CFB Boiler Modernisation for Utilisation of Retort Gas
(Room Rheinsaal 2)
28 Jun 17
11:00 AM
-
12:30 PM
Tracks:
Track F - Steam Based Generation
Speaker(s):
Kimmo Koskinen, Manager, technology modernizations and upgrades, SUMITOMO SHI FW; Raivo Attikas, Project Manager, Enefit; Yacine Layachi, Project Manager, Enefit; Timo Anttikoski, Director, Technology, Modernizations and Upgrades, Service, SUMITOMO SHI FW; Kalle Nuortimo, Market Analyst, SUMITOMO SHI FW
Eesti Energia is the world's biggest oil shale to energy company. Eesti Energia operates in Estonia, Latvia, Lithuania, Finland, Jordan and Utah, United States. In Estonia the company generates 95% of the consumed electricity, mainly with its Oil Shale power plants in Narva. In Narva, the company operates 8 units with Pulverised Combustrion (PC) boilers, one 300MW CFB boiler unit, and two Circulating Fluidized Bed (CFB) boiler units (each unit consists of 2 CFB boilers and 1 steam turbine) which were commissioned by Amec Foster wheeler in 2004 and 2005. In October 2016, Enefit Energiatootmine AS (a subsidiary company of Eesti Energia AS, 100% Owned by the Republic of Estonia), entered into a contract with Amec Foster Wheeler to modify a CFB boiler to increase its capabilities to utilise retort gas for the generation of electricity and to reduce the environmental impacts of power production. Retort gas is a high-calorific by-product of oil-shale based oil production. By utilising this by-product, electricity can be generated efficiently and environmentally friendly. Currently, retort gas is burned on a small scale in all the boilers of Eesti Energia´s power plants. However, in the future, almost the entire volume of generated gas can be combusted with the highest efficiency in the Auvere Power Plant and in the retrofitted CFB unit, therefore producing more electricity from gas and using the energy inherent in oil shale optimally, all while reducing the environmental impact of electricity generation. The substitution of Oil Shale with larger amounts of retort gas in one the boilers will reduce significantly the production of ashes (fly ash and bottom ash). Also, from the same volume of retort gas at least 40 GWh of extra energy is generated per year. The CFB boiler retrofit is scheduled to be completed by early 2019. This paper describes the benefits, technical concept and project delivery of the retort gas retrofit project.