STATISTICAL ANALYSIS ON COKE YIELDS IN VACUUM RESIDS AS A FUNCTION OF COMPOUND CLASSES AND ELEMENTAL ANALYSIS

ABSTRACT

This paper describes the statistical analysis of data on coke formation (measured by microcarbon residue) in five resids, as a function of compound classes, in order to identify variables wiih a significant effect on the former. In this sense, the SAS VARCLUS and Principal Component Analysis were used. The analysis carried out leads to a lineal combination of the H/C ratio, vanadium and nitrogen content as a model to explain coke yield, under non-catalytic conditions, as determined by MCR. Of all these factors, the H/C ratio has the most important contribution.     

EFFECTS OF H/C RATIO AND MOLECULAR WEIGHT ON MICROCARBON RESIDUE OF VACUUM RESID SUB-FRACTIONS

Studies in the literature have reported correlations of Microcarbon Residue (MCR) either with hydrogen to carbon atomic ratio (H/C) or with the number average molecular weight (M_n). The MCR value can be an indication of die coke yield in a commercial coking process. In this work a single correlation of MCR widi both H/C and M_n has been presented. Vacuum residue distillation fractions from hydroprocessing experiments were separated into five sub-fractions by preparative scale gel permeation chromatography, and characterized in terms of H/C, M„and MCR. In accordance with other correlations it was confirmed that increasing the H/C atomic ratio will decrease coke formation (MCR)- In addition this work has shown that for identical H/C ratio, molecules with smaller M_n values will produce less coke than those with larger M_n; values.     

EFFECTS OF H/C RATIO AND MOLECULAR WEIGHT ON MICROCARBON RESIDUE OF VACUUM RESID SUB-FRACTIONS

ABSTRACT

Studies in the literature have reported correlations of Microcarbon Residue (MCR) either with hydrogen to carbon atomic ratio (H/C) or with the number average molecular weight (M_n). The MCR value can be an indication of die coke yield in a commercial coking process. In this work a single correlation of MCR widi both H/C and M_n has been presented. Vacuum residue distillation fractions from hydroprocessing experiments were separated into five sub-fractions by preparative scale gel permeation chromatography, and characterized in terms of H/C, M?and MCR. In accordance with other correlations it was confirmed that increasing the H/C atomic ratio will decrease coke formation (MCR)- In addition this work has shown that for identical H/C ratio, molecules with smaller M_n values will produce less coke than those with larger M_n; values.     

歧化及烷基转移催化剂的运行及工业再生

介绍中海石油炼化有限责任公司惠州炼油分公司芳烃联合装置歧化及烷基转移单元高空速、低氢烃比条件下催化剂的运行及工业再生情况。采用C10+芳烃含量较高的原料,在较高空速、低氢烃比的条件下运行近2年,歧化催化剂积焦量达到39%以上,使催化剂活性下降。通过氢气汽提、低氧主烧焦和高氧清焦方法对催化剂进行再生,清除了约35.80 t焦炭,再生后催化剂反应性能良好,表明催化剂具有良好的再生性能。     

逐点程序升温氧化技术及其在积炭沸石催化剂烧炭中的应用

对逐点取样分析烧炭尾气组成的程序升温氧化技术进行了探讨，并将其应用于积炭沸石催化剂的恒温和程序升温氧化烧炭与通常的连续的程序升温氧化比较，本法可由一次试验同时获取烧炭速率、Ｈ／Ｃ比、积炭量等较全面的数据，准确判断烧炭起止温度（时间），避免通常方法因色谱基线飘移所引起误差。推导了求取烧炭速率等数据的简单计算公式。按烧炭温度和Ｈ／Ｃ比将积炭初步划分为低温、中温、高温炭三种。     

延迟焦化装置生产弹丸焦的临界操作研究

中国石化洛阳分公司建立了延迟焦化装置产生弹丸焦的临界卡边操作体系,即通过不断提高反应温度、降低循环比和反应压力等措施,使焦化反应无限接近于弹丸焦生成时的临界状态,以达到焦化装置液体产品收率最大化。同时提出了以焦炭塔C点中子料位计指示值、急冷油量、C点壁温以及焦炭塔工况为手段的弹丸焦产生预判体系,为产生弹丸焦临界卡边操作提供了安全保障和依据。     

合成气直接制低碳烯烃中K对铁基催化剂积炭特性的影响

采用浸渍法将K添加到氢氧化铁中获得不同K/Fe原子比催化剂,用KnFe表示,其中n=0,0.02,0.04,0.08,0.40,1.00。利用XRD,FT-IR,Raman,TG和元素分析等表征手段研究K/Fe原子比对其反应性能及积炭行为的影响。结果表明:适量K能够促进铁基催化剂CO加氢反应,提高C_2~=~C_4~=选择性,而过量K又会抑制CO加氢反应,降低烯烃选择性,最佳n(K)/n(Fe)为0.04;K的添加促进类石墨型积炭的生成,导致催化剂稳定性下降;随n增加,催化剂积炭量逐渐增加,且积炭中脂肪化程度以及H/C比均增加。     

RFCC沉降器内油浆重组分结焦反应过程的实验模拟

利用自制的热转化生焦实验装置和热量分析仪,考察了反应条件和油浆的性质对油浆重馏分热转化生焦的影响.结果表明,油浆的n(H)/n(C)、残炭值、结构族组成等性质对其牛焦率的影响要远大于反应时间、反应温度和油浆中催化剂含量等反应条件的影响.油浆中重组分馏分沸点的高低不能有效反映其生焦倾向,而重组分中的沥青质和胶质是生焦的主要前驱物,其芳碳率与生焦率有较好的线性对应关系.改变沉降器的操作条件可以缓解沉降器的结焦程度,但防止结焦的根本途径是通过调节主提升管的反应条件,从而减少进入沉降器的油气中的结焦前驱物胶质和沥青质的含量.     

RFCC沉降器内油浆重组分结焦反应过程实验模拟

 利用自制的热转化生焦实验装置和热重分析仪,考察了反应条件和油浆的性质对油浆重馏分热转化生焦的影响。结果表明,n(H)/n(C)原子比、残炭值、结构族组成等性质对其生焦率的影响要远大于反应时间、反应温度和油浆中催化剂含量等反应条件的影响。油浆中重组分馏分沸点的高低不能有效反映其生焦倾向,而重组分中的沥青质和胶质是生焦的主要前驱物,其芳碳率与生焦率有较好的线性对应关系。改变沉降器的操作条件可以缓解沉降器的结焦程度,但防止结焦的根本途径是通过调节主提升管的反应条件,从而减少进入沉降器内的油气中的结焦前驱物和沥青质的含量。     

固定床渣油加氢催化剂表面积炭分析

利用扫描电镜、热重-质谱联用、红外光谱、X射线荧光光谱及碳硫元素分析等手段,对工业运行450天的固定床渣油加氢工业脱金属催化剂RDM-32和脱硫催化剂RMS-30表面积炭进行表征,以研究催化剂积炭的组成及类型。结果表明：两种催化剂积炭量均从催化剂表面向中心不断降低,且脱硫催化剂积炭量下降更快;与脱金属催化剂相比,脱硫催化剂含有较高的积炭和较低的金属沉积,在积炭组成上,脱金属催化剂含有较多的软炭,占总炭的56.68%,脱硫催化剂基本为硬炭,占总炭的97.04%,在结构上,两种催化剂积炭的结构也有较大差别,脱硫催化剂表面积炭芳环缩合度高于脱金属催化剂,因此其积炭更加难以转化。     

预氧化HP40合金表面催化结焦的研究

为研究不同的表面状态对HP40合金表面催化结焦的影响,分别以水蒸气、空气为预氧化气氛,对HP40合金试样进行了不同温度的氧化处理以及氧化后结焦实验。利用XRD,SEM,TEM对氧化层和焦炭的形貌进行了表征,采用元素分析仪和拉曼（Raman）光谱仪对焦炭的碳氢比和结构进行了分析。结果表明：合金试样经水蒸气氧化后,表面形成了针状、富铁氧化物; 经空气氧化后,表面形成颗粒状、致密的富铬氧化物,随氧化温度升高部分试样的氧化层出现了剥落,剥落后的疏松、多孔表面对催化结焦有强烈的促进作用。焦炭主要为典型的催化丝状焦,焦丝的直径约80 nm,还含有少量的热裂解焦;焦炭缩合度较高,由有序状炭和无序状炭共同构成,且石墨化程度低。不同的预氧化气氛对合金表面氧化状态影响较大,但是对后续结焦过程,焦炭的形貌和结构无明显影响。     

A Study on the Coke Behaviors During Alkylation of Benzene with Ethanol Over Different HZSM-5 Catalysts

Abstract

Four different kinds of HZSM-5 zeolites with different acid properties and crystal size were used as catalysts in alkylation of benzene with ethanol to produce ethylbenzene and the coke behaviors were studied. The catalysts were characterized by X-ray diffraction (XRD), Brunacr-Emmett-Teller (BET), scanning electron microscopy (SEM), wet chemical analysis, NH₃-temperature programmed desorption (TPD), and Py-infrared (IR). The coke amount was measured by thermal gravity (TG) and the nature of the coke deposition was characterized by ultraviolet-visible (UV-Vis) and C/H analysis. The results showed that besides acid property, the crystal size could also affect the catalytic performance, coke content, and the nature of the coke deposition. The effect of reaction conditions including temperature, weight hourly space velocity, and time on stream on the catalytic performance and coke behaviors were also discussed over S-4.     

胶质添加量对胜利减压渣油加氢过程的影响

以不同胶质添加量的胜利减压渣油为原料,在高压反应釜中进行加氢反应,并对加氢前后的油样进行元素分析、平均相对分子质量测定、模拟蒸馏及金属（Ni、V）含量分析。结果表明：与原料相比,不同胶质添加量的胜利减压渣油加氢液相产物的平均相对分子质量、硫含量、氮含量、金属含量均不同程度减小,而H/C摩尔比均增大;随着胶质添加量增大,渣油加氢液相产物的平均相对分子质量和H/C摩尔比均逐渐增大,硫含量逐渐减小,氮含量和金属含量则先减小后增大;随着胶质添加量增大,渣油加氢液相产物中汽油+气体、加氢残渣油、焦炭的产率呈降低趋势,而柴油、加氢重油馏分的收率呈上升趋势。     

低碳烃芳构化催化剂结炭规律的研究

测定了低碳烃芳构化过程中Ga-ZSM-5的活性、结炭量、结炭C/H比、酸密度等,考察了结炭量与它们间的关系,提出了Ga-ZSM-5的多层多中心结炭失活模型:(1)结炭先发生在沸石晶体外表面(结炭2％前);然后主要在孔道交叉点结炭(2—8％间);结炭8％后,一些小分子烃被阻封在孔内,构成孔内积炭。(2)对Ga-ZSM-5,酸中心先结炭,只酸中心中毒。引起的失活效应小;当它与Ga中心同时结炭时,产生协同失活效应,引起的失活较显著。     

不同气体用作催化裂化原料雾化介质对裂化反应的影响

考虑到催化裂化装置普遍存在的蒸汽用于原料雾化所存在的弊端,结合中国石化股份有限公司荆门分公司催化裂解(DCC)装置的实际情况,提出一种新的原料油雾化技术,即采用炼厂干气代替现有的催化裂化雾化介质——蒸汽,以期克服蒸汽雾化所存在的问题。在小型固定流化床上采用工业装置的操作条件,考察了干气及其主要组分气体(如氢、乙烯、甲烷和乙烷等)作流化气对重油催化裂化产品分布的影响。结果表明,在干气环境下催化裂化产品分布所受到的影响,与干气组成尤其是干气中氢气和乙烯的含量有关：氢气环境下,干气、液化石油气、汽油和焦炭产率降低,柴油和重油的收率提高;乙烯环境下,干气、重油和焦炭产率提高,而液化石油气、汽油收率降低,柴油收率变化不大;干气代替蒸汽作流化气,在某种程度上提高了产品的柴汽比。     

Influence of coker-derived liquids on coking performance of Venezuelan heavy oil residue

Coking technological improvements are required to effectively upgrade/refine extra-heavy oil residues. The influence of types and blending ratios of coker-derived liquids on the coking performance of Venezuelan residue was studied in terms of product distribution and coke morphology. Blending of the coker diesel distillates (200–350?°C) with the residues was not suggested, given the negative interactions at all blending ratios (0–0.6) as concluded from coke yield analysis. Blending of the coker gas oil improved the coke quality and inhibited the coke formation. The recycle of heavy coker gas oil (430?°C+) at a blending ratio of 0.3 was most favorable.     

用UOP技术改造催化裂化装置

介绍洛阳石油化工总厂1号催化裂化装置采用UOP的涡流分离系统和高效汽提技术进行改造的情况。改造后装置的标定结果表明,反应油气和催化剂的分离效率得到提高,解决了油浆固含量较高的难题,油浆固含量降到2g/L;提高了汽提效果,待生剂上焦炭的氢碳比降到6．0％;减少了二次反应,产品分布得到改善,焦炭产率降低1．44个百分点,轻油收率提高0．31个百分点,柴汽比提高到0．82;装置处理量提高了48t/h。     

C5、C6正构烷烃异构化反应的热力学分析

对C5、C6正构烷烃异构化反应进行了详细的热力学分析。通过计算得到了不同反应温度下的异构化反应的平衡常数、产物分布和转化率。讨论了异构化反应的温度、压力和氢／烃摩尔比对反应的平衡和产物分布的影响。     

大型焦炭塔裙座裂纹探析及优化改进

介绍了2台材质为14Cr1MoR、规格为9 800mm×37 001mm×(30/32/34/38/42)mm的焦炭塔裙座产生贯穿性裂纹的情况。对裙座进行了受力分析,找出了产生裂纹的原因,制定了相关的返修方案,并提出了焦炭塔生产操作的注意事项及裙座结构优化和改进措施。     

AuCl3-BiCl3/C催化剂的制备及使用性能研究

以AuCl3为主催化活性组分,BiCl3为助剂,活性炭为载体,采用浸渍法制AuCl3-BiCl3/C催化剂,使用固定床转化器对催化剂在乙炔氢氯化反应中的催化活性（用乙炔转化率和氯乙烯选择性作为评价指标）进行测试,并采用BET,XRD,TEM方法进行了表征。结果表明：BiCl3的加入能提高乙炔转化率,0.3%AuCl3-0.9%BiCl3/C为最佳配比,活性组分分散度高,抗积炭能力好,在乙炔空速为20 h-1、V（C2H2）/V（HCl）=1:1.1、反应时间为24 h的条件下,乙炔转化率可达到98.9%,氯乙烯选择性高于99.7%,催化剂使用性能较好。