单斜相氧化锆的加入对氧化铝脱水活性的影响

将单斜相氧化锆加入到氧化铝中,评价其对甲醇脱水活性。结果表明,单斜晶相ZrO2的引入降低了催化剂的活性,Zr含量较少时,高温焙烧时易与Al结合,生成Al0.08 Zr0.92O1.96。单斜相ZrO2系列催化剂(相比氧化铝)表面弱酸强度增加,但是弱酸量有所降低,表面酸量与Zr含量无明显线性关系。单斜相ZrO2系列催化剂比表面较小,孔径较大,催化剂比表面大且呈多孔分布对脱水有利。     

间歇反应釜先进控制系统的设计与应用

根据乙二醇二甲醚生产工艺流程,结合实际生产要求,研制了以PC机作为先进控制层,以可编程控制器PLC作为基本控制层的经济适用型控制系统。本文详细阐述了该系统的硬件设计原理及选型配置,通过进料流量控制系统和反应釜温度控制系统软件设计和联锁实现,证明该系统完全符合生产自动化要求。     

数字化精密测距技术的研究

精密测距（DME/P）无线电导航系统与微波着陆系统配合,为进场飞机提供精密进场着陆引导。基于FPGA＋DSP硬件平台,提出了数字中频处理DME/P的一种实现方法,详细分析了数字化DME/P采用的技术：数字中频解调技术、DAC检测技术、信号识别和搜索技术以及α-β滤波技术。通过飞机实际飞行试验,该方法能够完全满足DME/P功能的性能指标,为DME/P设备的小型化和数字化提供了可靠的科学依据。     

A study on the reduction of exhaust emissions through HCCI combustion by using a narrow spray angle and advanced injection timing in a DME engine

This paper describes the combustion and emission characteristics as well as engine performance according to the narrow spray angle and advanced injection timing for homogeneous charge compression ignition (HCCI) combustion in dimethyl ether (DME) fueled diesel engine. The bowl shape of the piston head was modified to apply the narrow spray angle and advanced injection timing. The spray, combustion and emission characteristics in a DME HCCI engine were calculated by using numerical method of the KIVA-3 V code coupled with the detailed chemical kinetic model of DME oxidation. Model validation was conducted by a comparison of experimental results for the accurate prediction. The injection timing ranging from BTDC 80° to BTDC 10° and two fuel masses were selected to evaluate the combustion, emission and engine performance. The calculated results were in good accordance with the experimental results of the combustion and emissions of the engine. Nitrogen oxide (NOx) emissions at injection timing before BTDC 30° remarkably decreased, while hydrocarbon (HC) and carbon monoxide (CO) emissions at an injection timing of BTDC 70° showed high levels. Also, the IMEP and ISFC have decreasing and increasing patterns respectively as the injection timing was advanced.     

Experimental study on the hazards of the jet diffusion flame of liquefied dimethyl ether

Dimethyl ether (DME) has been considered as a substitute for diesel fuel because it has a low auto-ignition temperature and produces less NO_x, SO_x, and particulate matter. However, the introduction of DME vehicles needs widely available DME supply stations. Moreover, the preparation of safety regulations for DME supply stations is very important, and so safety data is needed. Therefore, the present paper reports the hazards of the DME jet diffusion flame, which is one of several hazardous properties of DME, by studying the results of leaking gas and liquid DME. DME jets were released horizontally from circular nozzles whose diameters were 0.2, 0.4, 0.8 and 2 mm, and the release pressure was varied from the saturated vapor pressure to 2 MPa. When gaseous DME was released at the saturated vapor pressure, the flame was blown out. However, when liquefied DME was released, the flame formed. We obtained the experimental equations for estimating the scale and thermal hazards of DME diffusion flames.     

粗甲醇经单塔分离作为MTO、二甲醚原料甲醇的方案探讨

介绍了甲醇合成过程中控制粗甲醇中水含量的方法,分析了以单塔分离脱除粗甲醇中轻组分的技术方案,得出的结论是:控制合成原料气中二氧化碳体积分数为2.5%左右时,粗甲醇中水质量分数在5%左右,粗甲醇采用单塔分离脱除轻组分后,可作为MTO或二甲醚装置的原料。与现有的多塔精馏工艺相比,采用粗甲醇单塔分离,简化了粗甲醇的精制流程,降低了设备投资和生产成本,可为MTO和二甲醚项目工艺方案的设计提供借鉴。     

Hydrogen production by steam reforming of dimethyl ether and CO-PrOx in a metal foam micro-reactor

A bi-function catalyst containing CuZnAlCr and HZSM-5 was used to generate hydrogen by stream reforming of dimethyl ether (SRD) in a metal foam micro-reactor and a fix-bed reactor. Dimethyl ether conversion of 99% and hydrogen yield of >95% was reached with HZSM-5/CuZnAlCr (mass ratio of 1:1) in the micro-reactor. A suitable balance between the dimethyl ether hydrolysis and methanol reforming steps requires the proper acidity and the metal sites. The CuZnAlCr/HZSM-5 properties, effect of CuZnAlCr to HZSM-5 mass ratio were investigated in the metal foam micro-reactor. Moreover, CO was removed from hydrogen-rich gas by preferential oxidation reaction (CO-PrOx) with PtFe/γ-Al₂O₃ catalyst in a similar metal foam micro-reactor follows the SRD stage. With the optimized O₂/CO ratio and reaction temperature, the CO concentration dropped to <10 ppm and hydrogen yield of ∼90% were achieved in the new-type SRD-COPrOx system. The SRD-COPrOx system provide a constant hydrogen production with CO concentration lower than 10 ppm during 20 h. The results indicate that metal foam micro-reactor has the great potential in the DME steam reforming to supply hydrogen for low-temperature fuel cells.     

二甲醚生产尾气中二甲醚及甲醇含量的测定

二甲醚生产过程中,洗涤塔放空尾气的成分对生产有着重要的指导作用。介绍了用气相色谱法测定洗涤塔放空尾气中二甲醚及甲醇含量的分析方法。试验结果表明,方法的重复性好、准确度高、分析速度快,能够为生产提供快速、准确的数据。     

山西沁水煤层气生产30×10^4t／a二甲醚项目工艺设计

介绍了山西沁水利用煤层气经三一段纯氧转化制甲醇再生产30×10^4t／a二甲醚项目的概况。重点介绍了该项目采用的我国最近开发的煤层气三一段纯氧转化制甲醇创新工艺,采用该工艺同量原料比传统一段转化工艺可增产35％,减排CO285％-90％,生产1t二甲醚的煤层气消耗量仅为1082m3。项目设计推荐购买美国GGG厂大型甲醇闲置设备进行改造的方案。经测算,采用以上方案建设这样一个项目,投资为6．2亿元,可创产值12亿元（以每吨二甲醚4000元计）,年利税5．84亿元,投资回收期约为1年。