Making Industrial Processes More Cost Efficient

FGD Cost Reduction

Reducing raw material costs of flue gas desulphurisation by nonlinear models

Any process can be run less efficiently or more efficiently. With a better quantitative knowledge of the effects of each important variable on the process consequences including operating costs, one can usually improve the efficiency of any process. This article explains in brief the basics of nonlinear modeling, and describes how nonlinear models can be used to tune processes like desulphurisation better, and save on raw material costs.

Hanasaari power plant owned by the city of Helsinki is one of the main power plants supplying electricity to the capital region. The coal fired power plant was built in 1977, and its desulphurisation unit in 1991. The power plant's capacity is 120 MW of power and 210 MW of heat. When operating at full capacity, it produces around 500 kNm3/h of flue gas from about 60 tons/h of coal. This flue gas typically contains 500 to 1500 mg/Nm3 of sulphur dioxide depending on the coal being burnt. Desulphurisation consumes hundreds of tons of slaked lime per year. Regulations for sulphur dioxide emissions are getting stricter, making desulphurisation even more important.