Thesis-2008-Sayyar.pdf (24.01 MB)
Direct oxidation of benzene to phenol
thesis
posted on 2014-07-07, 11:14 authored by Mohammad H. SayyarThis thesis deals with two major process routes for the direct oxidation of benzene to
phenol. The main objective of the first route was to understand the properties of the
porous stainless steel (PSS) needed for support of a catalyst deposited onto its surface,
to identify the morphologies of the Pd membrane deposited onto the PSS, to design a
catalytic membrane reactor, to characterise membrane in terms of its permeability to
hydrogen, and then to investigate hydroxylation of benzene using oxygen as an oxidant.
It was observed, using Mo or zeolites as a second catalyst and the reactor design affect
the productivity and selectivity towards phenol.
This research has also shown the effects of the catalytic properties of iron zeolites with a
focus on reactions involving the decomposition of nitrous oxide and direct oxidation of
benzene to phenol using nitrous oxide as the oxidant. The main objective of this second
route was to identify the active sites in the catalysts, and to a design catalyst based on
the acquired knowledge. The methodology was to incorporate iron either at framework
positions via hydrothermal synthesis of the zeolites followed by controlled migration to
extra-framework positions, or directly at extra-framework positions via sublimation of
FeCh or liquid ion-exchange. In this project, different catalysts were characterized and
their catalytic activities compared. It was observed contaminants such as N-containing
compounds, O2, CO, and water affected the catalytic properties and catalyst half-life.
In this thesis, two different methods were used to improve productivity when using a
PdlPSS membrane. First, changing design of the reactor, and second, using Mo as a
second catalyst. It was observed that higher productivity was obtained when the reactor
tube was packed with Fe/ZSM-5 and N20 using as the oxidant. From an economic
point of view, using N20 in the presence of zeolite in a fixed-bed reactor is expected to
offer more advantages than Pd membrane for oxidation of aromatic compounds.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Publisher
© Mohammad Hossein SayyarPublication date
2008Notes
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.603101Language
- en