Elevated Pressure Refinery Desulfurization
MOL Hungarian Oil & Gas Co. selected a LO-CAT® II Desulfurization
System for operation at its production unit in Szeged, Hungary. The
unit was custom-designed for direct treatment of sour associated
and process gas streams at elevated operating pressures and
relatively high CO2 partial pressures.
Recycled process gas and associated gases are collected from the
oil fields around the plant and transported via a mixed-phase
pipeline, followed by separation in a bank of gas-liquid separators.
The associated gas is combined with the recycled process-gas
stream, compressed to 16-18 barg, and sent to the LO-CAT II. Several
technological challenges arose during the project due to process
restrictions. Excessive liquid entrainment occurred whenever sour-gas
flow exceeded 60,000 normal cu m/hr, so a new, larger separator
was retrofitted into the plant. As a result, gas flow up to 80,000
normal cu m/hr was achieved. After startup, it was discovered that
considerable condensate was frequently introduced from the
process gas and the operation of the two-phase oil-gas pipeline. The
presence of excessive liquid hydrocarbons in the LO-CAT II unit
caused foaming and floating sulfur. The sour-gas transfer line was
modified by retrofitting a simple drainage boot to catch the
condensate. Later, a larger knockout pot replaced the original one,
reducing the foaming and floating sulfur and increasing the unit’s
effectiveness. The unit’s catalyst recirculation pump was replaced
when the LO-CAT II capacity exceeded the pump’s design. A new
pump with the required capacity was installed and continues to
operate successfully. The unit operates with a gas flow of 60,000 to
100,000 normal cu m/hr, with a sulfur load of about 50 kg/day (due
to low H2S concentration in the gas). Current H2S removal efficiency
is 90%, producing gas suitable for pipeline quality.
Customer comments
No comments were found for Elevated Pressure Refinery Desulfurization. Be the first to comment!