Beste Agroline Vorprojekt PM7 - CPH Chemie + Papier Holding AG

also being extended to include countries such as Kazakhstan,
Uzbekistan etc., which are joining this pipeline network.
We have recently heard that Switzerland is buying gas from
Iran. How does this work? The answer is that gas is put
into the pipeline network in Iran, where a series of large
pipelines carries the gas north through Turkey, across
the Balkans, Austria, Germany and Switzerland.
In the Middle East, however, the chosen method of transportation
is to liquefy this gas.
In order to do this, a plant is constructed which purifies the
natural gas to largely methane only and cools this gas down
to around -200°C, when the gas liquefies. It is then pumped
away to storage in massive tanks at a low temperature AND
at a low pressure. The temperature MUST be kept very low
to prevent the pressure building up. If the natural gas were
allowed to warm up to normal temperatures, the pressure
would be up to round 100 barg.
From these large cold tanks the LNG carriers are loaded on
specially built piers; and the ships use gas which boils off to
power the ship’s engines to the destination port in Europe,
North America, Japan or Korea.
Present day feeder terminals are sited in Qatar, Algeria,
Oman, Egypt, Indonesia, Malaysia, Australia and Nigeria.
One of the early steps in the plant to make the LNG is the
purification of the feed gas. This includes dehydration using
molecular sieve and CO2 removal, generally with an amine.
Hence Zeochem molecular sieve plays an important part in
the preparation of the gas for liquefaction. The gas is successively
compressed, cooled, and then recompressed
using a series of chilling cycles. It is like a massive deep
freezer, working down to -200°C.
The Egyptian LNG plant at Idku is on the Mediterranean
coast. It is one of two plants in Egypt, and has been running
successfully with Zeochem molecular sieve for around
three years.
Just recently Zeochem was asked to be present to check
the running of the molecular sieve adsorbers and then to
oversee and inspect the recharge.
Peter Hawes was on-site with Mohamed Fouad from our
Egyptian agents.
Breakthrough testing
In order to check the working of the molecular sieve, an instrument
called a hygrometer is used, which can measure
moisture contents down to fractions of a part per million.
The pictures give a panorama of the site
This instrument must be correctly calibrated before being
connected to the adsorbers on site. Round-the-clock monitoring
ensures that the breakthrough of moisture is seen
immediately, so no moisture passes through into the cryogenic
part of the plant.
Shut-down
Once this test was completed, the plant was shut down for
its three-yearly inspection.
As part of this shut-down, the molecular sieve adsorbers
are emptied, inspected and then refilled with a fresh molecular
sieve. Packing a column with tiny beads and ensuring
that no leaks can occur during the next three years is work
which needs thorough checking.
In this case the work was done by a company from Saudi
Arabia that specialises in changing out adsorbents and catalysts.
Our specialist has to get inside the vessel to inspect
the vessel itself, as well as the completed work.
Cranes then haul the 600 kg big bags up to the top of the
vessel where they are emptied into the clean vessel.
Including inert balls as special protection, there were a total
of six layers of packing in the column. All had to be levelled
off before the next layer was poured into the column.
Zeochem AG
Peter Hawes