丁辛醇加氢催化技术进展

介绍了丁辛醇工业流程中加氢部分的工艺及国外催化剂研制情况,同时对加氢催化剂的国产化进程作了重点介绍,认为丙烯氢甲酰化研究与开发项目中加氢部分的催化剂的选择完全可以立足国内.     

丙烯氧化制丙烯酸催化剂研究进展

介绍丙烯氧化制丙烯酸催化剂,综述丙烯一步氧化法和两步氧化法制丙烯酸催化剂的研究进展。丙烯两步氧化法通过Mo-Bi系丙烯醛催化剂和Mo-V系丙烯酸催化剂完成丙烯酸生产,目前通过催化剂制备工艺的研究,催化剂达到了较高性能水平。今后还应对添加各种助剂、制备工艺优化和改变催化剂成型方式等进行研究,进一步提高丙烯酸收率与稳定性。提出开发高丙烯空速催化剂,提高装置负荷是下一步的研究重点。     

一种生产纳米碳纤维的工艺及装置

一种纳米碳纤维的生产工艺,它包括下列步骤：①将催化剂均匀地分布到隔热反应器中;②将隔热反应器预热到反应温度;③将丙烯预热到反应温度后通入隔热反应器;④待反应完成后,将纳米碳纤维和催化剂移出隔热反应器;⑤将步骤④取出的纳米碳纤维和催化剂依次用1％的硝酸和水洗涤,然后干燥,即得纳米碳纤维。本技术提供的工艺操作简便,设备简单、能耗低、产率高;可制得大量纳米碳纤维,制成的纳米碳纤维均较为纯净,无定型炭等杂质的含量极少。本发明公开了生产设备。     

丙烯酸合成催化剂及工艺开发进展

综述了丙烯两步氧化和丙烷氧化制丙烯酸工艺的催化剂及反应过程优化研究进展,并对两种工艺进行经济性分析.指出丙烯氧化催化剂及工艺改进的目的主要是提高选择性和生产率.由于丙烯价格的迅速上涨,丙烷法出现新的转机.若催化剂性能得以进一步提高,则来自天然气的丙烷直接氧化制丙烯酸工艺具有良好的发展前景.     

国外用过氧化氢环氧化丙烯制环氧丙烷研发近况

介绍了国外用过氧化氢环氧化丙烯制备环氧丙烷（PO）工艺技术近期研发概况，内容包括所用过氧化氢来源（来自蒽醌法或氢、氧直接化合法）、丙烯环氧化反应以及反应产物精制和原料回收循环利用过程，工艺涉及催化剂、溶剂、流程、反应器、操作方法和试验结果等。不少工艺是将过氧化氢合成与丙烯环氧化加以耦合，形成完整体系，提高运转效率和经济效益。此外，简略介绍了用过氧化氢制PO工艺在产业化方面的最新进展。     

甲醇制丙烯(MTP)工艺过程中催化剂的再生过程分析

大连化物所的DMTO(甲醇制烯烃)工艺及鲁奇公司的MTP(甲醇制丙烯)工艺是目前世界上两种已经实现了商业化的甲醇制低碳烯烃技术,两种工艺均采用沸石催化剂。文章从工艺过程出发,介绍了MTP(甲醇制丙烯)工艺技术中所采用的沸石基甲醇制丙烯催化剂的再生操作过程。     

丙烯精制催化剂的工业应用

为了改善精制后丙烯性能,提高聚丙烯产品质量,降低催化剂消耗,采用西北化工研究院生产的丙烯精制催化剂对聚丙烯装置精制系统流程进行了改造。实践证明,该院生产的精制催化剂完全能满足在苛刻条件下,使精制后丙烯原料达到聚合级设计要求。     

丙烷裂解的过程模拟和技术经济分析

丙烷裂解是制烯烃的重要过程,同时还可副产高附加值的氢气.本文对丙烷脱氢制丙烯工艺建立全流程,在Pt-Sn/Al2O3为催化剂的反应动力学基础上,建立绝热平推流反应器的反应动态模型和深冷分离模型进行全流程模拟,并进行技术经济分析.结果表明,相对于煤和石油制丙烯路线,丙烷裂解制丙烯技术的原材料费用占产品成本组成比例最小,销...     

丙烷法制丙烯腈技术分析

<正> 世界 AN 生产能力,几乎所有的流程都采用索亥俄(Sohio)技术,丙烯氨氧化工艺占绝对优势,但丙烷与丙烯之间存在着巨大的价格差,而且丙烷资源丰富,从而使包括 BP/Sohio 公司在内的一些公司纷纷研究用丙烷作原料生产丙烯腈的工艺。丙烷法工艺可分2种,其一是丙烷在稳定催化剂作用下,同时进行丙烷的氧化脱氢和丙烯氨氧化反应;其二是丙烷经氧化脱氢后生成丙烯,尔后以常规的丙烯氨氧化工艺生产丙烯腈。以生产工业气体著称的 BOC 集团公司研究的工艺属于第2种,但它采用变压吸附技术对回收利用未反应的原料丙烷和     

Hypol工艺用BCZ-108H型催化剂的聚合行为

研究了丙烯聚合用BCZ-108H型催化剂在60～85 ℃时的聚合行为及所制聚丙烯的主要性能,并与Hypol工艺常规应用的NA型催化剂和市售催化剂进行了对比。结果表明:随着温度的升高,丙烯聚合反应速率和催化剂活性总体呈降低趋势,且聚合反应速率的衰减越来越快。在整个温度区间内,采用BCZ-108H型催化剂的聚合反应速率和活性远高于另外两种催化剂,温度为70 ℃时,3种催化剂用于丙烯聚合的反应速率和活性的差距最小;温度为80 ℃时,3种催化剂用于丙烯聚合的反应速率和活性的差距最大。     

红外光谱法研究水汽处理纳米HZSM-5催化剂表面羟基及其酸性质

采用红外光谱法对系列不同温度水汽处理改性纳米HZSM-5催化剂表面羟基及其酸性质进行了研究,结果表明纳米HZSM-5催化剂经温和水汽处理后,其酸性的变化既体现出与常规尺寸分子筛相同的趋势,又体现出纳米粒子自身的特性,即其内外表面的强酸对水汽处理的敏感程度不同.水汽处理较易脱除的是催化剂外表面的铝羟基,从而导致催化剂外表面酸量的骤减,而内表面酸量变化不大.当水汽处理温度升高后,开始发生骨架铝的脱除,因而内表面酸量开始减少,而外表面酸量与低温水汽处理比较变化不明显.     

A novel method for enhancing on-stream stability of fluid catalytic cracking (FCC) gasoline hydro-upgrading catalyst: Post-treatment of HZSM-5 zeolite by combined steaming and citric acid leaching

This article describes a novel modification method consisting of steaming and subsequent citric acid leaching to finely tune acidity and pore structure of HZSM-5 zeolite and thereby to enhance the on-stream stability of the zeolite derived fluid catalytic cracking (FCC) gasoline hydro-upgrading catalyst. A series of dealuminated HZSM-5 zeolites and their derived catalysts were prepared and characterized by X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), ²⁷Al MAS NMR, nitrogen adsorption, temperature programmed desorption of ammonium (NH₃-TPD) and infrared (IR) spectroscopy of chemisorbed pyridine. The results showed that the citric acid leaching could preferentially remove the extra-framework Al (EFAl) species formed by steaming treatment and thus reopen the EFAl-blocked pore channels of the steamed zeolite. The steaming treatment at a suitable temperature and subsequent citric acid leaching not only decreased the strength of acid sites to a desirable degree but also increased the ratio of medium and strong Lewis acidity to medium and strong Brönsted acidity, both of which conferred the resulting catalyst with superior selectivity to aromatics, good hydroisomerization activity and gasoline research octane number (RON) preservability, as well as enhanced on-stream stability. The results fully demonstrated that the treatments by steaming and followed citric acid leaching can serve as an important method for adjusting the physicochemical properties of HZSM-5 zeolite.     

Catalytic cracking of 1-butene to propylene by Ag modified HZSM-5

Silver modified HZSM-5 (AgHZ) zeolite catalysts were prepared by ion exchange method and their catalytic properties in the 1-butene cracking reaction were measured. The catalysts were characterized by infrared spec-troscopy with pyridine adsorption (Py-IR), N2 adsorption and X-ray diffraction (XRD). The effects of Ag loading and steaming treatment on catalytic performances were studied. It is found that the activity of HZSM-5 (HZ) cat-alyst significantly decreases with the steaming time, whereas AgHZ catalysts show stable activity in the steaming time of 24–48 h and their activities increase with the Ag loading. When the steaming time is 24–48 h, the yield of propylene over HZ catalyst significantly decreases, whereas it is stable over AgHZ catalysts. The AgHZ catalysts with Ag loadings of 0.28%–0.43%(by mass) show similar propylene yields (~30%), which are higher than that over the AgHZ catalyst with a Ag loading of 0.55%(by mass). These results indicate that the steam-treated AgHZ catalysts with optimum Ag loadings have higher yield of propylene and are more stable than the steam-treated HZ catalyst. The regeneration stability measurement in butene cracking also shows that the AgHZ catalyst steam-treated under a suitable condition has better stability than the HZ catalyst.     

Realumination of dealuminated HZSM-5 zeolite by citric acid treatment and its application in preparing FCC gasoline hydro-upgrading catalyst

This article describes a novel citric acid treatment method for realuminating dealuminated HZSM-5 zeolite and its application in enhancing the performance of the zeolite derived FCC gasoline hydro-upgrading catalysts. A series of modified HZSM-5 zeolites were prepared by streaming and/or acid treatments and the influences of the different modification methods on the acidity, pore structure and catalytic performance of the modified HZSM-5 zeolite supported catalysts were compared in the present investigation. The results showed that compared with the single HCl or citric acid treatment, the steaming treatment, and the steaming/HCl treatments, the citric acid treatment after steaming exclusively increased the amount of framework Al species due to its realumination effect on the steamed HZSM-5 zeolite. This realumination effect of the citric acid treatment could optimize the ratio of framework Al to extra-framework Al in the steamed HZSM-5 zeolite and thus greatly improve the acidity distribution and pore structure of the corresponding catalyst. The catalytic performance assessments of the different zeolite supported catalysts for FCC gasoline hydro-upgrading revealed that the catalyst supported on the steaming/citric acid treated HZSM-5 zeolite had balanced initial and long-term activities in hydrodesulfurization, hydroisomerization and aromatization, high liquid yield and improved gasoline road octane number. The superior catalytic performance of the catalyst could be closely related to its suitable ratio of framework Al to extra-framework Al achieved by the combinational use of the steaming dealumination and the citric acid realumination, fully demonstrating the effectiveness of the steaming and citric acid treatments in optimizing the physicochemical properties and catalytic performance of HZSM-5 zeolite supported catalysts.     

Effect of steam-drying treatment on moisture content,drying rate,color, and drying defects in juvenile wood of Tectona grandis from fast-growth plantations

Tectona grandis is the second most important species for reforestation in Costa Rica, and any improvement in its industrialization process is important, especially the drying process. Lumber obtained from a plantation of 12-year-old T. grandis trees was used to evaluate three drying schedules that include integrated steaming processes to determine the combined effect of the steam-drying system on the dried lumber. The variations in the moisture content (MC) and drying rate (DR) with drying time (DT) both before and after the steaming process were modeled mathematically for boards that have a flat and quarter grain pattern. For both types of boards that were dried with and without steaming, a relationship between MC and DT was observed. There was inflexion at 40%, and two mathematical models were computed. Additionally, the relationship between DR and DT for boards with flat and quarter grain patterns was not affected by the steaming process, and an inflection point was observed at 30?h (40% MC for the lumber). Moderate changes were observed in the CIELAB color system and dried lumber became darker. The steaming process, which was integrated in the drying schedule for boards with the flat and quarter grain pattern, decreased the incidence or magnitude of drying defects depending on the grain pattern and drying schedule used.     

封闭型水性聚氨酯的固色应用

采用封闭型水性聚氨酯对棉织物进行固色研究,探讨了水性聚氨酯的用量、催化剂的使用以及固色工艺对固色效果的影响。结果显示,当水性聚氨酯的用量为40~60 g/L,催化剂二月桂酸二丁基锡(T-12)为水性聚氨酯用量的0.7%时,固色后棉织物的湿摩擦牢度可达到4级,且汽蒸工艺有助于湿摩擦牢度的提高。用红外光谱差谱技术研究了固色机理,结果表明,水性聚氨酯因其成膜性以及覆盖染料的作用而提高色牢度,尤其是湿摩擦牢度。     

Oxidative Dehydrogenation of Propane with CO2 Over Cr/H[B]MFI Catalysts

Abstract  

Cr/silicalite-1 and Cr/H[B]MFI catalysts were prepared by the impregnation method, and Cr/H[B]MFI were further treated by steaming. The catalysts were employed for the oxidative dehydrogenation of propane to propylene with CO₂ as the oxidant. Cr/H[B]MFI showed significantly higher catalytic activity than Cr/silicalite-1, and steamed Cr/H[B]MFI was superior in the reaction stability to Cr/H[B]MFI. The nature of the supported chromium species have been characterized by a number of physicochemical techniques, such as Raman, UV–vis and NMR. It is concluded that the steaming led to the auto-reduction of some Cr⁶⁺ to Cr³⁺, and resultant Cr³⁺ species might be located near the boron center in the borosilicate framework to counterbalance the negative charge of the framework. The transformation of Cr⁶⁺ species to Cr³⁺ species, facilitated by the steaming process and the presence of boron in the catalyst, is responsible for the enhanced stability of oxidative dehydrogenation of propane to propylene with carbon dioxide as the oxidant.     

Padding,Drying, Steaming and Baking Stages in the Application of Dyes to Cellulosic Fibres and their Blends with Polyester Fibres

Padding, drying, steaming and baking are the basic unit processes of continuous dyeing; special aspects of this very wide range of processes have been examined. A new technique of padding has been developed in which the air in the material is removed by applying a high vacuum. The material is then immersed in the treating liquor without release of the vacuum; impregnation occurs on release of the vacuum. This technique can also be used in batchwise dyeing. Its advantages are that penetration is greatly improved and excellent results are obtained on completely unprepared material without the need to use wetting agents; in batchwise dyeing the uniformity of dye absorption during the initial stages of dyeing is improved. In this padding system, the pressure of the atmosphere forces the liquor into every interstice of the material, in contrast to the situation in conventional padding, where the trapped air opposes the pressure of the pad mangle. Results of the application of this technique are illustrated and discussed. Drying, steaming and baking have been considered as heat- and mass-transfer unit operations, and the techniques and data of chemical engineering have been applied to show that this approach can give much useful information to the dyer without the need for difficult empirical experimentation. There are, however, few data derived on a textile basis; even so, the standard data available show reasonable agreement with textile experience. More data in this field are required. Thoughtful use of such studies could lead to improved textile processing machinery. Finally, the ICI high-temperature (HT) steaming process (with superheated steam) and continuous pressure steaming are compared with comparable conventional treatments. The advantages and limitations of these systems are discussed. The two new methods are shown to be complementary, but the HT steaming process is more versatile in application and simpler in design.     

Synergistic effects of tungsten and phosphorus on catalytic cracking of butene to propene over HZSM-5

Synergistic catalysis effects among tungsten, phosphorus and HZSM-5 on 1-butene cracking to propene and ethene have been demonstrated by catalytic tests. The tungsten–phosphorus-modified HZSM-5 (W–P/HZSM-5) catalyst, with very low density of acid sites, offers a fairly high conversion rate of butene and selectivity to propene. The status of doped tungsten is characterized by using techniques of D₂/OH exchange, NH₃ adsorption microcalorimetry, FT-IR spectroscopy, Raman spectroscopy, N₂ adsorption and X-ray photoelectron spectroscopy. The tungsten would be monotungstate that interacted with phosphorus before steam treatment and partly congregated to polytungstate species during steaming process at high temperature. The enhanced performance of the catalyst for 1-butene cracking to propene and ethene can be correlated to the synergistic effect between the doped tungsten and phosphorous on the reaction network of the cracking process. The W–P/HZSM-5 is a promising catalyst for the 1-butene cracking to propene and ethene.     

Catalyst design and development for upgrading aromatic hydrocarbons

Background and strategy of catalyst development for upgrading aromatic hydrocarbons are intensively discussed. Originally prepared catalysts (hydrogenation and hydrocracking catalysts) were used for accelerated aging tests. Though each catalyst showed superior catalytic performance as compared to commercially available catalysts, a severe deactivation was observed on the hydrocracking (HC) catalysts. A new type of HC catalyst was designed and prepared, based on the understanding of catalyst deactivation. High silica NaY zeolites were synthesized using crown-ether. USY zeolites were then prepared by ion exchange, steaming and calcining. Surface properties and catalytic functions of well-crystallized USY zeolites were investigated to develop practical HC catalysts. The Ni–W catalyst prepared using the newly prepared USY zeolite showed a considerable improvement in the HC activity.