催化重整装置扩能改造思路探讨和工程实践

从扩能改造原因分析、工艺技术路线选择、改造原则明确、规模确定等对催化重整装置的扩能改造思路进行了探讨,并结合一套半再生重整装置的扩能改造实例对扩大装置原料来源、实施节能措施等进行了论述。有如下结论:催化重整装置扩能改造时,首先分析装置扩能改造的原因,进而根据原装置类型、产品要求、扩能幅度等选择合适的工艺技术路线,最后结合产品要求、原料性质和来源、装置现有依托等确定合理的改造规模。在原料不足时,应根据工厂可利用原料的性质和数量,尽可能扩大装置的原料来源。在扩能改造时,应尽量采用新工艺、高效设备等以使装置节能降耗。     

聚合装置的侧线改造难点和要点

介绍了目前中、小聚合装置改造的几种改造思路,通过装置改造提高装置的产品品种的多样性,进一步提升装置的盈利能力和生存能力;同时分析了改造方案中涉及到的难点和要点,介于装置改造过程中不可避免的涉及到长距离物料输送问题,同时也介绍了几种长距离物料输送改造需遵循的要点.     

顺序流程乙烯装置冷区扩能改造方案探讨

乙烯装置分离冷区工艺流程复杂,技术难度高,是全装置工艺设计的关键.以某200 kt/a乙烯挖潜改造、1100 kt/a乙烯装置改造和1190 kt/a乙烯装置改造为例,着重论述了顺序分离流程冷区改造的工艺技术特点,对深冷及脱甲烷系统、制冷系统和碳二分离系统的工艺改造方案进行了说明,分析了各装置在具体改造方案上的工艺技术...     

桂林立白磺化装置扩产改造

简要介绍了桂林立白1.6 t/h磺化装置改造前的使用情况,并对原装置进行优化设计和合理改造,使装置整体水平得到提高。通过对磺化装置改造前后磺酸产量、原料消耗及能源消耗的比较,显现了桂林立白1.6 t/h磺化装置扩产改造的必要性和意义。     

低温甲醇洗装置技术改造能效分析

采用航天炉粉煤加压气化技术对300 kt/a甲醇生产厂气化装置进行改造,同时对配套低温甲醇洗装置进行改造优化。通过改造前、后能量平衡分析发现,改造后低温甲醇洗装置的热效率提高了6.0%;通过分析发现,改造后低温甲醇洗装置的损失降低1.8×107k J/h,效率提高3.5%。     

大颗粒尿素造粒装置扩能改造工程述评

通过介绍宁夏石化公司大颗粒尿素装置增产50%的扩能改造工程,分别简述了扩能改造的工艺方案、装置布置、设备选型以及改进结构等多项技改措施;通过比较装置改造前后的运行状况和尿素成品质量指标,分析评述了技改效果,结果表明,此次改造在达到装置生产能力提高50%的前提下,装置的运行周期由20 d提高到30 d以上,且产品单耗、成品质量、环保控制等相关技术指标较改造前均有明显改善。     

脱盐装置工艺技术改造后的操作优化

武汉石油化工厂常减压装置扩能改造后,脱盐装置出现脱后含盐、含水和切水含油量上升的问题,通过对装置改造情况和操作条件的分析,采取一系列措施,脱盐效率得到有效提高,并对装置进一步改造提出建议。     

废氯气处理装置技术改造

介绍了废氯气处理装置工艺流程及过程控制。对运行过程中存在的问题进行分析论证,提出合理可行的技术方案,进行相应设备改造:改造一级、二级吸收塔连通方式,增加有效氯在线检测仪,更换循环碱泵出口管道材质,改造循环碱液冷却器温度自动调节装置,改造碱液高位槽出口阀联锁等。改造后,装置的运行稳定性提高,实现废氯气处理装置安全、稳定、高效运行。     

F370密炼机主机大修和改造

F370密炼机主机由于长时间使用有了很多故障。介绍了改造前F370密炼机主机的基本状况。对卸料装置、密封装置、混炼室、转子及支承装置、上顶栓、主减速机等部件的具体存在缺陷、改造工艺及方案、具体改造过程及需要注意的细节等作了详细介绍。最后总结了改造效果,对一些没有达到预期效果的改造提出了进一步改造的意见。     

中原石化碳四装置的工艺流程改造

阐述了中原石化碳四装置改造的原因,对改造方案的优缺点进行了说明,介绍了装置改造的内容,总结了改造的优化调整措施以及改造后的运行情况。装置经过改造后,产品质量等指标均达到要求,可根据不同的原料结构进行适应性操作,增加了装置的灵活性。     

Present or Past Herbivory: A Screening of Volatiles Released from <Emphasis Type="Italic">Brassica rapa</Emphasis> Under Caterpillar Attacks as Attractants for the Solitary Parasitoid, <Emphasis Type="Italic">Cotesia vestalis</Emphasis>

Females of the solitary endoparasitoid Cotesia vestalis respond to a blend of volatile organic compounds (VOCs) released from plants infested with larvae of their host, the diamondback moth (Plutella xylostella), which is an important pest insect of cruciferous plants. We investigated the flight response of female parasitoids to the cruciferous plant Brassica rapa, using two-choice tests under laboratory conditions. The parasitoids were more attracted to plants that had been infested for at least 6 hr by the host larvae compared to intact plants, but they did not distinguish between plants infested for only 3 hr and intact plants. Although parasitoids preferred plants 1 and 2 days after herbivory (formerly infested plants) over intact plants they also preferred plants that had been infested for 24 hr over formerly infested plants. This suggests that parasitoids can distinguish between the VOC profiles of currently and formerly infested plants. We screened for differences in VOC emissions among the treatments and found that levels of benzyl cyanide and dimethyl trisulfide significantly decreased after removal of the host larvae, whereas terpenoids and their related compounds continued to be released at high levels. Benzyl cyanide and dimethyl trisulfide attracted parasitoids in a dose-dependent manner, whereas the other compounds were not attractive. These results suggest that nitrile and sulfide compounds temporarily released from plants under attack by host larvae are potentially more effective attractants for this parasitoid than other VOCs that are continuously released by host-damaged plants.     

Corn Plants Treated with Jasmonic Acid Attract More Specialist Parasitoids, Thereby Increasing Parasitization of the Common Armyworm

We investigated whether corn plants treated with jasmonic acid (JA) increases the ability of the parasitic wasp, Cotesia kariyai, to find and control the common armyworm (Mythimna separata) under laboratory conditions. The rank order of attractiveness increased from intact plants treated with distilled water (DW) (2 d), JA-treated intact plants (2 d), DW-treated infested plants (2 d) to JA-treated infested plants (2 d). Single JA-treatment to either infested or uninfested plants increased attractiveness to C. kariyai over a period lasting at least 10 d. We then showed that the increase in attractiveness of infested corn plants by JA-treatment resulted in increased parasitism by C. kariyai. These results hold a promise for field application of JA-treatment. First, JA-treatment not only promotes the attractiveness of uninfested plants, but also armyworm-infested plants. Thus, parasitoids are not likely to waste time on JA-treated uninfested plants when JA-treated infested plants are available. Second, the effect of JA-treatment is lasting for at least 10 d, a result now obtained in two independent studies.     

Comparative cost analysis of nuclear versus oil-fired dual-purpose desalination plants

Prospects for the application of nuclear energy to sea water desalination for the Kingdom of Saudi Arabia have been evaluated here based only on economic considerations. Updated capital costs of power plants and current prices of oil and nuclear fuel are used. Information on the Kingdom's water demand and current status of water desalination is provided. A comparison is also made of costs of water production from power-cum-desalination nuclear plants versus oil-fired plants. Only dual-purpose nuclear plants are considered because of their overall economic advantages over single purpose (water only) plants. The scope of available data and information can not be provided in such detail as to allow for system planning or for a site-specific feasibility study. However, the results provide guidelines for more in-depth analysis. The results show that, compared to oil-fired plants, there is a net saving of costs in using nuclear plants for desalination. If interest on capital is disregarded in calculation of total capital costs and also in calculation of annual capital charges, the economic advantages of nuclear power plants improved significantly over the oil-fired power plants.     

Planungsansatz für modulare Anlagen in der chemischen Industrie

Modularly built production plants are considered for planning new chemical plants, in case they shall be designed quickly and transformable, flexible plants are required. To date, these plants are planned mostly by the conventional planning process, so that time saving is not achieved. This paper presents a module based planning approach, which allows a structured planning of new modular plants in a time‐efficient way. All required documents for building modules are stored in the Process Equipment Design documentation, which is available for re‐use in future projects.     

我国玻纤用叶蜡石和高岭土开发现状

叶蜡石是我国E玻璃纤维生产的主要原料.主要矿区在东南沿海的浙江、福建两省、目前已有三家专有矿粉厂加工生产,另有桐乡巨石、泰山玻纤集团自己的石粉加工厂,足可满足全国玻纤用量,2005年再扩展到60万t玻纤产量也能保证供给,而且还有正在开发的高岭土粉准备为玻纤生产服务.关键是各矿粉厂、玻纤厂如何选择优质叶蜡石粉保证长期、稳定的供贷渠道,以及如何注意矿粉的合理搭配使用,保证池窑拉丝的正常进行.     

Jasmonic Acid-Induced Changes in <Emphasis Type="BoldItalic">Brassica oleracea</Emphasis> Affect Oviposition Preference of Two Specialist Herbivores

Jasmonic acid (JA) is a key hormone involved in plant defense responses. The effect of JA treatment of cabbage plants on their acceptability for oviposition by two species of cabbage white butterflies, Pieris rapae and P. brassicae, was investigated. Both butterfly species laid fewer eggs on leaves of JA-treated plants compared to control plants. We show that this is due to processes in the plant after JA treatment rather than an effect of JA itself. The oviposition preference for control plants is adaptive, as development time from larval hatch until pupation of P. rapae caterpillars was longer on JA-treated plants. Total glucosinolate content in leaf surface extracts was similar for control and treated plants; however, two of the five glucosinolates were present in lower amounts in leaf surface extracts of JA-treated plants. When the butterflies were offered a choice between the purified glucosinolate fraction isolated from leaf surface extracts of JA-treated plants and that from control plants, they did not discriminate. Changes in leaf surface glucosinolate profile, therefore, do not seem to explain the change in oviposition preference of the butterflies after JA treatment, suggesting that as yet unknown infochemicals are involved.     

Plant virus-induced changes in aphid population development and temporal fluctuations in plant nutrients

Cucurbita pepo plants were infected with zucchini yellow mosaic virus or maintained noninfected.Aphis gossypii, which transmits the virus, lived longer and produced more offspring on infected than on noninfected plants. On infected plants, the intrinsic rate of natural increase forA. gossypii increased with time after inoculation. In a similar experiment, concentrations of phloem sap nutrients, including free amino acids, total protein, and sugars from infected and noninfected plants were compared for 37 days after inoculation. Significant differences in levels of individual amino acids from phloem exudate between infected and noninfected plants were found, yet the concentration of total amino acids was not substantially different between infected and noninfected plants. Beginning four days after inoculation, the total protein content of phloem exudate generally was lower in infected plants than noninfected plants. Likewise, the total sugar content of phloem exudate from infected plants was lower than that of noninfected plants beginning nine days after inoculation. In contrast with the results from analyses of phloem exudate, foliage from infected plants had higher levels of almost all amino acids than noninfected foliage beginning nine days after inoculation. Concentrations of individual and total amino acids in infected foliage increased throughout the experimental period. Although no temporal effects were observed in the foliage sugar content for either individual or total sugars, starch content decreased with time in infected plants, while in noninfected plants, starch content remained level.     

大型空分装置在煤化工中的应用与发展

在煤化工产业发展的推动下,以深冷分离为主的空气分离技术在产业链中日趋重要,空分装置逐渐成为产业链中的核心和龙头装置,业界对空分装置的可靠性、能耗、投资等方面提出了更高要求.近年来,空分装置在装置大型化、产品多样化、系统集成化方面取得了显著进步,国产空分装置的设计、制造水平显著提高.     

我国火电厂烟气脱硫工艺现状及发展综述

概述了我国火电厂烟气脱硫的必要性,以及国家为此出台的主要政策、法律、法规等,介绍了国际上控制火电厂SO2排放的主要途径,全面论述了我国火电厂烟气脱硫的历史、现状和采用的主要工艺及进展,以及脱硫生成物的综合利用,探讨了目前我国火电厂烟气脱硫存在的问题,提出应用国家政策推动火电厂烟气脱硫工作的全面实施,"循环经济"法则是治理我国火电厂烟气脱硫的最佳选择.     

Compatible and Incompatible Xanthomonas Infections Differentially Affect Herbivore-Induced Volatile Emission by Pepper Plants

Recent studies have alerted us to the potential for conflicts between pathogen- and herbivore-induced plant defenses. The lack of studies on the induced chemical changes that simultaneous insect and pathogen attacks have on the host plant has become apparent. In the present study, we found that pepper plant volatile profiles can be differentially induced by compatible and incompatible bacterial infection and beet armyworm (BAW) damage when applied alone or in combination upon the same host. We also found that plants under simultaneous compatible bacterial and BAW attack are able to produce volatiles in quantities greater than those produced by healthy plants in response to BAW feeding. In contrast, plants exposed to the incompatible pathogen challenge showed a total volatile release below the level of healthy plants exposed to BAW damage. This suppression of BAW-induced volatiles coincided with increased methyl salicylate production from incompatible bacteria-infected plants. Feeding choice experiments revealed that, when given a choice, BAW larvae fed significantly more on leaves of plants infected with the incompatible bacteria as soon as 2 d after inoculation, while a significant increase in insect feeding on the plants infected with the compatible bacterial strain was not seen until day 4 after inoculation. Additionally, survival for third instars to pupation was significantly higher when feeding on infected plants than on healthy plants, regardless of compatibility. These results are indicative of lowered herbivore defenses due to disease progression on the plants.