The thermo-chemical transformation of municipal sewage sludge (SS) into fuel and electricity is one of the most attractive technologies for handling the increasing amount of SS produced at the increasing number of sewage treatment plants (STP) across the globe. This work explores the feasibility of fluidized bed (FB) reactors for thermo-chemical conversion (TCC) of SS. The torrefaction process increases the calorific value and C/H ratio of SS while also reducing its mass and removing NOx, SOx, and other contaminants. Fast pyrolysis has been used to turn SS into a bio-oil product. Although the gasifying substance has a significant impact on the final fuel gas product’s composition, the yield distribution and the quantity of tar and other pollutants might vary significantly because of the complicated structure of SS. At temperatures usually above 1000 °C, SS needs an abundance of oxygen to burn all carbon and volatile elements. Producing heat and power, eliminating the negative effects of the SS component parts, and reducing the overall volume of SS are the three main objectives of SS combustion. BFBR and CFBR have gained popularity recently, and many of these incinerator designs have been quickly applied to the combustion of SS.