降低卷烟主流烟气一氧化碳释放量的研究进展

一氧化碳(CO)是卷烟主流烟气中的有害物质之一,降低烟气中的CO对提高卷烟安全性至关重要。卷烟使用的滤嘴、烟丝(烟草薄片)和卷烟纸是影响卷烟主流烟气中CO的释放量的三个决定性因素。文章即从这三个方面介绍当前降低卷烟主流烟气一氧化碳的研究进展,并就此做了相关展望。     

滤棒长度对卷烟主流烟气中7种有害物质的影响研究

为研究滤棒长度对卷烟主流烟气中一氧化碳（CO）、氢氰酸（HCN）、NNK、氨、苯并[a]芘、苯酚及巴豆醛等7种有害物质的影响,制造出滤棒长度分别为30,27,24,21 mm的4种卷烟,测定其主流烟气中单位焦油的7种有害物质含量。结果表明,卷烟主流烟气中单位焦油苯并[a]芘、巴豆醛、CO的含量随滤棒长度减小而减少;HCN、NNK、NH3、苯酚的含量则有相反的变化规律;而卷烟主流烟气中单位焦油的危害性变化不大。     

国内外名优卷烟烟气pH值与TPM和CO相关性的研究

为了研究国内外混合型卷烟主流烟气的pH值、烟气总粒相物(TPM)及一氧化碳(CO)的相互关系,采用烟气常规分析方法对市售混合型卷烟进行了分析。结果表明:混合型卷烟的pH值随总粒相物(TPM)和一氧化碳(CO)的增加而下降,一氧化碳(CO)随总粒相物(TPM)的增加而增加。     

荆芥挥发油-β-CD对苯酚的吸附及其在卷烟中的应用

采用饱和水溶液法制备荆芥挥发油-β-CD包合物,并用紫外可见分光光度法、X-射线衍射对包合物进行表征。研究了β-CD和荆芥挥发油-β-CD包合物吸附溶液中苯酚的性能。此外,还将β-CD以及荆芥挥发油-β-CD包合物作为添加剂添加到卷烟滤嘴中,研究其对卷烟主流烟气中苯酚的影响。结果表明,β-CD和荆芥挥发油-β-CD包合物吸附溶液中苯酚的动力学模型都是准二级动力学模型。当添加剂用量为30mg时,β-CD以及荆芥挥发油-β-CD包合物对卷烟主流烟气中苯酚的降低率分别为74.01%和88.9%。此外,添加剂还可以有效降低卷烟主流烟气中总粒相物的含量。     

卷烟纸特性对卷烟燃烧及主流烟气中CO释放量的影响

为考察卷烟纸特性对卷烟燃烧及主流烟气中CO释放量的影响,采用不同特性(透气度、定量、助燃剂含量)的卷烟纸卷制卷烟,测定卷烟燃烧温度和主流烟气中的CO释放量,并分析主流烟气中CO释放量与温度积分和最高抽吸温度的相关性,结果表明:主流烟气CO释放量与温度积分显著相关,与卷烟最高抽吸温度有一定相关或不相关。     

卷烟中添加α-紫罗兰酮对主流烟气挥发性成分影响的研究

为了准确评价香料单体α-紫罗兰酮在卷烟燃吸中对卷烟主流烟气的影响,了解其对卷烟的加香效果,采用吸烟机捕集卷烟抽吸过程中的主流烟气,用GC-MS分析了含有添加剂和空白卷烟主流烟气中的挥发性成分、为α-紫罗兰酮的致香作用提供更加科学的依据,为其在卷烟中的应用提供参考、     

活性炭与壳聚糖对卷烟主流烟气中挥发性羰基化合物释放量的影响研究

比较了在纸质滤芯上分别涂布活性炭和壳聚糖对主流烟气中羰基化合物及焦油、一氧化碳等的吸附效果。研究结果表明:活性炭与壳聚糖对纸质滤棒卷烟主流烟气中羰基化合物均有较好的吸附作用;壳聚糖对主流烟气中羰基化合物的吸附能力优于活性炭,对焦油、烟碱无明显影响,壳聚糖对羰基化合物具有选择性吸附作用。     

香叶醇对卷烟主流烟气挥发性成分影响的的研究

采用吸烟机捕集卷烟抽吸过程中的主流烟气,用GC-MS分析了有添加剂的和空白卷烟的主流烟气中的挥发性成分,为香叶醇在卷烟中的致香作用提供更加科学的依据,准确评价了香料单体香叶醇在卷烟燃吸中对卷烟气的影响,了解其对卷烟的加香效果,为其在卷烟中的应用提供参考.     

烟丝添加剂对卷烟燃烧温度和烟气成分的影响研究

利用自行开发的微小测温热电偶装置,对添加各种钾盐的卷烟的最高燃烧温度进行了测量,并对相应的卷烟的烟气成分进行了检测。研究发现,多种烟丝添加剂的加入都可以降低卷烟的最高燃烧温度,其中乙酸钾的效果最好,而且可以大幅度减少烟气中氰化氢、氨、苯酚、巴豆醛、NNK和一氧化碳等六种成分的释放量。另外,利用TG-DTA方法对添加钾盐的烟丝在空气气氛中的燃烧和氮气气氛中的裂解进行了研究,分析了钾盐对烟丝燃烧状态的作用机理。同时,重点讨论了钾盐的添加对降低卷烟主流烟气中CO释放量的影响机制。     

重金属元素在卷烟主流烟气中迁移率分析

本课题采用电感耦合等离子体质谱法测定卷烟及卷烟主流烟气中重金属元素铬（Cr）、镍（Ni）、砷（As）、硒（Se）、镉（Cd）和铅（Pb）含量,计算重金属元素在主流烟气中的迁移率,结果表明,卷烟重金属元素主要来源于卷烟烟丝,基本未迁移到卷烟主流烟气气相中,仅有一部分迁移到卷烟主流烟气粒相中,且迁移率均在10％以下.     

橡胶籽油还原作用下铜渣的贫化

针对铜渣贫化过程碳排放问题,以橡胶籽油取代柴油作为铜渣贫化的还原剂,研究铜渣贫化过程中的热力学,分析橡胶籽油贫化铜渣机理。在不同温度和时间条件下进行喷吹橡胶籽油贫化实验,分析铜渣磁性铁含量和粘度的变化,用XRD和SEM对贫化后炉渣进行分析。结果表明,喷吹还原过程中主要还原剂是裂解产生的碳单质、H2和CO。贫化过程中磁性铁被橡胶籽油在高温下的裂解产物(H2, CO, C)还原成FeO,与渣中的SiO2结合生成铁橄榄石(Fe2SiO4);随贫化温度升高,相同喷吹时间内铜渣的磁性铁含量和粘度逐渐降低,使渣中的Cu相互碰撞聚集,最终沉降到坩埚底部。随贫化进行铜渣中的铁橄榄石相增多,磁性铁相减少。在坩埚底部聚集的铜颗粒粒度由1 cm增至3 cm,铜回收率达86%。     

Experimental study on the laminar flame speed of hydrogen/carbon monoxide/air mixtures

Carbon monoxide and hydrogen are two important components in the syngas. In this study, the laminar flame speed of hydrogen/carbon monoxide fuel mixtures is measured over a large range of fuel compositions (0-100% volume fraction for hydrogen in the mixture) by using a Bunsen burner. The reaction zone area is used to calculate the laminar flame speed. The equivalence ratio covers from lean conditions to rich conditions. The experimental results show that by using the Bunsen flame, the laminar flame speed calculated with the reaction zone area is reliable. Based on the experimental results, empirical equations are derived which can be readily employed to calculate the laminar flame speeds of hydrogen, carbon monoxide, and hydrogen/carbon monoxide mixtures.     

一氧化碳耐硫变换催化剂提前升温硫化的应用

为节约一氧化碳耐硫变换催化剂硫化费用、缩短一氧化碳变换工段开车时间,贵州天福化工有限责任公司采用外购氢气和硫化剂——二硫化碳对一氧化碳耐硫变换催化剂进行硫化,达到了目的,节约了耐硫变换催化剂硫化费用,缩短了一氧化碳变换工段开车时间,为类似装置耐硫变换催化剂升温硫化提供借鉴和参考。     

Pyrolysis of brown coals. 3. Effect of cation content on the gaseous products containing oxygen from Yallourn coal

A study has been made of the evolution of water, carbon dioxide and carbon monoxide during the pyrolysis of Australian Yallourn brown coal, and of the way in which the evolution is influenced by exchange of the carboxyl groups in the coal with magnesium and barium cations. Virtually all the oxygen in the coal can be removed as carbon dioxide, water and carbon monoxide with the greatest rate of loss occurring at 300, 350 and 500 to 600 °C respectively. Increasing levels of cation alter the proportion of the volatile constituents but not the total amount of volatile matter evolved. Increased evolution of oxygen as carbon dioxide from a magnesium-form coal over that from acid-form coal is accompanied by a decrease in the amount evolved as water and carbon monoxide. Barium-form coals, however, show an increase in the amount of carbon monoxide evolved as the cation content increases. This is due in part to reactions involving the nitrogen gas used to provide a non-oxidizing atmosphere during pyrolysis. These reactions do not occur with magnesium-form coals. The amount of char formed by pyrolysis is the same for different levels of cation exchanged on the carboxyl groups. The results support conclusions that the carboxyl groups in a brown coal are associated with other oxygen groups, and that the mode of decomposition of the groups in this association (including carboxyl) is altered by the exchange of the carboxyl groups with cation.     

甲酸甲酯与甲醇钠合成碳酸二甲酯反应研究

通过对不同溶剂存在下甲酸甲酯与甲醇钠非催化合成碳酸二甲酯反应的研究,发现四氢呋喃比质子性溶剂甲醇和极性非质子性溶剂二甲基甲酰胺等更适合该合成反应,它兼有两者的优点,对两者的缺点又有不同程度的克服。本文重点考察了甲醇和一氧化碳对催化合成DMC反应的影响,结果发现当反应体系中有甲醇存在时,甲醇会与甲氧基负离子通过氢键结合,降低甲氧基负离子的亲核活性,影响反应生成DMC的速率。与甲醇不同,一氧化碳能有效抑制甲酸甲酯的分解反应,当使用CO/O2作氧化剂时,得到了较好的DMC收率和选择性。     

Transient studies of the elementary steps of Fischer–Tropsch synthesis

The pulse transient method has been used to study the kinetics of several key steps of Fischer–Tropsch (FT) synthesis over cobalt supported catalysts. These elementary steps involve chemisorption of hydrogen and propene, and chemisorption and hydrogenation of carbon monoxide. It is found that at the conditions of Fischer–Tropsch synthesis, hydrogen chemisorption is reversible and quasi-equilibrated, while carbon monoxide adsorption is generally irreversible. Chemisorption of propene on cobalt metal sites results in its rapid autohydrogenation to propane and simultaneous formation of C_xH_y surface species.

The transient response curves produced during hydrogenation of carbon monoxide pulses in a flow of hydrogen have been analyzed using the modified Kobayashi model, which involves irreversible chemisorption and dissociation of carbon monoxide, quasi-equilibrated adsorption of hydrogen and reversible adsorption of water. The kinetic analysis suggests that oxygen-containing species are probably the most abundant surface intermediates. Desorption of water from the catalysts seems to be much slower than hydrogenation of surface carbon species.     

On the determination of kinetic parameters for the regeneration of cracking catalyst

In the study of the regeneration of cracking catalyst, two approaches may be taken when determining the kinetic rate constant for the coke combustion reaction. A global coke burning rate equation may be considered, based on the observed oxygen concentration and carbon dioxide to carbon monoxide molar product ratio. This reaction may also be represented by an intrinsic coke burning equation which is a function of the oxygen concentration and the carbon dioxide to carbon monoxide molar ratio at the reaction site, combined with a carbon monoxide postcombustion equation. It is proposed in this paper that the rate constant for intrinsic coke burning, k^c, is essentially equal to the global coke burning rate constant, k_c, and that its value is independent of the rate equation chosen for the carbon monoxide post-combustion reaction.     

TRANSFER PLASMAS DESTROY PCB FLUIDS

High voltage, ac transfer arcs were used as a reaction zone to destroy polychlorinated biphenyls dissolved in transformer fluid. The extremely high temperature of the arc is of sufficient magnitude that it destroys both the PCB's and the oil in which the PCB's are dissolved.

Although fast pyrolysis is the major destructive mechanism, several other features of the process are unique. For example, the transfer arc discharge is submerged. The arc is created beneath the surface of the transformer oil at a water interface. Furthermore, the water phase is part of the electrical circuit; but it also participates in the reaction chemistry of the plasma arc. Water vapor created by the discharge reacts with the carbon and acetylene formed by pyrolysis to produce hydrogen and carbon monoxide. This retards carbon buildup within the system.

The presence of the water phase also provides a convenient adsorption medium for acid gases (HC1) which are formed by pyrolysis of the PCB's, These gases are infinitely more soluble in the water phase than they are in the transformer oil through which they would have to pass to escape the submerged reaction zone. As a result, this new technology provides a convenient small-scale destruction for oils contaminated with PCB     

CO吸附剂制备及其吸附脱除微量CO的性能

介绍了CO吸附剂的制备方法,研究了该吸附剂在固定床温度30 ℃、CO分压为6 kPa(a)下吸附一氧化碳的动态吸附性能,测定了穿透曲线,动态吸附容量为2.138 5 mmol/g,并用BET吸附仪测定了制备的CO吸附剂比表面积,用电感耦合等离子体原子发射光谱(ICP)测定其离子交换度为52%,含铜量为9.52%(质量分数)。通过粉末X射线衍射仪(XRD)和场发射扫描电子显微镜(SEM)表征发现,水热交换法制备CO吸附剂,Cu²⁺有效地取代了NaY原粉中Na⁺,经过焙烧还原后仍然能够维持原骨架结构的完整。用NH₃-TPD考察了改性前后吸附剂酸度的变化以及用H₂-TPR考察了吸附剂合适的还原温度。采用130 ℃氮气吹扫的方法再生,再生彻底并且吸附效果稳定。     

The combustion of cigarette paper

Studies have been carried out of the thermal decomposition and combustion of cigarette paper with heating rates and final temperatures similar to those encountered during the smoking of cigarettes. Measurements have been made in particular of the amounts of carbon monoxide formed from the paper, both on its own and when it forms part of a cigarette. The extent of formation of char from cigarette paper decreases as the heating rate is increased, but carbon monoxide yields pass through a maximum at a heating rate of ca 60° s⁻¹, due to the competing effects of temperature on the several different mechanisms by which carbon monoxide is produced. Measurements on cigarette papers impregnated with a wide range of inorganic and organic salts show that all the additives used tend to decrease carbon monoxide yields at low heating rates but to increase them quite sharply at very high ones. With cigarettes containing impregnated papers the concentration of carbon monoxide is increased in both the mainstream and sidestream smoke. Possible reasons for the behaviour observed with the various individual salts are discussed. Certainly, on the assumption that the results obtained with cigarettes are a good reflection of those on paper alone it seems unlikely that treatment of cigarette paper can ever reduce the amounts of carbon monoxide formed under cigarette smoking conditions, for all additives affect char formation in such a way that there is an overall increase in carbon monoxide yields.