Z501型轻油蒸汽预转化催化剂在制氢装置的应用

介绍别Z501型预转化催化剂在制氢装置的工业应用。传统的轻油蒸汽转化制氢工艺对原料的要求较高，运行周期不长。预转化工艺是对传统制氢工艺的重要改进，国产预转化催化刑的成功开发和应用，将极大地推动预转化工艺发展。     

A novel dynamic membrane reactor concept with radial‐flow pattern for reacting material and axial‐flow pattern for sweeping gas in catalytic naphtha reformers

Naphtha reforming units are of high interest for hydrogen production in refineries. In this regard, the application of membrane concept in radial‐flow tubular naphtha reactors for hydrogen production is proposed. Because of the importance of the pressure drop problem in catalytic naphtha reforming units, the radial‐flow reactors are proposed. A radial‐flow tubular membrane reactor (RF‐TMR) with the radial‐flow pattern of the naphtha feed and the axial‐flow pattern of the sweeping gas is proposed as an alternative configuration for conventional axial‐flow tubular reactors (AF‐TR). The cross‐sectional area of the tubular reactor is divided into some subsections in which walls of the gaps between subsections are coated with the Pd‐Ag membrane layer. A dynamic mathematical model considering radial and axial coordinates ((r, z)‐coordinates) has been developed to investigate the performance of the new configuration. Results show ～300 and 11 kg/h increase in aromatic and hydrogen production rates in RF‐TMR compared with AF‐TR, respectively. Furthermore, smaller catalyst particles with higher efficiency can be used in RF‐TMR due to a slight pressure drop. The enhancement in aromatics (octane number) and hydrogen productions owing to applying simultaneously the membrane concept and radial‐flow pattern in naphtha reactors motivates the application of RF‐TMR in refineries. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Theoretical investigation of aromatics production enhancement in thermal coupling of naphtha reforming and hydrodealkylation of toluene

In the current research, an exothermic reaction is proposed to be coupled with naphtha reforming reactions. Hydrodealkylation (HDA) of toluene, which is a well-known petrochemical reaction, is discussed and is suggested as a potential exothermic reaction to be coupled with the endothermic naphtha reforming reactions. The first, the second, and the third reactor of the conventional naphtha reforming process have been substituted in three different cases by thermally coupled reactors and optimized parameters of the final case have been investigated. Considering lower operational costs due to the elimination of inter stage heaters, investigation of thermally coupled reactors has been the first priority of this research. The investigation shows that substitution of the first two reactors and, in the final case, all conventional reactors by the new configuration can improve the production yield of the aromatics by 14% and 21%, respectively compared with conventional naphtha reforming process. The final case has been optimized as well, and 45% and 11% improvement in aromatics and hydrogen production has been observed.     

工业催化重整过程动态建模与仿真

A first principles-based dynamic model for a continuous catalyst regeneration (CCR) platforming process, the UOP commercial naphtha catalytic reforming process, is developed in this paper. The lumping details of the naphtha feed and reaction scheme of the reaction model are given. The process model is composed of the reforming reaction model with catalyst deactivation, the furnace model and the separator model, which is capable of capturing the major dynamics that occurs in this process system. Dynamic simulations are performed based on Gear numerical algorithm and method of lines (MOL), a numerical technique dealing with partial differential equations (PDEs). The results of simulation are also presented. Dynamic responses caused by disturbances in the process system can be correctly predicted through simulations.     

Coking characteristics of reforming catalysts

Coking rates were measured for two different γ-aluminas, each with and without platinum, under near commercial conditions using a gravimetric reactor. Coke on catalyst was characterized by a Temperature-Programmed Oxidation (TPO) technique. With a naphtha feed, coke formed on both aluminas at rates related to the respective population of α-sites as measured by IR. For the corresponding Pt on alumina catalysts, coke, as measured by TPO, predominantly formed on sites associated with alumina (“alumina coke”), while coke associated with Pt (“Pt coke”), was relatively minor. With a n-heptane feed, under the same conditions, coke formation on both aluminas was much less than with the naphtha feed. However, the corresponding Pt on alumina catalysts generated comparatively more coke with a higher proportion associated with Pt. A correspondence between this proportion of “Pt coke” and the decline in reforming activity was observed. It is postulated that most of the coke produced during naphtha reforming with an active catalyst is formed by a reaction between α-sites on alumina and certain components in the feed via a polymerization mechanism. This type of coke has minimal effect on the reforming reactivity of the catalyst. However, in n-heptane reforming, about 50% of the coke also results from precursors formed from reactions with Pt. In either case, coke associated with Pt appears to be the probable cause of deactivation.     

我国增产三苯的工艺路线评述

对中国未来的三苯(BTX)市场供求形势进行了分析,同时对传统的芳烃生产工艺(石脑油铂重整、蒸气裂解制乙烯)以及新开发的芳烃生产工艺(链烷烃沸石重整、轻烃芳构化)进行了详细介绍。在此基础上,对我国增产芳烃提出了建议。     

异构化技术及应用

采用异构化技术提高汽油辛烷值将成为一种新的有效手段。在临氢的条件下,C5、C6构烷烃与含铂（钯）的强酸性催化剂接触将发生结构异构化反应,可将轻质石脑油的辛烷值可提高10个单位以上。利用流程模拟设计,对异构化装置的设计进行了探讨,同时结合炼厂现有闲置重整装置的特点,提出了重整装置改建成异构化装置的方案。     

Formselektives Reformieren an zeolithhaltigen Reformierkatalysatoren

Use of bifunctional Pt/Al₂O₃ catalysts in catalytic reforming units significantly improved production. During the past four decades the power of such catalyst systems has been continuously increased by the introduction of various catalyst modifications. Use of reforming catalysts containing zeolites permits combination of shape selectivity with the conventional reforming reaction. Here, the suitability of an erionite containing catalyst for the reforming processes is demonstrated. Gasolines produced with zeolite catalysts are characterised by high values of octane numbers and low content of carinogenic benzene.     

煤基石脑油半再生催化重整制芳烃的工艺

采用工业铂铼双金属重整催化剂Pt-Re/γ-Al₂O₃开展了煤基石脑油半再生固定床催化重整单因素实验,并采用响应面法对工艺参数进行了优化与分析,最后对优化工艺条件下实验产物进行了分析。结果表明：加权平均入口温度（WAIT）、压力（P）、液时空速（LHSV）等操作条件对煤基石脑油芳烃型半再生重整产品质量、芳烃收率和C₅₊液体收率有很大的影响。煤基石脑油重整合适工艺参数区间：WAIT（500~520℃）、P（1.2~1.6MPa）和LHSV（2.0~3.0h^-1）;最佳工艺条件：WAIT为516℃,P为1.4MPa,LHSV为2.3h^-1。优化工艺条件下芳烃收率达到了79.81%,响应面实验操作条件区间内,WAIT、P和LHSV对芳烃收率影响大小顺序为：P > LHSV > WAIT。相比于石油基石脑油重整,煤基石脑油重整不仅纯氢产率和氢气纯度更高,还可获得更高的苯-甲苯-二甲苯（BTX）产率,其中苯收率：甲苯收率：二甲苯收率近似为1：3：2。     

Operability of an Industrial Catalytic Naphtha Reformer in the Presence of Catalyst Deactivation

Bifunctional naphtha reforming catalysts are deactivated by side reactions such as coking, sintering, and poisoning in the course of industrial operation. This results in a reduction of the octane number of the product in a commercial naphtha reforming unit. Catalyst deactivation is compensated for by increasing the operating temperature so that the primary product yields are kept constant during an operating cycle. In the present study, a deactivation model has been developed for industrial catalytic naphtha reformers. The parameters for the deactivation model have been estimated using plant data. The results of the model show that increasing the reactor weighted average inlet temperature (WAIT) can offset the decrease in aromatic yield. Concentration and temperature profiles have been obtained to provide information about the extent of conversion in the individual reactors. Reactor inlet temperature is an important parameter, which can significantly affect reformer performance, the aromatic yield increasing with an increase in temperature.     

MOLECULAR MODELING AND OPTIMIZATION FOR CATALYTIC REFORMING

In this paper, molecular modeling and optimization for the naphtha catalytic reforming process is studied. The catalytic reforming process is for producing high octane number gasoline by reforming reactions in three sequencing fixed bed reactors. Feed naphtha coming from an atmospheric distillation unit consisted of molecules from C5 to C10 including paraffin, iso-paraffin, naphthene, and aromatic. The molecular reaction network consisted of paraffin cracking, naphthene side-chain cracking, aromatic side-chain cracking, ring opening, ring closure, paraffin isomerization, dehydrogenation, and hydrogenation. A molecular model for catalytic reforming was built. On the basis of the simulation model, a process optimization was performed for feed temperature and pressure under constraints such as benzene content, aromatic content, and RON (Research Octane Number) limitations. High RON was contrasted to low benzene and aromatic content requirements. By optimizing and controlling the reaction pathway, we can obtain a final product with the highest profit and appropriate benzene and aromatic contents and RON value. This example shows significant benefits from applying molecular modeling to optimization in the process level. Since gasoline production is related to many different processes such as reforming, FCC, isomerization, alkylation, and so on, more benefits can be obtained by applying molecular modeling to plant-wide optimization.     

MOLECULAR MODELING AND OPTIMIZATION FOR CATALYTIC REFORMING

In this paper, molecular modeling and optimization for the naphtha catalytic reforming process is studied. The catalytic reforming process is for producing high octane number gasoline by reforming reactions in three sequencing fixed bed reactors. Feed naphtha coming from an atmospheric distillation unit consisted of molecules from C5 to C10 including paraffin, iso-paraffin, naphthene, and aromatic. The molecular reaction network consisted of paraffin cracking, naphthene side-chain cracking, aromatic side-chain cracking, ring opening, ring closure, paraffin isomerization, dehydrogenation, and hydrogenation. A molecular model for catalytic reforming was built. On the basis of the simulation model, a process optimization was performed for feed temperature and pressure under constraints such as benzene content, aromatic content, and RON (Research Octane Number) limitations. High RON was contrasted to low benzene and aromatic content requirements. By optimizing and controlling the reaction pathway, we can obtain a final product with the highest profit and appropriate benzene and aromatic contents and RON value. This example shows significant benefits from applying molecular modeling to optimization in the process level. Since gasoline production is related to many different processes such as reforming, FCC, isomerization, alkylation, and so on, more benefits can be obtained by applying molecular modeling to plant-wide optimization.     

Development of a high efficiency substitute natural gas production process

We have developed a high efficiency process for producing a substitute natural gas using LPG and naphtha as raw materials. In the process, sulfur poisoning of the steam reforming catalyst is protected and the amount of catalyst used can be reduced applying a high performance desulfurization technology developed. This technology enables the removal of trace amounts of sulfur which cannot be removed by a conventional hydro-desulfurization method. In addition, we have developed a high performance steam reforming catalyst which has a resistance to carbon deposition even under low S/C conditions. The catalyst makes it possible to reduce excessive steam for preventing carbon deposition, and to operate with high thermal efficiency.     

重整切尾油催化加氢生产优质溶剂油

介绍了中国石油抚顺石化公司石油三厂以重整切尾油为原料,通过加氢微型试验装置,筛选出加氢精制催化剂3996与加氢脱芳催化剂FV-1,将上述2种催化剂按照体积比1︰1进行组合装填,在加氢微型试验装置进行一段加氢法生产塑胶溶剂油试验,并经过了工业生产运行。结果表明,在适宜的操作条件下,可以出合格的塑胶油产品,并获得较好的经济效益。     

催化重整原料预加氢催化剂及其工业应用

重整催化剂活性组分中含有贵金属,因此对重整原料中的硫、氮和砷等杂质含量提出了严格要求。为确保重整装置的长周期稳定运转,使重整催化剂能够充分发挥其催化性能,需设置原料预处理单元,一般采用加氢精制工艺去除有害杂质。随着煤化工的发展,煤基石脑油也将成为重整过程原料的来源,针对煤基石脑油开发相关的加氢催化剂也将成为研究重点。综述了催化重整原料预加氢催化剂的活性组分及其结构模型理论。主活性组分一般为Mo或W,助活性组分一般为Co或Ni。针对不同原料,需选取不同活性组分。其结构模型理论指出,活性组分与载体可生成四面体或八面体配位,只有八面体配位才能有效地发挥作用。同时对催化剂载体的研究进行了综述,包括工业化应用广泛的γ-Al₂O₃及对其改性方法和新型载体的研发。介绍了目前工业化预加氢催化剂的应用情况。指出未来重整预加氢催化剂将向着活性高、选择性高及稳定性好的方向发展。     

Optimal design of a thermally coupled fluidised bed heat exchanger reactor for hydrogen production and octane improvement in the catalytic naphtha reformers

The present study combines simultaneously the definition of fluidisation and process intensification (thermally coupled heat exchanger reactor) concept and determines the optimum operational conditions in both sides of the reactor, using Differential Evolution (DE) optimisation approach. The exothermic hydrogenation of nitrobenzene to aniline takes place in a set of tubular reactors which is placed inside the naphtha reactors and thermally handle the endothermic reaction of reforming. A single objective function consists of four terms including aromatic mole fraction of the reformate and hydrogen production from each reactor in the endothermic side as well as the total molar flow rate of aniline and nitrobenzene conversion in the exothermic side is defined. Seven decision variables such as inlet temperature of exothermic and endothermic sides, exothermic molar flow rates for the first and the second reactors and the number of tubes are considered during the optimisation procedure. Temperature constraints have been considered in both sides during the optimisation in order to reduce the possibility of rapid catalyst deactivation by sintering. Results show approximately 464.4 and 598.9 kg/h increase in aromatic and aniline production rates in optimised thermally coupled fluidised bed naphtha reactor (OTCFBNR) compared with non‐optimised case (TCFBNR), respectively. Such a theoretical study is necessary prior to designing new pilot plants and revamping industrial units. © 2011 Canadian Society for Chemical Engineering     

Alternate use of heavy hydrotreatment and visbreaker naphthas by incorporation into diesel

In order to provide a solution for refineries having limited catalytic reforming capacity, a process scheme for incorporating most of the low octane heavy hydrotreatment and visbreaker naphthas into diesel is presented in this paper. This scheme involves blending the visbreaker naphtha with the feed to the diesel hydrotreatment units, processing this blend at the usual conditions for diesel hydrodesulfurization and changing the cut point in the diesel stabilizer.     

Thermal Integration of Sulfuric Acid and Continuous Catalyst Regeneration of Naphtha Reforming Plants

An optimal reactor design is proposed that simultaneously improves the naphtha reforming reactor performance and increases sulfur trioxide production. In this new configuration, the naphtha reforming process as an endothermic reaction is coupled with the oxidation reaction of sulfur dioxide, which is an exothermic reaction. The differential evolution optimization technique is applied to maximize the produced amounts and yields of aromatics and hydrogen. The results obtained with the optimized thermally coupled reactor are compared with those of the conventional and thermally coupled reactors, proving the superiority of the proposed configuration.     

石脑油水蒸气转化的集总动力学模型

根据烃类水蒸气催化转化反应过程的动力学特性,提出了相对反应速率常数a的概念,以此为依据,定义了石脑油的物种分布函数D(a)及烃组成分布函数y_0(a).假定各种烃在反应过程中仅生成CH_4、CO、CO_2及H_2等产物,并且水煤气变换反应按达到平衡处理.利用这两个函数建立了石脑油水蒸气转化的连续集总动力学模型,能满意地模拟实验结果.     

连续催化重整技术的研究

重点从连续重整工艺和催化剂两方面研究了国内外连续重整技术的进展,并介绍了连续重整的生产现状及催化剂的再生技术,指出石脑油原料短缺制约着我国催化重整的发展,应设法消除制约因素,打破国外公司对连续重整技术的垄断,大力发展利国利民的催化重整行业。