The Catalyst Review October 2024 - 11

coated, which is made from perfluorosulphonic acid (PFSA). It is not possible to burn PFSA due
to the release of toxic fluorine and sulphur compounds, and catalyst coated membranes (CCMs)
must be passivated, by grinding to a powder, then mixing with a calcium salt before incineration
- an approach practised by Umicore. The alternative strategy is to gently leach the CCMs with
solvents. Work is ongoing to commercialize and scale-up solvent-based processes. The work
carried out by the EU-funded Best4Hy consortium focused on improving this kind of technology.
(Best4Hy 2024). Work is ongoing to scale a technology of this type as part of the partnership
between Hensel Recycling, Germany and MasterMelt, UK (MasterMelt 2024).
The precious metals community has worked hard to grow the industry responsibly, addressing
regulatory, ethical and wider ESG aspects. Efficient refining is essential here, given the intense
focus on the metals and mining sectors to improve their sustainability credentials.
The financial benefits of metal recovery are often underestimated, and many companies have lost
large sums of money by mishandling precious metal bearing waste. A catalyst reactor for instance
can contain millions of dollars in precious metals - for example the production of ethylene oxide
(EO) which is a key intermediate in the production of monoethylene glycol (MEG), an intermediate
for making polyethylene terephthalate (PET). The process involves the epoxidation of ethylene
over a high-metal loading silver/ -alumina catalyst loaded into tubular reactors. A typical plant
can contain as much as $40M worth of silver at current prices. Because of the very large mass of
catalyst and reactor geometry, removal can be tricky resulting in crushed, chipped and severely
damaged catalyst pellets which can block the reactor and create significant amounts of dust
upon catalyst removal - a recipe for significant catalyst losses and plant downtime if the correct
procedures are not employed. In petroleum refineries, there have been instances when lack of
operator training has led to whole reactor loads containing platinum refinery catalysts for instance
being disposed of as general waste, leading to huge financial losses and environmental pollution
risks (OGJ 1996)!
The amount of time needed for refining a catalyst and returning a fresh catalyst to the chemical
manufacturer (Figure 3) can be several weeks from receipt, burning, assaying, and refining.
Refiners who can shorten this time also have a competitive advantage, reducing leasing costs for
customers and speeding up plant turnarounds.
Figure 3 Time needed for refining a catalyst and returning a fresh catalyst to the chemical manufacturer
Source: EnabledFuture nd
Take Home Messages
Precious Metals as a Community: The precious metals community has adapted and grown as the
applications of PGMs have become ever more technical. Stakeholders in this sector work hard to
improve the industries' ESG ratings, diversity, research & innovation, security and ethical sourcing.
Vital Role in Industry: Precious metals and PGMs are of high importance for a wide range of
industries beyond jewellery, including automotive, chemical, and energy sectors, where they play
key roles in catalysts, industrial parts, electronic components, and hydrogen technologies. They
are a key enabler of the energy transition and decarbonisation.
The Catalyst Review
October 2024
11

The Catalyst Review October 2024

Table of Contents for the Digital Edition of The Catalyst Review October 2024