乙二醇装置草酸二甲酯加氢系统催化剂运行性能及产品品质影响因素分析

河南龙宇煤化工有限公司2×200 kt/a煤制乙二醇装置采用河南能源化工集团拥有自主知识产权的“羰基化、加氢两步间接合成法”生产工艺及Cu/SiO₂加氢催化剂，加氢催化剂使用寿命较短，催化剂运行性能(含使用寿命)又进一步影响乙二醇产品的品质。基于草酸二甲酯加氢反应机理与反应条件及加氢反应系统工艺流程，分析与探讨加氢催化剂装填高度、草酸二甲酯进料纯度、加氢反应器列管直径、氢酯比、草酸二甲酯进料浓度、加氢反应器入口温度、草酸二甲酯中水含量、加氢压力、草酸二甲酯中碳酸二甲酯含量、加氢催化剂床层压差等对草酸二甲酯加氢催化剂运行性能及乙二醇产品品质的影响，提出提高原料氢气及循环氢气的纯度、控制好氢酯比、选择合适的加氢反应器汽包温度和进料温度、严格控制进料浓度/水含量、降低草酸二甲酯进料中杂质含量等操作优化措施，以提升催化剂的运行性能、有效延长催化剂的使用寿命。     

1,4-丁二醇低压加氢催化剂国产化及其工业应用

Reppe法ISP工艺是国内较为普遍使用的1,4-丁二醇生产工艺,但低压加氢催化剂长期依赖于进口,价格高、交货期长及付款方式严苛。对1,4-丁二醇低压加氢催化剂国产化开发过程进行了介绍,包括催化剂生产、物性指标分析和工业装置应用等方面。通过6个月的工业生产装置100%负荷运行数据及70%负荷运行数据可以看出,使用国产催化剂,反应器出口产品物料符合生产要求;国产催化剂平均单耗与进口剂一致。根据催化剂运行时沉降槽遗留物料催化剂含量对比,国产剂在沉降性能方面略微优于进口剂。因此,国产催化剂完全能够满足实际生产要求,成为进口催化剂的有效替代。     

乙炔前加氢催化剂在乙烯装置上的应用及评价

介绍了Kataleuna催化剂公司开发的KL7741B－T型乙炔前加氢催化荆在大庆石化公司乙烯新区装置上的应用情况。该催化剂在2010年8月再次应用于大庆石化公司乙烯新区装置，在投用后的半年时间内，一度出现催化剂活性下降的情况。通过调整前加氢反应器各段入口温度以及进料中CO、丁二烯、硫、砷杂质的含量，该催化剂活性下降的趋势得到有效控制，乙炔前加氢反应器的运行逐步趋于稳定。     

重整加氢反应器压降升高的原因及措施

针对重整生成油C6组分加氢脱烯烃反应器压降上升过快,影响装置长周期运行的难题,分析了主要的原因。通过采取改造反应物料加热器、选用新型选择性加氢催化剂HDO-18、控制原料中烯烃含量等措施,消除了反应器压降高的主要因素,延长了装置的开工周期。     

浆态床蒽醌加氢反应器模拟

基于浆态床二维轴对称流体力学模型,结合蒽醌加氢反应动力学、物质输送与扩散方程和热量传递模型,构建了浆态床蒽醌加氢反应器数学模型,获得了浆态床内气液固三相流场分布、组分浓度分布、温度分布及停留时间分布等关键信息。模拟结果表明：浆态床内物料呈现中心向上而壁面向下的循环流动特征,流体返混强烈,液体的返混状态接近于全混流,气体返混状态近似为两级等体积全混流;反应物浓度或催化剂含量表现为底部高而顶部低的分布规律,浆态床底部的反应更为强烈,气液传质特性对于蒽醌加氢反应有较大影响;受进料影响,温度分布为底部低而顶部略高,通过夹套换热,全塔温差控制在5 K以内。反应器模型的模拟结果与工业数据符合较好,可应用于工业装置的设计及优化。     

环戊二烯选择加氢制环戊烯

用Pd催化剂在固定床反应器中进行了环戊二烯选择加氢制备环戊烯研究;确定了第一段加氢催化剂采用Pd含量为0．5（wt）％载体为γ-Al2O3催化剂,第二段加氢催化剂为钯含量为0．3（wt）％载体为γ-Al2O3催化剂。第一段氢烃摩尔比为2—3,反应压力为1．2MPa,空速2～4h～,温度55—60℃,第二段氢烃摩尔比为3．5～4,温度80～85℃时,环戊二烯的转化率达99．5％,环戊烯的选择性在90％以上。     

渣油加氢装置杂质沉积规律与压降升高机理分析

反应器压降升高是影响固定床渣油加氢装置长周期运行的重要因素。选取三套加工不同典型原料的工业渣油加氢装置，分析不同位置不同种类运转后催化剂的杂质沉积和孔结构变化情况，采用扫描电子显微镜-二维元素分析方法对结块催化剂杂质沉积分布进行原位表征，获得渣油加氢装置杂质沉积规律。结合装置原料性质和运行工况，对反应器压降升高机理进行分析。结果表明，长周期运行过程中，前部反应器催化剂大量沉积金属杂质，积炭严重，催化剂孔结构发生显著变化；同时，在催化剂颗粒间隙沉积大量焦炭或含铁垢物，造成床层堵塞。Ni、V主要沉积在催化剂颗粒内部，Fe、Ca则沉积在催化剂颗粒之间或附着在催化剂外表面，结块催化剂颗粒间隙填堵大量焦炭。反应器压降升高遵循两种不同的机理或路径。原料Fe、Ca含量较低时，反应器下部脱金属催化剂因沉积金属Ni、V而失活，进而在催化剂颗粒之间形成大量积炭，导致床层板结、压降上升；原料Fe、Ca含量高时，Fe、Ca在床层上部保护剂颗粒间大量沉积，导致反应器堵塞，压降升高。在严格控制进料Fe、Ca含量的同时，还应针对性优化催化剂及其级配设计，延长运转周期。     

Pd/C催化剂粉碎的原因和对策

Pd/C粉碎的主要原因是:进入反应器浆料浓度过高,反应器的进料温度下降梯度过大,反应器卸压过快,催化剂表面复盖层过重等。采取的对策有:加氢反应进料的配制浓度应控制在反应温度下TA饱和浓度的85%以下;定期检查切水阀,及时切水冲洗,反应器压力控制阀高限位(最大开度为45%),注意返料质量,对催化系统进行碱洗、水洗等。     

煤制乙二醇加氢催化剂压差问题的探讨与分析

针对在草酸二甲酯加氢反应过程中催化剂床层压差持续上涨、氢气循环量不足造成装置被迫减负荷的问题,从工艺理论和设备上进行深入分析和讨论,逐步采取提升草酸二甲酯进料品质、改善进料方式、反应器入口增加过滤装置、反应器排列方式改变等一系列措施,最终成功地解决了草酸二甲酯加氢催化剂床层压差上涨的难题,为装置长周期满负荷运行创造了良...     

糠醛气相加氢制2—甲基呋喃催化剂初步研究

得到了糠醛气相加氢制 2 -甲基呋喃催化剂的最佳沉淀法制备条件 :沉淀温度 10 0℃ ;Cr、Cu质量比 0 .6 2 ;Ba的质量含量 0 .6 % ;Ca的质量含量 2 .7% ;沉淀溶液 pH值为 6。对催化剂失活原因进行了分析 ,认为失活是由于活性组分铜的重结晶造成的     

加氢操作反应机理及装置功能特性

通过反应物传质模型论述了加氢反应装置的反应机理;分析了反应阻力与其影响因素之间的关系;介绍了搅拌槽型加氢反应装置的结构形式和操作过程;以混合型加氢反应器和自吸式搅拌槽为例,论述了加氢反应器的性能特征、主要功能和技术管理要点。     

碳三液-气两相高负荷加氢工艺在乙烯装置中的应用

针对扬子石化公司乙烯工艺碳三液相加氢装置中催化剂性能较差、系统加氢负荷较低的问题,采用北京化工研究院研制的MAPD新型催化剂并对原工艺进行了改进,设计出碳三液-气两相高负荷加氢工艺。改进后的碳三液-气两相加氢反应器入口MA(丙炔)、PD(丙二烯)摩尔分数可从1.94%提高到3.0%,入口压力降低了0.2 MPa,加氢产品的循环量约减少了50%。     

Computer-aided electrochemical process design: simulation and economic analysis of an electrocatalytic soybean oil hydrogenation plant

The process flowsheet for a soybean oil electrohydrogenation plant has been devised and heat and mass balance calculations on unit operations equipment were performed using a commercially available process simulation software package (PRO/II from Simulation Sciences, Inc.). The design and anticipated performance (current efficiency and power requirements) of the electrochemical flow cells were based on a laboratory-scale radial-flow-through Raney nickel powder electrocatalytic hydrogenation reactor. A semiempirical porous electrode model, that reproduced laboratory-scale reactor data, was incorporated into the PRO/II software as a unit operations subroutine module. Operation of a 3.0×106kgy–1 electrochemical plant was simulated on a computer for different soybean oil/electrolyte feeds and reactor current densities. Based on the PRO/II results, an economic analysis of the process, including capital, installation and operating costs of all equipment was carried out. The lowest total production cost for a brush hydrogenation oil product (20% reduction in the number of double bonds) was obtained at a current density of 15mAcm–2 and a feed composition of 10wt:vol% soybean oil in solvent/supporting electrolyte (US0.13kg–1 for an assumed five year straight line depreciation of capital equipment). This cost was higher than that for a comparable-size chemical catalytic soybean oil hydrogenation plant (US0.019kg–1). When the cost of the soybean oil starting material (US0.68kg–1) was factored into the economic analysis, the production plus raw material cost of the electrocatalytic process was only 16% greater than that for the chemical catalytic plant. The production cost for the electrosynthesized hydro-oil product may be tolerable because the oil has a high nutritional value (a lower trans isomers content) which may command a higher selling price.     

1,4-丁二醇生产工艺条件对正丁醇含量的影响

利用小型加氢评价装置,通过在Raney-Ni催化剂上对丁炔二醇加氢反应过程中的物料浓度、pH值、反应压力、温度、搅拌速度等工艺条件的调整,考察了各工艺条件对丁炔二醇加氢效果及正丁醇产生的影响。     

Production of Low Acid Value Edible Oil with Reduced TFAs by Electrochemical Hydrogenation in a Diaphragm Reactor

A new diaphragm electrochemical system was devised and tested for hydrogenation of soybean oil under moderate processing temperature and atmospheric pressure. With proper loading of the catalyst Pd-C, the reactor was operated successfully for 6 h and yielded hydrogenated soybean oil containing 8.62% TFAs with an IV of 88.86 g I₂/100 g oil and an AV of 0.7 mg KOH/g oil. The low AV (acid value) of the hydrogenated oil, indicative of the oxidization tendency of the oil, is highly desirable from the industrial application standpoint. The low specific isomerization index was reached with 0.4 mol/L of formate ions at pH 5.0 under 60 °C using a constant applied current density (10 mA/cm²)_. The extent of hydrogenation was found to increase with increasing current density, formate ion concentration, reaction temperature, catalyst loading, and speed of agitation. It was characterized that the extent of hydrogenation under low pH (2.0–5.0) was controlled by the regeneration of formate ion, whereas under high pH (6.0–10.0) the hydrogenation was influenced strongly by the formate ion stability.     

Pd/C催化加氢法制备DSD酸

用水作反应介质,Pd/C为催化剂,研究了液相催化加氢法还原4,4′ 二硝基二苯乙烯 2,2′ 二磺酸(DNS)制备4,4′ 二氨基二苯乙烯 2,2′ 二磺酸(DSD酸)。通过一系列条件实验,确定的最佳工艺条件是:原料DNS10g,质量浓度为180g/L;Pd/C催化剂0 8g;助催化剂OVN80mg;反应体系pH=6;反应温度65℃;压力0 8MPa。在此工艺条件下,制得产品的质量分数大于99%,产品收率可达95%。     

600 kt·a-1乙烯装置碳二加氢系统运行状况及工艺改进

中国石油天然气股份有限公司大庆石化公司新建600 kt·a^-1乙烯装置碳二加氢单元首次开工时采用德国南方化学公司开发的OLEMAX 252催化剂,催化剂在低温充压过程中多次发生飞温现象,运行过程中对CO非常敏感,经常伴随热点出现,控制不好会引发连锁停车,为碳二加氢单元的平稳运行带来巨大困难。针对上述情况,通过改进反应器热电偶排布及结构、充压流程、稳定裂解炉操作和优化反应器进料等一系列措施成功消除了异常现象,使碳二加氢单元的运行趋于平稳。     

石油化工与催化 C4馏分加氢催化剂的应用

为了提高C₄馏分的利用价值并实现扩大乙烯裂解料的来源,使用自制的镍系加氢催化剂和钴-钼-镍系加氢精制催化剂,在固定床200 mL绝热评价装置上对C₄馏分液化石油气物料进行全加氢实验,论证镍系加氢催化剂适用于含有低碳含硫化合物C₄馏分的可行性,对模拟的某化工厂C₄馏分原料进行加氢饱和性能考察,对含有高浓度双烯烃和炔烃的丁二烯抽提装置尾气进行原料模拟和全加氢评价。结果表明,自制催化剂适用于含有低碳硫化物的C₄馏分全加氢,可以处理高含双烯烃的C₄物料,并具有良好的低温活性。     

Current efficiency for soybean oil hydrogenation in a solid polymer electrolyte reactor

Soybean oil has been hydrogenated electrocatalytically in a solid polymer electrolyte (SPE) reactor, similar to that in H2/O2 fuel cells, with water as the anode feed and source of hydrogen. The key component of the reactor was a membrane electrode assembly (MEA), composed of a precious metal-black cathode, a RuO2 powder anode, and a Nafion® 117 cation-exchange membrane. The SPE reactor was operated in a batch recycle mode at 60°C and one atmosphere pressure using a commercial-grade soybean oil as the cathode feed. Various factors that might affect the oil hydrogenation current efficiency were investigated, including the type of cathode catalyst, catalyst loading, the cathode catalyst binder loading, current density, and reactant flow rate. The current efficiency ordering of different cathode catalysts was found to be Pd>Pt>Rh>Ru>Ir. Oil hydrogenation current efficiencies with a Pd-black cathode decreased with increasing current density and ranged from about 70% at 0.050Acm–2 to 25% at 0.490Acm–2. Current pulsing for frequencies in the range of 0.25–60Hz had no effect on current efficiencies. The optimum cathode catalyst loading for both Pd and Pt was 2.0mgcm–2. Soybean oil hydrogenation current efficiencies were unaffected by Nafion® and PTFE cathode catalyst binders, as long as the total binder content was 30wt% (based on the dry catalyst weight). When the oil feed flow rate was increased from 80to 300mlmin–1, the oil hydrogenation current efficiency at 0.100Acm–2 increased from 60% to 70%. A high (70%) current efficiency was achieved at 80mlmin–1 by inserting a nickel screen turbulence promoter into the oil stream.