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1.
电石法生产PVC树脂的成本分析与控制   总被引:1,自引:1,他引:0  
介绍了石河子中发公司采用电石法生产PVC树脂的成本分析及采取的措施:(1)加强电石采购管理,次品电石使用量降至20%以下,使电石单耗降低;(2)氯化氢纯度控制应大于93%;(3)适当扩大生产能力(由8kgt/a增至2.5万t/a)。改进后生产成本由5419元/t下降至3955元/t。  相似文献   

2.
研发了催化裂化汽油中二烯烃选择性加氢催化剂FO-35T,并在90万t/a汽油加氢装置再次工业应用。结果表明,该催化剂能够使催化裂化汽油中的二烯烃质量分数降低90%以上,总烯烃含量下降≤3,RON降低≤1个单位,证明了FO-35T脱二烯烃催化剂良好的加氢选择脱二烯烃的性能。该催化剂活性高,选择性好,对烯烃及辛烷值影响较小,可以生产二烯烃质量分数≤0.2%的产品油,从而满足醚化进料的要求。  相似文献   

3.
In this paper we first describe the basic idea of adhesion and various methods for measuring adhesion. We then discuss the various state-of-the-art techniques for the improvement of the adhesion between diamond films and substrates. The techniques discussed are categorized into two main types: (a) those which reduce internal stress and (b) those which increase the ideal or basic adhesion itself. Techniques in category (a) include forming a composition gradient layer on top of an insert substrate surface to reduce the detrimental effect caused by the difference in thermal expansion with diamond, and/or the use of insert substrates themselves having a smaller difference in thermal expansion with diamond. Techniques in category (b) include modification of cemented carbide substrates so as to reduce the detrimental effect caused by Co and the increase of the mechanical interlocking effect using a special etching process.  相似文献   

4.
王旗威  耿兵  张炉青  张德宾  张书香 《精细化工》2011,28(4):347-349,374
研究了含氟烷基磷酸单酯类表面活性剂[分子式为H(CF2)6CH2OPO(ONa)2,记为DFH-PS]与无机盐和普通碳氢表面活性剂的复配性能,研究结果表明,DFH-PS水溶液最低表面张力为23.73 mN/m;当NaCl浓度为0.2 mol/L时,可使DFH-PS水溶液最低表面张力下降到21.62 mN/m;阴离子碳氢表面活性剂十二烷基硫酸钠(SDS)对该含氟表面活性剂影响显著,当n(DFH-PS)∶n(SDS)=5∶1时,可使水溶液表面张力在很低浓度时降至22.22 mN/m;与非离子表面活性剂辛基酚聚氧乙烯(10)醚(OP-10)混合,当n(DFH-PS)∶n(OP-10)=8∶1时,可使水溶液表面张力降至27.0 mN/m。  相似文献   

5.
考查了缺氧条件下Fe(Ⅱ)-有机质(DOM)的络合物将Cr(Ⅵ)还原为Cr(Ⅲ)的还原能力。研究发现在没有或有萨旺尼河黄腐酸(SRFA)和波尼湖黄腐酸(PLFA)存在的情况下,Fe(Ⅱ)都能够将Cr(Ⅵ)快速地还原(几分钟)。Fe(Ⅱ)-DOM溶液不一定比仅含有Fe(Ⅱ)单一的体系具有更强的还原力。DOM的组成也影响了Cr(Ⅲ)的还原机制,湿地(俄亥俄州老妇人河河口区)沉积物进行缺氧萃取得到的沉积物孔隙水能够将Cr(Ⅵ)更快地还原。这些研究数据表明自然界中富含Fe(Ⅱ)和DOM的缺氧孔隙水对Cr(Ⅵ)的非生物还原反应速率远大于生物还原反应速率,并且这一非生物还原反应是自然环境中Cr(Ⅵ)被还原的主要途径。  相似文献   

6.
An electrochemical process using reticulated vitreous carbon-supported polyaniline cathodes is proposed to reduce toxic hexavalent chromium, which is present in industrial wastewater. The effect of five variables was simultaneously studied: (1) flow velocity; (2) current density; (3) electrode thickness; (4) electrode porosity and (5) Cr(VI) concentration. Due to the number of variables, a Box–Behnken factorial-design was chosen in order to reduce the number of experiments required. The current efficiency, energy consumption and space–time yield were the variables evaluated. The process was also analyzed in terms of the polymer stability and the overpotential distribution inside the porous electrode.  相似文献   

7.
α,ω-triethoxysilane terminated poly(ethylene oxide) (PEO-Si) was prepared and used to produce organic/inorganic hybrids by the sol-gel approach. These hybrids were used as coatings for flexible PVC tubes in order to reduce the plasticizer leaching from PVC medical devices. Extraction tests carried out with hexane indicated that all coating composition investigated are able to strongly reduce (about one order of magnitude) the leaching of di-ethylhexyl phthalate in hexane. The best results were obtained by an accurate balance of organic and inorganic phases content. XPS analysis showed a preferential segregation of silica onto the outer surface suggesting that a high inorganic content at the coating-extraction medium interface was present.  相似文献   

8.
The cold-start of a prototype diesel engine exhaust aftertreatment system was analyzed using a simplified energy balance to study the impact of system design changes on the performance of the selective catalytic NOx reduction reactor. The simplified energy balance method is shown to be a viable tool for system-level analysis of the aftertreatment performance. The results indicate that without an external energy supply the best way to shorten the selective catalytic reduction (SCR) reactor light-off time is to reduce the system thermal inertia by including a metallic diesel oxidation catalyst (DOC) and moving the SCR reactor upstream. Such optimization of the aftertreatment architecture is found to significantly reduce SCR light-off time for the configurations examined. Electrical heating applied to the SCR and DOC reactors can also reduce the light-off time. The system architecture optimization, however, is subject to vehicle under-hood packaging restrictions. To meet more stringent emission standards in the future, a combination of architecture optimization and electrical heating will be required.  相似文献   

9.
Dietary polyunsaturated fatty acid (PUFA) supplementation has been shown to reduce the incidence of necrotizing enterocolitis (NEC) in a recent randomized, controlled trial. These compounds are known to modulate the inflammatory cascade and to influence intestinal health in a variety of ways. Although the pathophysiology of NEC is not well understood, recent evidence suggests that platelet-activating factor (PAF) is a key endogenous mediator of intestinal necrosis in animals. Using a neonatal rat model of NEC that includes the key risk factors of asphyxia and formula feeding, we investigated the role of dietary PUFA supplementation on the incidence and pathophysiology of NEC. Our findings suggest that PUFA reduce the incidence of NEC by modulating PAF metabolism and endotoxin translocation.  相似文献   

10.
马侠  陶芸 《化工进展》2013,32(6):1296-1299,1335
介绍了Co-Mn-Br催化对二甲苯氧化生产对苯二甲酸的反应历程,阐述了溴元素在对二甲苯的甲基氧化过程中的促进作用及带来的负面影响。研究通过添加剂促进对二甲苯氧化,减少溴的用量,对于减轻设备腐蚀、减轻溴排放具有重要的意义。本文先以对二甲苯(PX)和中间产物对甲基苯甲酸(PT酸)为原料,模拟对苯二甲酸(PTA)生产过程中氧化反应器中实际组成状况,通过自由基前体型添加剂对氧化反应促进的研究,开发出适合生产应用的对二甲苯氧化催化剂新体系,并进一步通过工业试验验证。结果表明,在保证PX氧化反应效果不变的前提下,反应体系中添加40×10?6的添加剂可以实现保持Co-Mn-Br三元催化剂中钴、锰浓度不变,氢溴酸使用浓度从500 ×10?6降低到250×10?6。  相似文献   

11.
Wei(1978) introduced the adaptive biased coin design to reduce experimenter bias and offer a compromise between perfect balance and complete randomization. In situations such as the Behrens-Fisher problem, balance is not necessarily desired and the optimal ratio of sample sizes is unknown. To reduce experimenter bias, by introducing randomization, an adaptive biased coin design is superimposed on Robbins, Simons, and Starr's(1967) sequential analogue of the Behrens-Fisher problem. The design has asymptotic properties similar to Robbins, Simons, and Starr's sequential procedure.  相似文献   

12.
Epoxy resins based on the triglycidyl ether of tris(hydroxyphenyl)methane (TETM) possess a very high heat distortion temperature and superior thermal oxidative stability over other types of epoxy resins. The high performance trifunctional epoxy resin (TETM) was synthesized by the condensation of a hydroxybenzaldehyde with phenol followed by epoxidation with a halohydrin. The structure of the synthesized TETM was confirmed by infrared (IR), mass spectra (MS), and nuclear magnetic resonance (NMR) spectroscopy. Amine terminated polydimethylsiloxanes (ATPDMS) were used to reduce the stress of trifunctional epoxy resin cured with phenolic novolac resin for electronic encapsulation applications. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing the coefficient of thermal expansion (CTE) and flexural modulus, while the glass transition temperature (Tg) is depressed by only a small amount.  相似文献   

13.
The ability of organic and inorganic additives (polyethylene terephthalate, titanium dioxide, finely disperse carbon, petroleum bitumen) to reduce the carcinogenic impact of coal-pitch carbonization is studied. Additives may reduce the quantity of pitch sublimates and their content of carcinogenic polycyclic aromatic hydrocarbons. Some additives are able to reduce the benz[a]pyrene content in the exhaust gases, but its complete elimination is impossible, since benz[a]pyrene is a natural product of the high-temperature pyrolysis of organic materials. For this reason, additions of petroleum products to coal pitch cannot reduce the benz[a]pyrene emissions in the exhaust gases.  相似文献   

14.
双通道平板型环路热管的传热特性   总被引:1,自引:1,他引:1       下载免费PDF全文
莫冬传  邹冠生  丁楠  吕树申 《化工学报》2012,63(Z1):114-118
以铜为主要材料、超纯水为工质研发了双通道平板型环路热管。分别在双通道环路热管的两根液管上安装阀门,通过阀门的开关,实现双通道平板型环路热管和单双道平板型环路热管的互相转换。通过实验,发现双通道平板型环路热管的传热性能比单通道平板型环路热管要好。在热源的加热量为30W时,蒸发器温度的降幅可达10℃。在不同的功率下,双通道环路热管比单通道环路热管总热阻的下降幅度在20%以上。但双通道平板型环路热管的总热阻与单通道平板型环路热管相比,降幅并没有达到50%,这是由于采用双通道的形式,只能减小通道压降造成的热阻以及冷凝热阻,但不能减小蒸发器热阻。  相似文献   

15.
There is an emergent need to reduce the emissions of toxic volatile organic compounds (VOCs) to the atmosphere. One strategy to reduce the emissions of VOCs from point sources is to use air pollution control devices on the sources' discharge streams. This paper describes the development of a new activated carbon cloth (ACC) adsorption system that is integrated with cryogenic vapor recovery to reduce the amount of VOCs emitted to the atmosphere from point sources and provide for reuse of the VOCs that are recovered. Electrical current is used to regenerate the ACC. ACC adsorption followed by electrothermal regeneration results in formation of a concentrated organic vapor which is cryogenically condensed from the gas phase. Electrothermal desorption allows for careful control of the desorption time and the concentration profile of the desorbed VOC to allow minimal use of cryogen. Adsorption, followed by cryogenic treatment enables VOC sources to meet air quality control regulations while providing a high quality liquid VOC product for reuse.  相似文献   

16.
RNA-seq has been a powerful method to detect the differentially expressed genes/long non-coding RNAs (lncRNAs) in schizophrenia (SCZ) patients; however, due to overfitting problems differentially expressed targets (DETs) cannot be used properly as biomarkers. This study used machine learning to reduce gene/non-coding RNA features. Dorsolateral prefrontal cortex (dlpfc) RNA-seq data from 254 individuals was obtained from the CommonMind consortium. The average predictive accuracy for SCZ patients was 67% based on coding genes, and 96% based on long non-coding RNAs (lncRNAs). Machine learning is a powerful algorithm to reduce functional biomarkers in SCZ patients. The lncRNAs capture the characteristics of SCZ tissue more accurately than mRNA as the former regulate every level of gene expression, not limited to mRNA levels.  相似文献   

17.
汽油调合调度优化   总被引:2,自引:1,他引:1       下载免费PDF全文
张冰剑  华贲  陈清林 《化工学报》2007,58(1):168-175
采用连续时间建模方法,建立了一种新的汽油非线性调合和调度集成优化的混合整数非线性规划(MINLP)模型,克服了当前在油品调合调度中采用线性调合模型或者将非线性调合过程和调度分开优化的缺陷。针对建立MINLP模型的特点,将原MINLP问题转化为求解一系列的混合整数线性规划(MILP)模型,避免了直接求解MINLP模型的复杂性。最后以某大型炼油企业为例,验证了模型和算法的实用性。  相似文献   

18.
研究了不同流动性苯乙烯-丙烯腈塑料(SAN)、填料、弹性体和消光剂对丙烯腈-苯乙烯-丙烯酸酯塑料(ASA)材料光泽度及其它性能的影响.结果表明,降低SAN的流动性对ASA材料光泽度降低很小.添加填料可明显降低ASA材料的光泽度,但会降低ASA材料悬臂梁缺口冲击强度.添加片状滑石粉和云母对ASA材料光泽度的降低最明显.选...  相似文献   

19.
电石法生产PVC树脂的成本分析   总被引:4,自引:4,他引:0  
介绍了目前国内电石法生产PVC树脂的成本分布情况。我国 1999年PVC的产量为 195万t/a(电石法为 111万t) ,2 0 0 0年PVC产量为 2 45万t/a(电石法为 12 4万t,比 1999年提高了 11.7% ,占总产量的 5 1% )。在用电石为原料生产PVC过程中 ,电石和氯化氢占总成本的 74.8% ,是影响生产成本的主要因素。进一步降低生产成本的措施是 :(1)回收合成气中未反应的氯化氢 ;(2 )改进生产配方 ,使用国产助剂 ;(3)提高电石水解温度 ;(4 )滤液、离心母液复用 ,将塔液密闭集中后用作电石水解 ;(5 )改变干燥的操作条件。改进措施后可节省费用 30 0元 / (t·PVC) ;连同 (6 )把电石消耗定额由 1.6t/ (t·PVC)降至 1.4t/ (t·PVC) ,将使总生产成本下降 70 0元 / (t·PVC)。文中还简述了电石泥综合利用的几种方法  相似文献   

20.
A high-performance trifunctional epoxy resin based on the triglycidyl ether of tris (4-hydroxyphenyl)-methane (TETM) was synthesized by the condensation of 4-hydroxybenzaldehyde with phenol followed by epoxidation with epichlorohydrin. The structure of TETM was confirmed by mass spectra, infrared and nuclear magnetic resonance spectroscopy. Amino-terminated poly(dimethylsiloxane)s were used to reduce the stress of the trifunctional epoxy resin cured with phenolic novolac resin for electronic encapsulation application. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing the coefficient of thermal expansion and flexural modulus while the glass transition temperature was hardly depressed.  相似文献   

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