一种由山梨醇制异山梨醇的连续化制备装置

<正>本实用新型公开了一种由山梨醇制异山梨醇的连续化制备装置。该连续化装置包括:原料预混装置(1)、一级脱水反应器(2)、中间脱水装置(3)、二级脱水反应器(4)、中和脱酸反应器(5)、精(提)馏塔(6)、异山梨醇冷凝器(7)、脱盐及杂质装置(8)、设备间连接管线及控制仪表和各种附件;所用的制备过程为山梨     

催化干气制乙苯装置工业操作方案优化与应用

介绍了干气制乙苯装置两台烃化反应器并联运行的可行性、操作方案及运行数据。大庆炼化公司干气制乙苯装置两个阶段的烃化反应器并联的实践证明：无论是采用调和汽油生产方案,还是乙苯生产方案,烃化反应器的并联,解决了在不开干气压缩机条件下束缚装置提高干气进料量的瓶颈,有效提高了原料干气中的乙烯转化率、以及产品产量,且不影响产品质量;同时,还可以有效降低反应器压降,为催化干气制乙苯装置工业操作方案优化及节能降耗提供参考和借鉴。     

乙烯齐聚的连续化反应研究

在四元催化体系间歇釜式反应的基础上 ,本文对乙烯齐聚的连续化反应进行了系统研究 ,设计并安装了一套连续化反应装置 ,包括预反应器、反应器和闪蒸后处理装置。在连续化反应装置上 ,分别考察了催化剂进料速度、反应压力和催化剂浓度对乙烯齐聚连续化反应的影响 ,同时获得了连续化反应的最佳反应条件。经过研究发现 ,该四元催化体系的间歇釜式反应的最佳反应条件 ,也同时是连续化反应的最佳反应条件 ,齐聚反应的催化活性、C=4 -10 的选择性、1-C=4 -10 的线性选择性及产物分布等基本相同。实验证明 ,该连续化反应工艺流程可行 ,可作为未来工业化的模型装置。     

天津河清化学工业有限公司

<正>连续化是化工生产的必经之路河清化学致力于提高各种合成工业的核心竞争力,已成功为国内四百多套生产装置进行了全流程连续化自动化改造,产品生产成本降幅显著,污染物大幅降低,生产过程本质安全。连续化特殊反应器技术,不同类型的反应体系采用最适宜的反应器各种不同的反应体系对传热传质要求均不同,连续化生产过程中,河清化学研究了数百种不同类型反应器以适应各种反应体系,彻底颠覆了传统生产过程用反应釜完成各种类型反应的方式,有效提高转化率及选择性。物耗降幅明显。     

重氮化、偶合新装置(连载之二)

2.连续化偶合装置(1)具有立式园筒反应器的连续偶合装置赫斯特公司发明的具有立式园筒偶合反应器的连续化偶合装置,可制得质量优良的偶氮染料、颜料。偶合组份由反应器底部成垂直层状流动进入,重氮液通过反应器壁上几个入口加入。反应终点用电位测定法自动控制。装置见图9。装置工作说明:把带有搅拌器的容器1中的偶合组份悬浮液,用泵2连续输送到带有夹套的立式园筒偶     

乙烯齐聚的连续化反应研究

在四元催化体系间歇釜式反应的基础上,本文对乙烯齐聚的连续化反应进行了系统研究,设计并安装了一套连续化反应装置,包括预反应器,反应器和闪蒸后处理装置。在连续化反应装置上,分别考察了催化剂进料速度,反应压力和催化剂浓度对然齐聚连续化反应的影响,同时获得了连续化反应的最佳反应条件。经过研究发现,该四元催化剂体系的间歇釜式反应的最佳反应条件,也同时是连续化反应的最佳反应条件,齐聚反应的催化活性,Ｃ的选择性     

连续均相反应器内的逆向混和与逗留时间分布

一、基本概念反应器操作的连续化带来了许多好处,如产品质量均匀、便于自动化及机械化、可以提高劳动生产率、改善劳动条件、减少操作上的危除性等等;但是在强化生产这一点上,连续化只是提供强化的可能性,连续化本身并不就是强化。如果不采取其他措施,连续化反而可能降低反应器的生产能力及产率。这是因为连续反应器中发生了逆向混和的关系。     

扬子公司研发成功PTA分离新技术

<正>日前,扬子石化公司化工厂PTA装置精制单元压力过滤机已连续运行超过100天,标志着该厂PTA工艺精制分离技术达到了世界一流水平。国内外大型PTA装置,绝大部分装置在精制单元都采用了两级分离技术,第一级为压力离心机分离,第     

焦炉煤气低温换热式甲烷化反应器性能研究

基于焦炉煤气低温换热式甲烷化工艺进行试验,考察了其核心装置低温换热式甲烷化反应器在甲烷化过程中的运行情况。试验结果表明,该反应器在升温过程中控温精确;在连续1 000 h运行过程中,装置运行平稳,反应器出口气组成稳定,其中出口气中CO_2转化率大于98.0%,CO转化率大于99.8%,能够一步完成焦炉煤气甲烷化反应。同时,该反应器可在负荷为1 650~1 900 m~3/h下稳定运行。     

生物柴油连续化生产设备及工艺进展

“碳中和”目标提出后，各行各业都在寻求减少碳排放的方法，生物质能源的使用是实现碳中和目标的重要手段之一。生物柴油以其优良的燃烧性能及环保性能成为一种较为理想的生物质燃料，其生产工艺是近年研究热点。连续化生产工艺对生物柴油的规模化制备与推广有着重要意义。目前连续化制备生物柴油的反应装置主要有微反应器、固定床反应器、管式反应器、膜反应器。本文综述了近年来国内外采用连续化工艺制备生物柴油的研究进展。这些研究表明，通过优化反应器结构、使用助溶剂、提高催化剂活性等均可提高生物柴油的收率。最后本文还分析了各反应器存在的不足，并提出了相应的建议，对生物柴油连续化生产进行了展望，以期为低成本、低能耗的生物柴油生产提供参考。     

A novel particle/monolithic two-stage catalyst bed reactor and their catalytic performance for oxidative coupling of methane

A novel two-stage catalyst bed reactor was constructed comprising of the 5%Na₂WO₄-2%Mn/SiO₂ particle catalyst and the 5%Na₃PO₄-2%Mn/SiO₂/cordierite monolithic catalyst. The reaction performance of the oxidative coupling of methane (OCM) in the two-stage bed reactor system was evaluated. The effects of the bed height and operation mode, as well as the reaction parameters such as reaction temperature, CH₄/O₂ ratio and flowrate of feed gas on the catalytic performance were investigated. The results indicated that the two-stage bed reactor system exhibited a good performance for the OCM reaction when the feed gases were firstly passed through the particle catalyst bed and then to the monolithic catalyst bed. The CH₄ conversion of 32.6% and C₂ selectivity of 67.5% could be obtained with a particle catalyst bed height of 10 mm and a monolithic catalyst bed height of 50 mm in the two-stage bed reactor. Both of the CH₄ conversion and C₂ selectivity have been increased by 4.8% and 2.5%, respectively, as compared with the 5%Na₂WO₄-2%Mn/SiO₂ particle catalyst in a single-bed reactor and by 7.7% and 16.1%, respectively, as compared with the 5%Na₃PO₄-2%Mn/SiO₂/cordierite monolithic catalyst in a single-bed reactor. The catalytic performance of the OCM in the two-stage bed reactor system has been remarkably improved. The TPR results indicate the high temperature reduction oxygen species in the monolithic catalyst might be favorable to the formation of C₂ products.     

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.     

国外生物质快速热解反应器现状

介绍了国外快速热解反应器如流化床、引流床、烧蚀反应器、旋转锥和真空移动床等的现状。评述了生物质快速热解的商业化状况。     

高纯度苯胺的大工业制备技术

采用清华大学研制的气体分布器、构件与两段流化床等专利技术,对兰州化学工业公司流化床制苯胺工艺进行技术改造,实现了单装置规模达7万t/a的苯胺制备的双层流化床制备苯胺工艺。新装置具有操作稳定、操作弹性大、硝基苯通量大、可促进硝基苯的深度转化、提高苯胺的纯度、催化剂寿命长、生产成本低等优点。     

Investigations on heat transfer and hydrodynamics under pyrolysis conditions of a pilot-plant draft tube conical spouted bed reactor

This paper describes the hydrodynamic and heat transfer performance of a pilot-plant scale conical spouted bed reactor designed for the pyrolysis of biomass wastes. The spouted bed reactor is the core of a fast pyrolysis pilot plant with continuous biomass feed of up to 25 kg/h, located at the Ikerlan-IK4 facilities.The aim of this paper is to obtain a deeper understanding of the spouted bed reactor performance at pyrolysis temperatures, in order to operate under stable conditions, improve the heat transfer rate in the reactor and minimize energy requirements. The influence of temperature on conical spouted bed hydrodynamics has been studied and wall-to-bed and bed-to-surface heat transfer coefficients have been determined.     

An NMR Imaging Study of Steady-State and Periodic Operation Modes of a Trickle Bed Reactor

NMR imaging has been applied to study the steady-state and the periodic operations of a functioning trickle bed reactor. It has been revealed that under conditions of the continuous supply of a liquid reagent to the catalyst bed, the bed was mostly filled with the liquid phase and was characterized by the uniform and stationary distribution of a liquid phase, whereas under conditions of the periodic supply of a liquid reagent to the catalyst bed with the same liquid flow velocity the bed was mostly dry and was characterized by a non-stationary distribution of the liquid phase. The oscillations of the liquid phase content within the bed, corresponding to the modulated liquid flow, have been observed. It has been shown that performing the hydrogenation reaction in a trickle bed reactor under conditions of the periodic supply of a liquid reagent to the catalyst bed leads to the intensification of the hydrogenation process. It becomes apparent in the significant increase of the temperature of the catalyst bed as well as in the increase of the conversion degree in the regimes under forced time-varying liquid flow rates in comparison to the steady-state regime of the reactor operation.     

Cell synchrony and periodic behaviour in yeast populations

The underlying basis for the behaviour of a population of cells is the cell growth and division cycles of the individual cells. Under certain special circumstances, oscillations in cell cultures can be observed that are a reflection of metabolic oscillations, such as in glycolysis, or cell cycle oscillations from a partially synchronized population. These oscillations can sometimes occur spontaneously, as in the chemostat culture of Saccharomyces cerevisiae at low dilution rates, or can be induced using chemical blockers or entrainment by a periodic nutrient environment. Continuous methods for inducing a synchronized culture include the pulsed chemostat, continuous phasing and self-cycling fermentation. Results obtained by studying both spontaneously oscillating cultures and synchronized cultures have provided insight into the mechanisms responsible for the progress and control of the cell cycle as well as the intimate relationship that exists between the cellular dynamics and the dynamics of the environment.     

Dynamic simulation and control of auto-refrigerated CSTR and tubular reactor for bulk styrene polymerization

Dynamic simulation and control of a two-stage continuous bulk styrene polymerization process is developed to predict the performance of auto-refrigerated CSTR and tubular reactors. The tubular reactor is subdivided into three temperature-control jacket zones. In this paper temperature control of auto-refrigerated continuous stirred tank reactor and tubular reactor are carried out, simultaneously. Two strategies are proposed for the control of tubular reactor. At the first strategy the controlled variable is jacket temperature and in the second strategy the controlled variable is the reactor temperature at the exit of each section. The set points for polymer grade transition are obtained using optimization of reactors temperatures via genetic algorithm (GA). Simulation results show that both of the control strategies are successful but second strategy has better performance in the control of polymer properties in the presence of disturbance and model mismatch.     

Growth rate dependence of enzyme synthesis in chemostat cultures: α-amylase, β-galactosidase,acid phosphatase and β-fructosidase

Specific rate of enzyme synthesis in microbial cells was correlated to specific growth rate in chemostat culture using three strains of microorganism. α-Amylase production by Bacillus subtilis was linearly associated with growth rate in a glucose-limited chemostat culture. β-Galactosidase production by Saccharomyces fragilis was rather invariable with growth rate in a galactose medium. β-Fructosidase production by Saccharomyces carlsbergensis in a phosphate-poor glucose medium was independent on growth rate, except at low dilution rates where it increased with growth rate. Production of acid phosphatase by the same microbe showed a maximum at a particular intermediate dilution rate. These relationships were summarised with an equation of induction—repression model. Comparison of the chemostat results with those of batch fermentation provided some enhancement factors of a continuous fermentation: 1.23–9.82 regarding enzyme productivity and 0.53–2.88 regarding enzyme concentration. The production of β-fructosidase was much improved among the enzymes tested when continuous culture methods were used.     

丙烯催化氧化制丙烯酸的两段流化床工艺

分别在一段和两段流化床反应器中对丙烯催化氧化制备丙烯酸过程进行了研究. 主要考察了温度、丙烯空速和氧/烯比等操作条件对丙烯氧化制备丙烯醛的第一步反应中丙烯转化率和液相收率的影响. 结果表明,在两段流化床反应器中,由于能够有效抑制气体和固体的返混及催化剂床层中气泡的增长,第一步反应中丙烯转化率和液相收率可以分别大幅度提高到94.2%和74.4%. 得到第一步反应的优化条件为：丙烯空速20~21 L/(h·kg),操作温度360~365℃,氧/烯摩尔比1.6~1.8,在此条件下,考察了连续两步反应中的丙烯转化率和液相收率.