Teruel power station

PennguardTM linings protect the FGD outlet ducts of a lignite fired power station

The Teruel Power Station of Endesa S.A. is situated roughly between Madrid and Barcelona, about 100 km southeast of the city of Zaragoza. This rugged part of Spain is a finding place for lignite and the power station is located near several large mines. The lignite is a low cost, abundant fuel and the Teruel Power Station, with its installed capacity of 3 x 350 MW, is used by Endesa as a base load plant.

The lignite from the local mines has a sulfur content of up to 7 % and a low heating value. A variable portion of imported coal is mixed into the lignite to obtain a fuel mix with a nominal sulfur content of 4,5%.

In 1992, Endesa decided to retrofit wet desulphurisation plants to all three units of the Teruel Power Station. After considering different options, Endesa selected a Mitsubishi (MHI) wet limestone FGD process. When in operation, this will be one of the world’s largest FGD plants in terms of SO₂ removal capacity.

Welding of alloy protection stips

A number of different options were also considered for the treatment and routing of the desulphurized gas streams coming out of the FGD absorbers. After considering all the environmental, operational and financial arguments, Endesa decided to continue the use of the existing, 343 m high chimney.

Endesa also decided that the flue gas should be reheated to at least 75 °C. The method chosen for reheating is the injection of hot air from the air preheaters into the desulphurized gas stream, at a point directly behind the FGD absorbers.

The FGD outlet ducts will be exposed to highly corrosive operating conditions and sometimes to a total or partial FGD bypass of the unscrubbed gas stream. The PennguardTM Block Lining System was selected for the internal protection of the three large FGD outlet ducts, which have a combined internal area of 7.035 m².