N-乙烯基吡咯烷酮的合成研究进展

N-乙烯基吡咯烷酮(NVP)是一种重要的精细化工产品。简要叙述NVP的国内外市场情况,分析了乙炔法、催化脱水法及吡咯烷酮法等NVP合成技术,对比分析反应历程、催化剂种类、产品的选择性及原料的转化率,提出了国内研究发展的建议。     

N—羟乙基吡咯烷酮催化脱水合成N—乙烯基吡咯烷酮的催化剂开发及应用研究

筛选出了以ZrO2-SnO2为基体的复合催化剂,确定了催化剂的配方及生产工艺,经小试和单管模试验以后,在800t/aN-乙烯基吡咯烷酮（简称NVP）生产装置上,以70％N－羟乙基吡咯烷酮（简称NHP）水溶液为原料,在340－350℃,液相空速1．0－1．4h^-1（kg/kg）条件下,取得了良好结果。     

ZSM-5分子筛催化γ-丁内酯气相胺解反应

采用金属盐溶液浸渍的方法对NaZSM-5分子筛进行改性,考察了ZSM-5分子筛对γ-丁内酯与乙醇胺之间气相反应合成N-羟乙基吡咯烷酮(NHP)的催化性能。研究表明ZSM-5分子筛是目标反应潜在的活性催化剂,其中CuZSM-5具有较高的催化活性,NHP收率达到30%以上。考察了原料组成、接触时间、反应温度、催化剂焙烧温度及颗粒大小等对反应的影响,确定了合适的反应条件为:n(乙醇胺)∶n(γ-丁内酯)=3~4,[p(乙醇胺)+p(γ-丁内酯)]∶p(N2)=1,接触时间25~32g.h/mol,反应温度250~270℃,催化剂粒径100~120目。     

Pt/HPW/ZrO_2催化甘油脱氧制取1,3-丙二醇

以磷钨杂多酸为钨前驱体用浸渍法制备系列具有不同Pt含量和不同HPW/ZrO2焙烧温度的Pt/HPW/ZrO2催化剂。通过BET比表面积、红外光谱和X线衍射方法表征催化剂的结构,在连续流动固定床反应器中考察其对甘油水溶液催化脱氧制取1,3-丙二醇(1,3-PDO)反应催化性能的影响。结果表明:ZrO2负载磷钨杂多酸经500℃以上温度处理,磷钨杂多酸分解为相应的氧化物,单斜相WO3和磷氧化物分散在ZrO2表面。Pt/HPW/ZrO2催化剂对甘油脱氧反应具有较高的催化活性。铂负载量、HPW/ZrO2焙烧温度、反应温度、压力及甘油浓度等因素的变化,对甘油转化率和1,3-PDO收率的影响较大。在4 MPa、130℃、液体体积空速(LHSV)为0.25 h-1的反应条件下,2.0%Pt/HPWZ10(700)催化剂上60%甘油水溶液催化脱氧反应可得到53.4%甘油转化率和44.5%的1,3-PDO选择性,产物中1,3-PDO与1,2-丙二醇(1,2-PDO)摩尔比值达到14.3。100 h稳定性实验表明催化剂性能稳定。     

三乙烯二胺的合成研究

对以哌嗪为原料的两步法合成三乙烯二胺的反应进行了研究。先用环氧乙烷与哌嗪合成粗N-羟乙基哌嗪(未经分离的N-羟乙基哌嗪和N,N-二羟乙基哌嗪的混合物),然后直接在固定床反应器上合成三乙烯二胺。催化剂的选择是反应的关键。筛选制备了一系列的催化剂,并对催化剂的催化性能进行了研究,发现含Ba~(2+)的SrHPO_4催化剂的催化效果最佳,反应的总收率在85％以上。     

SO_4~(2-)/Al_2O_3型固体超强酸固定床合成N-羟乙基吡咯烷酮的研究

采用在固定床工艺以SO~(2-)_4/Al_2O_3型固体超强酸为催化剂在加热条件下催化γ-丁内酯和乙醇胺脱水合成N-羟乙基吡咯烷酮(NHP)。通过正交试验对影响反应的各因素进行了分析,结果表明:反应温度为280℃、γ-丁内酯与乙醇胺的物质的量比为1:1.3、进料速度为0.3m L/min时产品NHP的反应效果最佳,转化率为78.3%、选择性45.6%。该合成方法反应步骤少,催化剂效率高,可连续反应,具有一定的优势。     

2-乙烯基吡啶的合成研究

研究了以2-羟乙基吡啶为原料,经脱水反应合成2-乙烯基吡啶的实验方法。探讨了反应过程中催化剂、反应温度、反应时间等影响因素,得出了适宜的反应条件:在固体氢氧化钾催化下,n(氢氧化钾)∶n(2-羟乙基吡啶)=0.2∶1,反应时间1~1.5 h,反应温度100℃,收率达到85%以上,产品纯度大于98%。反应过程催化剂采用循环套用的方法,减少了原料消耗,降低了生产成本,具有较强额实际生产意义。     

Y型分子筛催化γ-丁内酯气相胺解反应的催化性能

研究了经金属硝酸盐浸渍改性的Y型分子筛对γ-丁内酯与乙醇胺气相反应合成N-羟乙基吡咯烷酮(NHP)反应的催化性能,结果表明,分子筛的催化性能主要随改性阳离子的变化而不同。其中,CuY具有最高的初始活性,γ-丁内酯转化率达到50%以上,而经Cu离子改性的含稀土Y型分子筛具有较高的催化活性与稳定性。进一步考察了焙烧温度、反应温度、催化剂粒径等对催化剂性能的影响。再生实验表明,反应过程中分子筛的失活是不可再生的,说明是由于反应过程中生成的水蒸汽使分子筛的结构遭到破坏,而含稀土的分子筛由于含有稀土而使其具有较高的水热稳定性。     

WO3/ZrO2固体酸催化果糖制备5-羟甲基糠醛的工艺研究

通过偏钨酸铵水溶液浸渍氢氧化锆制备了WO3/ZrO2固体酸催化剂,并考察其在果糖脱水制备5-羟甲基糠醛过程中的催化性能。考察了WO3负载量、催化剂用量、反应时间、反应温度、果糖添加量对HMF产率的影响。实验结果表明:WO3负载量为30%,以二甲基亚砜(DMSO)为溶剂,120℃下反应2h时,催化剂表现出较高的反应活性,相应HMF收率为65.4%。该催化剂循环使用5次,HMF收率仍能保持62.1%。     

杂多酸及其盐催化D-果糖选择性合成5-羟甲基糠醛

考察了杂多酸及其盐对果糖脱水制备HMF的催化性能。研究表明,磷钨酸铯盐催化效果较好,高温反应对5-羟甲基糠醛(HMF)生成有利,添加助剂聚乙烯吡咯烷酮(PVP)可提高产率。通过对反应温度、催化剂、加料方式的考察,得出优化的反应条件为:将果糖溶于DMSO中,添加质量分数20%的PVP,升温至155℃加入占果糖摩尔分数1%的CsH2PW12O40,反应5 min,产率77.9%。     

REOx掺杂的ZrO2催化剂催化羟乙基吡咯烷酮脱水反应性能

Catalyst plays an important role in the dehydration of N-（hydroxylethyl）pyrrolidone （NHP） to prepare N-vinyl-pyrrolidone （NVP）. At present, NVP yield is only about 30% on commercial ZrO2 catalyst. A coupled precipitation and solid dispersion technique was designed to prepare the nano-ZrO2 catalyst, in which rare earth metal oxides （REOx） was used as electronic promoter. The results indicated that the catalyst doped REOx （S-1.0） exhibits the optimum performance of NHP dehydration at moderate conditions. NHP conversion and NVP selectivity are respectively 97.0%, 82.3%. Of special interest is that the indexes of the catalyst （S-1.0-1.0） are up to 98.4% and 89.2% respectively. Furthermore, this catalyst bears the good stability. It means that nano-ZrO2 doped REOx catalyst might be a potential commercial catalyst for the NHP dehydration.     

Investigation of N-(Hydroxylethyl)pyrrolidone Dehydration over REO_x-doped Nano-ZrO_2 Catalyst

1 INTRODUCTION Poly-N-vinyl-pyrrolidone (PVP) is a non-ionic water-soluble chemical, which is widely used in many industrial fields such as pharmaceutical, cosmetic, foodstuff, electronics, printing, paper-making, deter- gent and adhesive etc.[1]. Traditional acetylene process is dangerous because of using acetylene under high temperature and pressure[2] Nowadays, it is usually produced by polymerization of N-vinyl-pyrrolidone (NVP), which is produced by cata- lytic dehydration of N-(h…     

MaSibLacCed多元氧化物催化NHP脱水反应合成NVP

合成了一系列组成为M_aSi_bLa_cCe_d（M代表碱金属，a=0～1，b=0～50，c=0～1，d=0～1）的多元氧化物催化剂，在常压条件下评价了其对N-羟乙基吡咯烷酮（NHP）脱水反应活性的影响。研究发现，M_aSi_bLa_cCe_d对目标反应的活性随组成而变化，含有稀土的多元氧化物活性较高，双稀土具有相互促进的协同效果。以K₁Si₅₀La_0.1Ce_0.1为催化剂，探讨了反应温度和NHP分压等主要因素对反应的影响，重点研究了低压与N₂稀释至常压反应两种方法的效果。结果显示，采用N2稀释至常压反应的方法在技术上更具优势。     

高选择性合成1-甲氧基-2-丙醇固体催化剂的筛选和催化作用

对碱土金属氧化物和两性氧化物等10种氧化物作为合成1 甲氧基 2 丙醇固体催化剂进行了催化性能筛选。发现在碱土金属氧化物MgO、CaO和BaO中,中强碱MgO具有较高的环氧丙烷(PO)转化率(71 07%)和1 甲氧基 2 丙醇(PPM)选择性(92 53%)。在两性氧化物中,ZnO具有较高的PO转化率(55 26%)和PPM选择性(92 37%)。系统考察了反应温度、催化剂用量、反应时间和原料摩尔配比对MgO、ZnO的催化作用特点的影响,发现MgO在催化性能和1 甲氧基 2 丙醇选择性方面表现出的综合性能优于其他催化剂。     

Catalytic oxidation of saturated hydrocarbons on multicomponent Au/Al2O3 catalysts: Effect of various promoters

The performance of unpromoted and MO_x-(M: alkali (earth), transition metal and cerium) promoted Au/Al₂O₃ catalysts have been studied for combustion of the saturated hydrocarbons methane and propane. As expected, higher temperatures are required to oxidize CH₄ (above 400 °C), compared with C₃H₈ (above 250 °C). The addition of various MO_x to Au/Al₂O₃ improves the catalytic activity in both methane and propane oxidation. For methane oxidation, the most efficient promoters to enhance the catalytic performance of Au/Al₂O₃ are FeO_x and MnO_x. For C₃H₈ oxidation a direct relationship is found between the catalytic performance and the average size of the gold particles in the presence of alkali (earth) metal oxides. The effect of the gold particle size becomes less important for additives of the type of transition metal oxides and ceria. The results suggest that the role of the alkali (earth) metal oxides is related to the stabilization of the gold nanoparticles, whereas transition metal oxide and ceria additives may be involved in oxygen activation.     

氧化铝载体改性及其应用研究进展

氧化铝不仅价格低廉、易获取,且具有多孔性、大比表面积、高分散性、高热稳定性等优点,常用作催化剂载体,广泛应用于工业催化领域。氧化铝的孔结构对工业催化剂性能影响很大。为优化氧化铝载体的性能,对氧化铝的扩孔和添加助剂改性已进行了大量研究。扩孔改性可降低扩散阻力并改善传质、提高活性位点的有效利用率、增强抗结焦性能,进而提高加氢催化的产率;添加助剂改性可有效抑制氧化铝载体高温烧结和相变,防止孔结构被破坏,提高催化剂的寿命。本工作介绍了制备氧化铝的方法?拟薄水铝石脱水法和溶胶?凝胶法,综述了氧化铝的扩孔方法,总结了改性氧化铝载体的最新研究进展,包括自组装法、水热处理法、扩孔剂法;阐述了氧化铝添加助剂的改性方法,包括加入稀土金属氧化物、碱(土)金属氧化物、其它金属氧化物及非金属氧化物。最后,展望了氧化铝未来的研究和发展方向。     

废聚苯乙烯催化热裂解制苯乙烯的研究

研究了碱土金属氧化物和过渡金属氧化物对废聚苯乙烯（PS）热裂解的催化效果;考察了催化剂碱性对裂解结果的影响。开发了一种以CaO为主体、MgO和NaOH为助剂的混合催化剂。结果表明：混合催化剂对废PS裂解具有良好的催化性能。实验同时考察了废PS催化裂解温度对混合催化剂活性以及催化裂解产物组成的影响。     

在非等温条件下石膏和硼石膏的加热脱水动力学研究

Thermal dehydration of gypsum and borogypsum was investigated under nonisothermal conditions in air by using simultaneous thermogravimetric-differential thermal analyzer. Nonisothermal experiments were carried out at various linear heating rates. Kinetics of dehydration in the temperature range of 373-503 K were evaluated from the DTA (differential thermal analysis)-TGA (thermogravimetric analysis) data by means of Coats-Redfern,Kissinger and Doyle Equations. Values of the activation energy and the pre-exponential factor of the dehydration were calculated. The results of thermal experiments and kinetic parameters indicated that borogypsum is similar to gypsum from dehydration mechanism point of view although it consists of boron and small amount of alkali metal oxides.     

Structural and chemical promoter effects of alkali (earth) and cerium oxides in CO oxidation on supported gold

Nanostructured Au/Al₂O₃ catalysts prepared by deposition–precipitation with urea were characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) and tested for low temperature CO oxidation. The paper is focused on the effect of two different kinds of additives on the structure and reactivity of Au/Al₂O₃ for CO oxidation: (1) alkali (earth) metal oxides and (2) ceria. The structural properties of nanosized Au particles are drastically affected by the presence of additives. The main role of the alkali (earth) metal oxides is to stabilize the small Au particles against sintering, such that when BaO is added to Au/Al₂O₃, full CO conversion is already achieved at room temperature. For this reaction ceria addition does not result in a higher activity. However, when both BaO and CeO_x are added to Au/Al₂O₃, the catalytic performance of the multicomponent catalyst resembles that of Au/BaO/Al₂O₃.     

Cobalt and iron oxide modified mesoporous zirconia: Preparation, characterization and catalytic behaviour in methanol conversion

Mesoporous zirconia materials with different textural characteristics and degrees of crystallinity were obtained by various procedures and modified with cobalt and iron oxide nanoparticles. The obtained materials were characterized by N₂-physisorption, XRD, TEM, FTIR, Mössbauer spectroscopy, TPR-TG and methanol conversion as a catalytic test. Formation of finely dispersed iron and cobalt oxide species, hosted in the zirconia matrix, was observed after the modification. The obtained composites possess higher catalytic activity and different in comparison with the corresponding zirconia supports dehydration and dehydrogenation ability. It was demonstrated that the variations in the textural and surface features of zirconia support and the deposition of different metal oxides on it provided a great opportunity for the preparation of catalysts with tunable bi-functional acidic and redox properties.