Lamma Power
Station has an installed capacity of 3,420MW comprising 3x250MW and 5x350MW
coal-fire units, 1x365MW oil-fired combined cycle unit, 1x55MW and 4x125MW
oil-fired open cycle gas-turbine units.
The latest three 350MW coal-fired units, Units L6, L7 & L8, are
equipped with FGD plants. The proposed
retrofit project will include the installation of FGD plants with flue gas
desulphurization efficiency of 90% for the two 350MW coal-fired Units L4 &
L5 to reduce the overall SO2 emissions from Lamma Power Station.
At present,
the flue gas from Units 4&5 Boilers is directly discharged to the
atmosphere via a 210 m high chimney. The retrofit work will involve demolishing
the existing Nos. 4 & 5 Light Oil Tanks (each of 250m3 capacity)
and relocating some of the pipeworks located in front of the respective boiler
to provide areas for installing FGD plant for each of Units L4 & L5. Figures 2.1 & 2.2 show the location and the schematic of the proposed FGD plants.
The flue
gas from the boiler will be directed to the FGD absorber inside which removal
of SO2 will take place by reaction with limestone slurry. After
passing through the absorber, the treated flue gas will be heated up by a
gas-gas heater to over 80ºC at boiler rated capacity and directed back to the
existing chimney for discharge to the atmosphere.
As majority
of the existing common limestone powder/gypsum handling and storage facilities
for Units L6, L7 & L8 FGD plants have spare capacity to cater for two more
FGD units, the additional equipment required for Units L4 & L5 FGD
retrofits will be limited to the extension of the existing gypsum dewatering
system.
The equipment
to be installed for the proposed retrofit project for Units L4 and L5 includes:
·
Two
sets of FGD absorbers and associated ductworks
·
Two
sets of booster fans
·
Two
sets of gas-gas heaters
·
FGD
Switchgear and
·
Gypsum
dewatering system comprising two sets of hydrocyclones and belt filters
The
targeted key dates for the proposed FGD retrofit project are as follows:
· Commencement of demolition of Light Oil Tanks April 2006
· Commencement of civil works September 2006
· Commencement of plant erection for
L5 Unit October
2007
· Commencement of plant erection for
L4 Unit August 2008
· Commercial operation of L5 FGD Plant
July 2009
· Commercial operation of L4 FGD Plant
April 2010