NOx reduction to the new Wärtsilä Power Plant on the Greek island of Rhodes

Wärtsilä is a global leader in smart technologies and complete lifecycle solutions for the marine and energy markets.

Urea silos for raw material must be covered with proper insulation housing to protect them from rain and temperature changes.

Wärtsilä delivered a new, 115 MW power plant in the South Rhodes island in Greece in 2018. It generates electricity from seven Wärtsilä 18V46 diesel engines. Wärtsilä’s power solution includes state-of-the-art emissions cleaning technology to meet the strict environmental standards. Dosetec Exact delivered a urea storage and mixing station to this new power plant.

Reducing NOx using urea reagent

Urea dilution is widely used as the reactant added to exhaust gas mixture to reduce nitrogen monoxide and dioxide emissions. The selective catalytic reduction (SCR) method converts NOx molecules back to harmless nitrogen (N2) and water (H2O).

Extremely demanding material

Hydroscopic urea is a very demanding – even erratic – material to handle. It reacts heavily to changes in ambient conditions, temperature and humidity. Scaling and clogging may occur easily while conveying and storing urea granules.

Urea is widely used in NOx control systems to reduce nitrogen oxide emissions. Dosetec delivered reliable dosing and mixing system for urea dilution.

Experience is what counts

Wärtsilä has been a long-time customer of Dosetec. In 2015, Dosetec also supplied a urea dilution system when Wärtsilä delivered a 39 MW power plant to the Indian Ocean island of Mayotte. The combination of tropical climate and urea granules, was challenging and Dosetec’s experience with handling urea was therefore vital at that stage. “Despite challenging raw-material, Dosetec delivered both Mayotte and South Rhodes projects on time,” notes Jari Koskinen, Chairman of the Board, Dosetec Exact Oy.

Reliable urea storage and mixing

Dosetec delivered the equipment and engineering for the urea storage and mixing station to South Rhodes Power Station. The project included urea silos, an urea granule conveying system, a dilution system, mixing tanks and storage tanks. The raw material is stored at urea silos, which are covered with additional housing to protect the silos from rain and temperature variations.

A unique process for urea dilution is designed and achieved according to customer needs and tailored to fit operating conditions.

Strictly controlled mixing process

Urea dosing and mixing is a diverse and complex process. The urea dilution system includes the complete urea unloading and preparation system. Urea and water dosing is done by weighing the mixer tank, and after dissolving, the urea dilution is pumped to the storage tank. “Purpose-built design, functionality of the equipment and reliable process was the key aim of the project. Dosetec responded our expectations well,” told Ravindra Pandit, Project Manager, Wärtsilä Corporation. This project required both technical know-how and engineering design expertise. Dosetec Exact’s extensive experience and knowledge of dosing, weighing and mixing systems enabled them to build reliable solutions.