Studies of asphaltene diffusion and structure and their implications for resid upgrading

Sane, R.C.; Tsotsis, Theodore T.; Webster, Ian A.; Ravikumar, V.

doi:10.1016/0009-2509(92)87113-5

Cited by 25 publications

(20 citation statements)

References 9 publications

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“…Consequently, as the pore size decreased the estimated asphaltene size decreased. Significantly, the model estimates of the asphaltene molecular radius (3.8 -14.2 nm) are in good agreement with literature values, although in the latter case, the reported values are strongly dependent upon the experimental techmque used to measure the molecular size (Speight and Moschopedis, 1981;Sane et al, 1992). Baltus and Anderson (1983) studied asphaltene transport through mica membranes and estimated the molecular radius of various asphaltene fractions to be in the range 2 to 15 nm.…”

Section: Eflect Of Membrane Pore Diametersupporting

confidence: 87%

A model of ceramic membrane fouling during heavy oil ultrafiltration

Duong

Smith

1997

Can J Chem Eng

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Fouling of asymmetric, single tube ceramic membranes during ultrafiltration of Cold Lake heavy oil, is described by a pore restriction fouling model that predicts reduced permeate flux but increased asphaltene rejection with increased time-on-stream. Application of the model to experimental data showed that a 2nd-order rate of asphaltene adsorption/deposition within the membrane pores, described the data better than a 1 st-order model. The asphaltene molecular radius, estimated as a parameter of the model, was in the range 3.8 -14.2 nm, depending on the membrane pore diameter. These values are in good agreement with previously published estimates of asphaltene particle size, determined using different experimental techniques.On decrit I'encrassement des membranes en ceramique de

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Section: Eflect Of Membrane Pore Diametersupporting

confidence: 87%

A model of ceramic membrane fouling during heavy oil ultrafiltration

Duong

Smith

1997

Can J Chem Eng

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“…Hindered diffusion of heavy oil molecules has been studied extensively by diaphragm diffusion cell, adsorptive uptake, and reactive kinetic methods . All experimental results to date confirmed that the hindered effect is significant for residue molecules diffusing through pores with typical hydrotreating catalyst size.…”

Section: Introductionmentioning

confidence: 80%

Effect of composition and configuration on hindered diffusion of residue fractions through polycarbonate membranes

et al. 2012

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Diffusion behavior of narrow fractions of three residues and subfractions of a residue through four polycarbonate membranes was investigated using a diaphragm cell at 308 K. The results show that the diffusivities of fractions with similar molecular weight behaved differently. Comparisons among SAR subfractions (saturates, aromatics, and resins) of the same fraction show that saturates has the largest diffusion coefficient, followed by aromatics, and then resins. The diffusion coefficients of fractions fall among that of their subfractions. The regular variation of diffusivity along with the properties for fractions with similar molecular weight is an indication of the difference in their diffusivities resulting from the difference in their compositions and structures. Hindrance factors of the subfractions through membranes with small pores have a similar variation trend as their diffusion coefficients. The hindrance factors of the feedstocks in 50 and 80 nm pore size membranes are mostly larger than 0.90, but the values in 15 nm membranes range from 0.55 to 0.81. The study not only indicates that the diffusional limitations are significant in pores with the typical hydrotreating catalyst size but composition and configuration have an effect on the hindered diffusion of residue molecules. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1369–1377, 2013

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“…The variation is slight because of the narrow fraction used in their study. Sane et al 4 discovered the variations in diffusivity vs. time for Hondo California asphaltene. Table 2.…”

Section: Effective Diffusion Coefficientsmentioning

confidence: 98%

“…A significant pore size effect on diffusional transport of the solute has been found from their results. Sane et al [4][5][6] investigated the diffusion of asphaltenes through track-etched polycarbonate membranes. The results showed that the effective diffusion coefficient of asphaltenes varies as a function of experimental time.…”

Section: Introductionmentioning

confidence: 99%

Hindered diffusion of residue narrow cuts through polycarbonate membranes

Chen

Gao

et al. 2010

AIChE Journal

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Hindered diffusion plays an important role in catalytic processing of residue and heavy oil because of large size molecules in these feedstocks. Vacuum residue of Athabasca oil sand bitumen was fractionated into 13 narrow fractions and an end-cut by supercritical fluid extraction and fractionation (SFEF). Diffusion transport of five SFEF cuts through four polycarbonate membranes was investigated using a diaphragm cell at 308 K. The results showed that diffusion coefficients of the five SFEF cuts decreased as the experiment proceeded, which illustrates that these cuts are polydisperse in size. The effective diffusion coefficients varied with molecular size and pore size. Hindered diffusion of the five SFEF cuts is significant in the membranes with nominal pore diameter of 15 nm, which is around the average pore size of typical hydrotreating catalyst. Comparisons between experimental data and theoretical prediction revealed that the actual hindered degree for diffusion of the five SFEF cuts is higher than that calculated by the Renkin equation. There were slight differences in diffusivity among saturate, aromatic, and resin constituents.

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Studies of asphaltene diffusion and structure and their implications for resid upgrading

Cited by 25 publications

References 9 publications

A model of ceramic membrane fouling during heavy oil ultrafiltration

A model of ceramic membrane fouling during heavy oil ultrafiltration

Effect of composition and configuration on hindered diffusion of residue fractions through polycarbonate membranes

Hindered diffusion of residue narrow cuts through polycarbonate membranes

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