Experimental and modeling study of asphaltene adsorption onto the reservoir rocks

Abstract

In this work, amount of asphaltene adsorption onto the carbonate and sandstone rock samples was investigated at various initial concentrations of asphaltene in oil. Asphaltene adsorption onto both types of the reservoir rocks was increased by increasing the initial concentration of asphaltene. The amount of asphaltene adsorption onto the rock samples was predicted using Langmuir and Freundlich isotherm models. The results showed that Langmuir model had a better accuracy for prediction of asphaltene adsorption onto the rock samples than Freundlich model. Furthermore, asphaltene adsorption onto the reservoir rocks was studied in the presence of a recently developed asphaltene inhibitor. The inhibitor significantly reduced asphaltene adsorption at any initial concatenation of asphaltene. Moreover, changes in the rock permeability due to asphaltene precipitation were determined in the presence and absence of the asphaltene inhibitor.     

Experimental and modeling studies of the effects of different nanoparticles on asphaltene adsorption

Adsorption experiments for three commercial metal oxide nanoparticles (SiO₂, Al₂O₃, and MgO) were carried out to examine the effect of each nanoparticle on asphaltene inhibition. The results are reported on the basis of adsorption per mass of adsorbent. The adsorption data were used in four isotherm adsorption models (Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich models) for better understanding of adsorption mechanisms. Among the models, Dubinin-Radushkevich produced better prediction. According to the obtained data, the adsorption affinity toward asphaltene was in the following order: SiO₂ > MgO > Al₂O₃. Influence of the main factors such as surface chemistry and specific surface area shows significant effect on the amount of adsorption. It was found that the multilayer adsorption and physisorption mechanism plays an important role in asphaltene adsorption, which was confirmed by Freundlich, Temkin, and Dubinin-Radushkevich models.     

Effects of Nitrogen-Containing Biodegradation Enhancers on Sorption of n-Hexadecane in Soil-Water System

Effects of nitrogen-containing biodegradation enhancers(methyl diethanolamine oleate(MDEAO) and oleic diethanolamide(ODEA)) on the adsorption of n-hexadecane in soil were studied by laboratory batch experiments. The partition coefficients(K_d values) of n-hexadecane sorption in soil-water system and those partition coefficients normalized to organic matter(K_(oc) values) were both determined. The adsorption isotherm curve of n-hexadecane in soil-water system was plotted. The measured results demonstrated that K_(oc) values changed in the soil-water system with different enhancers but are relatively invariant for the soil at the same site. The K_d values rose with the increase of the organic matter content in different soil. The average values of K_(oc) in the soil-water system with MDEAO, ODEA,and blank soil were 0.412, 0.252,and 0.309, respectively. The critical micelle concentration of ODEA and MDEAO was 0.7 mg/L and 1.9 mg/L, respectively,denoting that the solubilization capacity of ODEA was much stronger than MDEAO in the soil-water system. Consequently,the adsorption of MDEAO onto the solid surface increased the organic matter content in soil,which could make it more effective in enhancing the n-hexadecane adsorption. On the contrary, ODEA could inhibit the adsorption of n-hexadecane because of its less adsorption rate onto the soil particle surface and higher concentration in the soil-water system. According to the correlation coefficients, it was found that both the Henry linear and the Freundlich nonlinear isotherm sorption models were fitted to the data very well, however the Freundlich model was better than the Henry model.     

Bio-sorption for tannery effluent treatment using eggshell wastes; kinetics,isotherm and thermodynamic study

Since, cobalt, zinc, mercury and lead ions are high toxic heavy metals; this work aims to investigate the efficiency of eggshell as a low cost sorbent for their ions from aqueous solution. Adsorption of heavy metals on surfaces of eggshell obeyed second order kinetics. Adsorption isotherm belonged to Freundlich model and displayed multilayer adsorption. The maximum adsorption capacity was estimated as 204, 153, 121 and 98 mg/g for Co³⁺, Zn²⁺, Hg²⁺ and Pb²⁺ respectively. The values of free energy of adsorption evidenced the physical adsorption occurrence. It is demonstrated that eggshell, as an industrial waste, was efficiently used as an adsorbent for wastewater treatment. Eggshells powder removed efficiently heavy metal ions from a tannery wastewater and removal efficiency reached up to 99%.     

含氮生物降解促进剂对土壤吸附正十六烷的影响

Effects of nitrogen-contained biodegradation enhancers: methyl diethanolamine oleate (MDEAO) and oleic diethanolamide (ODEA) on the adsorption behavior of n-hexadecane in soil were studied by laboratory batch experiments. The effect of two biodegradation enhancers on the partition coefficient (Kd values) and normalized to organic matter (Koc values) were determined. The adsorption isotherm curve of n-hexadecane in soil-water system were plotted. The measured results demonstrated that Koc values changed in the soil-water system with different enhancers but are relatively invariant for the same site soil. The Kd values rose with the increase of the organic matter content in different soil. The average values of Koc in soil-water system with MDEAO, ODEA and blank soil were 0.412, 0.252 and 0.309, respectively. The critical micelle concentration of ODEA and MDEAO were 0.7 mg/L and 1.9 mg/L, respectively, which means the solubilization capacity of ODEA is much stronger than MDEAO in soil-water system. Consequently, adsorption of MDEAO onto the solid surface increases the organic matter content in soil and makes it more effective in enhancing n-hexadecane adsorption. Oppositely, ODEA inhibits the adsorption of n-hexadecane due to less adsorption onto the soil particle surface and higher concentration in the soil-water system. According to the correlation coefficients, it was found that both Henry linear and Freundlich nonlinear isotherm sorption models were fitted to the data very well but the Freundlich model was better.     

油酸二乙醇酰胺对润滑油在水-土体系中吸附行为的影响研究

采用振荡平衡法对含油酸二乙醇酰胺（简称ODEA）润滑油在水-土体系中的吸附行为进行研究,考察在水-土体系中含ODEA润滑油的吸附动力学特征及其吸附等温曲线。结果表明：润滑油及含ODEA润滑油均能较快地被土壤吸附,吸附动力学曲线符合Lagergren伪二级动力学方程,吸附等温曲线符合Freundlich和Henry吸附等温模型;ODEA可以抑制润滑油在土壤中的吸附量和吸附速率,ODEA质量浓度为4 mg/L时,抑制吸附效果最为显著。     

Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions

The objective of this work is to enhance the adsorbing performance of the natural Egyptian phyllosilicate mineral, glauconite (greensand), through surface modification to obtain a particular combination of physical and chemical properties. It was found that Zn removal increased from 84% to 94%, while Pb removal varied from 96.67% to 99% by using 10–25 g/l modified glauconite in a solution having 50 mg/l Zn²⁺ and 30 mg/l pb²⁺ ions. Adsorption data were investigated using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Linear regression methods are used to determine adsorption capacities and optimum adsorption isotherms. R² value of Langmuir isotherm model for pb²⁺ is higher than other models. The maximum monolayer coverage (Q_o) from Langmuir isotherm model was calculated to be 15.363 and 21.654 mg/g and the separation factor indicating a favorable sorption experiment is 0.0324 and 0.13207 for Zn²⁺ and Pb²⁺ respectively. Also from Freundlich isotherm model, the intensities of adsorption (n) that indicated favorable sorption are 1.3036 and 1.364 for Zn²⁺ and Pb²⁺ respectively. The heat of sorption process was calculated from Temkin isotherm model to be 6.44101 and 4.1353 J/mol for Zn²⁺ and Pb²⁺ respectively, that indicated to the physisorption process which B < 20 kJ/mol so, Temkin isotherm is not fitted with experimental adsorption but the mean free energy was calculated from DRK isotherm which are 24.693 and 47.093 kJ/mol, where E_D < 8 proved that the adsorption experiment followed a chemisorption process. So the relative adsorption capacity for metals was in the order Pb < Zn.     

毛细凝聚和吸附-脱附回路的物理化学解释

在测定多孔介质的吸附等温线时,常出现脱附滞后现象,即在同一压力下,吸附等温线与脱附等温线不相重合,脱附曲线高于吸附曲线,形成所谓“吸附-脱附回路”。从物理化学中亚稳状态的基本理论出发,得到平面液体的饱和蒸气压与微小液滴的饱和蒸气压之间的关系—开尔文（Kelvin)方程,利用该方程解释了毛细凝聚现象,论证了产生吸附-脱附回路现象的原因,分析了在多孔介质中毛细管压力对油气体系相平衡的影响。     

Adsorption of asphaltenes onto CaO,Co3O4, Fe3O4 and ZnO supported on 13X zeolite - An isothermal study

Abstract

Asphaltene has the highest molecular weight and the most polar organizers from petroleum. In this paper, the content of the asphaltenes from a crude oil was extracted and the amount of asphaltene in crude oil was measured to be 3.88%. Four metal oxides were added to 13X zeolite and 13X,10%CaO, 13X,10%Co₃O₄, 13X,10%Fe₃O₄ and 13X,10%ZnO were prepared. The adsorption behavior of the adsorbents was evaluated in asphaltenes adsorption. The capacity of the adsorbent for asphaltenes adsorption is as follows: 13X,10%CaO> 13X,10%Co₃O₄> 13X,10%Fe₃O₄> 13X,10%ZnO. The isotherm of adsorption of the asphaltenes over the adsorbent was studied and resulted that the experimental data could best fit with the Langmuir model, indicating that adsorption is as a monolayer.     

Adsorptive desulfurization and denitrogenation of model fuel by mesoporous adsorbents (MSU-S and CoO-MSU-S)

Adsorption of heterocyclic sulfur- and nitrogen-containing compounds by mesostructure adsorbent (MSU-S) and its modified form with cobalt oxide is studied using model fuel. The results of characteristic tests (XRD, N₂ adsorption–desorption, FTIR, and SEM) indicate that CoO impregnation causes a negative impact on mesoporous structure, crystalline phase, and particle shape along with a positive effect on surface ion exchange. CoO modification increased the adsorption loadings of DBT and BT to about 33.6% and 45.7%, respectively. For nitrogen compounds adsorption with the model fuel, adsorption loadings of quinoline and carbazole increase by 6.7% and 8.6%, respectively. Data fitting for carbazole, DBT, and BT is achieved better by the Langmuir model than the Freundlich model, and the data of quinoline fitted very well to the Freundlich model for CoO-MSU-S.     

Modification and characterization of NaY molecular sieve by Cr3+ and its adsorptive denitrogenation from model fuel

Abstract

The CrY, which was modified by Cr³+ from NaY, was confirmed by characterization with FT-IR, XRD, N₂ adsorption-desorption, and it was used to adsorb quinoline from model fuel. The suitable modification conditions were modified twice by 0.5?mol/L cobalt nitrate solution at 40?°C. The FT-IR spectra indicated the disappearance of 1147?cm^?1 peak and the blue shift of 1024?cm^?1, implying that Cr³+ had exchanged Na⁺ and successfully incorporated into the framework of NaY. The static denitrogenation experimental results indicated that the adsorption between quinoline and CrY was the coordination adsorption and π complex adsorption. The suitable conditions were 30?min at room temperature and the adsorption temperature had minor effect on denitrogenation. The kinetic model of CrY adsorbing quinoline belonged to Langmuir and Freundlich adsorption model.     

污染土壤中多环芳烃热解吸影响因素研究

以某污染场地多环芳烃污染土壤为原料，考察了热解吸修复温度、时间、土壤粒径等对污染土壤中超标多环芳烃热解吸效率的影响，并对各粒径土壤热解吸数据进行了一级动力学拟合，得到了反应速率常数k。实验结果表明：处理温度越高、时间越长，热解吸效果越好；土壤粒径越小，土壤中的多环芳烃热解吸速率越快。对热解吸系统的设计具有实际意义， 有利于节能降耗和工艺优化。     

ADSORPTION OF ASPHALTENE FUNTIONALITIES AND ASPHALTENE ON GOETHTTE

ABSTRACT

Solid-stabilized water-in-oil emulsions cause many problems such as oil loss, fouling of a processing unit, and environmental hazard in the petroleum production and refining. The ability of finely divided solids to stabilize these emulsions is due to the adsorption of asphaltenes and other heavy constituents. This study presents the individual and competitive adsorption of asphaltene functionalities in cyclohexane solution and asphaltene in heptol solution onto goethite (FeOOH) particle surfaces at 25 °C to quantitatively understand the FeOOH particle-fluid interactions. The functionalities used were carboxylic acid (represented by benzoic acid), sulfoxide (by diphenylsulfoxide), and pyrrolic (by indole). The single component adsorption of these functionalities was well represented by both the Langmuir and Freundlich models, showing that adsorptive affinity for FeOOH increased in the order of indole < diphenylsulfoxide < benzoic acid. This observation was supported by the results of bi-component competitive adsorption of three functionality pairs on FeOOH, which were interpreted by the Fritz model. The adsorption of asphaltene was performed using dry and moist FeOOH surfaces and well represented by both the Langmuir and Freundlich models. The moist FeOOH yielded a decrease in the adsorption of asphaltene compared to adsorption on dry FeOOH.     

Effective biosorption of patulin from apple juice by cross-linked xanthated chitosan resin

In this work, cross-linked xanthated chitosan resin (CXCR) was prepared by inverse suspension cross-linking method, using glutaraldehyde as cross-linking agent and carbon disulfide as modification agent. The biosorption of CXCR for patulin from apple juice was investigated. Batch adsorption experiments were performed to evaluate the effect of pH, temperature, contact time and initial concentration. The adsorption of CXCR for patulin was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The results showed that the optimum adsorption conditions of CXCR for patulin was achieved at pH 4, 30 °C for 18 h. The adsorption data could be fitted with pseudo–second order kinetic model and Freundlich isotherm model. It indicated that CXCR is an appropriate adsorbent for the removal of patulin from apple juice.     

吸附树脂对山竹黄酮化合物吸附特性的研究

研究了S-8、LSA-5B、X-53种吸附树脂分离纯化山竹夹层中黄酮类化合物的静态吸附过程。吸附动力学实验表明树脂吸附速率较快,1.5h基本达到吸附平衡,符合拟二级动力学吸附方程,吸附速率常数:k_(X-5树脂)>k_(LSA-5B树脂)>k_(S-8树脂)。在等温条件下,LSA-5B树脂、S-8树脂对黄酮类化合物的吸附量随初始吸附浓度的变化遵循Langmuir和Freundich吸附等温方程,X-5树脂仅遵循Freundich吸附等温方程。3种树脂的吸附自由能ΔG<0,是自发吸附。     

Development of a Froth Flotation Process for Recovery of Used Emulsifiable Oil

Abstract

The separation behavior of the lubricating oil from wastewater was studied using the technique; electroflotation. The optimum conditions for oil flotation were determined and the results were discussed according to a kinetic model. Further, the surface properties of the cationic collector were investigated. Cement kiln dust was used as an adsorbent applied to the flotation solution to investigate the kinetic and the adsorption equilibrium involved. According to the adsorption isotherm of the oil on the kiln dust, the optimum conditions for oil separation was suggested.     

Detoxification of zearalenone by Lactobacillus pentosus strains

Zearalenone (ZEA) contamination in food samples plays a critical role in food safety, since it causes serious health problems. Usage of microorganisms, such as lactic acid bacteria (LAB), is a promising new approach for detoxification. Eight Lactobacillus pentosus strains were evaluated for their ability to remove ZEA from a sodium acetate buffer solution with initial ZEA concentrations of 5.51–74.70 μg/mL. The adsorption capacity increased with increasing ZEA concentrations. The strain JM0812 showed the highest adsorption capability, at 83.17%, in solution containing 74.70 μg/mL ZEA, followed by UM054 (82.78%) and UM055 (81.69%), respectively. Three adsorption isotherms were applied to predict the removal efficiency of ZEA and the Freundlich isotherm appeared to have the best-fit for ZEA sorption onto bacterial cells. Our results indicate that Lb. pentosus strains are novel promising strains to reduce mycotoxin contamination in food products.     

THE PROPERTIES OF WATER LAYERS ON COAL SURFACES

ABSTRACT

The results of programmed thermodesorption investigations of water from coal surfaces are presented and correlated with the measurements of water adsorption and desorption from the gaseous phase at a temperature of 20^°C. From the data obtained, the activation energies of water molecules were calculated and possible structures of water adsorbed layers on the coal surfaces were suggested. On the basis of the DTA curve, the water adsorption heat on the coal surfaces 20^°C was calculated and presented in the form of dependence on water adsorption value from the gaseous phase.     

H-103大孔树脂对对硝基苯酚吸附行为的研究

研究了H-103大孔树脂对水溶液中对硝基苯酚的吸附动力学及热力学特性,通过静态吸附实验,探讨了温度、初始浓度、振荡速度对吸附动力学的影响。该吸附符合一级动力学吸附方程,颗粒内扩散过程是影响吸附速率的主要控制步骤。吸附符合Freundlich等温吸附方程,吸附为放热的物理吸附过程,适当降低温度有利于吸附,     

Adsorption of Naphthenic Acids from Dewaxed Vacuum Gas Oil by Activated Clay: Kinetics,Equilibrium and Thermodynamic Studies

This work was mainly concentrated on the removal of naphthenic acids(NAs) from dewaxed vacuum gas oil(VGO) by adsorption using a commercial grade activated clay(AC) adsorption during lube base oil refining. The NAs in dewaxed VGO cut-4 were identified by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry(ESI FT-ICR MS). The AC sample from a refinery was characterized by XRD, BET, TG/DTA, and SEM. A series of experiments were carried out to investigate the performance of NAs adsorption by AC using a batch adsorption technique, in which some key experimental parameters such as temperature, contact time, initial concentration of NA in oil sample as well as the dosage of adsorbent were investigated. Equilibrium isotherms were analyzed using the Langmuir, Freundlich, Tempkin and Dubinin-Radushkevich(D-R) adsorption models. The pseudo-first order, the pseudo-second order, and intraparticle diffusion models were employed to describe the kinetics data. The results revealed that the D-R isotherm provided a better fit to the experimental data than other isotherms, and the adsorption kinetics followed the pseudo-first order kinetic equation. The thermodynamic data indicated that the adsorption process was feasible and spontaneous as an endothermic process. The results could provide a clear understanding of the NAs adsorption by AC during lube base oil processing at refineries.