共查询到17条相似文献,搜索用时 93 毫秒
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卷烟降焦是我国烟草行业一项重要而复杂的工程。文章对卷烟叶组配方设计、加料加香和辅材设计相关的降焦技术进行了综述。 相似文献
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一种新型吸附剂的研究 总被引:2,自引:0,他引:2
实验表明:利用经过适当加工、改型后的蒙脱石制成的复合滤嘴,具有明显的吸附卷烟烟雾中的焦油,而对烟雾中的尼古丁吸附得较少。利用顺磁共振波谱仪测定了焦油中自由基的浓度。通过对比实验,发现利用蒙脱石制成的复合滤嘴的每支卷烟焦油中自由基浓度,比醋酸纤维滤嘴卷烟自由基浓度下降(32±3)%。复合滤嘴卷烟在香味、杂气、刺激、余味等方面,与醋酸纤维丝柬滤嘴接近。吸附剂的来源广泛,成本低,可以广泛推广使用。 相似文献
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木材颗粒在卷烟滤嘴中的应用研究 总被引:2,自引:0,他引:2
通过电镜、比表面积及微孔物理吸附仪对木材颗粒表面形貌和比表面积进行表征。在卷烟对比实验中,研究木材颗粒复合滤棒和未采用木材颗粒醋纤滤棒的吸附性能。结果表明,木材颗粒表面呈鱼鳞状,具有介孔吸附材料特性;木材颗粒复合滤嘴可以降低卷烟主流烟气中的焦油和7种有害物质,对比未使用木材颗粒复合滤嘴下降幅度分别达到了焦油8.57%,CO 2.17%,B(a)P 22.22%,NNK 4.50%,巴豆醛3.49%,HCN 20.37%,氨离子3.77%和苯酚21.16%;木材颗粒复合滤嘴可以提升烟气浓度,增加烟香丰富性和改善舒适性。 相似文献
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氢氰酸是卷烟烟气中含量较少且具有挥发性毒性的物质,吸烟时会随着口腔进入人体或者挥发到周围的空气中,不但会抑制人体细胞呼吸酶,造成细胞内窒息,对人体健康造成很大的危害,同时对环境安全也会造成一定的影响。介微孔材料具有较大的比表面积、孔容、孔径和材料表面可修饰性,更重要的是多孔材料大多无毒无害、易制备且能选择性的降低卷烟烟气中的有害物质,因此可以作为吸附剂或者载体应用于卷烟滤嘴中,通过物理吸附和化学吸附选择性的降低卷烟烟气中的氢氰酸。综述了几种以不同方式制备的介微孔材料降低卷烟烟气中氢氰酸的效果,并展望了介微孔材料对于降低卷烟烟气中氢氰酸释放量的研究前景。 相似文献
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生物质气化焦油裂解用颗粒催化剂的再生性能 总被引:3,自引:2,他引:1
为开发适用于生物质气化焦油裂解的多孔白云石颗粒催化剂,以乙酸为生物质气化焦油的模型化合物,讨论了积炭对多孔白云石颗粒催化能力以及再生性能的影响。结果表明,在积炭率0~4.4%时,多孔白云石颗粒的催化能力随积炭率呈线性下降。当积炭率从0增加到4.4%时,颗粒的孔隙率从0.74 cm3·g-1减小到0.48 cm3·g-1,乙酸裂解率从99.3%降至32.3%。采用900 ℃和2 h焙烧法对积炭多孔白云石颗粒进行再生处理后,多孔白云石颗粒的强度基本不变,孔隙率增至0.55 cm3·g-1。在再生多孔白云石颗粒上,乙酸裂解率达到99.5%。多孔白云石颗粒催化剂具有良好的再生性。 相似文献
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Due to the increasing global demand for industrial gas,the development of large-scale cryogenic air separation systems has attracted considerable attention in recent years.Increasing the height of the adsorption bed in a vertical radial flow adsorber used in cryogenic air separation systems may efficiently increase the treatment capacity of the air in the adsorber.However,uniformity of the flow distribution of the air inside the adsorber would be deteriorated using the height-increasing method.In order to reduce the non-uniformity of the flow distribution caused by the excessive height of adsorption bed in a vertical radial flow adsorber,a novel parallel connection method is proposed in the present work.The experimental apparatus is designed and constructed;the Computational Fluid Dynamics (CFD) technique is used to develop a CFD-based model,which is used to analyze the flow distribution,the static pressure drop and the radial velocity in the newly designed adsorber.In addition,the geometric parameters of annular flow channels and the adsorption bed thickness of the upper unit in the parallelconnected vertical radial flow adsorber are optimized,so that the upper and lower adsorption units could be penetrated by air simultaneously.Comparisons are made between the height-increasing method and the parallel connection method with the same adsorber height.It is shown that using the parallel connection method could reduce the difference between the maximum and minimum radial static pressure drop by 86.2% and improve the uniformity by 80% compared with those of using the height-increasing method.The optimal thickness ratio of the upper and lower adsorption units is obtained as 0.966,in which case the upper and lower adsorption units could be penetrated by air simultaneously,so that the adsorbents in adsorption space could be used more efficiently. 相似文献
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Wenjie Liu Yang Wang Jingtao Li Baorang Li 《International Journal of Applied Ceramic Technology》2023,20(6):3584-3595
Fabrication of ceramic materials with interconnected pores is necessary to improve thermal energy storage efficiency in high-temperature infiltration technology. In the present study, industrial wastes such as coal gangue, steel slag, etc., were selected as the raw materials to prepare ceramics with interconnected pores. By adopting 50% cigarette butts as the pore-forming agent, steel slag–coal gangue mixtures with a mass ratio of steel slag to coal gangue of 1:9 were sintered at 1100°C, and ceramics with interconnected elongated pores were prepared successfully. The highest apparent porosity and lowest volume density of the as-prepared ceramics were ca. 73% and .74 g/cm3, respectively. Further measurements of the thermophysical properties indicated that no obvious mass loss was observed in the temperature range from ambient temperature to 800°C. The maximum values of specific heat and thermal conductivity were 1.38 J/(g K) and 1.661 W/(m K), respectively, and meanwhile the minimum compressive strength could exceed 3.5 MPa. These research results implied that the as-prepared steel slag–coal gangue ceramics can provide long-term service and offer excellent thermal stability over a wide temperature range. Therefore, they should have potential applications in high-temperature infiltration technology. 相似文献
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The development of advanced carbonaceous materials (ACMs) from biopitches is important to increase the revenue of the charcoal making industry and to stimulate the use of biomass, thereby attending to the appeals for environmental preservation. A pioneer study on the rheological behavior of eucalyptus tar pitches was carried out in this work. This behavior plays an important part in obtaining ACMs from pitch, particularly in the spinning step of carbon fiber production. Our results showed that biopitches have a strong dependence on the viscosity and temperature/softening point ratio. An Arrhenius‐type law gave the activation energies for viscous flow. Different from conventional polymers, this energy was higher for more polymerized pitches because of their higher molecular stiffness. The results obtained by the Williams–Landel–Ferry equation showed that the viscosity can be associated with the free volume. Lower viscosities correspond to larger free volume. The plot of the apparent viscosity versus the shear time at constant temperature and shear rate showed that the pitches have a purely viscous flow. Experiments that changed the shear rate showed that biopitches behave as Newtonian fluids. Purely viscous and Newtonian behaviors are desirable for more stable spinning. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 900–908, 2002; DOI 10.1002/app.10096 相似文献
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高温煤焦油悬浮床加氢裂化研究 总被引:2,自引:0,他引:2
利用悬浮床加氢对高温煤焦油进行加氢裂化研究。分析了煤焦油的性质,研究了反应条件对产物分布的影响。结果表明,随着温度的升高和时间的延长,反应裂解程度加深,反应生成更多的气体、石脑油和柴油馏分,同时甲苯不溶物的含量也在增高。反应压力低于15MPa,提高压力,汽柴油馏分产率提高显著,反应高于15MPa汽柴油产率提高不明显,甲苯不溶物含量显著提高。 相似文献
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苯胺是重要的化工原料和合成中间体,通过硝基苯的催化还原反应可以方便地制备苯胺类化合物。多孔碳材料因其高比表面积、发达的孔隙结构和容易回收等特点在催化领域越来越受到重视,然而其应用受到自身活性位点缺乏和化学惰性的限制。杂原子掺杂可以增强碳材料的表面极性,调节电子结构,改善其催化性能,可作为硝基苯催化还原反应的有效催化剂。本文对近年来掺杂多孔碳材料在硝基苯催化还原反应中的研究进展进行了总结。本文概述了氮掺杂型多孔碳材料、共掺杂型多孔碳材料、负载贵金属的掺杂多孔碳材料和负载廉价金属的掺杂多孔碳材料这4种主要的掺杂多孔碳材料的制备方法,并详细介绍了不同掺杂多孔碳材料在催化硝基苯催化还原反应时的催化性能、可能的催化活性位点以及催化机理。最后,指出目前掺杂多孔碳材料催化硝基苯还原还需要解决反应选择性、催化剂催化活性和生产成本等问题,以生物质为前体,开发共掺杂型和二元双金属负载的掺杂多孔碳材料是未来的重要发展方向之一。 相似文献