共查询到17条相似文献,搜索用时 89 毫秒
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在蒸汽裂解制乙烯过程中,硫化物的存在对裂解性能的影响比较复杂,主要影响裂解反应过程和结焦性能。从硫的种类和含量两方面叙述了石脑油中的硫化物对产物收率、原料转化率、结焦速率和一氧化碳生成量等方面的影响,同时根据不同硫化物的热分解情况分析硫化物在裂解过程中的作用。简要介绍了硫化物的抑制结焦可通过将其连续注入裂解原料或离线等方式在裂解炉管内表面形成含硫化合物实现。 相似文献
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烃类高温裂解生产乙烯过程中 ,炉管管壁结焦不仅导致传热系数下降 ,压力降增大 ,管子腐蚀 ,还会堵塞炉管 ,影响裂解炉正常运转 ,因此研究结焦机理 ,从而更有效地抑制结焦一直受到人们的重视。结焦过程涉及到不同形式的焦油和炭的复杂过程 ,虽报道的文章很多 ,但确切机理尚不清楚。目前综合国内外的有关文献报道 ,对烃类热裂解过程中的结焦机理进行了详细综述 ,着重阐述了以金属碳化物为中间产物的金属催化反应 ,即金属催化结焦 ;非催化结焦 ;自由基结焦三种结焦机理。同时叙述了用此三种结焦机理如何解释实验室和工业装置的结焦状况。为进一步探索结焦机理开发新的结焦抑制技术奠定了一定的基础。 相似文献
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大庆联谊石化股份有限公司50kt·a~(-1)芳烃抽提装置以常压石脑油为原料,在开工及生产过程中出现了芳烃混浊发泡、颜色发黄、抽余油芳烃含量不合格等问题,通过技术改造,解决了这些问题,优化了常压石脑油芳烃抽提工艺操作参数,取得了很好的经济效益。 相似文献
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The effect of benzene or thiophene addition to the feed on the rates of coke formation during naphtha pyrolysis has been investigated in a jet-stirred reactor at atmospheric pressure in the temperature range of 1073-1103 K. In addition, the effect of temperature, space time, weight ratio of steam to naphtha and the material of construction on the rate of coke deposition was also studied. The rate of coke formation increased as the temperature, space time and aromatic content of the feed was increased whereas it decreased with an increase in the weight ratio of steam to naphtha or the thiophene content of the feed. Addition of thiophene increased the rate of naphtha pyrolysis and significantly reduced the aromatic yields. Rates of coke formation for both thiophene-free and thiophene-containing naphtha could be modeled by power law expressions involving the aromatics. 相似文献
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催化裂化汽油是我国车用汽油的主要调和来源,但是硫含量远高于车用汽油质量标准的要求值;因此如何高效降低硫含量是催化裂化汽油精制处理的关键。本文综述了国内外催化裂化汽油脱硫精制生产技术。从选择性加氢脱硫技术(Prime-G+技术、SCANfining技术、CD Tech技术、RSDS技术、OCT-M技术和DSO技术),选择性加氢脱硫耦合辛烷值恢复技术(RIDOS技术和GARDES技术)以及吸附脱硫技术(S-Zorb技术)三方面来阐述国内外催化裂化汽油清洁化技术的原理、特点及其应用。指出深度脱硫和辛烷值保持、烯烃饱和率之间的矛盾,后续研究者仍需在工艺流程改进、工艺条件优化以及新型催化剂开发等方面做出巨大努力。 相似文献
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Iridescent patterns are insufferable molding defects during mass manufacturing of polymer optic devices by using injection molding (IM) technique and seriously affect the appearance and imaging performance of parts. However, at present, the research on the factors affecting iridescent pattern defects is lacking, resulting in the difficulty of obtaining effective methods to weaken iridescent pattern defects. This article aims to clarify the correlation mechanism between injection process parameters and iridescent patterns and provide a theoretical basis for reducing iridescent pattern defects. Based on the process characteristics of IM and the optical mechanism of iridescent patterns, the correlation between iridescent patterns and influencing factors such as optical characteristics and the material structure is established. The influence mechanism of process parameters on iridescent patterns is further clarified by experiments. The results show the iridescent pattern color is related to the retardation, while the iridescent pattern brightness is affected by the retardation and transmittance. Process parameters change the retardation and transmittance by varying factors such as the thickness, birefringence, and crystallinity. Higher mold temperature, reasonable melt temperature, injection speed, and holding pressure are conducive to reducing the colorful fringe area and iridescent pattern brightness, thereby weakening the iridescent patterns on the part. 相似文献