Combustion of waste solids in a fluidized bed to generate sustainable energy

Abstract

Exploring alternative options to address the impending global energy crisis while taking into account environmental concerns and climate change mitigation and addressing the sky-rocketing energy demand has become urgently essential. This need is further highlighted by the significant reliance of the Republic of Serbia on imported energy sources so that the focus of its energy sector strategy is rational use of energy resources, use of renewable energy sources (RES), and waste management with satisfying environmental regulations. The use of low-calorific and waste materials in conjunction with fluidized bed combustion technology is a method to achieve all the above goals synergistically. This paper presents experimental results of combustion of several solid wastes (coal mining waste from the “RB Kolubara” complex, Serbia, paper sludge and hazelnut shells), conducted in an industrial prototype and experimental bubbling FB boiler (capacity up to 500 kW). Burning these wastes has a variety of advantages, including recovering substantial energy remaining in the waste and minimizing the overall waste volumes. The work focused on determination of furnace temperature profiles, composition of the flue gas at the furnace outlet as well as fluidization air and fuel flowrates, the minimum fluidization rate, fluidization number, maximum heat output and the transferred heat of the tested fuels. Based on the obtained results, potentials of FBC of waste fuels and the possibility of utilization of their energy potential are evaluated.

Keywords

• low-grade fuels
• biomass
• paper sludge
• coal
• hazelnut shells
• bubbling fluidized bed combustor