Combustion behaviour of rice husk in a bubbling fluidised bed

The combustion of agro-industrial wastes in power plant seems to be an attractive possibility for the future. In Spain, the food industry generates around 618,000 tonnes of rice husk annually. The rice production is geographically focused in three regions: Valencia, Andalucia and Delta del Ebro. The rice husk is a suitable fuel for the fluidised bed combustors. An experimental combustion work using the rice husk as fuel was performed in a 30 kWth atmospheric bubbling fluidised bed pilot plant of CIEMAT. The influence of different variables such as temperature, fluidisation velocity on the combustion efficiency and CO emissions was investigated. Combustion efficiency in all test runs was higher than 97%. The characteristics of ash removed from the bed, cyclones and baghouse were studied. In the bed ashes, the potassium content increases along the operation hours.