Effect of Solvents for the Production of Cyclopentane by Extractive Distillation

In view of the rapid phasing out of fluorocarbons due to their adverse ozone-depleting potential, alternative environment-friendly chemicals are being explored for blowing polyurethane, the key insulation material in refrigeration industries. Cyclopentane with required physical and thermal conductivity properties has emerged as the most appropriate alternative as it can be acquired from light petroleum hydrocarbons, which are abundant. Light naphtha is a mixture of several closely boiling hydrocarbons and hence even a narrow fractional distillation may not enrich cyclopentane for required purity and instead it results only in an azeotropic mixture. This article describes the work carried out in obtaining commercially pure cyclopentane from light naphtha through an extraction-distillation combined operation which is commonly termed as “extractive distillation.” The solvent type and key operating parameters, namely, feed naphtha cut range (heart cut), solvent/feed ratio were studied and the results obtained were further correlated with simulated model prediction.     

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.     

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本文介绍单塔双釜接替式间歇精馏装置，从轻烃中分离出丙烷，丁烷，或丙丁烷混合物及Ｃ５，Ｃ６等窄馏分或宽馏分的溶剂。该装置的特点是塔操作的间歇时间短，产品精度高，可适应原料组成和进料量的变化。该技术是轻烃深加工综合利用的一种有效方法。     

Effect of nitrogen-containing compounds in catalytic feedstock on the composition of gasoline

Hydrotreated vacuum gasoil from straight-run distillation of a Russian export mixture (GRES) and the same gasoil after treatment with sulfuric acid (OGRES) so that nitrogen-containing compounds were totally removed and the hydrocarbon composition was almost unchanged were investigated as catalytic feedstock. Cracking was conducted on a MAT laboratory setup with different catalyst and feedstock ratios, constant reactor temperature of 527°C, and feedstock contact time with catalyst of 30 sec. Elimination of nitrogen-containing compounds from GRES increased the yield of cyclic hydrocarbons in the naphtha cut with lower aromatization and decreased the yield of macromolecular aliphatic hydrocarbons with lower olefination. In the absence of basic nitrogen, the activity and selectivity of the catalyst for the naphtha and light cyclic petroleum products increased. The naphtha obtained from OGRES, in comparison to the naphtha obtained from GRES, contains more cycloalkanes and less alkanes and alkenes and has lower research and motor octane numbers.     

380万t/a连续重整装置混合重石脑油原料的模拟优化及应用

利用广东辛孚科技有限公司开发的SP-Reform流程模拟软件,在浙江石油化工有限公司380万t/a连续重整装置上建立了全流程反应机理模型,并结合其3种重石脑油原料馏程差异的生产实际,进行了模型的模拟优化。结果表明:建模后的优化模拟结果与装置实际工况基本相吻合,特别是关键目标产品C≥6重整生成油性质相关指标与实际工况的相近,说明所建模型可靠,可用于该装置的工艺流程优化及生产指导;在保持柴油加氢裂化重石脑油与蜡油加氢裂化重石脑油的重整进料掺混比为1∶1情况下,焦化石脑油加氢重石脑油的掺混质量分数不宜超过57%,以确保C≥6重整生成油的溴指数合格;当市场上苯产品畅销且创效较好时,应控制该装置的精制重石脑油混合原料初馏点不高于86 ℃,以多产苯;否则,应将其控制不低于90 ℃,以多产轻石脑油去乙烯装置,助力生产其他高附加值产品;为了尽可能保留产物中C9~10 芳烃有效组分含量,同时减少C≥11重芳烃含量,宜控制其精制重石脑油混合原料终馏点不高于 172 ℃较好,以确保该装置经济效益最大化。     

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.     

神华煤液化轻质油的分离、分析及优化利用

采用常减压精馏工艺将神华煤液化轻质油切割为富含环烷烃的馏分A和富含芳烃的馏分B,并用气相色谱-质谱联用仪分析其组成。分析结果表明,环烷烃在馏分A中富集,芳烃在馏分B中富集;馏分A的芳烃潜含量(质量分数)高达75.73%,比煤液化轻质油提高了29%左右,约为直馏石脑油的2.5倍,是优质的催化重整原料;馏分B中芳烃的质量分数高达73.73%,主要为四氢萘及其C_1和C_2的烷基取代物、甲乙苯、萘、β-甲基萘,其中四氢萘及其C_1和C_2的烷基取代物较多,质量分数为38.08%,甲乙苯质量分数为13.90%,萘、β-甲基萘、茚满和C_1与C_2的烷基取代茚满的质量分数分别为3.86%,4.80%,4.31%,3.16%,具有较高的经济附加值。     

提高石脑油综合利用效率的措施及优化方案

作为生产芳烃和烯烃产品的重要原料,石脑油馏分的综合利用是优化炼化一体化加工方案的重中之重。通过分析石脑油的族组成及轻、重石脑油的组成变化对芳烃和烯烃生产的影响,优化石脑油的加工方案,为进一步提高石脑油资源综合利用水平提供思路。用关键组分来控制分离精度,代替传统的馏程控制,将石脑油进行烷烃正构、异构分离,特别是将轻石脑油进行烷烃正构、异构分离,正构轻石脑油送至乙烯装置作原料对乙烯及总烯烃收率的提高更为有利。调整重整装置的进料组成,提高芳烃收率,实现增产芳烃产品的目的。上述措施对优化炼化一体化原油加工方案、提高石脑油资源综合利用更为有效。     

VISCOSITY AND SOLUBILITY OF MIXTURES OF BITUMEN AND SOLVENT

Abstract

The solubilities of three bitumen samples (Suncor, Syncrude and Lloydminster) in five solvents were examined and prediction on the various bitumen-solvent mixture viscosities were made with Cragoe equation. By calculating the Cragoe constant ‘a’ for each mixture and using the average value in the Cragoe equation the prediction accuracy of the equation was improved by over 60%. Bitumen-naphtha mixtures showed the best viscosity prediction characteristics.

The solubility of the asphaltenes in the bitumen was highest in toluene among the five solvents However, naphtha, showed a moderate solvating power, which negligibly varied over the range of composition studied. Therefore naphtha, a solvent derived from bitumen was recommended as the most appropriate solvent for reducing the viscosity bitumen.     

窄馏分催化裂解汽油多产丙烯的研究

在实沸点蒸馏装置上将催化裂解汽油切割为不同沸点范围的窄馏分,在小型固定流化床装置上,对这些窄馏分汽油催化转化增产低碳烯烃进行了研究。试验结果表明：以初馏点~110℃的窄馏分汽油为原料时,反应温度为610℃时,丙烯产率最大,为25.49%;丙烯大部分来自原料中烯烃的裂解,少量的丙烯由正构烷烃、异构烷烃以及带有侧链的芳烃和环烷烃裂解得到;窄馏分汽油经芳烃抽提处理后丙烯产率增加。     

The Solubility of Asphaltenes in Different Hydrocarbon Liquids

Abstract

Bitumen miscibility in low-molecular-weight hydrocarbon liquids was evaluated. The presence of toluene in bitumen–solvent blends improved bitumen miscibility and led to the delay in onset of asphaltenes precipitation due to the dipole–dipole and heteromolecular interactions. For heavy naphtha, the results showed reduced asphaltenes precipitation and enthalpy of mixing due to strong hydrogen bonding and moderate homomolecular interactions. Hexane and light naphtha systems showed higher heats of mixing and higher asphaltenes precipitation due to homomolecular interactions. The best miscibility characteristics of heavy petroleum were obtained with aromatic solvents and solvent mixtures that contained increasing composition of toluene.     

Process for producing high octane gasoline having lower benzene content and distillation end point with its environmental effect of engine exhaust emissions

In this research, a process is discussed for upgrading reformate and power former in Iraq’s Al-Doura refinery, by reducing the amount of benzene in the gasoline product with simultaneous reduction in the gasoline’s ASTM distillation end point. The process consists of fractionation of the reformate and power former to recover that fraction (90–180°C) of hydrocarbons. This was directly used as gasoline without further conversion. The heavy bottom fraction (180°C—EBP) consisting of the aromatic and non-aromatic hydrocarbons was recovered and used as antiknock additives to gasoline. The other fraction with (IBP—90°C) was used as feedstock to producing benzene by solvent extraction. The reformate and power former fractions (90–180°C) are blended with light straight run naphtha at ratio (75: 25) to producing gasoline as well as Al Doura gasoline. It was found that the amount of benzene was reduced from 1.41 wt % in the original pool to 1.37 and 1.31 in the alternative products. Engine emissions were also reduced when using the alternative products compared with original pool product.     

基于分子管理的萃取分离工艺优化利用石脑油资源

In this paper, the separation of aromatics from light naphtha by using extraction process was investigated for improving the utilization efficiency of naphtha. It is indicated that, using a mixture of propylene carbonate-diethylene glycol as the solvent, the optimal extraction conditions cover: a volume fraction of propylene carbonate in the mixed solvent of 0.3, a solvent to feed ratio of 8, and an extraction temperature of 308 K. Through the extraction process, the aromatics mass fraction increases from 10.05% in naphtha to 27.74% in extract oil. It is found that the aromatics yield of extract oil, R_A, reaches 92.11%. As a result, in comparison with naphtha, the potential aromatics content of extract oil increases impressively by 18.03%. Meanwhile, the aromatics content of raffinate oil decreases to 1.33%, and the normal paraffin yield of raffinate oil, Rp, is 76.61%. Accordingly, higher total olefins yields can be obtained when using raffinate oil as the raw material for steam cracking. The present results show that the utilization efficiency of naphtha is improved through extraction process.     

近红外光谱快速测定轻质油品馏程及蒸气压

研究了近红外光谱测定汽油，溶剂油和煤油等轻质油品的馏程，蒸气压的方法，在济南炼油厂1年来的生产控制分析结果表明，该方法的精度和重复性均满足标准分析方法的要求，具有快速，准确等优点，值得推广。     

萃取精馏分离甲基环己烷和甲苯工艺过程的模拟

利用Aspen Plus流程模拟软件,采用双塔流程,以苯酚为萃取剂,对萃取精馏分离甲基环己烷(MC)和甲苯(MB)的过程进行模拟计算,并用实验验证。考察了萃取精馏塔的萃取剂进料位置、原料进料位置、萃取剂与原料的摩尔比(溶剂比)和回流比等因素对分离效果的影响。在满足MC产品的纯度和收率均达到99%的条件下,模拟优化的结果为:理论塔板数为24块,原料在第17块板进料,萃取剂在第5块板进料,溶剂比3.08,回流比5。模拟结果与实验数据吻合较好,说明采用的模拟方法适用于MC和MB混合物萃取精馏过程的模拟。     

低温异构化原料深度脱氮吸附剂及工艺的研发与应用

以中国石化塔河分公司（塔河分公司）重整预加氢后分馏塔顶拔头油（轻石脑油）作为原料进行深度脱氮剂和脱氮工艺的研究,考察脱氮温度、脱氮压力、空速对脱氮效果的影响,确定的最佳脱氮工艺条件为:脱氮温度40 ℃、脱氮压力0.5～1.0 MPa、空速5.0～10.0 h-1。该技术在塔河分公司300 kt/a异构化装置上的工业应用结果表明：以重整预加氢后分馏塔塔顶拔头油作为原料进行深度脱氮处理后,氮质量分数小于0.1 μg/g,能够满足后续低温异构化工艺对氮含量的苛刻要求,得到的异构化产品RON较原料增加20个单位。     

Desulfurization of FCC Gasoline by Solvent Extraction and Photooxidation

Abstract

A deep desulfurization process for FCC light gasoline has been investigated. The process is comprised of liquid-liquid extraction with acetonitrile, and photooxidation with ultraviolet light from a high-pressure mercury lamp. After the extraction the sulfur-containing compounds transfer from the oil to the solvent and then the solvent containing these sulfur compounds was photo-irradiated with ultraviolet light from a high pressure mercury lamp 300 W and with λ 200–300 nm, using strengthen electronic stirrer during the irradiation .The oil from the solvent was recovered with water. An azeotropic mixture (containing 86% acetonitrile and 14% water) was recovered successfully with one distillation column, and can reuse. The total sulfur content in this gasoline decreased from 309 to 68 ppm following 8 h of photo-irradiation .The total yield of the oil vary between 90–96%. The main sulfur compounds of this gasoline are alkyl substituted thiophenes.     

A DETAILED CHEMICAL ANALYSIS OF CHANGES TO BITUMEN PRODUCED BY THE IN SITU COMBUSTION PROCESS AT THE OXYGEN WOLF LAKE PROJECT,ALBERTA PART 2: DISTILLATION CUTS AND CHROMATOGRAPHIC FRACTIONS

ABSTRACT

The detailed chemical changes in bitumen brought about over a one year period by an in situ combustion process in an oil sands reservoir have been investigated. The analytical data for the distillation cuts and chromatographic fractions from a core sample and a number of produced oil samples revealed significant changes as a result of the recovery process, particularly for the naphtha and middle distillate cuts. The residue cut did not exhibit any increase in heteroatom or asphaltene content. None of the changes to the produced oil samples would be expected to negatively impact on the subsequent upgrading process. The relationship between the observed changes to the fractionated oil samples and the dynamics of the in situ combustion process are discussed.     

脱除环戊烷中微量苯和正己烷的技术研究及其应用

通过精馏技术可以生产出符合国家标准的工业用环戊烷,但难以达到欧盟标准（苯质量分数不大于0.000 05%,正己烷质量分数不大于0.000 8%）。为了脱除环戊烷中微量的苯和正己烷,开发了精馏-吸附复合技术。经过大量的吸附-脱附试验研究,筛选出普通市售的活性碳纤维-沸石分子筛作为复合吸附剂,并在工业生产流程中增设用于脱除水以及脱除苯和正己烷的两个吸附塔。工业试验结果表明,采用活性碳纤维-沸石分子筛复合吸附剂以及精馏-吸附复合技术可以生产出符合欧盟标准的环戊烷溶剂油;活性碳纤维-沸石分子筛复合吸附剂来源方便、无毒无害、可以循环使用;精馏-吸附复合技术操作简便、安全可靠,值得推广。     

STUDIES OF STRAIGHT CHAIN PARAFFINIC HYDROCARBONS IN QAIYARAH NAPHTHA FRACTION USING GAS CHROMATOGRAPHY/MASS SPECTROSCOPY (GC/MS)

ABSTRACT

This investigation deals with paraffinic hydrocarbons in crude oil using gas chromatography/mass spectroscopy. The study indicates that Qaiyarah paraffinic hydrocarbons, identified in the naphtha fraction, could be a major contributor and good feedstock in the petrochemical industry.