Practical Applications of a Process Simulator of Middle Distillates Hydrodesulfurization

Abstract

An analysis of the diesel hydrodesulfurization process using a developed reactor model is presented. The reactor model within process simulator architecture was applied to different industrial process schemes. The analysis in this work uses a commercial simulator (Aspen), to conform the process scheme with a user model for the reactor unit. This user model consists of a rigorous diesel hydrodesulfurization reactor model. To couple the user model with Aspen, the kinetic and the reaction network must be available and based on model compounds. The user model employs two model compounds for the hydrodesulfurization reactions. These represent the sulfur families (dibenzothiophene and 4,6-dimethyl-dibenzothiophene). The species take the reactivity range of the sulfur compounds found in the middle distillate fractions of the Mexican crudes. One and two rings aromatic compounds are represented by the cyclohexylbenzene and methylcyclohexyltoluene, the naphthenes by the dicyclohexane and the paraffins by the n-hexadecane. Results obtained are shown by using this model in three industrial plants. The results were used to analyze the critical variables of the process showing good agreement with industrial data. The use and application of the model show the advantages of this tool to analyze actual processes, to test new configurations and the effect on the product quality when different loads with different characteristics or different processability conditions are used.     

Practical Applications of a Process Simulator of Middle Distillates Hydrodesulfurization

An analysis of the diesel hydrodesulfurization process using a developed reactor model is presented. The reactor model within process simulator architecture was applied to different industrial process schemes. The analysis in this work uses a commercial simulator (Aspen), to conform the process scheme with a user model for the reactor unit. This user model consists of a rigorous diesel hydrodesulfurization reactor model. To couple the user model with Aspen, the kinetic and the reaction network must be available and based on model compounds. The user model employs two model compounds for the hydrodesulfurization reactions. These represent the sulfur families (dibenzothiophene and 4,6-dimethyl-dibenzothiophene). The species take the reactivity range of the sulfur compounds found in the middle distillate fractions of the Mexican crudes. One and two rings aromatic compounds are represented by the cyclohexylbenzene and methylcyclohexyltoluene, the naphthenes by the dicyclohexane and the paraffins by the n-hexadecane. Results obtained are shown by using this model in three industrial plants. The results were used to analyze the critical variables of the process showing good agreement with industrial data. The use and application of the model show the advantages of this tool to analyze actual processes, to test new configurations and the effect on the product quality when different loads with different characteristics or different processability conditions are used.     

生产清洁汽柴油燃料脱硫工艺的进展

介绍了国外汽、柴油燃料含硫新规范和汽、柴油脱硫技术进展，包括催化裂化进料预处理，催化裂化脱硫催化剂和助剂的开发，加氢脱硫后处理，以及深度脱硫的新途径。     

脱硫装置投资影响因素分析

提高"规模系数法"估算脱硫装置投资的精度,正确认识、把握、选取工艺参数是关键。影响天然气脱硫装置投资高低的主要工艺参数有四个,包括处理规模、原料气组分、原料气压力和原料气温度。以2个已建净化厂为例,分析了脱硫装置的投资构成,指出采用"规模系数法"估算脱硫装置投资应选取关键工艺参数,高压吸收系统主要根据单套处理规模和进厂原料气压力来估算投资,低压溶液再生系统主要根据脱硫剂(MDEA)溶液循环流量来估算投资。     

Desulfurization of FCC Gasoline by Solvent Extraction and Photooxidation

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.     

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.     

功率超声下柴油的深度氧化-吸附脱硫实验研究

在功率超声下柴油氧化脱硫工艺研究的基础上,研究了Fe盐、Cu盐的加入和不同吸附剂及其用量对脱硫效果的影响。结果表明,采用H2O2作为氧化剂,无机混合酸（硫酸与磷酸等体积混合）和Fe盐作为催化剂,反应温度为50 ℃, 柴油体积为80 mL,H2O2体积为1.2 mL,无机酸）体积为1.2 mL,Fe与H2O2质量比为30/100,在功率超声作用下将柴油氧化,氧化后的油样用等体积的2 mol/L KOH溶液进行碱洗;碱洗后的油样,用经硝酸氧化处理的活性炭进行吸附, 剂油体积比为20/10,脱硫后柴油中的硫含量从起始的699.12 μg/g下降到16.08 μg/g,脱硫率为97.70%,油收率为90.87%。     

Desulfurization of FCC Gas Oil by Solvent Extraction, Photooxidation, and Oxidizing Agents

A deep desulfurization process for FCC gas oil by a combination of liquid-liquid extraction, photochemical reaction, and treating with oxidation agents has been investigated. The process often represented by the model heterocyclic compounds, benzothiophenes (BTs) and dibenzothiophenes (DBTs). The process is comprised of three stages. Extraction of the sulfur-containing compounds from a catalytic cracked gas oil by acetonitrile, photooxidation, and photodecomposition of the sulphur compounds in the acetonitrile phase by ultraviolet irradiation from a high pressure mercury lamp, and recovery of the sulphur from the irradiated oil and treatment with oxidizing agent. The process was carried under conditions of room temperature and atmospheric pressure. Acetonitrile/water azeotropic mixture has been recycled successfully through distillation column. The sulfur in this gas oil has been decreased from 1800 ppm to 550 ppm after photo-desulfurization, and 508 ppm after treatment with the oxidizing agents. The total yield of the oil was 90-95%.     

Study on Desulfurization of Gasoline by Electrochemical Oxidation and Extraction

In order to further reduce the sulfur content in gasoline, a new desulfurization process was proposed by using catalytic oxidation and extraction realized in an electrochemical fluidized reactor. The fluidized layer of loaded catalyst particles consisted of lead dioxide (PbO2) supported on activated carbon particles (PbO2/C) and the electrolyte was aqueous NaOH solution. The PbO2/C particle anodes could remarkably accelerate the electrochemical reaction rate and promote the electrochemical catalysis of sulfur compounds. The sulfur compounds were at first oxidized to sulfones or sulfoxides, which were then re- moved after extraction. The experimental results indicated that the optimal desulfurization conditions were as follows: The cell voltage was 3.2 V, the concentration of hydroxyl ions in electrolyte was 0.12 mol/L, and the feed rate was 300 mL/min. Under these conditions the concentration of sulfur in gasoline was reduced from 310 ppm to 70 ppm. Based on these experimental results, a mechanism of indirect electrochemically catalytic oxidation was proposed.     

塔中油田汽提法原油脱硫化氢工艺技术

为了减少塔中联合站处理装置中大量高含H2S原油对非抗硫工艺管线和设备造成的严重腐蚀,消除外输原油和天然气H2S浓度严重超标带来的安全隐患,中国石油塔里木油田公司借鉴国内首套重质原油干法汽提脱硫装置在塔河油田三号联合站试验成功并且安全平稳运行的经验,在塔中作业区水平一转油站建成了日处理能力1 000 t的汽提法原油脱硫装置,对塔中一号气田试采单井原油进行脱硫处理,通过对温度、进液量及汽提比等参数进行不断优化将装置调整到最佳运行状态,采用3018固体脱硫剂对汽提脱硫装置中产生的高含H2S尾气进行全部回收,有效地防止了大气污染。     

采用选择性氧化和抽提脱硫工艺生产超低硫柴油

1　简介Petro Star Inc.从 1 996年开始研究柴油脱硫工艺即转化 /抽提脱硫工艺 (CED process)。目前我们已成功开发了新型的连续式脱硫组合工艺 ,通过转化抽提燃料油中的硫使产品硫含量小于 1 0 ppm。CED工艺在世界范围内为使用 HDS工艺的炼厂提供了有吸引力的替代工艺。我们已经在实验室对几个炼厂的样品进行实验研究 ,这些样品主要是柴油馏分。实验表明对含硫42 0 0 ppm的直馏柴油将硫含量脱到 1 0 ppm以下时柴油的性质不受影响。CED工艺的基础是在常压 ,小于 1 0 0℃条件下将硫化物氧化成极性的含氧含硫化物。接着用液—液萃取 (抽…     

WO3/C复合物的制备及其在燃料油中氧化脱硫应用

通过在520℃煅烧氧化物和氮化碳的混合物成功的合成WO3/C复合物。自制的样品通过XRD、EDS、SEM、IR和BET表征。与氧化钨和氮化碳相比较,WO3/C复合物展现出小的粒径,大的比表面积和高的脱硫活性。反应温度、催化剂用量、反应时间、氧化剂用量、硫化物类型和萃取剂用量对脱硫的影响都被研究。实验结果表明WO3/C复合物展现出比氧化钨高的脱硫活性。在催化剂用量为0.02 g,双氧水用量为0.2 mL, 1-丁基-3甲基咪唑硫酸酯用量为1.0 mL,反应温度为70 ℃,反应时间为180 min的最佳条件下,WO3/C复合物的脱硫率可达95.8%。催化剂循环使用5次,其脱硫活性没有明显的降低。     

加氢精制柴油选择性氧化-萃取深度脱硫

30 %H2 O2 -HCOOH氧化加氢精制柴油 (硫含量为 794× 10 - 6 (ω) ) ,然后使用溶剂萃取氧化处理后使油品达到深度脱硫。详细考察了搅拌速度、油水两相体积比、甲酸浓度、氧化剂加量、反应温度和时间对柴油氧化脱硫的影响。同时考察了萃取溶剂含水量和萃取剂油比对脱硫及油回收率的影响。实验结果表明 :30 %H2 O2 -HCOOH生成过氧甲酸 ,能有效氧化加氢精制柴油中的有机硫化合物 ,然后经过溶剂萃取能达到深度脱硫 ;过氧化氢 /硫 (摩尔比 )为 8时 ,柴油硫含量从 794× 10 - 6 (ω)降至 87×10 - 6 (ω)。搅拌速度、油水两相体积比、甲酸浓度、过氧化氢加量、反应温度和时间对氧化脱硫均有影响。搅拌速度超过 4 0 0r/min对反应影响不明显。过氧化氢加量、反应温度和时间及萃取条件均影响油回收率。     

油砂沥青改质所得中间馏分生产柴油和喷气燃料的研究

对Athabasca油砂沥青进行改质可以得到轻瓦斯油窄馏分,研究了将这些轻瓦斯油窄馏分作为柴油和喷气燃料时的性能。分析了轻瓦斯油窄馏分的馏程、十六烷值、烟点以及其他性质如芳烃含量、苯胺点、硫氮含量之间的关系。研究表明,选择合适的加工流程、选取恰当的馏分可生产出符合当前严格环境法规和未来产品规格要求的柴油和喷气燃料。同时,回归出了预测十六烷值和烟点的新型关联式,其变量包括密度、模拟蒸馏馏程、采用超临界流体色谱法测定的单环芳烃含量及总芳烃含量;这些关联式可用来预测油砂沥青改质得到的宽馏程中间馏分的十六烷值和烟点。     

Modeling of the FCC Gasoline Desulfurization Process by Liquid Extraction with Sulfolane

Abstract

Extractive desulfurization of fluid catalytic cracking (FCC) gasoline with sulfolane was studied in a batch apparatus. The influence of three inlet parameters (temperature, inlet sulfur content, and solvent ratio) on the process response, that is, desulfurization efficiency, was investigated with the use of a Box-Behnken experimental design by response surface methodology. A mathematical model that can be used for predicting sulfur content in raffinate after extractive batch processing with sulfolane was statistically developed and proven with analysis of variance. Statistical analysis showed that the largest influence on desulfurization efficiency was solvent ratio, the second most significant influence was inlet sulfur content, followed by temperature, and last the interaction between solvent ratio and inlet sulfur content. The obtained second-order polynomial model shows that maximum desulfurization efficiency of 65.34% can be achieved at temperature of 50°C and higher values of inlet sulfur content and solver ratio in the researched range of inlet parameter values.     

直接生产清洁汽油的FDFCC工艺

FDFCC是理想的降低FCC汽油烯烃和硫含量的工艺技术。中试及工业应用结果表明:FDFCC装置操作稳定可靠、工艺参数调节灵活。汽油提升管反应器对催化汽油的改质效果十分显著,改质汽油烯烃含量可下降至18%(φ)以下,芳烃增加13个百分点以上,硫含量下降20%～30%,改质汽油诱导期>1000min,MON和RON不下降,苯含量<1%。采用适当的FDFCC工艺形式,可直接生产满足国内清洁燃料或欧洲Ⅲ类燃料标准的清洁汽油。     

脱硫装置操作波动的原因分析及对策

重点分析二套催化裂化车间干气、液态烃脱硫装置波动的原因,并提出相应的对策。     

Process design for gas condensate desulfurization and synthesis of nano-13X zeolite adsorbent: equilibrium and dynamic studies

This paper summarizes the results of a study of adsorption of sulfur compounds from a high-sulfur feed on improved spherical-shaped nano-AgX zeolite. For this purpose, the nano-AgX zeolite was initially synthesized and improved with silver compounds such as silver nitrate, and then it was utilized in the adsorption process. In order to investigate the equilibrium and dynamics of the adsorption process, adsorptive desulfurization of real feed(i.e., sour gas condensate from the South Pars gas field) was carried out in batch and continuous processes under several operating conditions; a temperature-dependent Langmuir isotherm model was used to fit the equilibrium data. The value of monolayer adsorption capacity(q_m) and adsorption enthalpy(ΔH) were calculated to be 1.044 mmol/g and 16.8 kJ/mol, respectively. Furthermore, a detailed theoretical model was employed in order to model the breakthrough experiments. The results revealed that an increase in the feed flow rate and 1/T values will cause linear and exponential increase in the total mass transfer coefficient(ks). Isotherm and dynamic breakthrough models were found to be in agreement with the experimental data.     

Studies on Volatile Characteristics of Middle Distillates and Their Interdependency

Abstract

Standard test methods such as those published in American Society for Testing and Materials (ASTM)/Institute of Petroleum/Universal Oil Product are often used to characterize the fuel's properties. However, these chemical/physical characterization methods are not only expensive and protracted but also require a large quantity of samples. Every flammable liquid has vapor pressure, which is a function of its boiling point. The distillation and flash point are volatility-dependent characteristics; therefore, these properties are temperature dependent. Most researchers have derived the correlation of flash point with boiling point and vapor pressure for pure organic compounds. The present study proposes a user-friendly empirical model with a correlation technique to predict flash point using ASTM distillation data of middle distillates. In this study, 47 middle distillate samples were taken to predict the flash point with 5 and 10% volume recovery temperature of ASTM D-86 and volume average boiling point (VABP) separately. It was observed that the most appropriate prediction of flash point was with 5% recovery temperature of ASTM D-86 with an R² 0.997. This correlation model was compared with different models and found to be comparatively better and user friendly.