Details

Autor(en) / Beteiligte

• Aghaei, Erfan
• Karimzadeh, Ramin
• Godini, Hamid Reza
• Gurlo, Aleksander
• Gorke, Oliver

Titel

Improving the physicochemical properties of Y zeolite for catalytic cracking of heavy oil via sequential steam-alkali-acid treatments

Ist Teil von

• Microporous and mesoporous materials, 2020-03, Vol.294, p.109854, Article 109854

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• In this study, modified Y zeolite with high catalytic activity and long lifetime was successfully prepared using sequential steam-alkali-acid treatments. Different alkali agents (NaOH, Na2CO3 and CaCO3) with various concentrations were used in order to improve the catalytic performance of the synthesized Y zeolite in heavy oil conversion process. The physicochemical properties of the prepared samples were investigated using XRD, FESEM, EDX, solid-state29Si and 27Al NMR, BET, XRF, ICP, FTIR, and NH3-TPD techniques. In addition, the properties of the deposited coke on the used catalysts were studied by FTIR and TGA-DTA techniques. Al extraction via steam treatment created Si-rich regions in the Y zeolite samples. Then, the Si elements were easily extracted from these Si-rich regions by using alkali treatment. In addition, acid washing with weak EDTA solution resulted in removal of extracted elements from the zeolite structure and pore opening after steam and alkali treatments. Combination of these treatments stimulated mesopores formation and improvement in textural properties for the Y zeolite samples. Structural and textural properties of Y zeolite were found to be preserved after sequential treatments. Catalytic performance of the prepared catalysts was investigated for the heavy oil catalytic cracking process in a fixed bed reactor. Regardless of the type of alkali agent used for sequential treatments, the heavy oil conversion and gasoline selectivity were strongly improved for all the modified catalysts in reference to the parent catalyst. The catalytic activity tests showed that sample treated with 1 M CaCO3 solution could secure a high heavy oil conversion (70%) and high selectivity towards gasoline and kerosene (45%). Furthermore, modification with CaCO3 inhibits coke formation significantly and enhanced the catalytic lifetime. [Display omitted] •Modification of NaY zeolite by using sequential steam-alkali-acid treatments.•Using various concentrations of NaOH, Na2CO3 and CaCO3 for modification.•NaY textural and acidic properties enhancement by modification with alkali agents.•Implemented alkali modification improved the heavy oil conversion and gasoline selectivity.•Excellent catalytic performance and lifetime enhancement with 1 M CaCO3 modification.