中低温煤焦油加氢裂化集总动力学模型的研究

以煤焦油为原料,在高压固定滴流床反应器中,以工业NiMo/Al2O3为催化剂,考察了360-380℃范围内煤焦油的产物分布,基于此建立了5集总煤焦油加氢裂化动力学模型。动力学模型的集总包括：未反应的煤焦油、柴油、汽油、气体和焦炭。通过对实验产物与模型预测产物的对比数据,发现本文所建立的动力学模型可以用于煤焦油加氢裂化过程。同时,基于动力学模型,进一步分析了煤焦油的加氢裂化机理：在整个煤焦油加氢裂化过程中,柴油馏分可作为反应中间组分。     

沸腾床加氢-焦化组合工艺制备低硫石油焦

对沸腾床加氢-焦化组合工艺制备高品质石油焦的工艺路线进行研究,探究沸腾床未转化油（UCO）的焦化规律。结果表明：渣油沸腾床加氢反应过程中,提高温度或降低空速有利于渣油转化率和杂质脱除率提高;同样的操作区间内,渣油转化率的变化明显大于杂质脱除率;随着渣油转化率增加,UCO硫含量先降低再升高。UCO焦化过程中原料中60%左右的硫转移到焦炭中,明显高于渣油焦化过程中硫转移到焦炭的比例（约42%）;相比于渣油直接焦化得到的焦炭,较低硫含量的UCO制备的石油焦品质明显提升。UCO焦化所得石油焦收率和硫含量分别与UCO的残炭值和硫含量呈现良好的线性关系,可根据所需低硫焦牌号来指导沸腾床加氢过程的工艺优化。     

全馏分高温煤焦油悬浮床加氢裂化中试试验

采用150 kg/d悬浮床加氢裂化中试装置,以全馏分高温煤焦油为原料,考察了反应温度、反应质量空速及反应压力对煤焦油加氢裂化反应性能及产物分布的影响。结果表明：升高反应温度和降低反应质量空速,均可以促进煤焦油中重油和沥青质的深度转化,气体和焦炭收率增加,重油收率降低,但过高的反应温度会降低轻油馏分收率;提高反应压力可以抑制气体和焦炭的生成,促进沥青质的加氢转化,保证了较高的轻油收率。在反应温度为465℃,反应压力为22 MPa,反应质量空速为0.5 h-1,氢气/原料油（体积质量比,L/kg）为1 500的最佳条件下,重油和沥青质的转化率分别达到26.05%和62.95%,轻油收率为77.42%,气体和焦炭收率为17.28%。     

悬浮床加氢裂化集总动力学模型的研究

在不同反应温度、氢初压条件下,通过高压反应釜对克拉玛依常压渣油（KLAR）进行加氢裂化实验,以此模拟悬浮床加氢裂化过程,并根据实验数据及实际工艺中对各种轻油产品收率预测的需求建立了悬浮床加氢裂化六集总（气体、汽油、柴油、蜡油、减压渣油、焦）动力学模型,用matlab软件进行编程,采用最小二乘法对动力学参数进行估算,并进行误差分析。结果表明,建立的六集总动力学模型能很好的对各集总产品收率进行预测,计算结果与实验值基本吻合,大部分误差在5%以内。     

渣油悬浮床加氢裂化反应中助剂的作用机制Ⅰ

 在高压釜中对辽河常压渣油（LHAR）在分散型催化剂和助剂存在下的悬浮床加氢裂化反应进行了研究,从助剂对反应体系胶体性质的影响方面探讨了助剂的作用机制。结果表明,助剂的加入能在保证渣油转化率的同时显著降低生焦量,提高反应体系的胶体稳定性;在反应升温过程中,助剂能使反应体系在较广的温度范围内保持稳定的胶体结构,提高渣油对热扰动的免疫力,从而延长第二液相——沥青质聚集相的出现时间,降低生焦量。     

塔河减压渣油浆态床加氢改质反应条件的考察

以塔河减压渣油为研究对象,通过高压釜反应模拟浆态床加氢反应过程,考察反应条件对塔河减压渣油加氢转化过程生焦率、转化率及产物分布的影响。结果表明,随反应温度的升高,渣油转化率及生焦随之增加;氢初压的提高对生焦有明显的抑制作用,起初渣油转化率随之降低,当超过8 MPa时略有增加;反应时间的增加对渣油转化率及生焦都有促进作用;催化剂的存在可以抑制生焦反应,同时在一定程度上也抑制了裂化反应,应控制适量。综合考虑,确定适宜的反应条件为：反应温度不宜高于430 ℃,氢初压7～8 MPa;反应时间40～60 min;催化剂的加入量2 000～6 000 mg/kg。     

减压蜡油加氢裂化催化剂组合动力学模型

以高压加氢裂化六集总动力学模型为基础,建立预测催化剂组合体系产品分布的数学模型。按固定馏程间隔将原料油和加氢裂化生成油划分为减压蜡油 加氢裂化尾油（>360℃）、柴油馏分（290～360℃）、喷气燃料馏分（175～290℃）、重石脑油馏分（65～175℃）、轻石脑油馏分（<65℃）和炼厂气（C4-）6个集总。分别以2种不同类型加氢裂化催化剂的实验数据为基础,采用Matlab 2011b数值计算软件和非线性最小二乘法对动力学模型参数进行了优化回归。以优化回归后的动力学模型参数为初值,调整部分模型参数,建立了预测催化剂组合体系产品分布的数学模型。用该模型计算得到的加氢裂化产品分布与实验值之间的一致性较好,其偏差均小于2%。     

An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.     

减压渣油热转化集总动力学的建模研究

以洛阳减压渣油为例,研究了减压渣油热转化集总动力学模型.对洛阳减压渣油分别在410、420、430和440℃下进行的热转化反应,通过数学分析建立了6集总动力学反应模型.减压渣油热转化反应生成裂化气、汽油、轻瓦斯油、重瓦斯油与焦炭,其反应均为2级反应;轻、重瓦斯油将继续发生2次反应,生成焦炭;动力学参数中缩合反应的活化能大于裂化生成馏分油的活化能,表明缩合反应对反应温度的变化更为敏感.计算结果表明,所建模型可以用来预测减压渣油热转化反应产物分布,预测值与实验值吻合较好.     

塔河常压渣油及其亚组分的非等温热转化反应性能研究

采用热重分析法对塔河常压渣油(THAR)及其亚组分的热转化反应性能进行了考察;在Sharp微分法基础上,采用分段动力学拟合,获得了渣油及其亚组分热转化速率峰值、速率峰值处的反应温度、转化率和剧烈裂解温度区间等动力学基本数据以及各亚组分的生焦性能。结果表明：各亚组分生焦率由低到高依次为饱和分＜芳香分＜胶质＜沥青质,沥青质是焦炭的主要来源;四组分按组成加权后的生焦率较THAR生焦率高4.21百分点,表明THAR亚组分混合物共焦化有利于抑制各亚组分的生焦;饱和分可促进其它亚组分生焦,而芳香分和胶质可抑制沥青质生焦,且芳香分的抑焦性能更强;在热转化反应过程中,裂化反应活性由高到低的顺序为饱和分＞芳香分＞胶质＞沥青质,各亚组分在低温段和高温段的活化能由低到高的顺序均为饱和分＜芳香分＜胶质＜沥青质,表明胶质和沥青质大分子的热转化过程需要提供较多的能量。     

An Active Carbon Catalyst Prevents Coke Formation from Asphaltenes during the Hydrocracking of Vacuum Residue

Abstract

Active carbons were prepared by the steam activation of a brown coal char. The active carbon with mesopores showed greater adsorption selectivity for asphaltenes. The active carbon was effective at suppressing coke formation, even with the high hydrocracking conversion of vacuum residue. The analysis of the change in the composition of saturates, aromatics, resins, and asphaltenes in the cracked residue with conversion demonstrated the ability of active carbon to restrict the transformation of asphaltenes to coke. The active carbon that was richer in mesopores was presumably more effective at providing adsorption sites for the hydrocarbon free-radicals generated initially during thermal cracking to prevent them from coupling and polycondensing.     

Maximizing Diesel Production From Vacuum Gas Oil Using a Two Stage Hydrocracker

In this study, a six-lump model was sufficient to describe the kinetics of vacuum gas oil (VGO) hydrocracking in order to maximize the production of middle distillate diesel. The kinetic lump model target was to obtain the reaction rate constants that represent all the hydrocracking reactions in the process. The operating conditions such as temperature, pressure, and hydrogen severity were tested to find the optimum parameters that maximize diesel yields. Mild hydrocracking operating conditions of temperature and pressure were used in a commercial hydrocracker with hydrogen severity similar to hydrotreating processes. The main reaction was the VGO conversion to diesel based on its high reaction rate constant compared with other reactions. In addition, the main reaction had the highest effect on catalyst deactivation based on the resulted deactivation factor. A multi-linear regression correlation was obtained for maximizing diesel production as a function of operating pressure, temperature, and hydrogen amount, keeping the diesel specifications within the market demand.     

沥青质裂解反应选择性分析

在703 K 下,考察了1种正戊烷不溶的沥青质的热裂解、临氢热裂解和 NiMo/γ-Al₂O₃存在时的临氢催化裂解反应。结果表明,在相同的反应物转化率水平下,3种裂解反应按液体产物选择性从大到小的排列顺序为临氢催化裂解、临氢热裂解、热裂解反应,而按焦炭的选择性的排列顺序则相反。在热裂解反应中,沥青质中大量的硫被转化生成高硫焦炭;在临氢热裂解反应中,氢气分子对高硫焦炭的生成只起到有限的抑制作用;在临氢催化裂解反应中,催化剂充分激活氢气分子,使其有效地对沥青质及中间产物发生“加氢”（氢化）作用,显著地抑制了焦炭的生成,提高了液体产物的稳定性、选择性和品质（低相对分子质量和低硫含量）。     

催化柴油加氢裂化催化剂积炭形态及成因探讨

采用小型固定床加氢装置和Ni Mo型加氢裂化催化剂进行催化裂化柴油(LCO)加氢裂化反应,采用TG MS、GC MS、13C NMR和元素分析手段研究了催化剂积炭的类型和组成,并探讨了积炭的形成原因。结果表明,根据积炭燃烧的难易程度,催化剂积炭分为3种类型。积炭为缩合程度较高的稠环芳烃,侧链较少,且以短侧链为主。积炭中难溶性积炭较多,可溶性积炭主要为芘及其同系物和晕苯及其同系物,并含有少量氮杂环化合物。积炭前身物主要为芳烃,而LCO中芳烃含量过高以及较高的反应温度、低的氢分压是LCO加氢裂化过程催化剂积炭形成的主要原因。     

渣油悬浮床加氢裂化与热裂化反应过程中胶体稳定性的比较

考察克拉玛依常压渣油热裂化和悬浮床加氢裂化在不同反应时间的生焦量与生焦诱导期以及反应后产物的六组分质量分数及其数均相对分子质量，并利用质量分数电导率法研究了热裂化和悬浮床加氢裂化不同反应时间的胶体稳定性。结果表明，渣油悬浮床加氢裂化和热裂化两种反应体系在生焦诱导期内的胶体稳定性下降迅速，在生焦诱导期后的胶体稳定性下降趋于缓慢。在氢与加氢催化剂的作用下，渣油悬浮床加氢裂化在相同反应条件下比热裂化的生焦诱导期长，胶体稳定性好。     

Mild Hydrocracking—A Review of the Process,Catalysts, Reactions,Kinetics, and Advantages

Abstract

The demand for high quality middle distillates is increasing world wide while the demand for residue and fuel oil is decreasing. Hydrocracking is the major conversion process that meets the twin objectives of producing more middle distillates of very high quality. Since hydrocracking is a capital-intensive process, many refiners consider the option of converting their existing vacuum gas oil hydrotreating units into mild hydrocracking units. The use of mild hydrocracker bottom as FCC feedstock can improve the quality of FCC products. In view of the advantages of mild hydrocracking process, it is essential to understand the process, catalysts used, reactions, kinetics, and advantages. This article reviews recent literature on MHC process, various catalysts used, reactions involved and advantages of mild hydrocracking process in terms of improved product qualities and increased distillates. The kinetics of the mild hydrocracking process and kinetic challenges with respect to aromatic saturation have been summarized. The limitations of the process and future scope of work in this area are also discussed briefly.     

渣油加氢裂化反应中催化剂与表面活性剂的协同作用

 在高压釜中，以克拉玛依常压渣油(KLAR)为原料，考察了添加表面活性剂对悬浮床加氢裂化反应生焦的影响。结果表明，在渣油加氢裂化反应过程中，表面活性剂与加氢裂化水溶性分散型催化剂之间存在协同作用。表面活性剂SA1，SA4和SA5的加入能更有效地抑制渣油加氢裂化反应过程的生焦，其中添加SA4的抑焦效果最好，反应总生焦率由添加表面活性剂前的2.34%降至添加后的0.79%。表面活性剂与催化剂协同抑焦效果与表面活性剂的添加量有关，当表面活性剂的添加量较少时, 抑制生焦的效果较好；但当添加量超过一定值时, 甚至会促进生焦。红外光谱分析表明，SA4可以在沥青质表面吸附，从而起到稳定沥青质、降低生焦的作用。     

沥青质加氢热裂解和催化加氢裂解反应动力学与选择性

A pentane-insoluble mixture of asphaltenes was processed by thermal hydrocracking and catalytic hydrocracking over Ni-Mo/γ-Al2O3 catalyst in a microbatch reactor at 430 ℃.The experimental data of asphaltene conversion adequately fit second-order kinetics to give the apparent rate constants of 2.435×10-2 and 9.360×10-2 (wt frac)-1 min-1 for the two processes,respectively.A three-lump kinetic model is proposed to evaluate the rate constants for parallel reactions of asphaltenes producing liquid oil (k1) and gas+coke (k3),and consecutive reaction producing gas+coke (k2) from this liquid oil.The evaluated constants for asphaltenes hydrocracking,in the presence and absence of the catalyst,respectively,show that k1 is 2.430×10-2 and 9.355×10-2 (wt frac)-1 min-1,k2 is 2.426×10-2 and 6.347×10-3 min-1,and k3 is 5.416×10-5 and 4.803×10-5 (wt frac)-1 min-1.As compared with the thermal hydrocracking of asphaltenes,the catalytic hydrocracking of asphaltenes promotes liquid production and inhibits coke formation effectively.     

氢分压对加氢裂化过程的影响

分析了氢分压加氢裂化过程各种反应的影响以及加氢裂化过程中氢分压对裂化转化率，产品分布及产品性质的综合影响，提出了后的加氢裂化过程对催化剂和工艺的一些基本要求。     

Mild Hydrocracking—A Review of the Process, Catalysts, Reactions, Kinetics, and Advantages

The demand for high quality middle distillates is increasing world wide while the demand for residue and fuel oil is decreasing. Hydrocracking is the major conversion process that meets the twin objectives of producing more middle distillates of very high quality. Since hydrocracking is a capital-intensive process, many refiners consider the option of converting their existing vacuum gas oil hydrotreating units into mild hydrocracking units. The use of mild hydrocracker bottom as FCC feedstock can improve the quality of FCC products. In view of the advantages of mild hydrocracking process, it is essential to understand the process, catalysts used, reactions, kinetics, and advantages. This article reviews recent literature on MHC process, various catalysts used, reactions involved and advantages of mild hydrocracking process in terms of improved product qualities and increased distillates. The kinetics of the mild hydrocracking process and kinetic challenges with respect to aromatic saturation have been summarized. The limitations of the process and future scope of work in this area are also discussed briefly.