轻烃及石脑油综合利用技术开发及工业应用

分析了汽油质量升级过程中高辛烷值组分烯烃和芳烃含量的降低对汽油辛烷值下降的影响，轻烃及页岩气作为蒸汽裂解原料带来的石脑油相对过剩及芳烃供给结构的变化，新能源及新能源车的国家发展战略对传统炼油行业的挑战；提出了轻烃及石脑油综合利用技术的开发思路，按照转型发展及分子炼油的理念，开发了轻烃脱氢、轻烃芳构化、C₅~C₆异构化及石脑油催化重整成套技术等系列技术，并实现了工业化。通过这些技术与传统技术的集成，可以灵活调整产品方案。     

催化裂化装置加氢石脑油回炼对产品分布的影响

为确保全厂生产平衡,满足不同标号汽油产品生产要求,催化裂化单元间歇回炼轻质污油,轻质污油自距一段提升管反应器出口下方500 mm处经一次雾化后喷入。用加氢石脑油作为轻质油回炼期间,随着加氢石脑油回炼量的增加,干气、液化石油气、柴油和焦炭收率整体呈下降趋势,汽油收率明显提高,油浆收率也有小幅提高,但气体产品中烯烃含量明显降低,汽油辛烷值和芳烃含量也呈下降趋势。分析石脑油回炼前后产品分布以及相关表征公式发现,随着加氢石脑油回炼量的增加,异构化反应和氢转移反应强度逐渐增加,催化裂化反应强度始终高于热裂化反应。了解加氢石脑油回炼对反应过程和产品分布的影响,可以对未来生产调整提供数据参考。     

加氢裂化装置提高轻油收率方案的探讨

对国内加氢裂化装置提高石脑油收率的方案进行分析和探讨。结果表明:通过提高反应温度和降低空速,轻重石脑油总收率可以提高13.02个百分点;通过掺炼催化裂化柴油,轻重石脑油收率可增加0.96~4.24个百分点;通过提高尾油循环量可以大幅度提高轻重石脑油收率,轻重石脑油收率最高可达60.78%,比原生产方案高37.59个百分点;通过提高石脑油干点也可以提高石脑油的收率,这些措施为寻求提高石脑油收率的同类装置提供了一定的借鉴和参考。     

石脑油芳构化改质工艺方案的分析与应用

石脑油芳构化改质工艺技术(GAP),是利用择形分子筛催化剂将石脑油中烷烃转化为芳烃来提高汽油辛烷值的新的工艺技术。GAP工艺技术总液体收率高达93％～96％,其中高辛烷值汽油组分收率65％～75％,液化石油气收率20％～30％;汽油辛烷值(RON)根据需要可在86～93之间灵活调节。根据各个厂家的不同情况,可以选择汽油辛烷值高的GAP—Ⅰ和GAP—Ⅱ工艺方案,也可以选择总液体收率高的GAP—Ⅲ工艺方案。该工艺技术为炼油厂生产清洁汽油开辟了一条新途径。     

络合法分离富集重石脑油中正构烷烃

从石脑油中分离或富集正构烷烃可以降低催化重整和乙烯生产的成本,优化原料组成,提高生产效率。使用尿素和硫脲为络合剂、质量分数95%的乙醇为活化剂,将正辛烷、异辛烷、甲基环己烷、甲苯按不同比例混合作为模拟石脑油进行络合富集,考察络合相产品中各组分含量及正辛烷收率。结果表明：使用尿素/硫脲络合富集重石脑油中的正构烷烃是可行的,络合试验最佳反应条件为：质量分数为95%的乙醇活化剂用量80 mL,模拟石脑油用量60 mL,尿素/硫脲质量比50/21,络合温度-10℃,时间1 h;少量芳烃会对正辛烷分离效果产生一定的负面影响,工业上可以先用萃取法分离芳烃,然后再进行络合分离。     

延迟焦化汽油蒸汽热裂解性能实验室评价

在裂解评价装置上对加氢前后的延迟焦化汽油油品进行了裂解性能评价.结果表明:未加氢的焦化汽油裂解性能较差,结焦严重;加氢后的焦化汽油是一种优异的乙烯裂解原料,可以单独裂解或与石脑油混合裂解,其裂解的乙烯收率和三烯(乙烯、丙烯和丁二烯)总收率均较高,分别约为30%,50%,接近西部裂解性能很好的库西石脑油的水平;于停留时间约为100 ms,在一定范围内提高焦化加氢汽油的裂解温度,对提高其乙烯收率和三烯收率有利,适宜的裂解温度为890 ℃.     

齐鲁石化烯烃厂优化生产

近年来，齐鲁石化公司烯烃厂为提高企业竞争力优化原料，实现了乙烯收率较高的石脑油为第一主原料，并逐步摸索轻烃、石脑油、重质原料的最佳混合裂解比例，不断增加轻烃原料的比重，使乙烯收率、装置加工损失率等技术指标逐步趋优。     

浅谈轻石脑油异构化在国内炼油厂的应用

国家车用汽油质量标准对汽油中的硫含量、烯烃含量和饱和蒸气压等指标的限制与规定日趋严格,清洁汽油的生产需要低硫、低烯烃并且辛烷值较高的调和组分,轻石脑油异构化油不含硫、不含烯烃、不含芳烃,采用不同的轻石脑油异构化技术和加工流程可以使轻石脑油辛烷值(RON)提高10~20。轻石脑油异构化技术是成熟的工艺,在国外应用广泛。国内轻石脑油异构化技术研究也有较好的基础,并已有工业应用装置。随着乙烯裂解和制氢等装置的原料结构优化,将为轻石脑油异构化装置提供更多的轻石脑油作原料。轻石脑油异构化不仅可以解决轻石脑油的产品出路问题,而且对于炼油厂的产业结构调整、生产流程优化、汽油质量升级都具有积极的作用。轻石脑油异构化将是国内清洁汽油生产的重要技术手段之一。     

轻质烃共裂解技术优化研究及应用

采用BSPA乙烯原料裂解性能评价试验装置,对乙烷和丙烷共裂解技术、油田轻烃及拔头油与石脑油分组裂解和按不同掺混比例混合裂解技术进行试验研究。研究结果表明,乙烷和丙烷共裂解可提高乙烯收率和双烯收率,且掺入乙烷的质量分数不低于80%为宜。油田轻烃和拔头油适于“分储分裂”,如其储量不足且必须与石脑油混合共裂解,则掺入油田轻烃的质量分数应不低于30%,尽量≥70%;掺入拔头油的质量分数应不低于40%,尽量≥70%。将研究结果应用于工业乙烯裂解装置,取得了显著的工业应用效果。      

LHAT-M连续移动床轻烃芳构化技术及其应用

介绍了LHAT-M连续移动床轻烃芳构化技术及工艺流程特点。以中海油某炼油厂新建一套500 kt/a轻烃芳构化装置为例,对LHAT-M技术的实际应用效果进行了分析。该装置按照生产芳烃工况设计,同时可满足生产汽油调合组分的工况。分析结果表明:通过灵活调整原料结构和操作条件,LHAT-M工艺具备生产芳烃和汽油调合组分的能力。在芳烃工况下,以液化石油气和轻烃为原料,可实现55%以上的液体收率,生产的芳烃通过精馏可分离出符合国标的甲苯和混二甲苯产品,并副产氢气;在汽油工况下,可实现60%以上的液体收率,汽油组分中苯体积分数小于0.8%,芳烃的体积分数不大于35%,可作为国Ⅵ汽油的调合组分。装置能耗为97.44 kg/t(以kg/t表示千克标油每吨),吨油加工效益为209.03元/t。     

轻石脑油优化利用的经济性分析

为提高轻石脑油的利用价值,实现“宜油则油,宜烯则烯”的原料优化目的,通过正异构烷烃分离使不同组分物尽其用,富含异构烷烃的轻石脑油辛烷值高,用作汽油调合组分以提升全厂汽油池辛烷值及改善辛烷值分布,富含正构烷烃的轻石脑油用作蒸汽裂解原料提高乙烯收率。在企业汽油池辛烷值不足的情况下,实施轻石脑油正异构烷烃吸附分离项目可以提高全厂汽油池辛烷值以及增加高标号汽油产量,同时也可以增加蒸汽裂解装置的乙烯收率。以某企业为例的测算结果表明,轻石脑油正异构烷烃吸附分离方案实施后对企业的经济效益有很大提升,按2019年布伦特原油60美元/bbl(1 bbl=159 L)价格体系测算,汽油和烯烃产品收入可增加73 964万元/a,扣除燃料动力费用和辅助材料费用增加的7 674万元/a,项目净收益为66 290万元/a。     

汽油+芳烃型重整装置原料组分的优化

在石脑油原料过剩的情况下,针对汽油+芳烃型重整装置开展了原料组分优化的研究。通过对预加氢精制油和加氢裂化石脑油各个馏分段的族组成进行分析,模拟测算各馏分段在重整反应过程中的变化,提出应将在重整反应过程中对辛烷值增加贡献最大的石脑油组分作为重整原料。装置试验结果表明,将加氢裂化石脑油120~140℃的馏分由调合汽油改为作重整原料,预加氢精制油初馏点提高至80℃,终馏点降低至169℃,可在装置加工负荷不变的情况下,每月增加效益320万元。     

Light Naphtha Isomerization Process: A Review

The isomerization process is gaining importance in the present refining context due to limitations on gasoline benzene, aromatics, and olefin contents. The isomerization process upgrades the octane number of light naphtha fractions and also simultaneously reduces benzene content by saturation of the benzene fraction. Isomerization complements catalytic reforming process in upgrading the octane number of refinery naphtha streams. Isomerization is a simple and cost-effective process for octane enhancement compared with other octane-improving processes. Isomerate product contains very low sulfur and benzene, making it ideal blending component in refinery gasoline pool. Due to the significance of isomerization to the modern refining industry, it becomes essential to review the process with respect to catalysts, catalyst poisons, reactions, thermodynamics, and process developments. The present research thrust in this field along with future scope of work is also discussed briefly. The isomerization process is compared with another well-known refinery process called the catalytic reforming process.     

ADVANCES IN THE CHEMISTRY OF CATALYTIC REFORMING OF NAPHTHA

Catalytic reforming of naphtha remains the key process for production of high octane gasoline and aromatics (BTX) which are used as petrochemicals feedstocks. The increased demand for these products has led refiners to investigate ways for improving the performance of the reforming process and its catalysts. Moreover, in order to comply with environmental restrictions, the reduction in lead content would require further increase in the reformate octane number. In response to these requirements, refiners and catalyst manufacturers are examining the role of the catalysts in improving the selectivity to aromatics and in octane enhancement. By understanding the chemistry and the mechanism of the reforming process, higher performance catalysts with longer life on stream and lower cost can be developed.

This review covers recent developments in reforming catalysts, process reaction chemistry and mechanism. It also highlights prospective areas of research.     

DISTILLATION CHARACTERISTICS AND COMPOSITIONAL ANALYSIS OF ARABIAN LIGHT STRAIGHT RUN NAPHTHA

Straight run naphtha is a basic constituent of refined petroteum products. It consists mainly of aliphatic hydrocarbons along with small amounts of naphthenic and aromatic hydrocarbons. It has a wide boiling range between 95°F and 410°F. Currently, its main utilization is as gasoline blend, however, naphtha is a potential feedstock for the production of various petrochemicals. Continuous catalytic reforming of naphtha can produce aromatic compounds in amounts up to 70% of the reformat. Nevertheless, the catalytic reforming process is usually associated with various limitations that may be related to the wide-ranging composition of naphtha. In this study straight run naphtha derived from Arabian Light crude oil was fractionated, and the hydrocarbon composition of its different distillation cuts was determined. The results indicate that, straight run naphtha can be split into two main fractions. A light fraction boiling between ambient temperature and 225°F, consists mainly of C₇^(-) and a medium heavy fraction boiling between 225°F and 335°F, consists mainly of C₇⁽⁺⁾. Detailed distillation characteristics, along with compositional analysis of SRN seems to be useful for diversifying its processing technologies, and upgrading currently applied processing practices to yield various high-value products and petrochemicals feed stocks.     

提升轻石脑油辛烷值的方案比选

为了应对车用乙醇汽油调和组分油国Ⅵ质量标准升级,满足清洁化生产要求,更多企业考虑在汽油池中增加异构轻石脑油的掺入比例来提高全厂汽油辛烷值以及改善辛烷值分布。介绍了几种提高轻石脑油辛烷值的方法,重点分析脱异戊烷分离和吸附分离两种方案,探讨对全厂汽油池的影响及提高经济效益的可行性。     

DISTILLATION CHARACTERISTICS AND COMPOSITIONAL ANALYSIS OF ARABIAN LIGHT STRAIGHT RUN NAPHTHA

ABSTRACT

Straight run naphtha is a basic constituent of refined petroteum products. It consists mainly of aliphatic hydrocarbons along with small amounts of naphthenic and aromatic hydrocarbons. It has a wide boiling range between 95°F and 410°F. Currently, its main utilization is as gasoline blend, however, naphtha is a potential feedstock for the production of various petrochemicals. Continuous catalytic reforming of naphtha can produce aromatic compounds in amounts up to 70% of the reformat. Nevertheless, the catalytic reforming process is usually associated with various limitations that may be related to the wide-ranging composition of naphtha. In this study straight run naphtha derived from Arabian Light crude oil was fractionated, and the hydrocarbon composition of its different distillation cuts was determined. The results indicate that, straight run naphtha can be split into two main fractions. A light fraction boiling between ambient temperature and 225°F, consists mainly of C₇ ^(?) and a medium heavy fraction boiling between 225°F and 335°F, consists mainly of C₇ ⁽⁺⁾. Detailed distillation characteristics, along with compositional analysis of SRN seems to be useful for diversifying its processing technologies, and upgrading currently applied processing practices to yield various high-value products and petrochemicals feed stocks.     

FCC汽油烃重组生产高辛烷值汽油并联产乙烯裂解料

采用烃重组技术处理催化裂化(FCC)汽油(已经过加氢脱硫处理),既可获得质量满足国Ⅲ、国Ⅳ标准且研究法辛烷值比加氢前提高2个单位的汽油,同时联产可作为优质乙烯裂解原料使用的烷烃.蒸汽裂解评价结果表明,以烃重组C≥6石脑油为原料,三烯收率大于48％,m(丙烯)/m(乙烯)约为0.5.烃重组技术不仅可显著提高炼化一体化程度,还可为炼油厂优化FCC、重整等生产装置,增产高附加值产品增加机会,经济效益显著.     

Research on Optimized Utilization of Naphtha Resources Based on Adsorptive Separation with Zeolite

By means of molecular scale management, the technology of separating normal paraffins from naphtha through adsorption using 5A molecular sieves was studied with the purpose of optimizing the utilization of naphtha. The raw materials used in steam cracking and catalytic reforming processes could be allocated properly. During the adsorption process, the separation efficiency of the normal paraffins was above 99.9% with the purity of normal paraffins in the desorption oil exceeding 98.2%. With the use of the desorption oil as the feedstock of steam cracking, the ethylene yield increased from 29.7%--35.0% to 41.4%-49.2% compared to that of the naphtha in the existing plant under similar operation conditions. The potential aromatic content of the raffinate oil rose from 30.6% to 43.5% compared to that in naphtha. The research octane number of the raffinate oil reached more than 85 with an increase of 20 units compared to that of naphtha, so the raffinate oil is more suitable for use as a blending component for high-octane clean gasoline.