CDM-系列国产催化精馏模块在轻汽油醚化装置的工业应用

介绍某石化企业轻汽油醚化装置催化精馏塔更换为CDM-系列开窗导流式国产催化精馏模块的工业应用情况。结果表明:国产催化精馏模块具有优异的"催化反应"和"组份分离"双重功能,模块催化剂活性高、催化性能稳定,能有效地降低汽油的烯烃含量和蒸汽压,提高汽油的辛烷值和氧含量。通过运行数据分析:催化精馏塔活性异戊烯转化率达86.45%,总转化率达97.54%;调和汽油产品辛烷值平均为92.1,较轻汽油进料提高了0.5～1个单位。     

CDM催化精馏模块在碳减排中的工业应用

CDM催化精馏模块具有优异的"催化反应"和"组分分离"双重功能,可应用于甲基叔丁基醚(MTBE)、轻汽油醚化、甲缩醛、叔丁醇脱水和汽油加氢脱硫等工艺中.介绍了 CDM催化精馏模块产品特点及在碳减排中的工业应用情况.     

国产轻汽油醚化催化精馏模块的工业应用

中化泉州石化有限公司160万t/a汽油加氢装置轻汽油醚化单元核心设备为美国某公司的醚化催化精馏塔。实际运行表明,其醚化催化精馏模块催化剂失活速率快,寿命低于设计值。将该催化精馏模块更换为丹东明珠特种树脂有限公司、福州大学和天津大学联合开发的CDM系列Winpack催化精馏模块后,平均转化率达到88.0%,应用效果良好。     

交错型开窗导流填料的流体力学性能

为了提高规整填料通量,对传统开窗导流填料结构进行改善,提出一种新型交错式开窗导流填料。在不同喷淋密度下,采用空气-水系统对3种不同交错高度的开窗导流填料进行冷模实验,研究分析了其流体力学性能,并与传统开窗导流填料进行对比。实验结果表明:新型交错规整填料的压降随着喷淋密度的增加而增大,填料盘的交错式结构有效降低塔压降,提高通量,改善气液分布。与传统开窗导流填料相比,3种新型填料盘的干塔压降、湿塔压降显著降低,液泛气速显著提高。其中180-20型填料的压降降低最为显著,220-20型填料的液泛气速最低。同时,在LEVA模型和Bain-Hougen模型的基础上,获得了实验条件下干塔压降、湿塔压降和液泛气速的关联式,其计算结果与实验数据吻合较好。     

C3选择性加氢热耦合催化精馏流程模拟

针对C₃ 选择性加氢过程中冷剂费用过高问题提出将选择性加氢催化反应器设置在脱乙烷精馏塔的提馏段,并通过原流程的3 个精馏塔的不同热耦合方式所构成的3 种热耦合催化精馏结构;对三热耦合催化精馏结构分别进行严格模拟和评价,表明通过分离和加氢反应的结合增加了加氢反应的转化率,并通过热耦合降低了分离能耗,年度总费用降低显著。模拟结果表明,3 种方案的年度总费用节约效果分别为4.107%、6.420%和10.337%。     

催化精馏技术及其应用进展

叙述了催化精馏技术的原理和催化精馏塔的结构,重点介绍了板式塔装填、填充式装填、悬浮式装填和催化剂散装四种催化剂填料方式,阐述了催化精馏技术在酯化反应、水解反应、烷基化反应和其他反应中的应用,对催化精馏技术的发展进行了总结.     

C16、C18混合脂肪酸分离技术研究进展

C16、C18混合脂肪酸中含有很多经济价值很高的组分,若能将这些组分分离出来加以利用,将极大地提高混合脂肪酸的利用价值,因此研究C16、C18混合脂肪酸的分离技术具有非常重要的意义。本文介绍了减压精馏、低温结晶、尿素包合、银离子络合、生物酶催化法等C16、C18混合脂肪酸分离方法在近十年来的研究进展,并分析了各种分离方法的优缺点和适用范围。减压精馏可以有效地将混合脂肪酸分离成C16组分与C18组分,但该法的主要问题是加热易使不饱和组分变质。尿素包合法最常用来分离C16、C18混合脂肪酸中的饱和组分与不饱和组分,目前对该法的研究主要集中在工艺条件的优化与改善。生物酶催化法选择性高、反应条件温和、绿色环保,目前已被用来分离α-亚麻酸以及γ-亚麻酸且效果良好。最后展望了C16、C18混合脂肪酸分离技术的发展前景,指出两种或多种分离方法组合以及生物酶催化法将是未来的发展趋势。     

催化精馏技术在烷基化反应中的应用

介绍了催化精馏技术在烷基化反应中的应用,特别在基本有机化工原料生产中,如乙苯、异丙苯、直链烷基苯生产中的应用,提高了反应的转化率、原料利用率和产品选择性。对当前催化精馏现状进行了讨论,并对催化精馏研究前景进行了展望。     

C3选择性加氢能量耦合催化精馏结构与分析

提出了一种C₃选择性加氢能量耦合催化精馏新工艺,首先将催化精馏构件放置在丙烯精馏塔的提馏段,再将丙烯塔与脱乙烷塔通过气液流股连接成热耦合结构。与传统加氢工艺相比,能量耦合催化精馏工艺通过分离和加氢反应的结合使丙炔、丙二烯加氢过程的选择性得到较大幅度的提高,并通过热量耦合消除丙烯在脱乙烷塔内的返混,从而降低分离能耗。采用Aspen Plus化工流程模拟软件对该流程进行模拟。模拟结果表明,能量耦合催化精馏工艺可以使丙烯收率提高0.74%～2.19%,年度冷剂费用降低2.44%～3.61%。同时,热量耦合催化精馏工艺对于重质裂解原料油具有更好的适用性。     

C9芳烃催化烷基化法生产高纯度均三甲苯过程与技术改造

装置采用C9芳烃与丙烯进行催化烷基化反应,再对反应产物进行精馏获得高纯度均三甲苯。通过均三甲苯装置进行改造设计,提高了产品的质量。     

C_5/C_6烷烃异构化催化剂性能研究

研究分子筛种类、硅铝比、扩孔剂和晶粒大小及孔结构对C_5/C_6异构化催化剂Pd/分子筛性能的影响。结果表明,复合型、硅铝比在(18～22)的小晶粒分子筛能获得较好结果,分子筛载体成型时加入扩孔剂X,可进一步提高催化性能。对催化剂进行300 h稳定性测试,异构化性能始终保持稳定,无明显下降。     

NO decomposition and reduction by C3H6 over transition metal oxides supported on MgF2

The monooxides copper, manganese, molybdenum and chromium catalysts supported on MgF₂ were tested in NO decomposition and reduction by propene. The effect of the oxides content, time on stream and O₂ concentration in reaction mixture during NO reduction on their catalytic activity was investigated. All the catalysts showed the optimum active phase concentration corresponding to 2–4 wt.% of the metal. For the best copper catalyst an effect of introduction of another oxide (manganese or chromium oxide) on the catalytic performance was studied. The double copper-manganese oxide sample containing 2 wt.% Cu and 4 wt.% Mn was proved to ensure the best catalytic performance.     

软模板法制备多级孔ZSM-5分子筛的研究进展

相比传统ZSM-5分子筛,多级孔ZSM-5分子筛具有空间位阻小、传质效率高、焦炭少等特点,近年来在分子筛领域应用广泛。多级孔分子筛通常可用后处理法和模板剂法制备,相比后处理法,模板剂法能更好地控制介孔的结构和孔道尺寸。概述了采用传统表面活性剂、两亲性的有机硅烷、双功能多季铵盐表面活性剂及高分子聚合物等软模板法合成多级孔ZSM-5分子筛的研究进展。分析不同软模板剂的特点和作用机理,阐述了合成后分子筛的结构特点及催化性能等。指出在今后的研究中,可以设计价格较低的新型功能化模板剂,优化合成过程,致力于在理解合成机理的前提下,寻找操作简单、绿色环保的合成路线,并将其推行到实际工业生产中。     

Kinetics of the selective catalytic reduction of NO by NH3 on a Cu-faujasite catalyst

The kinetics of the selective catalytic reduction (SCR) of NO by NH₃ in the presence of O₂ has been studied on a 5.5% Cu-faujasite (Cu-FAU) catalyst. Cu-FAU was composed of cationic and oxocationic Cu species. The SCR was studied in a gas phase-flowing reactor operating at atmospheric pressure. The reaction conditions explored were: 458<T_R<513 K, 2503 (ppm) < 4000, 12 (%) < 4. The kinetic orders were 0.8–1 with respect to NO, 0.5–1 with respect to O₂, and essentially 0 with respect to NH₃. Based on these kinetic partial orders of reactions and elementary chemistry, a wide variety of mechanisms were explored, and different rate laws were derived. The best fit between the measured and calculated rates for the SCR of NO by NH₃ was obtained with a rate law derived from a redox Mars and van Krevelen mechanism. The catalytic cycle is described by a sequence of three reactions: (i) Cu^I is oxidized by O₂ to “Cu^II-oxo”, (ii) “Cu^II-oxo” reacts with NO to yield “Cu^II-N_xO_y”, and (iii) finally “Cu^II-N_xO_y” is reduced by NH₃ to give N₂, H₂O, and the regeneration of Cu^I (closing of the catalytic cycle). The rate constants of the three steps have been determined at 458, 483, and 513 K. It is shown that Cu^I or “Cu^II-oxo” species constitute the rate-determining active center.     

Selective catalytic reduction of NO by C2H2 over MoO3/HZSM-5

Molybdenum impregnated HZSM-5 zeolite catalysts with MoO₃ loading from 1 to 8 wt.% were studied in detail for the selective catalytic reduction (C₂H₂-SCR) of NO by acetylene. A 83.9% of NO could be removed by the reductant at 350 °C under 1600 ppm of NO, 800 ppm of C₂H₂ and 9.95% of O₂ in He over 2%MoO₃/HZSM-5 catalyst with a specific activity of in NO elimination and the competitiveness factor (c.f.) of 33.6% for the reductant. The NO elimination level and the c.f. value were ca. 3–4 times as high as those using methane or propene as reductant over the catalyst in the same reaction condition. About same reaction rate was estimated in NO oxidation as that in the NO reduction over each xMoO₃/HZSM-5 (x = 0–8%) catalyst, which confirms that NO₂ is a crucial intermediate for the aimed reaction over the catalysts. Appropriate amount of Mo incorporation to HZSM-5 considerably enhanced the title reaction, both by accelerating the intermediate formation and by strengthening the adsorption NO_x on the catalyst surface under the reaction conditions. Rather lower adsorption tendency of acetylene compared with propene on the catalysts explains the catalyst's steady performance in the C₂H₂-SCR of NO and rapid deactivation in the C₃H₆-SCR of NO.     

A comparative study of the water-gas shift activity of Pt catalysts supported on single (MOx) and composite (MOx/Al2O3, MOx/TiO2) metal oxide carriers

The water-gas shift (WGS) activity of platinum catalysts dispersed on a variety of single metal oxides as well as on composite MO_x/Al₂O₃ and MO_x/TiO₂ supports (M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Y, Zr, La, Ce, Nd, Sm, Eu, Gd, Ho, Er, Tm) has been investigated in the temperature range of 150–500 °C, using a feed composition consisting of 3% CO an 10% H₂O. For Pt catalysts supported on single metal oxides, it has been found that both the apparent activation energy of the reaction and the intrinsic rate depend strongly on the nature of the support. In particular, specific activity of Pt at 250 °C is 1–2 orders of magnitude higher when supported on “reducible” compared to “irreducible” metal oxides. For composite Pt/MO_x/Al₂O₃ and Pt/MO_x/TiO₂ catalysts, it is shown that the presence of MO_x results in a shift of the CO conversion curve toward lower reaction temperatures, compared to that obtained for Pt/Al₂O₃ or Pt/TiO₂, respectively. The specific reaction rate is in most cases higher for composite catalysts and varies in a manner which depends on the nature, loading, and primary crystallite size of dispersed MO_x. Results are explained by considering that reducibility of small oxide particles increases with decreasing crystallite size, thereby resulting in enhanced WGS activity. Therefore, evidence is provided that the metal oxide support is directly involved in the WGS reaction mechanism and determines to a significant extent the catalytic performance of supported noble metal catalysts. Results of catalytic performance tests obtained under realistic feed composition, consisting of 3% CO, 10% H₂O, 20% H₂ and 6% CO₂, showed that certain composite Pt/MO_x/Al₂O₃ and Pt/MO_x/TiO₂ catalysts are promising candidates for the development of active WGS catalysts suitable for fuel cell applications.     

C1 to acetyls: catalysis and process

Carbonylation of methanol and methyl acetate to acetic acid and acetic anhydride are the only current examples of C₁ processes displacing petrochemical routes for the manufacture of commodity chemicals. Modem carbonylation processes are based upon an iodide promoted, homogeneous rhodium catalyst operating under mild reaction conditions (150°C–200°C, 25–45 bar). This highly selective catalytic cycle is described, and contrasted with other catalytic metals. The embodiment of Rh/I catalysis in commercial BP Chemicals methanol and methyl acetate carbonylation processes is also described, illustrating the process simplicity arising from high selectivity.

The now extensive literature on attempts to support the rhodium catalyst in iodide promoted systems is reviewed. In the liquid phase, catalytic behaviour similar to that for the homogeneous system is claimed, although proper comparative data and conclusive evidence for catalyst immobilisation is generally lacking. A number of supported rhodium systems are reported to be active under vapour phase conditions, and activated carbon is also found to promote carbonylation activity of certain base metals, notably nickel. Issues affecting commercial viability include catalyst lifetime, gaseous by-product formation and efficiency of utilisation of precious metal components.

Literature on carbonylation in the absence of iodide promoter, and on direct routes to acetyls from synthesis gas or methanol only is also reviewed. All require step changes in catalytic performance in order to approach commercial viability.     

Copper-impregnated Al–Ce-pillared clay for selective catalytic reduction of NO by C3H6

The selective catalytic reduction (SCR) of NO by hydrocarbon is an efficient way to remove NO emission from lean-burn gasoline and diesel exhaust. In this paper, a thermally and hydrothermally stable Al–Ce-pillared clay (Al–Ce-PILC) was synthesized and then modified by SO₄²⁻, whose surface area and average pore diameter calcined at 773 K were 161 m²/g and 12.15 nm, respectively. Copper-impregnated Al–Ce-pillared clay catalyst (Cu/SO₄²⁻/Al–Ce-PILC) was applied for the SCR of NO by C₃H₆ in the presence of oxygen. The catalyst 2 wt% Cu/SO₄²⁻/Al–Ce-PILC showed good performance over a broad range of temperature, its maximum conversion of NO was 56% at 623 K and remained as high as 22% at 973 K. Furthermore, the presence of 10% water slightly decreased its activity, and this effect was reversible following the removal of water from the feed. Py-IR results showed SO₄²⁻ modification greatly enhanced the number and strength of Brönsted acidity on the surface of Cu/SO₄²⁻/Al–Ce-PILC, which played a vital role in the improvement of NO conversion. TPR and XPS results indicated that both Cu⁺ and isolated Cu²⁺ species existed on the optimal catalyst, mainly Cu⁺, as Cu content increased to 5 wt%, another species CuO aggregates which facilitated the combustion of C₃H₆ were formed.     

邻苯二甲酸C7／C10混合酯的开发与应用

介绍了邻苯二甲酸G／C10混合酯的性能、生产的主要技术路线与最佳的操作条件及有关进展情况：对工业化生产邻苯二甲酸C7／C10混合酯的工艺特点进行了分析和总结；阐述了国内外研究开发的现状与发展趋势；并探讨了扩大应用范围的前景与市场需求。