Hydrothermal extractive upgrading of bitumen without coke formation

Vilcáez, Javier; Watanabe, Masaru; Watanabe, Noriaki; Kishita, Atsushi; Adschiri, Tadafumi

doi:10.1016/j.fuel.2012.07.024

Cited by 90 publications

(76 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar mechanism was proposed 20) after our research to support the validity of this model. Figure 9 shows the proposed reaction model.…”

Section: 1 Effect Of Water On Hydrogenationsupporting

confidence: 85%

See 1 more Smart Citation

Upgrading of Heavy Oil by Hydrogenation through Partial Oxidation and Water-gas Shift Reaction in Supercritical Water

Sato

2014

J. Jpn. Petrol. Inst.

View full text Add to dashboard Cite

Partial oxidation of hydrocarbons including heavy oil in supercritical water forms CO and CO2, which undergoes the water-gas shift reaction to form active hydrogen and then hydrogenation of heavy oil proceeds. In the case of partial oxidation of hydrocarbons and bitumen in supercritical water, the selectivity for partial oxidative products such as CO increased with increasing water density. In the case of hydrogenation of heavy oil in supercritical water through the water-gas shift reaction, reverse water-gas shift reaction and decomposition of formic acid that is a reaction intermediate of the water-gas shift reaction, coke formation was suppressed compared to that in only supercritical water. The main factors for suppressing coke formation were as follows: high water density improving the reactivity of hydrogen source in the oil-rich phase that enhanced hydrogenation of asphaltene core, direct injection of hydrogen source into the oil-rich phase increasing the concentration of active hydrogen in that phase, and coexisting gases with supercritical water facilitating the extraction of coke precursor from the oil-rich phase. The upgrading of heavy oil through a series of partial oxidation and hydrogenation reactions in supercritical water proceeded in the presence of catalyst and possible optimum conditions were proposed.

show abstract

“…A similar mechanism was proposed 20) after our research to support the validity of this model. Figure 9 shows the proposed reaction model.…”

Section: 1 Effect Of Water On Hydrogenationsupporting

confidence: 85%

“…7. Upgrading of bitumen in SCW probably involves two phases in the reactor according to previous studies 9), 20) , the upper water-rich phase and the bottom oil-rich phase. The asphaltene, that is, the coke precursor, was mainly in the oil-rich phase.…”

Section: Non-catalytic Reactionmentioning

confidence: 96%

Upgrading of Heavy Oil by Hydrogenation through Partial Oxidation and Water-gas Shift Reaction in Supercritical Water

Sato

2014

J. Jpn. Petrol. Inst.

View full text Add to dashboard Cite

show abstract

“…First, NaOH could react with carboxyl group ( COOH) in asphaltene interfaces to form more hydrophilic compounds ( COONa), which increased the solubility of asphaltene in SCW and accelerated the WGS reaction (−COONa + H 2 O → − CO 3 Na + H 2 ) [25]. Second, NaOH accelerated the WGS reaction through the formation of Na 2 CO 3 and NaHCO 3 and shifted the WGS reaction equilibrium to the forward direction by capturing CO 2 in the gas product [26]. Third, the active-hydrogen Table 3 Rate constants for asphaltene transformation, maltene + gas and coke formation in SCW (supercritical water) and SCW + NaOH.…”

Section: Asphaltene Transformationmentioning

confidence: 99%

“…In recent years, with the depletion of the conventional light crude oil reserve and skyrocketing oil prices, the refineries have to take heavy oils with huge potential as an oil substitute and convert them into light fractions to meet the ever-growing energy demand [1][2][3][4]. Heavy oil contains a significant portion of highly polar macromolecular compounds, such as asphaltene (1000-200,000 g/mol) [5].…”

Section: Introductionmentioning

confidence: 99%

“…However, it is worth noting that the asphaltene in heavy oil could not be completely solubilized into the SCW phase to form a homogeneous phase even with a temperature as high as 440 • C, which seriously influences the performance of asphaltene transformation and increases the formation of coke [3]. At present, asphaltene emulsification may be a better way to increase the solubility of asphaltene in SCW through a saponification reaction between amphiphilic molecules in asphaltene interfaces and bases to form a more hydrophilic compound [25].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of NaOH on asphaltene transformation in supercritical water

Yan

Zhang

et al. 2015

The Journal of Supercritical Fluids

View full text Add to dashboard Cite

Lumped reaction kinetic models for pyrolysis of heavy oil in the presence of supercritical water

et al. 2015

View full text Add to dashboard Cite

The reaction kinetics of the pyrolysis of heavy oil in the presence of supercritical water (SCW) and high pressure N 2 were measured. At any reaction temperature applied, the pyrolysis under SCW environments is faster than that under N 2 environments. Meanwhile, at lower temperatures the pyrolysis under both environments is accelerated by the introduction of coke into the feedstock. On the basis of a first-order four-lump reaction network consisting of the sequential condensation of maltenes and asphaltenes, the pyrolysis in whichever medium can be preferably described either by the lumped reaction kinetic model modified with autocatalysis and pseudoequilibrium or by the model modified solely with pseudoequilibrium. Benefited from the reduced limitation of diffusion to reaction kinetics, the pyrolysis in the SCW phase is more sensitive to the increase in reaction temperature than that in the oil phase, disengaging readily from the dependence on autocatalysis at a lower temperature.

show abstract

Hydrothermal extractive upgrading of bitumen without coke formation

Cited by 90 publications

References 19 publications

Upgrading of Heavy Oil by Hydrogenation through Partial Oxidation and Water-gas Shift Reaction in Supercritical Water

Upgrading of Heavy Oil by Hydrogenation through Partial Oxidation and Water-gas Shift Reaction in Supercritical Water

Effect of NaOH on asphaltene transformation in supercritical water

Lumped reaction kinetic models for pyrolysis of heavy oil in the presence of supercritical water

Contact Info

Product

Resources

About