Microstructural Investigation of Coke Deposition in Pelleted Catalyst during Downhole Catalytic Upgrading of Heavy Crude Oil Using Porosimetry and X-ray Computed Tomography

Catalytic performance and industrial test of HY zeolite for alkylation of naphthalene and α-tetradecene

“…On the one hand, this was because the product diffused more easily in larger pores, thus coke was not easily formed. A similar observation was made in the study by Hart et al, 29 in which it was reported that micropores suffer more from coke than mesopores. Therefore, the micropore volume was greatly reduced.…”

“…This is also one reason why the catalyst cannot be completely regenerated, which was also reported in other literature. 29 After further analysis, it can be considered that the poor catalytic activity of in situ regenerated catalyst under industrial conditions was due to the fast heating rate and untimely temperature control, resulting in the incomplete removal of coke.…”

Catalytic Copyrolysis of Heavy Oil with Polypropylene

“…1 However, catalytic conversion of heavy residues always is accompanied by strong formation of coke as a byproduct. 11,12 The coke deposited on the catalyst blocks the pores, rendering the catalyst less active and nonselective. 2,3,11−13 It also limits the conversion of macromolecules to low boiling point fractions with a subsequent decrease in the liquid yield and increase in the percentage of the wax.…”

“…Hydrocracking catalysts, shape-selective zeolite-based dewaxing catalysts, and zeolite acidic catalysts are widely used to process heavy oils into clean fuels. , These catalysts are very versatile with high activity and selectivity for important hydrocarbon transformation reactions . However, catalytic conversion of heavy residues always is accompanied by strong formation of coke as a byproduct. , The coke deposited on the catalyst blocks the pores, rendering the catalyst less active and nonselective. ,,− It also limits the conversion of macromolecules to low boiling point fractions with a subsequent decrease in the liquid yield and increase in the percentage of the wax. − In most commercial processes, the cost of catalyst deactivation is very high. Hence, facilitating the catalyst stability and optimizing regeneration is an important measure of controlling the activity and selectivity of the catalyst. , Coke formation can be suppressed by increasing the hydrogen pressure. ,,, The addition of hydrogen can offer alternative reaction pathways, by means of inhibiting the dehydrogenation reactions and lowering the amount of coke precursors in the reaction media, ,, resulting in less coke formation and high liquid yield. ,, However, the use of hydrogen is very expensive. ,,, Alternative technologies with lower processing costs are highly desirable.…”

“…16,17 Coke formation can be suppressed by increasing the hydrogen pressure. 1,12,15,17 The addition of hydrogen can offer alternative reaction pathways, by means of inhibiting the dehydrogenation reactions and lowering the amount of coke precursors in the reaction media, 12,15,17 resulting in less coke formation and high liquid yield. 15,16,18 However, the use of hydrogen is very expensive.…”