含硫原油加工对加氢裂化装置的影响及对策探讨

通过对加工俄罗斯蜡油的分析,阐述了加工含硫蜡油后给加氢裂化装置操作带来的影响、硫化氢的腐蚀、对产品质量的影响,以及采取的相关措施,并摸索出加工含硫蜡油的应对办法。     

低温费托合成蜡油加氢裂化精制技术的研究进展

低温费托合成技术因具有产品质量性好、反应耗能低、生产能力大且催化剂种类广泛等优点在煤化工领域备受关注,低温费托合成的蜡油产品可通过加氢裂化精制获取高品质清洁油品,具有巨大的应用价值。本文首先阐述了费托合成的产物特性,分析了加氢裂化过程的反应特点、双功能催化剂的碳正离子反应机理及蜡油主要反应历程。在此基础上,着重综述了蜡油加氢裂化双功能催化剂的研究进展,讨论了活性金属组分、载体以及助剂对加氢裂化过程的影响,分析表明活性金属的负载量、载体的酸量和孔道结构对催化性能有极大影响,合理优化和平衡加氢金属活性位和裂解酸性位是确保蜡油加氢裂化催化剂活性的关键。更为重要的是,基于分子筛载体的择形效应,实现载体多级孔结构和活性位的理性集成无疑会促进蜡油加氢产物的合理分布。     

A two-stage fixed-bed reactor for direct hydrotreatment of volatiles from the hydropyrolysis of biomass: effect of catalyst temperature, pressure and catalyst ageing time on product characteristics

This investigation involved the hydropyrolysis of biomass (eucalyptus globulus) and the immediate catalytic hydrocracking of pyrolytic oils in the second stage of the reactor. The effects of temperature, pressure and the catalyst ageing time on the final product tar have been studied using the catalyst Zeolite H-ZSM5. The catalytically hydrocracked tar/oil products were characterised and compared with the hydropyrolysis product from the first stage of the reactor to determine the effect of catalytic hydrocracking. The carbon deposition on the catalyst has been examined using thermogravimetric analysis. The tar yields after catalytic hydrocracking decreased with increasing pressure and temperature of the cracking stage. The tar yields at 10 bar pressure were greater than those at 40 bar pressure. The fresh zeolite catalyst trapped more than 40% of the product from the hydropyrolysis stage and TGA evidence indicated that this was not as carbon deposition but as volatiles trapped in the zeolite matrix. Reuse of the catalyst resulted in little more uptake of volatiles; however, extended use of the catalyst did not result in increased yields of liquid products but in increased production of light volatiles or gas. The H-ZSM5 catalyst appeared to act as a more active cracking catalyst rather than to promote hydrogenation or deoxygenation of the liquids produced in the hydropyrolysis stage. Characterisation of the liquids by SEC and UV fluoresence indicated that structural changes were relatively minor despite the significant changes in yields of liquids with process conditions. Available reaction routes do not appear to allow specific deoxygenation pathways to predominate without disintegration of parent molecules to lighter volatiles, under the conditions used here.     

Catalytic coprocessing of LDPE with coal and petroleum resid using different catalysts

Catalytic coprocessing of low density polyethylene (LDPE) with coal and heavy petroleum resid was investigated using four different catalysts that included both hydrotreating and hydrocracking catalysts. Reaction systems that were evaluated included LDPE alone; LDPE with coal; and LDPE, coal, and resid. The catalysts used were NiMo/Al₂O₃, a hydrotreating catalyst with some hydrocracking activity, and the hydrocracking catalysts Zeolyst 753, NiMo/zeolite, and HZSM-5. These catalysts were reacted individually or in combinations of 10 wt.% of each hydrocracking catalyst in NiMo/Al₂O₃. The catalytic reactions were performed at two temperatures, 400 and 430°C, using 1 wt.% of each catalyst or a combination of catalysts on a total feed basis. The effects of the different catalysts on the reaction products were measured in terms of solvent fractionation and total boiling point distribution. Reactions at the higher reaction temperature of 430°C resulted in substantially higher conversion and production of lighter products than the reactions at 400°C. The LDPE reaction system was sensitive to the catalyst type, and yielded increased conversion and lighter products when Zeolyst 753 and NiMo/zeolite were used. By contrast, the conversion and product slate obtained from the LDPE and coal systems were low and showed no effect due to the different types of catalyst. Introduction of resid to the LDPE/coal system increased the reactivity of the system and allowed the catalysts to have a larger effect. The hydrocracking catalysts were the most active in producing more conversion and hexane soluble material. Comparison of the effect of increasing the reaction time up to 5 h with 1 wt.% catalyst loading to the effect of increasing the catalyst loading from 1 wt.% to 10 wt.% for a reaction time of 1 h showed that increased reaction time was much more effective than catalyst loading in converting the solid LDPE to liquid reaction products.     

固定床渣油加氢工艺发展与运行问题研究

近年来,随着我国国民经济的迅猛增长及石油价格的不断攀升,重油轻质化的要求越来越迫切,同时为了符合国家相关环保要求,渣油的回收再利用成为炼化界普遍关注的热点。渣油加氢工艺是处理渣油最有效的工艺方案,其能够较为彻底地去除渣油中的硫、氮、金属及残炭等杂质对环境的污染。本文从渣油加氢工艺的发展、反应原理及运行问题等方面分析入手,简要说明了渣油加氢工艺的应用现状。     

Hydro-thermal cracking of heavy oils and its model compound

Liquid-phase cracking of vacuum gas oil (VGO) was performed over NiMo supported nonacidic catalysts under 713 K and 8.0 MPa of hydrogen in a batch reactor, which is termed hydro-thermal cracking. Compared with VGO thermal cracking under the same reaction conditions the new process showed the suppressed naphtha yield (from 22.4 to 13.5 wt.%) and VGO conversion (from 65.7 to 64.0 wt.%) and increased the middle distillate yield (from 44.3 to 49.3 wt.%). At the same conversion level, the yield ratio of middle distillates to naphtha for this new process was two times higher than that for VGO hydrocracking. The VGO hydrocracking over USY-supported NiMo proceeded at much lower temperatures but gave higher naphtha yields. Both the thermal cracking and the hydro-thermal cracking of n-dodecyl benzene (C₆H₅(CH₂)₁₁CH₃) yielded toluene as the major aromatic product, whereas its hydrocracking over NiMo/USY yielded benzene as the major aromatic product. The reaction mechanism of this new process was assumed to consist of thermal cracking of hydrocarbon molecules via the free radical chain mechanism and the catalytic hydroquenching of free radicals.     

100万t/a加氢裂化装置开工总结

中国石油辽阳石化100万t/a加氢裂化装置于2010年10月底顺利完成装置中交,2011年4月24日装置出合格产品,实现一次开车成功。介绍装置概况、工艺特点和主要产品,阐述自催化剂装填到开工进油的主要开工过程,包括催化剂装填、催化剂硫化、低氮油开工等一系列开工步骤,并对主要产品性质及反应系统的操作参数进行了分析,最后初步评价了装置初期生产情况。     

Conversion of plastics/HVGO mixtures to fuels by two-step processing

A blend containing 20 wt.% low density polyethylene (PE) and 5 wt.% polyvinylchloride (PVC) in heavy vacuum gas oil was pyrolyzed at 623 K (dechlorination step). This mixture was then thermally and catalytically cracked in the presence of hydrogen at 673–723 K in a batch reactor (hydrocracking step). The liquid products from hydrocracking contained no chlorine compounds although the chlorine amount in the dechlorinated mixture was 700 ppm. Experiments have shown that the dechlorination step and the temperature had great effect on the product distribution from the hydrocracking step. It was observed that the dechlorination step led to both degradation of PE and dechlorination of PVC and that PE could be completely cracked with/without a catalyst by hydrocracking even though at 673 K. The use of a catalyst decreased the gas yield and led to an increase in coke yield at 723 K. The effect of the catalyst on the boiling point range of liquid product obtained from hydrocracking depended on the reaction temperature. The chlorine compounds in dechlorinated mixture affected the catalytic activity of the catalyst especially at 723 K. 75% and 55% of the liquid products obtained at 723 K with and without a catalyst, respectively, were hydrocarbons having boiling points ranging from 323 to 473K.     

加氢裂化装置掺炼焦化蜡油工艺研究

介绍了焦化蜡油的主要加工方法,即混入催化裂化进料中或混入加氢裂化进料中,通过文献和试验从对装置、产品分布及产品性质的影响讨论比较了两种加工过程的优缺点,提出了加氢裂化装置大比例掺炼焦化蜡油的可能性.     

减压柴油管式炉裂解制烯烃

中国某些产地的原油具有低硫、高石蜡烃和低芳烃含量的特性。用这类原油炼制所得的减压柴油馏分具有同样特征,因而预测将有良好的裂解性能。为此进行了工艺研究。 在处理量约为2公斤/时,温度和压力分布可以模拟的裂解装置中,进行了中国减压柴油动力学研究和裂解产品分布规律试验。根据模试结果;综合中试和部分工业数据,提出了减压柴油裂解反应速度常数方程的有关参数值,以及原料特性和工艺参数对裂解产品收率关联图及数学关联式。 在处理量为100公斤/时的中试裂解装置中进行产品分布试验和工艺过程有关技术研究,着重考察了炉管对流段、辐射段的运转情况、高压急冷锅炉的操作特性。 研究结果表明,在760℃中等裂解深度时,汽油比为0.75—1,停留时间0.4—0.5秒,烃分压0.8公斤/厘米~2,主要产品收率为:乙烯22.5—23%,丙烯16—17.5%,丁二烯4.7—5.2%,重质燃料油10—12%。该油品与国外中东轻柴油裂解所得产物收率相仿,是工业管式炉的一种好原料。     

Hydrocracking of petroleum gas oil over NiW/MCM-48-USY composite catalyst

MCM-48-USY composite materials were prepared by coating USY zeolite by a layer of MCM-48 mesoporous material at different meso/microporous ratios (SiO₂/USY ratios of 0.1, 0.2, 0.3, 0.4, 0.5) and used as support for nickel and tungsten. The NiW/MCM-48-USY catalysts were prepared using the incipient wetness method. The prepared catalysts were characterized by TPD-TGA acidity, TGA thermal stability, BET surface area, pore volume, pore size, XRD, SEM and TEM and then tested for hydrocracking of petroleum gas oil at reaction temperature of 450 °C, contact time of 90 min and catalyst to gas oil ratio of 0.04. In all prepared samples, the catalyst activity and properties were improved with increasing SiO₂/USY ratio and found that maximum values of a total conversion and liquid product (total distillate fuels) were obtained at SiO₂/USY ratio of 0.5. Finally, the obtained results from hydrocracking of gas oil over composite MCM-48-USY catalysts were compared with those obtained over physically mixed USY and MCM-48 catalysts.     

Laboratory evaluation of the impact of the addition of resid in FCC

The conversion and product distributions from a mixture of 10% atmospheric tower bottom resid and a DO hydrocarbon cut similar to LCO that represented commercial feedstocks were assessed over two equilibrium commercial FCC catalysts in a laboratory CREC Riser Simulator reactor. The reaction temperature was 550 °C, the catalyst to oil ratio was 5.8 and the reaction times were up to 25 s. The conversion of the mixture as compared to the DO base feed was higher in the case of the most active, conventional catalyst, and remained very similar on the resid catalyst. Since the yields of the main hydrocarbon groups dry gas, LPG, gasoline and coke followed very similar trends when the two pure feedstocks were converted, the corresponding yields from the mixture also obeyed that behaviour, and were the consequence of the conversion reached. The impact of the different catalyst formulations was observed in, for example, the selectively different yields obtained from the conversion of the resid, and in the composition of the gasoline. Independently of the catalyst, the gasoline was more olefinic and less aromatic when the resid was present. It was shown that in order to evaluate properly a given combination of feeds, catalysts and conditions, they must be considered together.     

Prediction of product quality for catalytic hydrocracking of vacuum gas oil

The main objective of this work is to develop a predictive model for predicting the product quality of vacuum gas oil (VGO) hydrocracking process. Experimental data were obtained using a pilot plant hydrocracking catalytic reactor loaded with the same catalyst type used in a local refinery. Two sets of experimental runs were conducted under various operating conditions. The first one consisted of 18 runs and was used for parameter estimation, while the second set consisted of 29 runs and was used for model validation. Distillation curves of the cracked products were obtained using the simulated distillation (SimDist) test. A distribution model based on probability density function was used to develop the predictive model. The distribution model presents the boiling point as a function of the distilled weight fraction. Model parameters were estimated and related to the specific gravity of the cracked product. Model validation results showed that the proposed model is capable of predicting the distillation curves of the hydrocracked products accurately, especially at high operating severity. Simplicity and accuracy of the developed model makes it suitable for online analysis, to estimate the conversion as well as the product distribution of hydrocracking units in refineries.     

Behavior of sulfur species present in atmospheric residue in fluid catalytic cracking

The selective removal of sulfur species in atmospheric residue (AR) is strongly wanted since the species of the hydrodesulfurized AR (HDS-AR) define the sulfur content of the product gasoline in the subsequent fluid catalytic cracking (FCC). Hence, the correlations between sulfur species in HDS-AR and FCC gasoline were explored in the present study. HDS-AR was fractionated into vacuum gas oil (VGO) and vacuum residue (VR) by distillation. Reactivities of HDS-AR (S = 3000 mass ppm) and its VGO (S = 900 mass ppm) were measured by micro activity test to clarify which fractions and sulfur compounds in HDS-AR were converted into gasoline and its sulfur species. The yields and sulfur contents of the product gasoline were 45.0 mass% and 52 mass ppm from HDS-AR and 47.7 mass% and 14 mass ppm from VGO, respectively. The sulfur content of the gasoline from HDS-AR was markedly higher than that from HDS-VGO. The saturate and aromatic fractions in HDS-AR are mainly converted to the gasoline in the FCC process, providing similar gasoline yields from HDS-VGO and HDS-AR. Thiophene, methylthiophenes, and benzothiophenes were major sulfur species in both gasolines from HDS-AR and HDS-VGO. Such sulfur species are concluded to be derived from benzothiophenes in VGO and dibenzothiophenes in VR fractions, respectively through hydrogen transferring ring opening and dealkylation during FCC. Sulfur compounds are also produced from H₂S and olefins in FCC, increasing the sulfur content in the product gasoline. The larger sulfur content in the gasoline from HDS-AR than that from HDS-VGO is ascribed to more H₂S being produced during the FCC process as well as dibenzothiophenes being present in the feed.     

煤焦油加氢转化技术

分析了国内已经研究开发的煤焦油加氢转化技术,按照各技术的特点和轻油产品收率将现有煤焦油加氢转化技术划分为轻馏分油固定床加氢精制、减压馏分油固定床加氢裂化、全馏分油固定床加氢裂化、延迟焦化-固定床加氢裂化联合加工、悬浮床和沸腾床加氢裂化5类技术,分别介绍了每种技术的工艺流程特点和发展状况,分析了各自的优缺点、局限性、技术难点和实用性。建议今后应关注煤焦油生产芳烃产品、酚类产品技术的开发,以及开发煤焦油脱水脱盐技术,进一步完善、配套煤焦油加氢转化技术。     

超重力技术应用于不同磺化剂合成石油磺酸盐表面活性剂

With the application of HIGEE process intensification technology, petroleum sulfonate surfactant used for enhanced oil recovery was synthesized from petroleum fraction of Shengli crude oil with three sulfonating agents, including diluted liquid sulfur trioxide, diluted gaseous sulfur trioxide and fuming sulfuric acid. For each sulfonating agent, different operation modes (liquid-liquid or gas-liquid reaction with semi-continuous or continuous operation) were applied. The effects of various experimental conditions, such as solvent/oil mass ratio, sulfonating agent/oil mass ratio, gas/liquid ratio, gas concentration, reaction temperature, rotating speed, circulation ratio, reaction time and aging time, on the content of active matter and unsulfonated oil were investigated. Under relatively optimal reaction conditions, the target product was prepared with high mass content of active matter (up to 45.3%) and extremely low oil/water interfacial tension (4.5×10–3 mN•m–1). The product quality and process efficiency are higher compared with traditional sulfonation technology.     

Catalytic hydrocracking of bitumen at mild experimental condition

Mo-containing catalysts were prepared by impregnation method using silica-based porous supports and their physical properties were characterized by BET, XRD and TEM. Catalytic hydrocracking of bitumen extracted from oil sand was carried out in a high pressure reactor using Athabasca oil sand over 5 wt% Mo containing catalyst supported on SiO₂, MCF(Meso Cellular Foam) and SBA-15, respectively, under the conditions of 200 °C, 20 h and 10 atm of H₂ gas. Catalytic hydrocracking activity was estimated by analyzing H/C mole ratio based on EA data, and TGA was employed to compare the thermal behavior of bitumen before and after reaction. Upon hydrocracking over Mo/MCF catalyst, H/C was increased from 1.50 (bitumen itself) to 1.66.     

Naphtha derived from polyolefins

Conversion of polyolefins (HDPE, LDPE and PP) into feedstock naphtha was investigated by hydroliquefaction process. Hydroliquefaction experiments were carried out under cold hydrogen pressure of 5 MPa at the temperatures between 375 and 450 °C in absence and presence of catalyst. Two types commercial catalysts were used, a hydrocracking catalyst (DHC-8) and a hydrogenation catalyst (HYDROBON). The effect of temperature and catalyst type on product yields and composition of gas and liquid products was investigated. The temperature was the main effect in hydroliquefaction. DHC-8 showed good cracking activity, but it gave the liquid product containing high olefin content same as thermal run. Although HYDROBON catalyst produced the sufficient amount of liquid (and naphtha fraction) at the higher temperature, it gave the liquid product with very low olefin content. The naphtha fractions obtained from polyolefins under the optimal hydrocracking conditions were analyzed by PIONA instrument to determine the hydrocarbon groups. PIONA analysis showed that the naphtha obtained from hydroliquefaction over HYDROBON catalyst could be used as a petrochemical feedstock. However, the naphtha obtained in presence of DHC-8 catalyst, which is to be used a feedstock, was needed further hydrogenation treatment.     

宽馏分油加氢制取溶剂油和白油的研究

以洛阳金达石化有限责任公司特种油品厂10×104 t/a宽馏分装置的宽馏分油为原料,采用催化剂a和催化剂b组合工艺,在金达研发中心200 m L加氢装置上进行高压加氢制取溶剂油和白油等特种油品的研究。考察了反应压力(16.5~18.5 MPa)、反应温度(315~355℃)、质量空速(WHSV)(0.3~0.6 h-1)和氢油体积比(1 000:1~1 800:1)对加氢精制产物油性质的影响,并确定最佳的工艺参数。结果表明,产物油硫含量随着反应温度、压力、氢油体积比的增大而减小,随着空速的增大而增大;产物油芳烃含量随着反应压力、氢油体积比的增大而减小,随着反应温度和空速的增大而增大。对加氢产物油进一步蒸馏切割得到25%溶剂油馏分、60%白油馏分和11%减底尾油馏分。对产物油馏分进行含量分析,生成的产品油分别满足溶剂油和白油标准。     

220万吨/年加氢裂化装置开工技术总结

中国石油广西石化220万吨/年加氢裂化装置于2010年6月底顺利完成装置中交,2010年9月28日装置出合格产品,实现一次开车成功。本文对此次开工过程的主要工作,如系统气密,分馏水联运、冷油运、热油运,催化剂装填,硫化,切换蜡油等进行了总结,并对开工中遇到的问题进行了分析。