共查询到20条相似文献,搜索用时 125 毫秒
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对煤制烯烃的工业技术进行了分析,从砷平衡的角度分析了砷在煤制烯烃工业中的危害。综述了目前在化学工业中可以采用的有效脱砷技术和方法,包括控制气化原料煤中的砷含量、采用湿法技术脱除合成气中的砷、采用脱砷催化剂脱砷。重点介绍了铜系、铅系、锰系和镍系等4类脱砷催化剂的研究进展。对煤制烯烃脱砷方案提出了建议。 相似文献
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赵新涛 《化学工业与工程技术》2014,(1):31-34
介绍了锦西石化公司15万t/a聚丙烯装置丙烯脱砷流程,结合KTA-2型脱砷剂的实际应用过程及生产运行数据,对KTA-2型丙烯脱砷剂在炼厂丙烯精制中的工业应用进行了总结。工业应用表明:KTA-2型脱砷剂具有较好的脱砷活性,精制丙烯中含砷化合物的质量分数小于20×10-9,脱砷率达99.1%以上,满足高效催化剂对丙烯中砷含量要求;KTA-2型脱砷剂具有较高的砷容,穿透砷容(w)可达10%。 相似文献
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煤制合成气脱砷技术及净化剂的研究开发 总被引:1,自引:0,他引:1
本文介绍了煤制合成气脱砷技术及脱砷剂的开发及工业应用结果。试验表明, TAS-02 型脱砷剂适用于高水汽比、高CO水煤气气氛的脱砷净化, 稳定性良好, 有较高的砷容和脱砷净化效果。 相似文献
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随着食品、医药及电子行业的不断发展,磷酸及磷酸盐的市场需求量不断增大,并且对磷酸的品质要求也越来越高,尤其是对湿法磷酸中砷杂质的要求,湿法磷酸中砷的含量将直接影响其在磷精细化工领域的应用,因此湿法磷酸中砷的高效、安全去除是亟待解决的一大难题。本文主要对湿法净化磷酸脱砷技术的研究情况进行综述,比较了几种湿法净化磷酸脱砷工艺的优缺点,介绍了较常见的化学沉淀法、结晶法,以及新兴的电沉积法、垂直区域熔融法和微反应器脱砷工艺的应用前景,并指出这些新兴的脱砷工艺将成为今后湿法磷酸的净化脱砷的发展方向,如能解决将这些脱砷工艺在实际中的问题,将会对磷酸工业的发展提供一个更有力的支持。 相似文献
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采用自动快速蒸馏装置对脱砷前后的催化裂化汽油进行窄馏分切割,利用原子荧光光谱法对各窄馏分砷化物含量进行分析,研究催化汽油脱砷前后砷化物分布规律,为催化裂化汽油脱砷剂开发及脱砷工艺流程选择提供指导。实验结果表明:随着各窄馏分沸点增加,砷化物所占比例逐渐增大,90%以上砷化物均分布在80℃以上的重汽油组分中,尤其170℃以上馏分砷化物所占比例陡增,占总砷化物65.82%~96.31%。吸附脱砷剂对汽油150℃之前馏分中砷化物实现了全部脱除,而对150℃之后的重馏分脱砷率略有下降;临氢脱砷剂对汽油中80℃之前轻馏分和170℃之后重馏分中砷化物具有较高的脱除率,达到90%以上,而对中间馏分中砷化物脱除率较低。 相似文献
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The physicochemical features of the interaction between nanofilms of iron triad metals and the gallium arsenide surface during thermal oxidation are analyzed. The role of oxides formed upon oxidation of iron, cobalt, and nickel metal films in the course of thermal oxidation of gallium arsenide is demonstrated, and the influence of the metal deposition method on the kinetics of oxidation, the composition, and the properties of the prepared samples is determined. Schemes are proposed for the development of the oxidation processes under investigation with due regard for the chemical specific features of the iron triad metals and their compounds. 相似文献
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Pressure sintering of gallium arsenide was studied in vacuum at 900° to 1000 °C and 9000 to 43,200 psi. The optical transmission of nearly theoretically dense gallium arsenide was about one-fourth less than that of equally thick single crystals. Density-time curves indicated that at least two densification mechanisms occur and apparently overlap. Microscopic observations indicated that plastic flow was one of the mechanisms. Plastic flow was further evidenced by the crystallographic texture of the grains, as determined by X-ray diffractometry. The rapid initial plastic flow densification stage is not adequately described by the McClelland densification rate equation. Diffusional secondary densification mechanisms may be operative at higher densities. 相似文献
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极少量的砷化物可使加氢催化剂发生永久性中毒,为了保护加氢催化剂长期稳定运行,必须对催化裂化汽油中的砷化物进行脱除。对研制的TAs-15型FCC汽油脱砷剂进行原料适应性、1 600 h以上稳定性试验以及工艺条件对脱砷剂性能影响评价。结果表明,TAs-15脱砷剂具有较好的原料适应性及较高的脱砷性能,在反应温度(10~50) ℃、反应压力(0.5~2.0) MPa和空速(0.5~3.0) h-1条件下,出口汽油中砷含量≤10×10-9,完全可用于催化裂化汽油中砷化物的脱除。 相似文献
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《Diamond and Related Materials》1999,8(2-5):373-376
The deposition of gallium nitride and aluminium nitride thin films on GaAs(100) substrates by chemical beam epitaxy is reported. In-situ dynamic optical reflectivity has been used to compare growth rates of the nitride layers as a function of substrate temperature with their arsenide analogues. The relative growth efficiency of gallium nitride/gallium arsenide from triethyl gallium was found to be in the range 75–85%. The growth temperature for gallium nitride extends to higher temperatures, compared with gallium arsenide, probably due to lower evaporation rates of Ga bound to the nitride surface. At the same beam equivalent pressure, the growth rate of aluminium nitride from ethyldimethyl aluminium alane is approximately one-third of that for gallium nitride from triethyl gallium. Atomic force microscopy reveals that the gallium nitride surface formed at 500 °C is facetted, whereas an aluminium nitride surface deposited at 400 °C exhibits a rounded columnar type growth habit. Reflection anisotropy spectra indicate that atomic nitrogen readily reacts with the GaAs(100)-c(4×4) As stabilized surface at temperatures as low as 400 °C but without the gross facetting that has been observed at higher temperatures. 相似文献
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A fully automatic system which directly plots semiconductor carrier concentration profiles to any required depth is described. An electrolytic Schottky barrier permits simultaneous controlled dissolution and capacitance-voltage measurements. Examples of profiles obtained in multiple epitaxial layer structures ofn-type gallium arsenide are given. 相似文献
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A method for determining the carrier concentration of n-type gallium arsenide by an electrochemical technique is described. The minority carrier diffusion length is also obtained, and using subsidiary measurements the minority carrier lifetime can be estimated. The extension of this treatment to the characterization of epitaxial layers is discussed. 相似文献
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I. Ya. Mittova E. V. Tomina A. A. Lapenko B. V. Sladkopevtsev 《Glass Physics and Chemistry》2011,37(2):230-234
The specific features of the interaction of vanadium(V) oxide nanofilms with the surface of gallium arsenide and indium phosphide
semiconductors under thermal oxidation conditions have been considered. The kinetics and mechanism of thermal oxidation of
GaAs and InP with deposited V2O5 layers 15 and 25 nm in thickness have been studied. It has been revealed that vanadium(V) oxide exerts a specific effect
on the oxidation of gallium arsenide and indium phosphide as compared to other d-metal oxides. It has been established that the oxidation occurs with the formation of a phase predominantly consisting of
indium phosphates or gallium arsenates and intermediate products based on vanadium compounds in different oxidation states.
Schemes have been proposed for the development of the oxidation processes with due regard for the chemical nature of vanadium(V)
oxide. 相似文献
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The depletion layer capacitance of n-type gallium arsenide was measured as a function of its anodic potential in an electrochemical cell. It was shown that these measurements can lead to accurate values of carrier concentration, and are compatible with stripping by electrochemical dissolution, provided that surface area is preserved. The experimental conditions required to maintain the electrolyte-semiconductor contact area constant, are described. Also, it is shown that excursions into regions outside those specified lead to significant enhancement of capacity (via real area increase). Under these conditions the carrier concentration can no longer be obtained but much can be learnt about the internal structure of the material. 相似文献