大孔磺酸树脂催化FCC汽油烷基化脱硫降烯烃性能的研究

针对大孔磺酸树脂催化FCC汽油组分烷基化脱硫和降烯烃的问题,研究了FCC汽油内部关键组分之间的反应规律。结果表明,NKC-9、D005-Ⅱ、Amberlyst 35和Amberlyst 36 4种大孔磺酸树脂中Amberlyst 36的催化效果最好,最佳反应温度是90℃。在Amberlyst 36催化下,与含硫化合物反应时,烯烃的活性顺序是:异戊烯2,3-二甲基-2-丁烯2,3-二甲基-1-丁烯2-戊烯1-戊烯1-己烯。含硫化合物中硫醇反应活性最高,3-甲基噻吩反应活性大于噻吩。Amberlyst 36催化下,异戊烯、2,3-二甲基-2-丁烯和2-戊烯可以与异戊烷发生烷基化反应,降烯烃效果明显。而1-戊烯、2,3-二甲基-1-丁烯和1-己烯主要是发生自身异构化反应。     

大孔磺酸树脂催化噻吩类硫化物烷基化反应

考察了NKC-9,CT-175,D005-II和LSI-600四种不同磺酸树脂在噻吩类硫化物和烯烃烷基化反应中的催化性能.结果表明,NKC-9有优于其它树脂的烷基化催化性能,其合适的反应条件为常压、90 ℃和料剂体积比15∶1.在此条件下,硫的转化率高于92.32%,NKC-9对FCC汽油中硫醇向高沸点产物转化也有很好的催化作用.考察了NKC-9的选择性和稳定性,发现它适合催化噻吩类硫化物与C4和C5烯烃的烷基化反应,稳定性好.     

FCC汽油中的噻吩类硫化物烷基化硫转移反应脱硫

以模型硫化物噻吩与异戊烯的烷基化反应为探针，研究了反应温度、反应压力以及原料中二烯烃杂质对三氯化铝固载改性的磺酸树脂催化剂AlCl3 CT175烷基化性能的影响. 结果表明，在反应温度为100~110℃、反应压力低于3.0 MPa条件下，原料中的二烯烃明显影响催化剂的活性稳定性，这与二烯烃在催化剂表面发生聚合反应结焦有关. 当反应压力高于3.0 MPa时，AlCl3 CT175催化剂催化模型硫化物噻吩与异戊烯的烷基化反应不仅具有很高的活性，噻吩硫化物均接近于完全转化，而且具有较理想的活性稳定性. 以噻吩的甲基取代衍生物相对集中的FCC汽油60~150℃馏分段为原料，在110℃, 3.0 MPa，质量空速2.33 h 1的反应条件下，考察了该馏分段中的噻吩类硫化物与烯烃在AlCl3 CT175催化剂上烷基化反应硫转移脱硫效果，结果表明占总硫98.27%的硫化物参与了烷基化硫转移反应，且该馏分段中的二烯烃含量也得到有效的降低.     

FCC汽油预处理对烷基化硫转移反应过程的影响

为保证流化催化裂化(FCC)汽油烷基化硫转移反应催化剂的稳定性,采用蒸馏水或盐酸作为萃取剂、D101树脂或NKC-9大孔干氢树脂作为吸附剂,考察了FCC汽油原料中碱性氮去除的预处理过程,并比较了预处理过程对FCC汽油硫形态及其含量的影响、烷基化硫转移效果的影响。结果表明,盐酸萃取、NKC-9树脂吸附,能够快速有效的除去FCC汽油中的碱性氮化物,而且NKC-9树脂能够吸附微量的硫化物。脱除碱性氮化物后的FCC汽油进行烷基化反应,几个主要的噻吩硫化物的硫转移率都能达到90%以上。     

FCC汽油烷基化脱硫研究

分别采用大孔磺酸树脂NKC-9及FCC汽油烷基化催化剂SW—I对FCC汽油进行静态及动态烷基化脱硫研究。结果表明,SW—I烷基化脱硫操作条件更为缓和,其催化活性及寿命均优于NKC-9树脂。在反应温度60℃、反应时间60 min和剂油质量比1:100的条件下,SW—I烷基化脱硫汽油硫含量降至181.7μg·g~(-1),脱硫率63.49%,收率85.30%。SW—I对不同硫含量的FCC汽油均具有一定的脱硫效果,脱硫适应性较强。通过对汽油烷基化反应前后硫化物的分布分析发现,烷基化反应使FCC汽油中的大部分噻吩类化合物反应生成沸点更高的产物,通过蒸馏分离将其除去,达到脱硫目的。     

FCC汽油噻吩烷基化脱硫催化剂研究进展

在简要介绍烷基化脱硫原理基础上,综述了近年来对FCC汽油中噻吩和烷基噻吩等小分子噻吩类硫化合物烷基化反应催化剂的研究进展,着重从分子筛、负载型杂多酸及固体磷酸、离子液体和离子交换树脂等方面来介绍催化裂化汽油烷基化脱硫催化剂的研究应用,最后对汽油烷基化脱硫催化剂的研究重点进行了展望。     

HY分子筛催化噻吩类硫化物的烷基化反应动力学

以HY分子筛为催化剂,考察流化催化裂化(FCC)汽油中的噻吩类硫化物的烷基化反应性能,并对反应动力学进行研究。结果表明:在反应温度433 K,反应时间1 h时烷基化硫转移率(低于393 K的馏分)达到90%以上,反应温度在403～433 K,FCC汽油中的噻吩类硫化物烷基化反应动力学方程符合一级反应速率方程,其活化能为44.70 kJ/mol,指前因子为6.47×105h-1。     

硫化物在纳米HZSM-5催化剂上催化转化性能及机理研究

研究了催化裂化（FCC）汽油中硫化物类型和含量，特别考察了各种硫化物在纳米HZSM-5催化剂上的催化转化性能，并探讨了硫化物的加氢脱硫转化机理。结果表明FCC汽油中硫化物主要为硫醇、噻吩、烷基取代噻吩和苯并噻吩等，其中，烷基取代噻吩占总硫化物的65％-73％。在纳米HZSM-5催化剂作用下，FCC汽油的硫化物都较易被脱除。烷基取代噻吩脱硫机理一方面含有直接加氢脱硫反应路线，另一方面含有裂解反应、烷基化反应和异构化反应路线。     

硫化物在OTA催化剂上催化转化性能

考察了催化裂化(FCC)汽油中硫化物和模型硫化物在OTA(Olefin To Aromatics)催化剂上的催化转化性能.结果表明FCC汽油硫化物总脱硫率为86.3 %,其中,硫醚和四氢噻吩的转化率都达到100 %,硫醇硫转化率96.6 %,噻吩硫转化率78.8 %,烷基噻吩转化率85.8 %,苯并噻吩转化率81.4 %.3-甲基噻吩在OTA催化剂上的转化产物中含有小分子(噻吩),异构硫化物(2-甲基噻吩),以及大分子异构硫化物(如2,5-二甲基噻吩、2,4-二甲基噻吩和2,3-二甲基噻吩).烷基噻吩和苯并噻吩硫化物在OTA催化剂上脱硫反应网络一方面含有直接加氢脱硫反应,另一方面经历歧化、异构化和裂解等反应.     

FCC汽油加氢脱硫反应过程及其催化剂研究进展

综述了国内外有关FCC汽油中硫的存在形态、HDS反应原理及其催化剂的研究进展.一般认为,FCC汽油中的硫化物形态主要为噻吩类化合物,且主要集中在重馏分中,汽油的HDS反应原理的研究也都集中在噻吩的加氢脱硫反应上.传统的HDS催化剂由于烯烃饱和率过高不适于FCC汽油的HDS,可通过改变催化剂的酸性来调整其HDS/HYD选...     

Gasoline alkylation desulfurization over Amberlyst 35 resin: Influence of methanol and apparent reaction kinetics

Gasoline desulfurization is receiving attention worldwide due to the increasing stringent regulations on sulfur content for environmental protection purpose. As conventional hydrotreating technology leads to significant octane number loss and processing costs, the gasoline alkylation desulfurization process, which consists of weighing down the sulfuric compounds by catalytic alkylation with olefins present in the feed and distillation followed by, is a rather attractive way. In this paper, firstly alkylation of thiophenic compounds was researched over macroporous sulfonic resin Amberlyst 35 in methanol presence to increase the selectivity of catalyst, then kinetics of thiophenic sulfurs alkylation in FCC gasoline was researched without and with methanol. Results found that appropriate methanol (?2 wt.% methanol in model gasoline and ?1 wt.% methanol in FCC gasoline) could inhibit olefins oligomerization significantly without influence on the conversions of thiophenic compounds. The alkylation of thiophenic sulfurs could be described as pseudo first order reaction regardless of the existence of methanol. The introduction of methanol decreases the reaction rate constant and increases the activation energy of alkylation reactions.     

Comparative study of IPTBE synthesis on HZSM-5 and ion-exchange resin catalysts

The title ether was synthesized using a batch reactor at 70–90°C and 1.6 MPa. The ion-exchange resins Amberlyst 15, Amberlyst 35 and Purolite CT275, and HZSM-5 zeolites with a SiO₂/Al₂O₃ ratio between 28 and 120 were used as catalysts. IPTBE synthesis rapidly reaches chemical equilibrium in the presence of resins with selectivities of 95–97%, diisobutene being the main byproduct. HZSM-5 zeolites are less active and selective than resin catalysts. Resins, especially Amberlyst 35, are suitable catalysts for obtaining IPTBE industrially.     

Amberlyst15催化7-羟基-4-甲基香豆素的无溶剂合成

研究了在无溶剂条件下,Amberlyst15催化间苯二酚和乙酰乙酸乙酯合成7-羟基-4-甲基香豆素,较系统地考察了反应温度、反应时间、催化剂用量、原料配比对反应产率的影响,得到最优反应条件：反应时间160min,反应温度110℃,催化剂用量0．5g,间苯二酚与乙酰乙酸乙酯的物质的量比为1：1。上述条件下,7-羟基-4-甲基香豆素的产率达到65．16％。     

The performance of solid phosphoric acid catalysts and macroporous sulfonic resins on gasoline alkylation desulfurization

Sulfur removal has received increasing attention in recent years primarily for environmental protection purpose. As an attractive technology in the case of gasoline, OATS (olefinic alkylation of thiophenic sulfur) proposed to separate sulfur compounds by distillation after being weighed down by alkylation with olefins in the feed. In this paper, alkylation reactions of thiophenic compounds were studied over solid phosphoric acid catalysts (SPAM and SPAS using MCM-41 and Silicalite-1 zeolite as supporters respectively) and macroporous sulfonic resins (including NKC-9, D005-2 and Amberlyst 35) with model gasoline and FCC (fluid catalytic cracking) gasoline. Results showed that macroporous sulfonic resins showed better performance than solid phosphoric acid catalysts under milder conditions in both feeds. Among the resins, Amberlyst 35 was the most suitable catalyst for the application of catalytic distillation for its good performance at the temperature range of 353-413 K in FCC gasoline. However, the selectivity of isoamylene dimerization over Amberlyst 35 decreased with the temperature, which was harmful to the product yield and catalyst stability. Besides, different activity orders of solid phosphoric acid catalysts in model gasoline and FCC gasoline were explained by combining the acidic properties of the catalysts with the species of olefins in two feeds.     

Dynamic analysis of adsorption equilibrium and rate parameters of reactants and products in MTBE,ETBE and TAME production

Adsorption equilibrium constants of ethanol, methanol, isobutylene, isoamylenes (2M2B, 2M1B), MTBE and TAME on Amberlyst 15 catalyst were evaluated from the packed bed moment technique. Adsorption equilibrium constants of alcohols were found to be two orders of magnitude greater than the adsorption equilibrium constants of i-olefins and the corresponding tertiary ethers. However, their apparent heat of adsorption values are quite low (-6,7 kJ/mol and ?8.3 kJ/mol for methanol and ethanol, respectively). Among the i-olefins, isobutylene gave the highest adsorption equilibrium constant and the heat of adsorption (-54.2 kJ/mol The adsorption equilibrium constant of 2M2B on a catalyst, which was pretreated with ethanol, was about three times greater than the corresponding value obtained on fresh catalyst. Second moment analysis indicated that diffusion resistance in both macropores and microspheres of the catalyst are equally significant.     

Production of 4-Hydroxybutyl Acrylate and Its Reaction Kinetics over Amberlyst 15 Catalyst

Esterification of acrylic acid (AA) with 1,4-butanediol (BD) was carried out over a solid acid catalyst to produce 4-hydroxybutyl acrylate (HBA), an environmentally benign coating agent. The Amberlyst 15 catalyst was more active for the reaction than other ion exchanged resin catalysts such as Amberlyst 35 and DOWEX HCR-S(E). The quasi-homogeneous model was chosen to express the esterification reaction kinetics over Amberlyst 15. The stirring speed was changed from 300 rpm to 750 rpm and the reaction rate showed no influence of external mass transfer. The reaction temperature was varied from 100°C to 120°C to calculate activation energies of the reactions. The calculated activation energies were 58.3 kJ/mol and 86.7 kJ/mol for HBA and BDA (1,4-butanediol diacrylate, by-product) productions, respectively. The catalyst concentration was also changed from 0.0043 g/ml to 0.0171 g/ml to find its effect on the rate constant. The complete kinetic equation of esterification to produce HBA over the Amberlyst 15 catalyst based on the quasi-homogeneous model was developed.     

Water effect on the kinetics of 1-pentanol dehydration to di-n-pentyl ether (DNPE) on amberlyst 70

Experiments performed at 433 K and 453 K with 1-pentanol/water and 1-pentanol/DNPE (di-n-pentyl ether) clearly states the inhibiting effect of water released in the liquid-phase dehydration of 1-pentanol to DNPE on ion-exchange resin. The inhibiting effect of water was described by an empirical correction factor in the Eley–Rideal rate model deduced in a previous work. Best results were obtained with a factor including a Freundlich-like adsorption isotherm expression. The activation energy of dehydration reaction lowers slightly on splitting off the water effect, and it is 114.0 ± 0.1 kJ/mol.     

Catalytic and kinetic study of methanol dehydration to dimethyl ether

Dimethyl ether (DME), as a solution to environmental pollution and diminishing energy supplies, can be synthesized more efficiently, compared to conventional methods, using a catalytic distillation column for methanol dehydration to DME over an active and selective catalyst. In this work, using an autoclave batch reactor, a variety of commercial catalysts are investigated to find a proper catalyst for this reaction at moderate temperature and pressure (110–135 °C and 900 kPa). Among the γ-alumina, zeolites (HY, HZSM-5 and HM) and ion exchange resins (Amberlyst 15, Amberlyst 35, Amberlyst 36 and Amberlyst 70), Amberlysts 35 and 36 demonstrate good activity for the studied reaction at the desired temperature and pressure. Then, the kinetics of the reaction over Amberlyst 35 is determined. The experimental data are described well by Langmuir–Hinshelwood kinetic expression, for which the surface reaction is the rate determining step. The calculated apparent activation energy for this study is 98 kJ/mol.     

Determination of Cadmium(II) in Water and Soil Samples after Preconcentration with a New Solid Phase Extractor

Abstract

A new simple and reliable method has been developed to separate and preconcentrate trace cadmium ion from water and soil samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). Cadmium ions adsorbed quantitatively on Amberlyst 36 cation exchange resin were eluted with a 5 mL of 3 mol/L hydrochloric acid solution. Different factors and matrix effects for the preconcentration step were examined. The analytical figures of merit for the determination of cadmium are as follows: analytical detection limit, 0.51 µg/L; precision (RSD), 2.9%; enrichment factor, 200; capacity of resin 192 mg/g. The method was applied for cadmium determination in tap water, natural drinking water, soil, and roadside dust samples. The accuracy of the method is confirmed by analyzing standard reference material (Montana Soil, SRM 2711).     

Kinetic study of ethyl octyl ether formation from ethanol and 1‐octanol on Amberlyst 70

An option to introduce bioethanol to diesel, improving at the same time its fuel quality, is by adding ethyl octyl ether (EOE). It can be obtained successfully by the dehydration reaction between ethanol and 1‐octanol over acidic ion‐exchange resins. In the present work, the kinetic study of EOE synthesis on Amberlyst 70 in the liquid phase is performed in a 20‐cm³ fixed‐bed reactor and in a 100‐cm³ batch reactor at 423–463 K and 2.5 MPa. EOE synthesis takes place together with diethyl ether (DEE) formation as main side reaction. A mechanistic kinetic model in terms of component activities is proposed for EOE synthesis (E_a=105 ± 4 kJ/mol) and for DEE formation (E_a =100 ± 5 kJ/mol). Reaction rates were highly inhibited by the adsorption of the formed water on Amberlyst 70. The inhibitor effect of water is well represented as a competitive adsorption with alcohols reactants on the catalysts surface. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2918–2928, 2014