Low Temperature Catalytic Cracking of Heavy Feedstock Optimized by Response Surface Method

Document Type : Research Paper


1 Chemical Engineering Faculty, Tarbiat Modares University, Tehran, Tehran, P.O. Box 14155-4838, Iran

2 Department of Materials and Chemical Engineering, Buein Zahra Technical University, Buein Zahra, Qazvin, P.O. Box 34517-45346, Iran


Upgrading of cracked PFO (Pyrolysis fuel oil) for production of fuels, such as gasoline and light gasoil, was carried out in a semi batch reactor. Two different kinds of mesoporous and microporous catalysts, MCM-41 and ZSM-5, were used. Modification methods, such as ion exchange and impregnation with Fe and Ti, were done for tuning the acidity of the catalyst. XRD, FT-IR, and XRF analyzes were used to identify the structure and composition of the catalysts. Among the catalysts used in low temperature catalytic cracking of cracked PFO in a moderate temperature (380 °C), 3%Ti/H-MCM-41 showed the best catalytic performance. After choosing the best catalyst, an experimental design was carried out using response surface method with a five-level central composite design model. The effect of 3 main parameters, i.e. reaction temperature (360-400 °C), catalyst to feed ratio (0.04-0.1), and loading of Ti (0-5%) were investigated on liquid productivity and light olefin production. Design Expert software was used to maximize the sum of liquid yield and olefins in the gas. The best catalyst is 2.5%Ti/H-MCM-41. In optimum, 380 °C with the ratio of 0.1 g/g catalyst to feed over 2.5%Ti/H-MCM-41, the wt.% of liquid, gas, and solid products are 80 wt. %, 10 wt. %, and 10 wt. %, respectively. At this condition, 26 wt. % of liquid product was in the range of gasoline (C5-C10) and the rest (i.e. C11+) was considered in the range of light gas oil. Light olefins of the obtained gas products were about 2.74 wt. %.


[1] Zhichang LI, Xianghai ME, Chunming XU, Jinsen GA. Secondary cracking of gasoline and diesel from heavy oil catalytic pyrolysis. Chinese Journal of Chemical Engineering. 2007 Jun 1;15(3):309-14.
[2] Meng X, Xu C, Gao J, Zhang Q. Effect of catalyst to oil weight ratio on gaseous product distribution during heavy oil catalytic pyrolysis. Chemical Engineering and Processing: Process Intensification. 2004 Aug 1;43(8):965-70.
[3] Basily IK, Souaya ER, Ibraheem NN. Gas-liquid chromatographic determination of the gaseous products of the two-stage pyrolysis of heavy oils. Microchemical Journal. 1988 Dec 1;38(3):283-94.
[4] Gao X, Qin Z, Wang B, Zhao X, Li J, Zhao H, Liu H, Shen B. High silica REHY zeolite with low rare earth loading as high-performance catalyst for heavy oil conversion. Applied Catalysis A: General. 2012 Jan 31;413:254-60
[5] Zhang Y, Yu D, Li W, Gao S, Xu G, Zhou H, Chen J. Fundamental study of cracking gasification process for comprehensive utilization of vacuum residue. Applied Energy. 2013 Dec 1;112:1318-25.
[6] Zhang Y, Yu D, Li W, Gao S, Xu G. Bifunctional catalyst for petroleum residue cracking gasification. Fuel. 2014 Jan 30;117:1196-203.
[7] Ding F, Ng SH, Xu C, Yui S. Reduction of light cycle oil in catalytic cracking of bitumen-derived crude HGOs through catalyst selection. Fuel Processing Technology. 2007 Sep 1;88(9):833-45.
[8] Li X, Li C, Zhang J, Yang C, Shan H. Effects of Temperature and Catalyst to Oil Weight Ratio on the Catalytic Conversion of Heavy Oil to Propylene Using ZSM-5 and USY Catalysts. Journal of Natural Gas Chemistry. 2007 March 1;16(1):92-9.
[9] Vuong GT, Hoang VT, Nguyen DT, Do TO. Synthesis of nanozeolites and nanozeolite-based FCC catalysts, and their catalytic activity in gas oil cracking reaction. Applied Catalysis A: General. 2010 Jul 15;382(2):231-9.
[10] Ishihara A, Kimura K, Owaki A, Inui K, Hashimoto T, Nasu H. Catalytic cracking of VGO by hierarchical ZSM-5 zeolite containing mesoporous silica–aluminas using a Curie point pyrolyzer. Catalysis Communications. 2012 Nov 5;28:163-7.
[11] Aguado J, Serrano DP, Escola JM, Peral A. Catalytic cracking of polyethylene over zeolite mordenite with enhanced textural properties. Journal of Analytical and Applied Pyrolysis. 2009 May 1;85(1–2):352-8.
[12] Angyal A, Miskolczi N, Bartha L, Tungler A, Nagy L, Vida L, Nagy G. Production of steam cracking feedstocks by mild cracking of plastic wastes. Fuel Processing Technology. 2010 Nov 1;91(11):1717-24.
[13] Singh J, Kumar MM, Saxena AK, Kumar S. Studies on thermal cracking behavior of residual feedstocks in a batch reactor. Chemical Engineering Science. 2004 Nov 1;59(21):4505-15.
[14] Asgharzadeh Shishavan R, Ghashghaee M, Karimzadeh R. Investigation of kinetics and cracked oil structural changes in thermal cracking of Iranian vacuum residues. Fuel Processing Technology. 2011 Dec 1;92(12):2226-34.
[15] Serrano DP, Aguado J, Escola JM, Rodriguez JM, Peral A. Catalytic properties in polyolefin cracking of hierarchical nanocrystalline HZSM-5 samples prepared according to different strategies. Journal of Catalysis. 2010 Nov 19;276(1):152-60.
[16] Wang L, Wang Y, Hao J, Liu G, Ma X, Hu S. Synthesis of HZSM-5 coatings on the inner surface of stainless steel tubes and their catalytic performance in n-dodecane cracking. Applied Catalysis A: General. 2013 Jul 10;462–463:271-7.
[17] Al-Shammari AA, Ali SA, Al-Yassir N, Aitani AM, Ogunronbi KE, Al-Majnouni KA, et al. Catalytic cracking of heavy naphtha-range hydrocarbons over different zeolites structures. Fuel Processing Technology. 2014 Jun 1;122:12-22.
[18] Jeon SG, Kwak NS, Rho NS, Ko CH, Na JG, Yi KB, Park SB. Catalytic pyrolysis of Athabasca bitumen in H2 atmosphere using microwave irradiation. Chemical Engineering Research and Design. 2012 Sep 1;90(9):1292-6.
[19] Luik H, Luik L, Johannes I, Tiikma L, Vink N, Palu V, Bitjukov M, Tamvelius H, Krasulina J, Kruusement K, Nechaev I. Upgrading of Estonian shale oil heavy residuum bituminous fraction by catalytic hydroconversion. Fuel Processing Technology. 2014 Aug 1;124:115-22.
[20] Han SY, Lee CW, Kim JR, Han NS, Choi WC, Shin CH, Park YK. Selective Formation of Light Olefins by the Cracking of Heavy Naphtha over Acid Catalysts. Studies in Surface Science and Catalysis. 2004;153:157-60.
[21] Fesharaki MJ, Ghashghaee M, Karimzadeh R. Comparison of four nanoporous catalysts in thermocatalytic upgrading of vacuum residue. Journal of Analytical and Applied Pyrolysis. 2013 Jul 1;102:97-102.
[22] Basily IK, Ahmed E, Ibraheam NN. Upgrading heavy ends into marketable products. New concepts and new catalysts for two-stage catalytic pyrolysis. Journal of Analytical and Applied Pyrolysis. 1995 Apr 1;32:221-32.
[23] Ali MA, Tatsumi T, Masuda T. Development of heavy oil hydrocracking catalysts using amorphous silica-alumina and zeolites as catalyst supports. Applied Catalysis A: General. 2002 Jul 10;233(1–2):77-90.
[24] Gao X, Tang Z, Zhang H, Ji D, Lu G, Wang Z, Tan Z. Influence of particle size of ZSM-5 on the yield of propylene in fluid catalytic cracking reaction. Journal of Molecular Catalysis A: Chemical. 2010 Jun 15;325(1–2):36-9.
[25] Zhao L, Gao J, Xu C, Shen B. Alkali-treatment of ZSM-5 zeolites with different SiO2/Al2O3 ratios and light olefin production by heavy oil cracking. Fuel Processing Technology. 2011 Mar 1;92(3):414-20.
[26] Coriolano ACF, Silva CGC, Costa MJF, Pergher SBC, Caldeira VPS, Araujo AS. Development of HZSM-5/AlMCM-41 hybrid micro–mesoporous material and application for pyrolysis of vacuum gasoil. Microporous and Mesoporous Materials. 2013 May 15;172:206-12.
[27] Chen W, Han D, Sun X, Li C. Studies on the preliminary cracking of heavy oils: Contributions of various factors. Fuel. 2013 Apr 1;106:498-504.
[28] Rosenholm JB, Rahiala H, Puputti J, Stathopoulos V, Pomonis P, Beurroies I, et al. Characterization of Al- and Ti-modified MCM-41 using adsorption techniques. Colloids and Surfaces A: Physicochemical and Engineering Aspects. 2004 Dec 1;250(1–3):289-306.
[29] Schacht P, Noreña-Franco L, Ancheyta J, Ramírez S, Hernández-Pérez I, García LA. Characterization of hydrothermally treated MCM-41 and Ti-MCM-41 molecular sieves. Catalysis Today. 2004 Nov 24;98(1–2):115-21.
[30] Hao K, Shen B, Wang Y, Ren J. Influence of combined alkaline treatment and Fe–Ti-loading modification on ZSM-5 zeolite and its catalytic performance in light olefin production. Journal of Industrial and Engineering Chemistry. 2012 Sep 25;18(5):1736-40.
[31] Wang S, Shi Y, Ma X. Microwave synthesis, characterization and transesterification activities of Ti-MCM-41. Microporous and Mesoporous Materials. 2012 Jul 1;156:22-8.
[32] Trong On D, Nguyen SV, Hulea V, Dumitriu E, Kaliaguine S. Mono- and bifunctional MFI, BEA and MCM-41 titanium-molecular sieves. Part 1. Synthesis and characterization. Microporous and Mesoporous Materials. 2003 Jan 16;57(2):169-80.
[33] Lin K, Pescarmona PP, Vandepitte H, Liang D, Van Tendeloo G, Jacobs PA. Synthesis and catalytic activity of Ti-MCM-41 nanoparticles with highly active titanium sites. Journal of Catalysis. 2008 Feb 15;254(1):64-70.
[34] Sedighi M, Keyvanloo K, Towfighi J. Kinetic study of steam catalytic cracking of naphtha on a Fe/ZSM-5 catalyst. Fuel. 2013 Jul 1;109:432-8.
[35] Varzaneh AZ, Kootenaei AHS, Towfighi J, Mohamadalizadeh A. Optimization and deactivation study of Fe–Ce/HZSM-5 catalyst in steam catalytic cracking of mixed ethanol/naphtha feed. Journal of Analytical and Applied Pyrolysis. 2013 Jul 1;102:144-53.
[36] Taghipour N, Towfighi J, Mohamadalizadeh A, Shirazi L, Sheibani S. The effect of key factors on thermal catalytic cracking of naphtha over Ce–La/SAPO-34 catalyst by statistical design of experiments. Journal of Analytical and Applied Pyrolysis. 2013 Jan 1;99:184-90.
[37] Wei Y, Liu Z, Wang G, Qi Y, Xu L, Xie P, He Y. Production of light olefins and aromatic hydrocarbons through catalytic cracking of naphtha at lowered temperature. Studies in Surface Science and Catalysis. 2005 Jan 1;158:1223-30.