Simulation of a Hydrogen Peroxide Oxidation Tower
Typ
Examensarbete för masterexamen
Program
Innovative and sustainable chemical engineering (MPISC), MSc
Publicerad
2022
Författare
Larsson, Sara
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Hydrogen peroxide is a strong oxidizing agent used in a great variety of applications.
Its main usage is as a bleaching agent where the pulp and paper industry dominates.
One of the world’s producer of hydrogen peroxide is Nouryon, who produce about
4% of the market volume. The primary way of producing hydrogen peroxide today
is by the cyclic hydrogenation and autoxidation of anthraquinones (usually referred
to as the AO process). The most commonly used raw materials for this process
are hydrogen produced by steam reforming and air. With the current technical
development, it is expected that electrolyzers producing green hydrogen is going
to be used to a greater extent in the future. If this were to be implemented in a
hydrogen peroxide plant it would enable the use of the by-produced oxygen as a
cheap raw material in the oxidation tower. Using this pure oxygen would in turn
make it possible to use a higher concentration of air in the gas feed which could be
utilized in a smaller oxidation tower and with smaller ancillary equipment. This is
therefore interesting since it may lead to lower investment and operating costs.
This work has been done for Nouryon with the purpose to set up a simulation
tool to be used for simulation of a hydrogen peroxide oxidation tower. The aim
was also to use this simulation tool to investigate how different tower designs and
operating conditions may affect the size and operating conditions of the tower. The
project has successfully resulted in a simulation tool set up in the process simulation
software HYSYS v12.1. The simulation tool consists of a kinetic model for the
oxidation reaction and a flowsheet setup representing the oxidation tower. The
model was designed and successfully validated by the use of reference data from
multiple oxidation towers. The simulation tool has been used to simulate the operation of a hydrogen peroxide
oxidation tower with higher inlet oxygen concentrations, lower oxygen excess and
higher operating pressure. It has also been used to simulate an oxidation tower with
recirculation of the off-gas. From these simulations it have been concluded that it
is possible to operate the oxidation tower with a higher inlet oxygen concentration
with the drawback of getting a higher outlet oxygen concentration. The results have
suggested that this higher outlet concentration may be decreased by the operation
with lower oxygen excess or recirculation of a part of the exhaust gas. As expected,
the simulations have implied that the use of a higher oxygen concentration indeed
should make it possible to reduce the oxidation tower size and still maintain the same
productivity of hydrogen peroxide. Simulating the tower with a higher pressure has
implied that it may also be possible to use an increased pressure to reduce the
required tower volume. It has also been proposed that a higher pressure may be
used to increase the productivity of a tower of a certain set size.
Beskrivning
Ämne/nyckelord
hydrogen peroxide , oxidation tower , AO process , simulation , HYSYS