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Fluid catalytic cracking: recent developments on the grand old lady of zeolite catalysis.

Vogt ET, Weckhuysen BM - Chem Soc Rev (2015)

Bottom Line: These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels.In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level.These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials.

View Article: PubMed Central - PubMed

Affiliation: Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands. e.t.c.vogt@uu.nl b.m.weckhuysen@uu.nl.

ABSTRACT
Fluid catalytic cracking (FCC) is one of the major conversion technologies in the oil refinery industry. FCC currently produces the majority of the world's gasoline, as well as an important fraction of propylene for the polymer industry. In this critical review, we give an overview of the latest trends in this field of research. These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels. After providing some general background of the FCC process, including a short history as well as details on the process, reactor design, chemical reactions involved and catalyst material, we will discuss several trends in FCC catalysis research by focusing on ways to improve the zeolite structure stability, propylene selectivity and the overall catalyst accessibility by (a) the addition of rare earth elements and phosphorus, (b) constructing hierarchical pores systems and (c) the introduction of new zeolite structures. In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level. These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials.

No MeSH data available.


(Top) Structure of zeolite ZSM-5, viewed along the 10-MR straight channels. (Bottom) View along the zig-zag channels.
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fig14: (Top) Structure of zeolite ZSM-5, viewed along the 10-MR straight channels. (Bottom) View along the zig-zag channels.

Mentions: In this review paper, we will exclusively focus on ZSM-5-containing additives. Argauer and Landolt first reported ZSM-5, this structure shown in Fig. 14, as a synthetic molecular sieve in 1972.22 Although Kokotailo et al. solved the structure of ZSM-5 already in 1978,74 recent work has shed new light on this material. Even though zeolite ZSM-5 was first described as a synthetic material, a natural mineral form (named Mutinaite) also exists as it was discovered in Antarctica adjacent to deposits of natural zeolite Beta.75 Zeolite ZSM-5 can be prepared both in the presence and absence of organic SDAs. The typical SDA molecule is tetrapropylamine (TPA), which can be located in the pores of the synthetic material.76 Materials with a silica-to-alumina ratio (i.e., molar SiO2/Al2O3 ratio) up to about 25 can be synthesized without SDA, for higher silica-to-alumina ratios typically an SDA is required. The essentially all-silica form, known as silicalite, has a slightly different structure than the low-SAR material, it has a monoclinic unit cell, whereas the low SAR material crystallizes in an orthorhombic cell. The framework is exactly the same for both phases. The structure of ZSM-5 consists of a 3D pore system circumscribed by 10 T-atoms. The pores are slightly elliptical and have diameters of 5.1–5.6 Å. The structure has a straight 10-MR pore along the [010]-direction, and a zig-zag 10-MR pore along the [100]-direction. The pores intersect, and molecules (of the correct dimensions) can reach any point in the pore system from any other point. ZSM-5 normally crystallizes in lozenge- or coffin-shaped crystals that are frequently twinned.


Fluid catalytic cracking: recent developments on the grand old lady of zeolite catalysis.

Vogt ET, Weckhuysen BM - Chem Soc Rev (2015)

(Top) Structure of zeolite ZSM-5, viewed along the 10-MR straight channels. (Bottom) View along the zig-zag channels.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594121&req=5

fig14: (Top) Structure of zeolite ZSM-5, viewed along the 10-MR straight channels. (Bottom) View along the zig-zag channels.
Mentions: In this review paper, we will exclusively focus on ZSM-5-containing additives. Argauer and Landolt first reported ZSM-5, this structure shown in Fig. 14, as a synthetic molecular sieve in 1972.22 Although Kokotailo et al. solved the structure of ZSM-5 already in 1978,74 recent work has shed new light on this material. Even though zeolite ZSM-5 was first described as a synthetic material, a natural mineral form (named Mutinaite) also exists as it was discovered in Antarctica adjacent to deposits of natural zeolite Beta.75 Zeolite ZSM-5 can be prepared both in the presence and absence of organic SDAs. The typical SDA molecule is tetrapropylamine (TPA), which can be located in the pores of the synthetic material.76 Materials with a silica-to-alumina ratio (i.e., molar SiO2/Al2O3 ratio) up to about 25 can be synthesized without SDA, for higher silica-to-alumina ratios typically an SDA is required. The essentially all-silica form, known as silicalite, has a slightly different structure than the low-SAR material, it has a monoclinic unit cell, whereas the low SAR material crystallizes in an orthorhombic cell. The framework is exactly the same for both phases. The structure of ZSM-5 consists of a 3D pore system circumscribed by 10 T-atoms. The pores are slightly elliptical and have diameters of 5.1–5.6 Å. The structure has a straight 10-MR pore along the [010]-direction, and a zig-zag 10-MR pore along the [100]-direction. The pores intersect, and molecules (of the correct dimensions) can reach any point in the pore system from any other point. ZSM-5 normally crystallizes in lozenge- or coffin-shaped crystals that are frequently twinned.

Bottom Line: These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels.In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level.These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials.

View Article: PubMed Central - PubMed

Affiliation: Inorganic Chemistry and Catalysis Group, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands. e.t.c.vogt@uu.nl b.m.weckhuysen@uu.nl.

ABSTRACT
Fluid catalytic cracking (FCC) is one of the major conversion technologies in the oil refinery industry. FCC currently produces the majority of the world's gasoline, as well as an important fraction of propylene for the polymer industry. In this critical review, we give an overview of the latest trends in this field of research. These trends include ways to make it possible to process either very heavy or very light crude oil fractions as well as to co-process biomass-based oxygenates with regular crude oil fractions, and convert these more complex feedstocks in an increasing amount of propylene and diesel-range fuels. After providing some general background of the FCC process, including a short history as well as details on the process, reactor design, chemical reactions involved and catalyst material, we will discuss several trends in FCC catalysis research by focusing on ways to improve the zeolite structure stability, propylene selectivity and the overall catalyst accessibility by (a) the addition of rare earth elements and phosphorus, (b) constructing hierarchical pores systems and (c) the introduction of new zeolite structures. In addition, we present an overview of the state-of-the-art micro-spectroscopy methods for characterizing FCC catalysts at the single particle level. These new characterization tools are able to explain the influence of the harsh FCC processing conditions (e.g. steam) and the presence of various metal poisons (e.g. V, Fe and Ni) in the crude oil feedstocks on the 3-D structure and accessibility of FCC catalyst materials.

No MeSH data available.