Modeling of H2S solubility in aqueous MDEA solution using electrolyte SRK plus association equation of state

H₂S solubility in MDEA aqueous solution at different solution compositions, temperatures, pressures, and acid gas loadings was correlated using electrolyte SRK-cubic plus association equation of state. A total of 302 experimental data were used in this work. At first pure components parameters were obtained from literatures. Then binary interaction parameters were calculated through binary subsystems investigation. Finally, ternary system modeled using a reactive bubble point pressure calculation method. Considering number of binary interaction parameters that should be optimized, three scenarios were proposed. All of the scenarios present good results with acceptable absolute average deviation percentage (AAD%) but the third one shows better outputs. The AAD% in this scenario is 17.02.     

Implementation of CPA EoS for simultaneous solubility modeling of CO2 and H2S in ionic liquid [OMIM][Tf2N]

In this study, solubility of pure CO₂ and H₂S and their mixture in [OMIM][Tf₂N] modeled applying CPA EoS. CPA combines the SRK equation with an advanced association term, which is similar to that of SAFT. From a practical point of view, the target in the CPA project was to develop a thermodynamic model capable of describing complex equilibria of mixtures containing polar/associating chemicals through a simple procedure with respect to the SAFT.

The AAD% for binary systems, including H₂S+ IL and CO₂+ IL are 6.81, 5.21 respectively. Moreover, AAD% equal to 13.89 was achieved for the ternary system.     

NaCl-NaBr-H_2O三组分物系的固液平衡

用等温溶解平衡法研究了NaCl-NaBr-H2O三组分物系在相平衡温度为313,333K时的相平衡关系,测定了平衡液相的密度和折光率等物化参数。实验结果表明,该三组分物系313K时的固液平衡等温曲线由一个零变量点(E)、两条单变量曲线和两个固相区(Na(Cl,Br).2H2O和Na(Cl,Br))构成,E点对应的液相组成为wLiq(NaCl)=4.91%,wLiq(NaBr)=42.99%;相对应的固相组成为Na(Cl,Br).2H2O+Na(Cl,Br)。333K的溶解度等温图由一条单变量曲线和一个固相区构成。该物系属于固体溶液型。用Pitzer半经验统计力学模型校验了测得的该物系313,333K时的溶解度,计算值与实验值基本吻合     

长庆油田某天然气净化厂实现GB 17820-2018达标工艺方案研究

针对GB 17820-2018《天然气》标准中更为严格的天然气气质要求,长庆油田某天然气净化厂存在净化气中H 2S含量不满足进入长输管道要求的现象。为解决这一问题,利用HYSYS软件对该厂MDEA脱硫工艺进行了流程模拟。分析了溶液循环量、MDEA质量分数、吸收塔塔板数、原料气温度、原料气压力以及贫液入塔温度对净化气中H 2S、CO2含量的影响,并根据不同工艺参数的影响程度对参数进行排序。在此基础上,建立以最小能耗为目标函数的多参数优化模型,利用HYSYS自带的工具箱求解模型,得到满足净化气中H 2S质量浓度<5 mg/m^3、CO2摩尔分数<2.8%的最优操作参数组合。优化结果可对指导现场采取调整措施提供参考。     

The CPA EoS application to model CO2 and H2S simultaneous solubility in ionic liquid [C2mim][PF6]

The CPA EoS was utilized for solubility modeling of pure CO₂ and H₂S and their mixture in [C₂MIM][PF₆]. The model is comprised of SRK EoS in addition to Wertheim's association term. Up to now, several associating models such as SAFT variants have been successfully applied to such systems. Considering the complexity and time consuming nature of SAFT EoSs, CPA can be a good alternative due to its accuracy and simplicity with respect to the SAFT.

The AAD % for binary systems including H₂S+ IL and CO₂+ IL are 11.78, 10.40 respectively. Moreover, the ternary system show AAD% equal to 16.51.     

The Feasibility of Lab-scale Cyclic CO2 Injection in Fractured Porous Media

A comprehensive analysis of the CO₂ Huff-n-Puff process with application to representative light oil system contained within a fractured porous media is present in this article. To accomplish this work, a simulation model representative of the laboratory experimental model was built and constrained under similar laboratory conditions. Six sets of CO₂ Huff-n-Puff experiments were conducted at injection pressures of 1723–10342 kPa; moreover, additional sensitivity analysis was performed on the 5170 and 6894 kPa conditions for different permeability and porosity. Results of this study demonstrate that cyclic injection of CO₂ under miscible conditions performs more favorably than under immiscible injection conditions.     

ANFIS modeling of carbon dioxide capture from gas stream emissions in the petrochemical production units

Amino acid salt, especially sodium glycinate, was known as a new class of environment-friendly solution that is now being studied as a favorable alternative to amines. In the present collaboration, the Adaptive Network-based Fuzzy Inference System (ANFIS) was employed to estimate CO₂ loading capacity in the presence of aqueous sodium glycinate solution under broad ranges of temperature and pressure. The outcomes of suggested ANFIS model indicated their brilliant agreement with corresponding experimental values. The calculated values of mean relative error and R-squared were 2.93 and 0.988, respectively. Our suggested model can be of huge value for process engineers to have a simple and accurate tool in order to have rapid estimations of CO₂ solubility as a function of temperature, pressure, and mass composition of sodium glycinate solution.     

KINETIC INVESTIGATION OF METHYLCYCLOPENTANE REFORMING ON FRESH AND DEACTIVATING Pt/Al2O3 CATALYST

ABSTRACT

The conversion of methylcyclopentane (MCP) in hydrogen on fresh and deactivating Pt/Al₂O₃ catalyst to hydrogenolysis products (2-methylpentane, 3-methylpentane and n-hexane), cyclohexane and benzene was studied in a Berty CSTR at various partial pressures of MCP and H₂, and at a total pressure of 1 atm. For the kinetic studies, temperatures between 370 – 400° and W/F values up to 0.33 g min/cm³ were used. The conversion of MCP was found to increase with increase in temperature at all the MCP partial pressures investigated. The hydrogenolysis products and benzene composition generally increased with increase in temperature and W/F. The mechanism for the reforming of MCP was similar to that proposed by Dartigues et al. (1978) except that the formation of hydrogenolysis products was accounted for in this formulation. Eleven rate models were developed and tested and six satisfied the set criteria. Since hydrogenation/dehydrogenation and desorption steps are relatively rapid, the conversion step to hydrogenolysis products was deemed the only rate determining step with an activation energy of 36.31 kcal/gmol. For the deactivation studies, the model of Corella and Asua (1982) was used for the development of two deactivation models. The only model found to predict the deactivation behavior was the step leading to the formation of the coke precursor as rate controlling.     

Oxidative Desulfurization of Dibenzothiophene Catalyzed by VO(acac)2 in Ionic Liquids at Room Temperature

A simple extraction and catalytic oxidative desulfurization (ECODS) system composed of VO(acac)₂, 30% H₂O₂, and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF₄) has been found to be suitable for the deep removal of dibenzothiophene (DBT) in model oil at room temperature. The optimal conditions were as follows: [n(H₂O₂)/n(DBT)/n(catalyst) = 100:20:1], model oil = 5 mL, ionic liquid [IL] = 1 mL, T = 30°C, t = 2 hr. With the ECODS system, the sulfur removal of DBT could reach 99.6%, which was superior to that of the simple extraction with IL (15.6%) or oxidation without catalyst (17.1%). The IL could be recycled five times without a significant decrease in activity.     

硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。     

The Modeling of CO2 Removal From a Gas Mixture by 2-amino-2-methyl-1-propanol (AMP) Using the Modified Kent Eisenberg Model

In this paper, the solubility of CO₂ in AMP solution has been measured at temperature range of 293, 303, 313, and 323 K. The amine concentration ranges studied are 2.0, 2.8, and 3.4 M. A solubility apparatus was used to measure the solubility of CO₂ in AMP solution on samples of flue gases from thermal and central power plants of Esfahan Steel Company. The modified Kent Eisenberg model was used to correlate and predict the vapor-liquid equilibria of the (CO₂ + AMP + H₂O) system. The model predicted results are in good agreement with the experimental vapor-liquid equilibrium measurements.     

超重力CO2吸收过程的Aspen模拟计算

目的 模拟超重力CO₂的吸收过程,从而为实验工艺参数的优化提供指导。方法 建立了超重力NaOH碱液吸收CO₂的Aspen计算模型,考查了多个影响因素对CO₂脱除率的影响。结果 通过对比可知,将超重力反应器等价转化为常规填料塔后,NaOH质量分数、碱液进料量和压力对CO₂脱除率的影响与超重力实验室的变化规律一致,但模拟值仅为实验值的1/2左右。对传质参数进行进一步修正,修正后的模拟计算结果与实验值接近,平均偏差仅为0.77%。结论 建立的超重力CO₂吸收模型准确可靠,可为后续实验提供一定的方向性指导。     

CH_(3)COONa改性ZSM-5分子筛及其类芬顿催化性能北大核心CSCD

目的利用改性ZSM-5分子筛负载Fe高效降解有机胺废水。方法实验采用不同浓度的CH_(3)COONa溶液对ZSM-5分子筛进行改性处理,通过XRD、N_(2)吸附及SEM方法对处理前后的样品进行表征,考查了不同浓度的CH_(3)COONa溶液对ZSM-5分子筛结构特征和物化性能的影响。将处理前后的ZSM-5分子筛负载Fe,进行高浓度有机胺废水的催化降解。结果CH_(3)COONa溶液改性对分子筛晶体形貌影响较小,能够在对分子筛微孔结构破坏程度较小的基础上,形成微孔-介孔多级孔结构。结论当CH_(3)COONa溶液浓度为4 mol/L时,有机胺废水的COD去除率高达93.1%。     

Hydrogen production by catalytic gasification of petroleum residue

The liquid fuel gasification to obtain a clean flue gas for power generation and produce chemicals such as methanol is a most promising attempt to reduce the greenhouse gas emissions and air pollutants. In this paper, an equilibrium model of liquid fuel gasification was developed by the method of Gibbs free energy minimization. Two kinds of catalysts: Ni/CeO₂/Al₂O₃ and Ni/Al₂O₃ were used to explore the influence of catalysts and operating conditions on hydrogen yield and char conversion. Over the ranges of operating conditions studied, the maximum hydrogen yield reached 52.47 vol%, whereas the char conversion varied between 45.2% and 98.5%. The results indicated that an appropriate reaction temperature is favorable for higher hydrogen production and char conversion. The model was validated with experimental data obtained from a fluidized bed gasifier.     

Desulfurization of FCC Gasoline Over Mordenite Modified with Al2O3

Abstract

Mordenite modified with Al₂O₃ (Al₂O₃/mordenite) was synthesized and used for the desulfurization of FCC gasoline. The influences of operating parameters on the results were studied for the model solution composed of dibenzothiophene (DBT) and isooctane. Al₂O₃/mordenite exhibits higher sulfur capacity than other kinds of chemisorbents. The suitable composition of the chemisorbent is 30 wt% Al₂O₃ to 70 wt% mordenite. The optimal operating parameters are: temperature 160°C; velocity 3 h^?1 (WHSV). Under the stated conditions, desulfurization was carried out for the FCC gasoline with sulfur content of 220.4 μg/g. The chemisorbent can maintain the sulfur content under 50 μg/g for 40 h and has good regeneration ability after desorption using benzene.     

富含CO_2天然气净化技术现状及研究方向

富含CO2天然气净化技术面临天然气气质和尾气排放标准的双重挑战,故在综述国内外富含CO2天然气脱除CO2技术现状的基础上,分析了现有净化技术存在的问题,即活化甲基二乙醇胺(aMDEA)法CO2吸收剂循环量大、装置能耗高,变压吸附法和膜分离集成法工艺不成熟等。进而提出了活化剂、工艺流程及其操作参数优化、变压吸附和膜分离集成技术等新的研究方向,以期形成适用于富含CO2天然气净化的系列配套技术,助推我国富含CO2天然气的高效开发。     

NaAlO2溶液中铝酸根离子的微观结构

 应用IR、²⁷Al NMR 和UV3种波谱方法对不同方式配制的Al₂O₃浓度和苛性系数基本相同的四种NaAlO₂溶液进行了详细的表征。结果表明IR、²⁷Al NMR和UV3种光谱方法给出的信息可以相互补充支持,共同给出NaAlO₂溶液中铝酸根离子的微观结构。溶液配制方式对NaAlO₂溶液中铝酸根离子的微观结构具有显著影响,4种NaAlO₂溶液中铝酸根均以四配位[Al(OH)₄]^-为主体离子,可以排除六配位[Al(OH)₆]^3-的存在; 二聚[Al₂O(OH)₆]^2-含量因配制方式不同存在显著差别,在方式Ⅰ配制的溶液中二聚[Al₂O(OH)₆]^2-含量很少或不存在,在方式Ⅱ、Ⅲ、Ⅳ配制的溶液中显著存在二聚[Al₂O(OH)₆]^2-,在溶液Ⅱ、Ⅲ中还存在尚未确定结构的离子。     

天然气净化厂Cansolv尾气处理装置废水处理

目的 解决Cansolv尾气处理装置胺液净化单元(APU)废水高盐、高有机物与还原性硫的高浓水质特征影响水处理系统的稳定运行问题。方法 详细分析了两个天然气净化厂的文丘里和APU废水的水质特征,其中,APU废水成分复杂,是影响水处理系统稳定运行的关键。采用臭氧(O₃)、O₃耦合催化剂、臭氧/双氧水(O₃/H₂O₂) 3种氧化技术处理APU废水,通过废水中COD值和TOC值变化来评价有机物降解效果,研究了反渗透膜污堵原因和O₃/H₂O₂降解有机物机理。结果 O₃/H₂O₂氧化技术为去除废水中有机物的最优方法,当200 mL废水中O₃质量浓度为22 500 mg/L、H₂O₂投加量为2 mL、反应时间为60 min时,达到最佳处理效果,COD去除率为60.8%。结论 采用O_3<...     

Effects of the compound system of alkali and alkyl glycosides on the stability of oil-in-water emulsions

Abstract

The effects of Na₂CO₃, nonionic surfactant octyldecyl glucoside (APG0810), and inorganic salt addition on the water separation ratio and apparent viscosity of oil-in-water (O/W) emulsions were investigated. The influences of this compound system on the stability of the emulsion and its synergistic mechanism were also analyzed. Results revealed that in the first compound situation, when APG was selected as the main surfactant and had a concentration of 0.1%, the mass concentration of Na₂CO₃ was 0.4%, the emulsion exhibited the strongest stability, and the water separation ratio at 30?°C for 120?min was 20.3%. In the second compound situation, when Na₂CO₃ was used as the main surfactant and had a concentration of 0.1%, the mass concentration of APG was 0.4%, the emulsion displayed the strongest stability, and the water separation ratio at 30?°C for 120?min was 57.8%. The stability of the O/W emulsion increased with increased NaCl addition, and a higher salt concentration corresponded to a lower water separation ratio. After CaCl₂ addition, the apparent viscosity of the emulsion increased sharply, and the O/W emulsion underwent phase inversion to become an water-in-oil (W/O) emulsion. Within the set mass concentration range, increased salt concentration caused the apparent viscosity of the W/O emulsion measured at 50?°C and 30?rpm to decrease gradually but still exceeded 1500?mPa·s.     

Modeling of CO2 Removal From Gas Mixture by 2-amino-2-methyl-1-propanol (AMP) Using the Deshmakh-Mather Model

This work presents an experimental and theoretical investigation of CO₂ absorption into aqueous of 2-amino-2-methyl-1-propanol (AMP). The solubility of CO₂ in AMP solution has been measured at temperature range of 293, 303, 313, and 323 K. The amine concentration ranges studied are 2.0, 2.8, and 3.4 M. A solubility apparatus was used to measure the solubility of CO₂ in AMP solution on samples of flue gases from thermal and central power plants of Esfahan Steel Company. The Deshmakh-Mather model was used to correlate and predict the vapor-liquid equilibria of the (CO₂ + AMP + H₂O) system. Data on CO₂ loading in aqueous solutions of AMP were fitted to generate the different interaction parameters required to calculate the activity coefficients in the model. The model predicted results are in good agreement with the experimental vapor-liquid equilibrium measurements.