Project

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Visualization of pores in individual catalyst particles

Applicant van Bokhoven Jeroen Anton
Number 153556
Funding scheme Project funding (Div. I-III)
Research institution Paul Scherrer Institut
Institution of higher education Paul Scherrer Institute - PSI
Main discipline Inorganic Chemistry
Start/End 01.10.2014 - 31.03.2018
Approved amount 192'550.00
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All Disciplines (2)

Discipline
Inorganic Chemistry
Chemical Engineering

Keywords (8)

FCC; catalyst particle; ptychography; porosity; X-ray imaging; electron imaging; microtomography; nanotomography

Lay Summary (German)

Lead
Das sogenannte FCC (für „Fluid Catalytic Cracking“) ist einer der bedeutensten Umwandlungsprozesse, um leicht flüchtige Olefine, Benzin usw. aus schweren Erdölfraktionen zu gewinnen. Derartige Katalysatoren sind aus Partikeln aufgebaut, deren poröser Aufbau gewährleistet, dass Moleküle zur Oberfläche des Katalysators hin und Reaktionsprodukte von dort fort gelangen können. Trotz der enormen wirtschaftlichen und ökologischen Bedeutung des FCC Processes konnte bislang keine klare Beziehung zwischen der Morphologie des Katalysators und seiner katalytischer Effizienz etabliert werden.
Lay summary
Da makroskopische Porositätsmessungen haben nur eine eingeschränkte Aussagekraft, weil sie stets über das gesamte vermessene Volumen mitteln, setzen wird in diesem Forschungsprojekt vor allem elektronen- und röntgenmikroskopische Verfahren ein.  Diese erlauben uns, Porengröße, Größenverteilung und Konnektivität ortsaufgelöst und auf allen Längenskalen zu quantifizieren.  
Insbesondere die maßgeblich am PSI entwickelte ptychographische Röntgencomputertomographie nimmt dabei eine wichtige Funktion ein.  Sie hat eine Brückenfuntion zwischen der Elektronenmikrosopie, die hohe Auflösung bei eingeschränktem Bildfeld bietet, und “Standard”-Röntencomputertomographie, die zwar statistisch repräsentative Volumen vermessen kann, aber nur bei geringerer Auflösung.  Wir können so alle relevanten Längenskalen vermessen und zu einem Gesamtbild zusammenfügen, um über dieses Einblick in die Einflussfaktoen auf die katalytische Effizienz zu erhalten.
Direct link to Lay Summary Last update: 16.11.2014

Lay Summary (English)

Lead
Fluid catalytic cracking is the most important conversion process in the refinery, upgrading the heavy fraction in oil into gasoline and volatile olefins. The catalyst is a complex composite of various components shaped in spheres of about 100 microns. Since large molecules must react on the surface of the catalytic particles encompassed in the pre-shaped catalyst bodies, these pre-shaped bodies are porous. The project’s aim is to quantify in detail pore size, size distribution, and connectivity at length scales from 100 microns down to sub-nanometer and correlate these to macroscopic measurements on these quantities and catalytic activity.
Lay summary
The project’s aim is to quantify in detail pore size, size distribution, and connectivity at length scales from 100 microns down to sub-nanometer and correlate these to macroscopic measurements on these quantities and catalytic activity.Up to now the porosity of individual particles has not been visualized or quantified, and there is no clear relation to catalytic performance. We propose to visualize the pores in the fluidized catalyst cracking (FCC) catalyst at all relevant length scales, from sub-nm  by electron tomography, to nanometer by X-ray ptychographic tomography, and micron by transmission X-ray tomography. All of these methods are available at ETH Zurich and the Swiss Light Source at the Paul Scherrer Institute. Of particular interest are current developments made in the field of X-ray ptychography, which has by now the resolving power to assess the three-dimensional pore structure of realistic catalysts and to bridge the resolution gap between electron microscopy and transmission X-ray microscopy.
The project’s aim is to quantify in detail pore size, size distribution, and connectivity at length scales from 100 microns down to sub-nanometer and correlate these to macroscopic measurements on these quantities and catalytic activity. The combination of X-ray fluorescence and measuring the complex-valued index of refraction, i.e., both the materials’ absorption and phase advance, allows the elemental distribution to be identified within individual FCC bodies. This is of particular relevance to spent catalysts, which contains deposited metals, such as Ni and V, in addition to changed pore structure by coke deposition and change in crystallinity of zeolitic compounds.
Direct link to Lay Summary Last update: 16.11.2014

Responsible applicant and co-applicants

Employees

Associated projects

Number Title Start Funding scheme
169623 Improved multislice nanotomography using ptychography with angular diversity 01.01.2017 Project funding (Div. I-III)
183320 Improved capabilities at the Powder Diffraction station for contrast-enhanced experiments. / New X-ray detector 01.03.2019 R'EQUIP
178943 Catalyst structures in three dimensions 01.08.2018 Project funding (Div. I-III)
166304 X-Ray Fourier Ptychography 01.04.2016 Project funding (Div. I-III)
178788 Temporal tomographic synthesis for nanoscale characterization of electrode materials 01.04.2018 Project funding (Div. I-III)

Abstract

Fluid catalytic cracking is the most important conversion process in the refinery, upgrading the heavy fraction in oil into gasoline and volatile olefins. The catalyst is a complex composite of various components shaped in spheres of about 100 microns. Since large molecules must react on the surface of the catalytic particles encompassed in the pre-shaped catalyst bodies, these pre-shaped bodies are porous. Up to now the porosity of individual particles has not been visualized or quantified, and there is no clear relation to catalytic performance. We propose to visualize the pores in the fluidized catalyst cracking (FCC) catalyst at all relevant length scales, from sub-nm by electron tomography, to nanometer by X-ray ptychographic tomography, and micron by transmission X-ray tomography. All of these methods are available at ETH Zurich and the Swiss Light Source at the Paul Scherrer Institute. Of particular interest are current developments made in the field of X-ray ptychography, which has by now the resolving power to assess the three-dimensional pore structure of realistic catalysts and to bridge the resolution gap between electron microscopy and transmission X-ray microscopy. The project’s aim is to quantify in detail pore size, size distribution, and connectivity at length scales from 100 microns down to sub-nanometer and correlate these to macroscopic measurements on these quantities and catalytic activity. The combination of X-ray fluorescence and measuring the complex-valued index of refraction, i.e., both the materials’ absorption and phase advance, allows the elemental distribution to be identified within individual FCC bodies. This is of particular relevance to spent catalysts, which contains deposited metals, such as Ni and V, in addition to changed pore structure by coke deposition and change in crystallinity of zeolitic compounds.One PhD student will perform the synchrotron measurements and macroscopic characterization of commercially available FCC catalysts. In addition, methods to analyze these measurements and to visualize and quantify pore size, size distribution, and connectivity will be developed.
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