甲醇制芳烃反应的研究进展

简单介绍了甲醇制芳烃(MTA)目前所面临的困难,以及MTA反应所适用的催化剂ZSM-5及其优势。指出以HZSM-5做催化剂时,MTA反应的最优化反应条件,并综述了国内外目前对于ZSM-5催化剂的几种改性方法。并提出适用MTA的催化剂的开发方向。     

Application of Minihydrocyclones in Methanol‐to‐Olefin Process Wastewater Treatment

A significant amount of wastewater containing fine catalyst particles is produced in the methanol‐to‐olefin (MTO) process, which restricts the long‐period operation of the processing unit. To address this key problem, a minihydrocyclone was designed for MTO wastewater treatment and tested in the laboratory. Good separation performance and a small cut diameter were achieved under certain feed conditions. Furthermore, a group composed of 300 parallel‐arranged minihydrocyclones was applied to the industrial unit in the MTO quench water treatment. The obtained results indicated that the separation efficiency and precision of the minihydrocyclone can meet the requirements of fine catalyst particle separation, and the designed minihydrocyclone group with reasonable parallel configuration exerted an outstanding application effect on the treatment of MTO quench water.     

压力对芳烃抽提装置产品质量的影响及对策

简要介绍了压力对芳烃抽提装置溶剂回收塔和苯塔的产品质量的影响及消除压力的影响,保证产品质量所采取的相应措施。     

甲醇制烯烃技术研究进展

综述了甲醇制烯烃常用催化剂ZSM-5和SAPO-34分子筛的开发,阐述了影响ZSM-5和SAPO-34分子筛催化性能的重要因素以及对分子筛改性的方法。并对甲醇制烯烃和甲醇制丙烯的工艺开发和工业放大进展进行了介绍。     

甲醇制烯烃催化剂积炭的形成机理

采用二氯甲烷超声波萃取,提取甲醇制烯烃(MTO)待生催化剂和不完全再生催化剂外表面可溶性积炭,采用氢氟酸溶解及碳酸钠溶液中和后再用二氯甲烷超声波萃取,提取待生催化剂和不完全再生催化剂孔道内可溶性积炭,结合气相色谱-质谱(GC-MS)分析了其组成,并对MTO催化剂积炭形成的机理和再生烧炭的机理进行了分析探讨。结果表明:MTO待生催化剂外表面可溶性积炭主要是饱和烃和芳烃,其中饱和烃以C23~C31的正构烷烃为主,芳烃以一环和二环芳烃为主;孔道内可溶性积炭均为芳烃,以三环和四环芳烃为主,从质谱峰强度计算约占总量的80%,菲和芘约占总量的50%。MTO不完全再生催化剂外表面可溶性积炭主要是沸点较高的C23~C31正构烷烃;孔道内可溶性积炭主要是几个高含量组分如芘和菲等的残留。在催化剂外表面的饱和烃可能是由小分子烯烃类化合物经过一系列聚合而成,而催化剂外表面的一环和二环芳烃应该是从分子筛孔道内形成并溢出,在分子筛孔道口吸附。分子筛催化剂孔道内的多环芳烃,是由小分子烃类化合物经过一系列低聚、氢转移、环化和脱氢等反应生成。     

Deoxygenation of Methanol over ZSM‐5 in a High‐Pressure Catalytic Pyroprobe

Deoxygenation is a critical step in making hydrocarbon‐rich biofuels from biomass constituents. Although the thermal effects of oxygenate aromatization have been widely reported, the effect of pressure on this critical reaction has not yet been closely investigated, one primary reason being the unavailability of a reactor that can pyrolyze oxygenates, especially those in solid form, under pressurized conditions. Here, the first of a series of studies on how oxygenates behave when catalytically pyrolyzed under elevated pressure and temperature conditions is reported. Methanol, the simplest alcohol, was selected as the candidate to study the chemical phenomena that occur under pressurized catalytic pyrolysis. The reactions were carried out over the shape‐selective catalyst ZSM‐5 (SiO₂/Al₂O₃ = 30) under varying pressure (0 to 2.0684 MPa (300 psi) in 0.3447 MPa (50 psi) increments) and temperature (500 to 800 °C in 50 °C increments) conditions. Benzene, toluene, ethyl benzene, and xylenes (BTEX) were analyzed as the deoxygenated products of the reaction. The results indicate that the reactor pressure significantly affects deoxygenated product composition.     

Treating Methanol‐to‐Olefin Quench Water by Minihydrocyclone Clarification and Steam Stripper Purification

In the chemical industry, methanol‐to‐olefin (MTO) technology is a novel process for producing ethylene and propylene from naphtha thermal cracking. The process of recovering MTO quench water by minihydrocyclone and steam stripping treatment was successfully applied in industrial plants. The fine catalyst in the quench water is removed by the two‐stage minihydrocyclone separation. The method and equipment for this system present various advantages: the quench water can be recycled in the cooling system and prevents heat loss in heat transfer systems; and the stripping tower can be blocked by the catalyst. Maintenance activities are reduced and a stable operation cycle is extended. The proposed treatment process improves the economic efficiency of the MTO device.     

减少烯烃分离装置开工损失的措施

介绍了目前国内煤制烯烃项目投产情况,叙述了烯烃分离装置典型工艺流程和技术特点;分析了烯烃分离装置在开工过程中的物料损失原因;提出了减少烯烃分离装置开工损失的措施;分析了压缩机组在开工过程中非计划停车的常见原因及相应对策。     

甲醇制烯烃催化剂研究进展

综述了甲醇制烯烃催化剂的研究进展,从晶体结构、改性方法、催化性能等方面分析了两种重要的甲醇制烯烃催化剂ZSM-5和SAPO-34;并介绍了由上述分子筛开发出的ZSM-5/磷酸铝复合分子筛。     

Effect of Phosphate Modification on the Brønsted Acidity and Methanol‐to‐Olefin Conversion Activity of Zeolite ZSM‐5

Phosphate‐modified ZSM‐5 zeolites were studied by standard characterization techniques and solid‐state nuclear magnetic resonance spectroscopy, and in the methanol‐to‐olefin (MTO) conversion. Considering the physicochemical properties of the ZSM‐5 zeolites, the most important effects of the phosphate modification are a deposition of polyphosphates in the pore system and a decrease of the acid site density, but not of the acid site strength. The significant increase in the selectivity to C₂ – C₄ alkenes and the decrease of C₅₊ formation in the MTO reaction for a phosphate coverage of about 5 wt % are explained by extra‐framework phosphate species near the crossing intersections of the ZSM‐5 pore system, which hinder the formation of large intermediates and reaction products.     

低烯烃汽油生产中降烯烃催化剂和MGD工艺的应用

为适应清洁汽油的要求、降低汽油烯烃含量,锦州石化公司先后将3种降烯烃催化剂和MGD工艺在重油催化裂化装置上成功地进行了工业应用,使稳定汽油中的烯烃含量由初始标定的61％左右达到40％以下,接近35％的指标。     

甲醇制丙烯工艺冷凝液处理的改进

甲醇制丙烯工艺冷凝液中的含铁量和含油量,会因工艺换热器的渗漏而超标,致使传统的除油除铁设施频繁出现故障,为此,经过对工艺冷凝液除油除铁系统的工艺改进,有效地解决了传统除油除铁设施存在的不足,满足了后续冷凝液精制单元稳定、长周期运行的需求。     

不同硅铝比HZSM-5分子筛的甲醇制芳烃性能

采用固定床反应器,以甲醇为原料,在反应温度为430℃和反应空速为2 h-1的条件下,考察了不同硅铝比HZSM-5分子筛催化剂的甲醇制芳烃反应(MTA)性能,并采用X射线衍射(XRD)、氨气程序升温脱附(NH3-TPD)、物理吸附、傅立叶红外光谱(FT-IR)等技术对催化剂进行了表征。结果表明:MTA反应是强酸主导的催化反应,随着分子筛硅铝比的降低,分子筛总酸量逐渐增加,强酸相对总量逐渐提高,其中弱酸相对总量降低。这主要是由于分子筛中Al含量逐渐上升,作为强酸位的Si-OH-Al逐渐增加所致,催化剂反应活性与之呈正向相关的关系。当HZSM-5催化剂中的强弱酸总量比由0.3增加到0.6时,苯-甲苯-二甲苯(BTX)的选择性由36%增至64%,说明催化剂的活性显著提高;当强弱酸总量比由1.1增至1.5时,BTX选择性变化仅为0.92%,催化性能提升不明显,HZSM-5分子筛的MTA反应性能与其硅铝比呈反向相关关系。     

微孔-双介孔核壳型HZSM-5@BMMs催化甲醇芳构化

采用外延法,以HZSM-5为核,双介孔分子筛BMMs为壳制备了多级孔核壳型HZSM-5@BMMs甲醇芳构化(MTA)催化剂。采用XRD、BET、NH3-TPD、SEM和TEM对催化剂进行了表征。结果表明:HZSM-5@BMMs具有明显的核壳结构和微孔-双介孔多级孔孔道,孔径集中分布于0.9、2.2和5.3 nm,其比表面积(510.8 m2/g)和孔容(0.399 cm3/g)均高于HZSM-5的比表面积(408.4 m2/g)和孔容(0.190 cm3/g),而酸量(0.573 mmol/g)和酸强度均低于HZSM-5的酸量(0.883 mmol/g)和酸强度。相同反应条件下HZSM-5@BMMs寿命比HZSM-5增加38 h,最高芳烃收率为25.7%,最高BTX(轻质芳烃:苯、甲苯、二甲苯)选择性为55.3%。     

神华宁煤甲醇制丙烯装置产物分布探讨

考察了甲醇制丙烯催化剂第一周期运行情况,研究了反应产物选择性以及丙烯收率随时间的变化趋势,探讨了其产物变化规律。随着反应时间的延长,催化剂活性位逐渐被积炭覆盖,导致酸性位数降低,从而使丙烯收率逐渐升高,气相中丙烷选择性降低,LPG收率也逐渐降低,其他副产品变化不是很明显。     

Control of acid-site location of ZSM-5 zeolite membrane and its application to the MTO reaction

ZSM-5 zeolite membrane, which shows high selectivity toward olefins in the methanol conversion, was developed by controlling the location of the acid sites. First, the ZSM-5 zeolite catalyst membrane without pinholes was successfully prepared by synthesizing a ZSM-5 zeolite layer on an outer surface of a cylindrical alumina ceramic filter. The membrane was used as the catalytic membrane reactor to recover olefins from methanol. Though the olefins were successfully produced from methanol with high selectivity (ca. 80%), production of paraffin and aromatics was observed at the feed side of the zeolite membrane. To prevent the such production, the location of the acid site of the ZSM-5 zeolite membrane was controlled by a new method called the catalytic cracking of silane (CCS) method. Selective deactivation of acid sites at the outer surface of the zeolite membrane (feed side of reactant) by the CCS method allowed us to increase the selectivity of the olefins by 10% as compared to the untreated membrane.     

油水分离技术在甲醇制烯烃装置的应用

甲醇制烯烃工艺在生成轻烯烃产品的同时副产大量的水,同时有少量油类物质产生,这部分油类物质和水一起冷凝,不仅影响净化水的COD指标,在水系统中凝固还会导致系统换热器、空冷器堵塞,效率下降,影响装置长周期运行。本文介绍了油水分离技术在甲醇制烯烃装置的应用情况。     

催化裂化轻汽油醚化工艺中试研究

针对催化裂化汽油烯烃含量高、汽油安定性差的问题,采用催化轻汽油醚化工艺技术,在2 L/h的醚化中试装置上,进行了催化轻汽油醚化工艺研究。研究结果表明:经该工艺技术处理后,可使催化裂化汽油烯烃含量降低8.03～11.68个百分点,RON辛烷值增加0.8～1.2个单位。     

我国发展煤制烯烃产业的必要性和可行性探讨

随着现代煤化工技术的发展,以煤为原料替代石油制取低碳烯烃的工艺在技术上已趋于成熟,在国际石油价格居高不下的背景下在经济上日益显示出明显的竞争力。这一新兴产业有望成为石油化工的重要补充,建议国家对煤制烯烃工艺的产业化发展予以重视和支持。     

Synthesis of modified catalyst and stabilization of CuO/NH4‐ZSM‐5 for conversion of methanol to gasoline

In this article, the catalytic conversion of methanol to gasoline range hydrocarbons has been studied over CuO/ NH₄‐ZSM‐5(3,5,7,9%) catalysts prepared via sono‐chemistry methods. In order to improve, copper oxide can be used as a booster on NH₄‐ZSM‐5 this catalyst property. Accordingly, the conversion process of Methanol to Gasoline (MTG) was conducted under a pressure of 1 atm and temperature of 400°C by a fixed‐bed reactor on copper oxide catalysts which were prepared based on synthetic NH₄‐ZSM‐5. The synthetic catalyst was investigated by such analyses as BET, XRD, FT‐IR, and SEM. Formation of copper oxide phase and proper distribution of copper oxide were proven on the basic level of using XRD analysis. BET analysis showed the reduction in catalyst level and SEM images depicted the proper distribution of particles. The present investigation is to study the effect of CuO loading on NH4‐ZSM‐5 support for conversion of methanol to gasoline range hydrocarbons. A series of CuO/ NH4‐ZSM‐5 catalysts were prepared, characterized, and experimented for their performance on methanol conversion and hydrocarbon yield.