甲醇合成催化剂失活问题分析与处理

介绍了Shell粉煤气化制甲醇工艺中甲醇合成系统流程及生产运行情况。对合成塔催化剂运行情况进行了总结;就催化剂失活、更换频率过快问题进行了分析;并对合成回路系统进行了一系列改造:在现有合成塔上并联1台新的合成塔,分担现有合成塔一部分负荷,以降低现有合成塔催化剂生产强度,降低床层热负荷,增强催化剂抗中毒能力,延长催化剂寿命。结果表明:改造后,降低了经济运行成本,每年直接节省334万元,且确保了装置的长周期、高负荷稳定运行。     

提高现有甲醇装置生产能力的途径

通过对转化、合成工序的改造，提高甲醇装置的生产能力。改进转化催化剂外形，转化炉处理气量可以增加１０％。采用新型的脱毒催化剂，可以延长铜基催化剂的使用寿命；转化工序适量加入ＣＯ２，使合成气组分更接近甲醇合成的最佳配比。另外，还可以采用预转化工艺，降低一段炉负荷。改造转化炉、甲醇合成塔、改进合成回路等均可提高甲醇装置的能力。     

合成氨蒸发器运行问题分析

0 前言 兖矿鲁南化肥厂合成氨系统在2001年改造中，为进一步降低合成塔的阻力、提高合成塔的生产能力，对原两轴一径氨合成塔内件进行了更换。该冷激式氨合成塔新内件为一轴两径，并装填低温高活性A110-1型催化剂，新内件和催化剂对人塔气气体成分和系统稳定性要求比较严格。     

A110—5Q催化剂升温还原小结

兖矿鲁南化肥厂是我国首家引进美国德士古水煤浆加压气化技术的大型化工企业，其第二氮肥厂以水煤浆加压气化装置为龙头，主要生产合成氨、尿素、甲醇产品。该厂与水煤浆加压气化装置相配套的氨合成塔为φ1200mm轴径向复合式氨合成塔，年设计生产能力80kt合成氨。随着企业的不断挖潜改造，生产能力已达到年产合成氨100kt，本次系统大修进行了内件和催化剂的更换，现就该塔首次使用A110－5Q催化剂的情况作一小结。     

A110-4、A201-1催化剂在一轴二径氨合成塔中升温还原总结

兖矿鲁南化肥厂德士古水煤浆加压气化装置开车时,氨合成塔采用二轴一径合成塔.为了进一步降低合成塔阻力,提高生产能力,2001年11月更换了合成塔内件,更换为一轴二径形式,装填了山东环球股份有限公司制造的A110-4、A201-1型氨合成催化剂,并于2001年11月26日～12月2日成功地进行了催化剂的还原.     

甲醇合成塔压差增大的原因分析及技术改造应用

介绍了益达公司焦炉煤气制甲醇的工艺流程和甲醇合成塔的压差变化情况。针对甲醇合成塔进出口压差增大、总碳转化率明显下降的问题,从合成塔内部构造进行了分析,认为甲醇合成塔进出口压差增大主要由支撑瓷球间隙小、催化剂之间接触紧密、催化剂粉化严重等原因引起。在合成塔催化剂更换期间,通过改变合成塔支撑瓷球和合成催化剂的规格及合成催化剂的装填方法等,使合成塔压差降低至0.203 MPa、总碳转化率提高至98.15%。     

ICI-AMV工艺合成回路的生产运行与技改方案

某30万t/a合成氨装置采用ICI-AMV低压合成工艺,分析了该装置合成回路废锅换热能力不足、泄漏以及合成塔催化剂平面温差大、氨分离器液位漂移等问题的原因;提出了更换催化剂、调整床层盲区、改造废锅等项措施;针对系统中仍存在的问题提出了进一步技改方案.     

林达低压甲醇合成塔效果显著

哈尔滨气化厂采用杭州林达公司ＪＷ2 0 0 0低压均温型甲醇合成塔取得显著效果。该厂为煤气联产低压甲醇合成 ,原有甲醇装置从俄罗斯引进 ,甲醇合成塔是2 0 0 0冷激型 ,生产能力为 4万吨甲醇 /年 ,于 1 993年投产使用至今年 4月 ,触媒使用寿命 1～ 2年。1 999年哈尔滨气化厂经国家经贸委立项决定对该甲醇装置进行改造以提高生产能力 ,改造的关键技术采用杭州林达工业技术设计研究所的合成塔技术 ,并于 1 999年底签订了专利实施许可合同和合成塔订货合同。该项目要求在既不增加原合成塔装置动力设备 (单台压缩机、循环机 )和静止设备 ,又…     

C207型甲醇合成催化剂使用小结

我公司联醇装置设计生产能力为20kt／a，装置串联于铜洗前，合成塔为均温型1M甲醇塔，操作压力12．0～14．0MPa。采用南京化学工业公司生产的C207型甲醇催化剂，于2003年5月投入生产，2005年1月退出，更换新一炉催化剂。现将C207型催化剂在我公司甲醇合成塔上的使用情况作一简要小结。     

粗甲醇分离器内件改造对生产产生的影响

甲醇装置中粗甲醇分离器是一个关键设备,其内件结构对粗甲醇气液相分离效率有着决定性的影响,进而直接影响粗甲醇产品的产量、质量,以及甲醇合成催化剂的使用寿命和其他设备的运行情况。神华包头煤化工有限责任公司对合成工段粗甲醇分离器内件进行改造后,解决了粗甲醇分离器出口气相带液、循环气压缩机超负荷、膜分离单元无法满负荷运行等诸多问题,对生产系统各单元工况产生了积极的影响,有效提高了甲醇产品的产量和质量,降低了单位产品能耗,延长了设备和甲醇合成催化剂的使用寿命及装置的平稳运行周期,取得了显著的经济效益。     

Improved Design of the Lurgi Reactor for Methanol Synthesis Industry

Current studies are devoted to promote the production yield of the methanol synthesis process for treating large feed capacities in Algerian methanol manufacture industry by designing new reactor technologies. In order to achieve a high yield of methanol, the performance of methanol synthesis is improved by substituting the quench reactor by a new Lurgi reactor. The design of operating parameters of the Lurgi reactor involves the effect of CO₂ injection on methanol production yield and the catalyst deactivation. The simulation results demonstrate that under the same industrial operating conditions the conversion rate of reactants increases from 23 % in the quench reactor to 37 % in the Lurgi reactor and the methanol yield can be increased by 33 % when substituting the quench reactor by the Lurgi reactor     

Methanol synthesis in a novel axial-flow, spherical packed bed reactor in the presence of catalyst deactivation

Since in the foreseeable future liquid hydrocarbon fuels will play a significant role in the transportation sector, methanol might be used potentially as a cleaner and more reliable fuel than the petrochemical-based fuels in the future. Consequently, enhancement of methanol production technology attracts increasing attention and, therefore, several studies for developing new methanol synthesis reactors have been conducted worldwide. The purpose of this research is to reduce the pressure drop and recompression costs through the conventional single-stage methanol reactor. To reach this goal, a novel axial-flow spherical packed bed reactor (AF-SPBR) for methanol synthesis in the presence of catalyst deactivation is developed. In this configuration, the reactor is loaded with the same amount of catalyst in the conventional single-stage methanol reactor. The reactants are flowing axially through the reactor. The dynamic simulation of the spherical reactors has been studied in the presence of long-term catalyst deactivation for four reactor configurations and the results are compared with the achieved results of the conventional tubular packed bed reactor (CR). The results show that the three and four stages reactor setups can improve the methanol production rate by 4.4% and 7.7% for steady state condition. By utilizing the spherical reactors, some drawbacks of the conventional methanol synthesis reactors such as high pressure drop, would be solved. This research shows how this new configuration can be useful and beneficial in the methanol synthesis process.     

Dynamic Simulation and Optimization of a Dual‐Type Methanol Reactor Using Genetic Algorithms

In this investigation, a dynamic simulation and optimization for an auto‐thermal dual‐type methanol synthesis reactor was developed in the presence of catalyst deactivation. Theoretical investigation was performed in order to evaluate the performance, optimal operating conditions, and enhancement of methanol production in an auto‐thermal dual‐type methanol reactor. The proposed reactor model was used to simulate, optimize, and compare the performance of a dual‐type methanol reactor with a conventional methanol reactor. An auto‐thermal dual‐type methanol reactor is a shell‐and‐tube heat exchanger reactor in which the first reactor is cooled with cooling water and the second one is cooled with synthesis gas. The proposed model was validated against daily process data measured of a methanol plant recorded for a period of 4 years. Good agreement was achieved. The optimization was achieve by use of genetic algorithms in two steps and the results show there is a favorable profile of methanol production rate along the dual‐type reactor relative to the conventional‐type reactor. Initially, the optimal ratio of reactor lengths and temperature profiles along the reactor were obtained. Then, the approach was followed to get an optimal temperature profile at three periods of operation to maximize production rate. These optimization approaches increased by 4.7 % and 5.8 % additional yield, respectively, throughout 4 years, as catalyst lifetime. Therefore, the performance of the methanol reactor system improves using optimized dual‐type methanol reactor.     

聚乙烯醇交联改性聚乙烯锂离子电池隔膜的制备

将聚乙烯(PE)隔膜用乙醇润湿,然后将其放入聚乙烯醇(PVA)溶液中浸润,使PVA进入隔膜孔结构中,再将隔膜放入交联溶液[pH=2,25%(w)戊二醛]中进行交联反应,制备了PVA交联改性PE隔膜。采用傅里叶变换红外光谱和能量色散X射线光谱对隔膜的表面与断面进行了表征,并研究了改性隔膜的物理性能及电池性能。结果表明:PVA交联改性PE隔膜的表面亲水性和抗高温热收缩性提高,瞬时水接触角由初始的98.6°降至66.5°,且组装的锂离子电池的循环性能和倍率容量均有一定程度的改善,PE隔膜的离子电导率由0.463 mS/cm升至0.864 mS/cm。     

由合成气生产二甲醚过程反应协同作用的研究

Influence of reaction temperature, pressure and space velocity on the direct synthesis of dimethyl ether (DME) from syngas is studied in an isothermal fixed-bed reactor. The catalyst is a physical mixture of C30 copper-based methanol (MeOH) synthesis catalyst and ZSM-5 dehydration catalyst. The experimental results show that the chemical synergy between methanol synthesis reaction and methanol dehydration reaction is evident. The conversion of carbon monoxide is over 90%.     

Dynamic simulation of a cascade fluidized-bed membrane reactor in the presence of long-term catalyst deactivation for methanol synthesis

In this work, a dynamic model for a cascade fluidized-bed hydrogen permselective membrane methanol reactor (CFBMMR) has been developed in the presence of long-term catalyst deactivation. In the first catalyst bed, the synthesis gas is partly converted to methanol in a water-cooled reactor, which is a fluidized-bed. In the second bed, which is a membrane assisted fluidized-bed reactor, the reaction heat is used to preheat the feed gas to the first bed. This reactor configuration solves some observed drawbacks of new conventional dual type methanol reactor (CDMR) and even fluidized-bed membrane dual type methanol reactor (FBMDMR) such as pressure drop, internal mass transfer limitations, radial gradient of concentration and temperature in both reactors. A dynamic two-phase theory in bubbling regime of fluidization is used to model and simulate the proposed reactor. The proposed model has been used to compare the performance of a cascade fluidized-bed membrane methanol reactor with fluidized-bed membrane dual-type methanol reactor and conventional dual-type methanol reactor. The simulation results show a considerable enhancement in the methanol production due to the favorable profile of temperature and activity along the CFBMMR relative to FBMDMR and CDMR systems.     

JW型甲醇合成塔运行总结

介绍了JW型甲醇合成塔的结构以及JW3000均温型甲醇合成塔的实际应用情况。实践证明,JW型甲醇合成塔具有催化剂床层阻力小、气体分布均匀、操作方便、调节灵活、对气质要求比较低、催化剂装卸方便等优点。大型JW型甲醇合成塔的推广,对提高我国甲醇合成技术的装备能力是具有非常现实的意义的.     

Low-temperature methanol synthesis in a circulating slurry bubble reactor

A circulating slurry bubble reactor was developed to synthesise methanol via methyl formate from the gas mixture of carbon monoxide and hydrogen at low temperature. The strategy for designing and scaling up the bubble reactor involved a preliminary understanding of fluid dynamics in a cold model, continuous operations under industrial conditions and a parallel experiment in an autoclave. Per-pass syngas conversion was investigated during 100-h operations. The axial profile of solid catalyst concentration was measured just before the shutdown and the composition of liquid product was analysed after the shutdown. These results show that the circulating slurry bubble column will become a potential reactor for the commercial process of low-temperature methanol synthesis after the catalyst system has been improved.     

A comparison of auto-thermal and conventional methanol synthesis reactor in the presence of catalyst deactivation

This study proposed a one-dimensional dynamic plug flow model to analyze and compare the performance of an auto-thermal and a conversional methanol synthesis reactor in the presence of catalyst deactivation. An auto-thermal two-stage industrial methanol reactor type is a system with two catalyst beds instead of one single catalyst bed. In the first catalyst bed, the synthesis gas is partly converted to methanol in a water-cooled reactor. In the second bed which is a gas-cooled reactor, the reaction heat is used to preheat the feed gas to the first bed. To analyze the effect of important control variables on the rector performance, steady state and dynamic simulations are utilized to investigate effect of operating parameters on the performance of reactors. The simulation results show that there is a favorable profile of temperature along the two-stage auto-thermal reactor type in comparison with conventional single stage reactor type. In this way the catalysts are exposed to less extreme temperatures and, catalyst deactivation via sintering is reduced. Overall, this study resulted in beneficial information about the performance of the reactor over catalyst life-time.     

Comparison of two-phase and three-phase methanol synthesis processes

A comparison is made between the ICI (two-phase) methanol synthesis process and a three-phase slurry process based on a multi-stage agitated reactor. The process calculations are based on a complete reactor system consisting of the reactor itself, a recycling system and a gas-liquid separator. The basic kinetic and thermodynamic data were taken from previous studies carried out in our laboratory. The results show that both reactor systems produce comparable methanol yields under the same process conditions except for the reactor temperature. Carbon conversion to methanol values close to 100% can be achieved. The three-phase process is more efficient in terms of heat recovery and power consumption. This is primarily caused by the fact that the three-phase process generates high-pressure steam and the ICI two-phase process yields boiler feed water of 90°C. Furthermore, the pressure drop in the three-phase reactor is smaller than in the two-phase reactor, resulting in a smaller duty of the recycle compressor. However, for the present low energy prices, the annual financial savings, coupled with these energetic aspects, are not sufficient to compensate for the higher capital investment of the three-phase reactor system relative to the ICI two-phase reactor system. A relatively high natural gas price of US $4.1 per gigajoule is needed to reach the economical break-even point between the two processes. More active catalysts may be developed in the near future. Our results show that a relative increase in the catalyst activity by a factor of 1.5 or more (for both processes) will make the three-phase process of economic interest at a natural gas price of US $2.5 per gigajoule.