Solid wastes conversion into electric and thermal energy using a gasifier and an electrochemical generator

Abstract

In Russia, 3.4 billion tons of municipal solid wastes (SW) are accumulated annually. Over 40 thousand hectares of fertile lands have been used for solid waste disposal; and the areas to be disposed each year for the SW landfills amount to as much as three thousand hectares. This work presents calculation results are reported from the study of a power plant based on the solid oxide fuel cells (SOFCs), which utilizes as fuel the synthesis gas generated through the SW steam gasification in an autothermal gasifier. Solid oxide fuel cells (SOFCs) are the most convenient for such a combined system, as due to high operating temperatures they do not require high fuel quality. The calculations have demonstrated the following: the temperature in the reaction vessel of the gasifier is at 1,000°С, the synthesis gas output is 55 m3/h, the chemical efficiency is 35.4%, and the synthesis gas combustion heat is 1.6352 kJ/kg of synthesis gas. The electric power electrochemical generator is 97.86 kW, the (total) electric efficiency of electrochemical generator is 39.1%, the temperature of gases effluent from the boiler-utilizer is at 630°С. Theorized the possibility of solid waste into electrical and thermal energy with full efficiency more than 79%. © 2017 WIT Press.