In-situ Crystallized Zeolite/Kaolin Catalysts with Reduced Crystal Size for Enhanced Heavy Oil Cracking

Abstract

Reducing mass transfer and diffusion resistance of heavy oil macromolecules on catalyst surface is critical for improving the cracking performance of fluid catalytic cracking (FCC) catalysts. One effective approach is the synthesis of nano-sized zeolites, which shortens diffusion pathways and enhances catalytic efficiency. In this study, a low-cost alkaline functional additive was incorporated into an in-situ crystallization process to prepare FCC catalysts containing small-crystal Y zeolite. The effects of zeolite crystal size on texture properties and catalytic performance were systematically investigated. The resulting catalysts exhibited a distinct structure, with nano-sized Y zeolite primarily distributed in the outer layer of the microspheres. Compared with the conventional sample (ZK-T, average crystal sizes ca. 600 nm), the nanosized sample (ZK-N) showed higher crystallinity, a larger Brunauer-Emmett-Teller (BET) surface area, and a greater density of Brønsted acid sites. Adsorption experiments using macromolecular probes, together with advanced catalyst evaluation (ACE) tests, confirmed that smaller zeolite crystals significantly enhanced mass transfer and heavy oil cracking performance. These findings demonstrate that FCC catalysts performance depends not only on zeolite content but also on diffusion path length. Reducing zeolite crystal size offers a practical and scalable strategy for improving heavy oil conversion efficiency.

Keywords

Fluid catalytic cracking (FCC) / In-situ crystallization / Crystal size / Effective diffusion / Heavy oil cracking performance

References

[1] Cejka J, Bekkum H V, Corma A, Schueth F. Introduction to Zeolite Molecular Sieves, 2007, Amsterdam, Elsevier Science

[2] Su X M, Wang Y Q, Bu L Z, Zhang X, Li Y N, Sang J C, Ren G M, Wen M H. Chem. Res. Chinese Universities, 2025, 41: 919

[3] Yue Y Y, Kang Y, Bai Y, Gu L L, Liu H Y, Bao J, Wang T H, Yuan P, Zhu H B, Bai Z S, Bao X J. Appl. Clay. Sci., 2017, 158: 177

[4] Zheng M D, Chen Y, Liu Z, Lv J M, Ye B, Sun M H, Chen L H, Su B L. Chem. Res. Chinese Universities, 2024, 40: 704

[5] He Y, Tang S, Yin S, Li S. J. Clean. Prod., 2021, 306: 127248

[6] Lam A, Rivera A. Micropo. Mesopor. Mat., 2006, 91: 181

[7] Wu M, Jiang W B, Jiang J L, Zou Y Q, Zhang P Y, Mao P, Xu Y, Shi Y Y. Bull. Mater. Sci., 2020, 43: 289

[8] Chu K L, Wang Y Q, Liu W R, Bu L Z, Huang Y T, Guo N D, Qu L P, Sang J C, Li Y N, Su X M, Zhang X. Chem. Res. Chinese Universities, 2024, 40: 1151

[9] Wang S, Peng Y. Chem. Eng. J., 2010, 156: 11

[10] Weisz P B, Frilette V J. J. Phys. Chem., 1960, 64: 382

[11] Frilette V J, Weisz P B, Golden R L. J. Catal., 1962, 1: 301

[12] Weisz P B, Frilette V J, Maatman R W, Mower E B. J. Catal., 1962, 1: 307

[13] Meyers R A. Handbook of Pertoleum Refining Processes, 2004, New York, McGraw-Hill Education

[14] Vermeiren W, Gilson J P. Top. Catal., 2009, 52: 1131

[15] Zaarour M, Dong B, Naydenova I. Micropo. Mesopor. Mat., 2014, 189: 11

[16] Valtchev V, Tosheva L. Chem. Rev., 2013, 113: 6734

[17] Zhu K K, Sun J M, Liu J, Wang L Q, Wan H Y, Hu J Z, Wang Y, Peden C H F, Nie Z M. ACS Catal., 2011, 1: 682

[18] Vuong G T, Hoang V T, Nguyen D T. Appl. Catal. A-Gen., 2010, 382: 231

[19] Chen X Y, Wendell K, Zhu J J, Li L, Yu X X, Zhang Z J. Bioresour. Technol., 2012, 110: 79

[20] Vuong G T, Do T O. J. Am. Chem. Soc., 2007, 129: 3810

[21] Song W, Justice R E, Jones C A, Grassian V H, Larsen S C. Langmuir, 2004, 20: 4696

[22] Mintova S, Gilson J P, Valtchev V. Nanoscale., 2013, 5: 6693

[23] Burel L, Tuel A. Micropo. Mesopor. Mat., 2013, 174: 90

[24] Esmaeili N, Kazemian H, Bastani D. Iran. J. Chem. Chem. Eng., 2011, 30: 9

[25] Xie B, Song J W, Ren L M, Ji Y Y, Li J X, Xiao F S. Chem. Mater., 2008, 20: 4533

[26] Reding G, Mäurer T, Kraushaar-Czarnetzki B. Micropo. Mesopor. Mat., 2003, 57: 83

[27] Serrano D, Aguado J, Rodriguez J, Peral A. Stud. Surf. Sci. Catal., 2007, 170: 282

[28] Tago T, Konno H, Nakasaka Y, Masuda T. Catal. Surv. Asia, 2012, 16: 148

[29] Ni Y M, Sun A M, Wu X L, Hai G L, Hu J L, Li T, Li G X. Micropo. Mesopor. Mat., 2011, 143: 435

[30] Bao S G, Liu G Z, Zhang X W, Wang L, Mi Z T. Ind. Eng. Chem. Res., 2010, 49: 3972

[31] Covarrubias C, Gracia F, Palza H. Appl. Catal. A-Gen., 2010, 384: 186

[32] Zhang H B, Ma Y C, Song K S, Zhang Y H, Tang Y. J. Catal., 2013, 302: 115

[33] Liu B, Wu Q M, Chen Z H, Xiao F S. Chem. Res. Chinese Universities, 2024, 40: 646

[34] Louis B, Vicente A, Fernandez C, Valtchev V. J. Phys. Chem. C, 2011, 115: 18603

[35] Brown S M, Durante V A, Reagan W J, Speronello B K. Fluid Catalytic Cracking Catalyst Comprising Microspheres Containing More than about 40 Percent by Weight Y-Faujasite and Methods for Making and Using It, 1983US 4493902

[36] Zhang Y M, Xiong C R. Cat. Sci. Technol., 2012, 2: 606

[37] Wei B Y, Liu H Y, Li T S, Cao L Y, Fan Y, Bao X J. AIChE, 2010, 56: 2913

[38] Zhang L, Hu Q X, Qin Y C, Liu H H, Zhao X Z, Gao X H, Song L J, Sun Z L. Ind. Eng. Chem. Res., 2022, 61: 11628

[39] Zhang L, Hu Q X, Qin Y C, Liu H H, Liu H F, Cao G Z, Gao X H, Song L J, Sun Z L. Micropo. Mesopor. Mat., 2023, 359: 1

[40] ASTM International. Standard Test Method for Determination of Relative X-Ray Diffraction Intensities of Faujasite-Type Zeolite-Containing Materials, 2019International Standard: D3906-19, April

[41] Emeis C A. J. Catal., 1993, 141: 347

RIGHTS & PERMISSIONS

Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH