than those of diesel fuel at the same injection conditions, respectively.     

Combustion and emission characteristics of DME as an alternative fuel for compression ignition engines with a high pressure injection system

The subject of this work is the investigation of the injection characteristics of neat dimethyl ether (DME) and the effect of DME fuel on the exhaust emission characteristics and engine performance of compression ignition engines. In order to analyze the injection characteristics of DME fuel as an alternative fuel for compression ignition engines, experiments were conducted to obtain the injection rate profile. The effective nozzle diameter and its velocity, and the discharge coefficient of the nozzle were analyzed by applying a nozzle flow model that accounted for the effect of cavitation. In addition, combustion characteristics of DME and diesel fuel in terms of combustion pressure, rate of heat release, indicated mean effective pressure (IMEP), and ignition delay at various injection timings were investigated on a constant energy input basis.When a constant pulse width was applied, the results of DME injection characterization showed that the actual injection duration of DME was longer than that of diesel fuel because the injection started faster and ended with more delay. The DME fueled engine showed slightly higher IMEP and NO_x emission with drastically lower CO and HC emissions and the possible reasons for the higher IMEP of DME fuel was discussed.     

A study of natural gas/DME combustion in HCCI engines using CFD with detailed chemical kinetics

Combustion characteristics of natural gas and dimethyl ether (DME) mixture in a homogeneous charge compression ignition (HCCI) engine were studied numerically. Detailed chemical kinetics with 83 species and 360 reactions was used with an engine CFD code to simulate the combustion process. Operating conditions with different fuel compositions were simulated. Combustion, nitrogen oxides emissions and effects of fuel compositions on engine operating limits were well predicted by the present model. Chemical kinetics analysis indicated that ignition was achieved by DME oxidation which, in turn, induced combustion of natural gas. Low-temperature heat release is more pronounced as the amount of DME increases. Engine operations become unstable as the excess air ratio of natural gas is reduced near 2. The model also captures the HCCI features of low-combustion temperature and low-nitrogen oxides emissions for the alternative fuels used in this study.     

A comparative study of n-heptane, methyl decanoate, and dimethyl ether combustion characteristics under homogeneous-charge compression-ignition engine conditions

Combustion characteristics of n-heptane, a surrogate for hydrocarbon diesel, methyl decanoate, a surrogate for biodiesel, and dimethyl ether, a fuel that can be derived from bio-feedstocks, are investigated with a homogeneous constant-pressure reactor model and a homogeneous-charge compression-ignition engine thermodynamic simulation model, with focus on two variables: ignition delay and NO formation, under conditions of varying oxygen concentration. Negative temperature coefficient (NTC) behavior is observed for the three fuels. Reducing oxygen concentration increases ignition delay for all fuels. The results and conclusions with the two models differ because it is necessary to vary initial conditions in the engine model to optimize combustion phasing and maximize indicated efficiency.     

二甲醚-21世纪清洁燃料

二甲醚是一种性能好、有发展前途的清洁燃料。本文分析了二甲醚的性能,制备二甲醚所使用原料的变化及制备技术的进展,预示二甲醚成为21世纪新燃料。