Heterogeneous catalysts have been a central element in the efficient conversion of fossil resources to fuels and chemicals, but their role biomass utilization is more ambiguous. Zeolites constitute promising class heterogeneous developments recent years demonstrated potential find broad use biomass. In this perspective we review discuss that taken place field using zeolites. Emphasis put on lignocellulosic material conventional zeolites as well sugars Lewis acidic produce useful chemicals.

Abstract In petroleum science, the term resin generally implies material that has been eluted from various solid adsorbents, whereas maltenes (or petrolenes) indicates a mixture of resins and oils obtained as filtrates asphaltene precipitation. Thus, after asphaltenes are precipitated, adsorbents added to n-pentane solutions oils, by which process adsorbed subsequently recovered use more polar solvent, remain in solution. The fraction plays an important role stability prevents separation...

The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable and deposit) were mixed at several concentrations or dispersions into waxy crude oil. These blends evaluated by viscometry yield stress measurement compared with original A complex asphaltene−wax interaction as a function of concentration degree dispersion under dynamic static condition was observed. crystallization network strength strongly...

The past two decades of research on Carbon Capture and Storage (CCS) seem to have finally become fruitful as global leaders energy-intensive industries are cooperating materialize CCS projects reach the promised reduction in CO2 emissions. Traditionally, targeted mostly high permeability sandstone formations, despite numerous carbonate fields undergoing injection for Enhanced Oil Recovery (EOR) United States or Canada. Because reactivity between calcite minerals saturated water, chalk...

New data are reported from powder X-ray diffraction (XRD) investigations of fractions obtained separation the bulk heptane−asphaltenes into subfractions using toluene−heptane mixtures. The latter indicate that when removing large parts heptane−asphaltene fraction by extraction with solvent mixtures having an increased toluene content, stacking distance (or intensity 002 peak) or other parameters derived not particularly changed. Hence, this infers no increase in molecular interaction takes...

Interfacial tension (IFT) is one of the major parameters which govern fluid flow in oil production and recovery. This paper investigates interfacial activity different natural surfactants found crude oil. The main objective was to better understand competition between carboxylic acids asphaltenes on toluene/water interfaces. Dynamic IFT measured for water-in-oil pendant drops contrary most studies using oil-in-water drops. Stearic acid (SA) used as model compound surface-active crude....

The impact of surface active indigenous components on interfacial tension (IFT) crude oil–water systems is an important parameter in many aspects oil production such as emulsion stability, reservoir wettability, and capillary number calculations. These may affect productivity across the due to variations concentrations. In most cases simulation IFT not taking activity into account purely based bulk properties. this paper we examine two oils their subfractions maltenes, deacidified crude,...

Asphaltenes separated from a Maya type of crude oil were suspended in toluene and later fractionated by solubility polar (acetone) nonpolar (n-heptane) precipitating solvent. The two sets derived fractions characterized using size exclusion chromatography (SEC), elemental analysis, Fourier transform infrared spectroscopy (FTIR), synchronous fluorescence proton nuclear magnetic resonance (1H NMR) spectroscopy. results show that the acetone-precipitated asphaltene have larger structural...

The abundantly used technique of flocculation onset titration (FT) asphaltenes is investigated, and it shown how additional information on asphaltene oil properties in terms solubility parameters may be derived from the data obtained. classical ways interpreting results are outlined. Analysis effect concentration FT to add stability oil. Application various areas related problems shown. This includes emulsion by asphaltenes, change conversion, field deposition, segregation, dispersant...

In the prolific literature about asphaltenes, effects of temperature and pressure on their stability are subjects discussion. A new high-pressure cell, requiring a very small amount sample with wide working conditions, has been built in order to study asphaltene phase behavior after injection various gases precipitants. filtration technique is used conclude temperature, pressure, composition. The precipitant this work CO2. Two crude oils (from South America Middle East) were studied up 383 K...

The relation between the often reported micellization of petroleum asphaltenes in organic solvents and content trace water solvent was investigated using calorimetric titration. toluene (ranging from 0 to 0.047%) found be driving force establishing a measurable critical micelle concentration range 0.2 8 g/L solvent. It determined that, for three different analyzed, presence 0.01% more likely indicates stepwise association rather than classical formation mechanism. On basis this result,...

Micellization of asphaltenes in solution has been investigated using a micro calorimetric titration procedure (Andersen, S. I.; Birdi, K. J. Colloid Interface Sci. 1991, 142, 497). The method uses the analysis heat dissociation and dilution asphaltene micelles when pure solvent (or mixture) is titrated with same solvent. concentration injected at level above critical micelle (CMC). In present paper applied investigation as well subfractions obtained by extraction toluene/heptane mixtures....

The conversion of asphaltenes in heavy oil hydroprocessing is important as the asphaltenic fraction often contains most refractive components. In residual feeds, content sulfur amounts to less than 20% total content; hydrotreated products, however, more 60% may be asphaltenic. When hydrotreating oils, both non-asphaltenic phase and undergo a chemical conversion, which lead unstable products well increased coke lay-down on catalyst. To able explain behavior different catalysts, asphaltene...

ABSTRACT Solid petroleum asphaltenes have been fractionated according to solubility in toluene/n-heptane mixtures of increasing toluene content. A large hysteresis was observed between this dissolution and the precipitation from crude oil. In order shed light on solution mechanism, fractions obtained analyzed using size exclusion chromatography (SEC-HPLC-UV-vis), VPO, elemental analysis, UV-vis adsorption spectroscopy phenol interaction values methylene content by FTir. Less polar...

ABSTRACT Asphaltenes has been precipitated from a Kuwait flash residue using different n-alkanes (n-C5 to n-C8) at various temperatures ranging 4°C reflux of the used precipitants. Structures in asphaltene fractions revealed U.V. fluorescence spectroscopy, elemental analysis and some extent 1H-nmr. These shows that asphaltenes same amount but temperature with solvents have merely composition. For all curves versus show maxima about 25°C, implying shift solubility asphaltenes.The impact...

ABSTRACT Petroleum asphaltenes have been precipitated in solvent mixtures of n-heptane and toluene at various temperatures, likewise dissolved under similar conditions. This give added evidence to apparent hysteresis phenomenon between the two processes. The Asphaltenes characterized showing that although data is scattered convergence certain structural parameters as incipient flocculation approached. are seen consist an associating a non-associating part. solubility has correlated/modelled...