ATMOSPHERIC RESIDUE AS FEEDSTOCK TO HIGH-SEVERITY FLUID CATALYTIC CRACKING

ABSTRACT

The effect of atmospheric residue as a feedstock to a high-severity fluid catalytic cracking (HS-FCC) process has been investigated using a small-scale HS-FCC pilot plant (0.1 b/d) with a down flow reactor. This novel FCC process has been developed to enhance the yield of light olefins under high severity reaction conditions. Hydrotreated and virgin vacuum gas oils (VGO) as well as hydrotreated and virgin atmospheric residues (AR) were tested in the study. The yield of desired products such as gasoline and light olefins produced from virgin VGO cracking was 79 wt%, much higher than that obtained from a conventional FCC process whereas in case of hydrotreated VGO, the yield of desired products decreased to 76%. On the other hand, AR feeds exhibited performance similar to VGO with a slight increase in coke formation.     

ATMOSPHERIC RESIDUE AS FEEDSTOCK TO HIGH-SEVERITY FLUID CATALYTIC CRACKING

The effect of atmospheric residue as a feedstock to a high-severity fluid catalytic cracking (HS-FCC) process has been investigated using a small-scale HS-FCC pilot plant (0.1 b/d) with a down flow reactor. This novel FCC process has been developed to enhance the yield of light olefins under high severity reaction conditions. Hydrotreated and virgin vacuum gas oils (VGO) as well as hydrotreated and virgin atmospheric residues (AR) were tested in the study. The yield of desired products such as gasoline and light olefins produced from virgin VGO cracking was 79 wt%, much higher than that obtained from a conventional FCC process whereas in case of hydrotreated VGO, the yield of desired products decreased to 76%. On the other hand, AR feeds exhibited performance similar to VGO with a slight increase in coke formation.     

反应温度对LCC-2催化剂催化裂解制低碳烯烃性能的影响

以中国石油大庆炼化公司重油催化裂化装置所用原料油为原料,在固定流化床催化裂化试验装置上评价了LCC-2型催化剂的反应性能。结果表明,反应温度升高时,汽油、柴油和重油收率逐渐下降,干气和焦炭收率逐渐增加;液化气收率先升高后降低,590℃时达到最大值;乙烯收率逐渐增加,但丙烯和丁烯收率先升高后降低,均在620℃达到最大值。当反应温度为560~590℃时,低碳烯烃总收率最高可达到23.93%,液化气、汽油和柴油总收率最高为81.35%,干气、重油和焦炭的产率相对较低,产物分布较好。     

5种催化裂化原料的裂化性能研究

利用XTL-5型提升管中试装置,对中国石油化工股份有限公司洛阳分公司催化裂化原料各组分的裂化性能进行了评价。结果表明:在完全相同的催化剂和操作条件下,减压蜡油、脱沥青油、常压重油、混合原料和拔头轻油浆的转化率分别为74.00%,69.91%,70.43%,67.16%和36.84%;其裂化性能从优到劣的顺序为:减压蜡油,脱沥青油(与常压重油相似),混合原料,拔头轻油浆;其中掺炼拔头轻油浆对催化进料的裂化性能影响很大,使催化裂化产品的分布明显变差。     

劣质重油高选择性催化裂化(RTC-G)技术开发

为了达到劣质重油催化裂化多产汽油和低碳烯烃的目的,基于拟全浓相、拟均温、拟匀速反应概念,提出使用快速流化床反应器对劣质重油原料进行催化裂化的思路。以中国石化济南分公司2号催化裂化装置原料油为原料,进行了快速流化床反应器催化裂化反应研究,开发了劣质重油原料高选择性催化裂化(RTC-G)技术。研究结果表明：相比于提升管反应器,使用快速流化床反应器催化裂化时的液化气产率和汽油产率分别高2.33百分点和0.35百分点,干气产率低0.34百分点,产品转化率和高价值产品选择性均有一定优势。在快速流化床反应器内选用适当的催化剂,可使劣质重油催化裂化的液化气产率达25.52%,丙烯产率达11.84%。     

FCC轻汽油组合回炼增产丙烯的研究

 以恒源石化提供的FCC轻汽油(LCG)和回炼油以及大庆炼油厂提供的蜡油(VGO)和常压渣油(AR)为原料,以自制LTB-2为催化剂, 在小型提升管装置中,研究了FCC轻汽油催化裂解增产丙烯的可行性以及与不同重质原料油组合进料对增产丙烯的协同效应.结果表明, LCG与回炼油、AR以及VGO组合进料回炼时,缩短了LCG的停留时间,在600℃、停留时间0.03s的反应条件下,干气产率明显降低,由9.94%～16.92%降到5.52%～6.33%,丙烯产率达到13.26%～17.91%,焦炭产率为0.69%～3.50%.     

催化裂化轻循环油生产高辛烷值汽油或轻质芳烃(LTAG)技术关键及实践

基于对催化裂化轻循环油(LCO)烃类组成分子水平表征、LCO中稠环芳烃加氢反应规律和加氢LCO中四氢萘类单环芳烃的催化裂化与氢转移反应规律的认识,开发了将LCO高效转化为高辛烷值汽油或轻质芳烃的LTAG技术。LTAG技术是LCO加氢与催化裂化的集成技术,其技术关键是将LCO中稠环芳烃通过选择性加氢饱和反应生成四氢萘类单环芳烃,再通过强化加氢LCO中四氢萘类单环芳烃的催化裂化反应和抑制氢转移反应,实现LCO的高值化利用。加氢单元可采用LCO单独加氢或LCO与蜡油或渣油混合加氢模式;催化裂化单元可采用以下两种模式:①加氢LCO单独催化裂化生产高辛烷值汽油馏分或轻质芳烃;②加氢LCO与重油原料分层顺序进料催化裂化生产高辛烷值汽油馏分。LTAG技术对于炼油企业降低柴汽比、调整产品结构和提升产品质量提供了有力的支撑。该技术既解决了劣质LCO的出路问题,又弥补了市场短缺的高辛烷值汽油馏分或轻质芳烃的不足,具有显著的经济效益,在炼油企业得到广泛的应用。     

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.     

Advanced Reaction-Terminating Technique for FCC Riser Reactor

Numerical simulation of the performance of a commercial FCC riser reactor was carried out by using a three-dimensional gas-particle, two-phase, turbulent flow-reaction model. Results showed that overcracking of desired products, such as diesel or light fuel oil, occurs and the optimum yields of desirable FCC products could be achieved at a critical riser height of less than 20 m above the feed inlet. This suggests that injection of quenching media above the critical riser height can be an effective option for optimizing the yields of desirable products. The reaction-terminating technique conducted in a commercial FCC riser reactor, using light waste oil, straight-run gasoline, and desalted water as quenching media produced favorable results. Light fuel oil yields increased by 1.3 wt% and 0.95 wt% for using the first two quenching media. Liquefied cracking gas yields increased by 0.43 wt% and 1.03 wt%, whereas the yields of dry gas and coke decreased slightly. Desalted water produced better results than either light waste oil or straight-run gasoline. The improvements of gasoline and liquefied gas yields using desalted water are 0.95% and 0.49% more than those of using straight-run gasoline, respectively.     

Comparison of Downer and Riser Based Fluid Catalytic Cracking Process at High Severity Condition: A Pilot Plant Study

Abstract

Integration of refining and petrochemicals offers economic benefits to both the industries. Converting low value refinery products to high value petrochemicals require novel processes and extra investment. Though FCC is not a new process to the refining industry, it still has a potential for modification to enhance light olefins demanded by reformulated gasoline and the petrochemical industry. In this article a novel, High Severity FCC process based on the downer reactor is presented. Supported by the pilot plant study and comparison with riser, it is shown that the downer FCC reduces backmixing, which is the main cause of gasoline overcracking. Reduction of backmixing reduces coke and dry gas formation, resulting in increased yield of gasoline. Despite the operation at higher temperature, there is reduction in the thermal cracking. Though the light olefins yield is lower in case of downer, the total yield of useful products (gasoline + light olefins) is higher in downer as compared to the same from a riser. The increased yield of gasoline from downer can be converted to light olefins by using ZSM-5 based additives.     

掺炼焦化蜡油对催化裂化反应性能的影响

以减压蜡油掺炼焦化蜡油为原料,在小型固定流化床实验装置上考察了焦化蜡油掺炼比对催化裂化(FCC)反应性能的影响。结果表明:焦化蜡油掺炼比每增加1个百分点,FCC反应转化率约降低0.7个百分点,重油收率约增加0.7个百分点;随着焦化蜡油掺炼比的增加,液化气和汽油收率下降,干气收率上升,柴油和焦炭收率均先增大后减小,且在焦化蜡油掺炼比为20%时,柴油和焦炭收率均达到峰值。     

Additional Feedstock for Fluid Catalytic Cracking Unit

Abstract

Fuel refineries are configured with Fluid Catalytic Cracking Unit (FCCU) to convert Vacuum Gas Oils (VGO) into higher value gasoline and middle distillates. But such refineries also generate 8–12% of heavy oils known either as decant oil or clarified oil (CLO), which has to be downgraded as furnace oil. The recycling of the decant oil into FCCU along with VGO feed is restricted to maintain the coke formation within design limits so that there is no decrease either in conversion or yield of liquid products from FCC operations. The condensed aromatic ring compounds present in CLO makes it undesirable feedstock for cracking, as it promotes heavy coke formation on the catalyst. Hence, CLO is disposed by absorbing in the residual fuel oils.

Of late, FCC units are being operated with higher severity to maximize gasoline, and this has resulted in much higher concentration of condensed aromatics in CLO. Hence, better utilization of CLO depends on separating its saturated hydrocarbon components as a good feedstock for recycling into FCCU with the simultaneous production of extract with enriched poly condensed aromatics as a value added product, namely Carbon Black Feed Stock (CBFS). This article describes several extraction studies carried out on CLO to obtain raffinate for which cracking studies were carried out in automated Micro Activity Test (MAT) unit. The quality of extract phase from each of the above studies was evaluated for its suitability as feedstock for carbon black.     

加氢预处理对俄罗斯渣油催化裂化性能的影响

以硫、氮、金属含量及残炭均较高的俄罗斯减压渣油与减三线蜡油的混合油作原料,考察加氢预处理对渣油混合原料催化裂化性能的影响.结果表明:与未加氢预处理相比,混合原料加氢预处理所得大于350℃加氢渣油进行催化裂化时,产物的总液体收率提高4.41百分点,汽油收率提高5.74百分点,轻油收率提高5.12百分点,焦炭产率下降3.4...     

直馏柴油催化裂化加工技术探索

采用小型固定流化床实验装置,探索研究了直馏柴油催化裂化加工技术路线的可行性。结果表明：催化裂化是将直馏柴油转化为高附加值产物的切实可行的工艺技术;采用催化裂化技术路线时,直馏柴油直接催化裂化反应具有较高的汽油和丙烯收率,分别可达48%和8%左右;采用催化裂解技术路线时,直馏柴油直接催化裂解反应具有较高的低碳烯烃和BTX（苯、甲苯和二甲苯）收率,在反应温度为620℃时乙烯、丙烯和BTX总收率可达39%以上,并可副产22％以上的高辛烷值汽油,其 RON在99以上;重油原料掺炼直馏柴油时,直馏柴油掺入比例较高时催化裂化反应性能较好,但会导致汽油产物中芳烃含量增加。     

催化裂化过程芳烃转化及生焦关系探索

在小型固定流化床试验装置上考察了催化剂微反活性和剂/油质量比对加氢蜡油催化裂化反应中芳烃转化以及生焦量的影响。根据焦炭产率变化,按转化率将加氢蜡油催化裂化反应分为3个阶段,分别考察了各阶段中芳烃转化以及生焦之间的关系。定义了催化剂表观活性概念,并以此考察了汽油芳烃摩尔产率和焦炭产率与催化剂表观活性的关系。通过分析各馏分段中芳烃含量及生焦量随催化剂表观活性的变化得出,芳烃特别是多环芳烃对生焦反应至关重要。在剂/油质量比相同条件下,随着催化剂微反活性增加,汽油芳烃含量和焦炭产率增大;原料转化率相同条件下,随着催化剂表观活性增加,焦炭产率增大。     

加拿大合成原油减压馏分油催化裂化反应性能的研究

以大港石化公司提供的工业平衡催化剂LBO-16为催化剂,在小型固定流化床实验装置上考察了反应温度、剂油比和重时空速对加拿大合成原油（SCO）减压馏分油（VGO）、混合原油（SCO：大港原油为3：7）减压馏分油及大港原油减压瓦斯油的催化裂化产物产率和分布的影响。研究结果表明,反应条件对三种减压馏分油的催化裂化产物变化规律的影响是一致的,反应条件对大港减压馏分油的影响较大。在最优的反应条件下,加拿大合成原油减压馏分油的轻质油收率为64．5％,混合减压馏分油的轻质油收率为66％左右,加拿大合成原油减压馏分油和大港减压瓦斯油相比,有较低的焦炭和液化石油气产率以及较高的柴油产率。     

INFLUENCE OF FEEDSTOCK COMPOSITION ON THE YIELD OF TOTAL CYCLE OIL IN FLUID CATALYTIC CRACKING

ABSTRACT

With a view to gaining an insight into the understanding of the factors responsible for the maximization of the total cycle oil (TCO) in the fluid catalytic cracking of the vacuum gas oils (VGOs) including the one from Bombay High (BH), necessitated by a greater demand for the diesel fuel compared to gasoline, in India, studies have been carried out on three different VGOs in a Xytel Auto Mat II unit over two REY based FCC catalysts differing in their zeolite content using a fixed bed reactor. The fact that the yield of CLO (370^°C+) from BH VGO was much higher than would be expected for a predominantly paraffinic feedstock has led to studying the cracking to compositionally different concentrates isolated from BH VGO and the results are discussed.     

MIP技术在提高液体产品收率上的先进性分析

对具有代表性的工业MIP装置与FDFCC装置、FCC装置和TSRFCC装置的液体产品收率进行对比分析。结果表明：无论是以加氢重油还是以加氢蜡油或者是常压渣油为原料,采用MIP工艺时,汽油与液化气产率均较高,而干气与油浆产率较低,液体产品收率较高;与其它同类技术相比,其液体产品收率最少提高2百分点;且MIP技术的汽柴比高,所生产汽油硫含量低、烯烃含量较低而辛烷值与其它技术相当或较高。这主要是由于MIP技术采用具有独特的双反应区的提升管反应器,并在不同反应区内设计了与烃类反应相适应的工艺条件,可强化重油转化能力,减少干气和焦炭产率,从而提高总液体产品收率。     

抗焦活化剂在重油催化裂化装置上的应用

中国石油抚顺石油化工公司在其1.5Mt/a重油催化裂化装置上进行了Z-18型抗焦活化剂的工业应用。结果表明,加入活化剂后,对装置生产操作和产品质量无不良影响。汽油、干气、焦炭产率分别下降1.17,3.43,0.38个百分点,液化气、柴油、油浆产率分别提高1.40,3.30,0.28个百分点,创效约16355万元/a。     

催化裂化增产汽油的分析与探讨

增产汽油应从占汽油池70%以上的催化裂化工艺技术着手,通过优化加工流程提供具有较好裂化性能的催化裂化原料,选择对大分子裂化能力强的催化剂,维持较高的平衡剂活性,优化反应-再生系统的工艺操作参数,强化催化裂化反应,提高单程转化率;采用催化裂化柴油馏分回炼技术,尤其是富含链状烃和单环芳烃的柴油轻馏分有助于增产高辛烷值汽油;严格控制分馏和吸收稳定系统的操作条件,用足汽油干点和蒸气压质量指标等措施,可有效增加催化裂化汽油产率。