Co-gasification of Sewage Sludge and Shiitake

Abstract

The co-gasification process may be a cleaner alternative solution to sewage sludge valorization and the production of valuable synthetic gases In this study the pyrolysis characteristics of sewage sludge shiitake substrate and their blends were analyzed via a thermogravimetric analysis (TGA) combined with Fourier transform infrared spectroscopy From TGA the addition of the sludge in the shiitake might improve the decomposition of char and inhibit the decomposition of inorganic materials in the pyrolysis The addition of sludge to the blends decreased the alkanes aliphatic aldehyde C=O groups and C=C in aromatic compound emissions An increase in the emitted C-O and C-H was found for blending ratio (BR) = 75% This study presents the gasification performance results based on different scenarios These scenarios included co-gasification of sewage sludge and shiitake and variations in the air supply and operating temperature Increases in the operating temperature led to increases in Lower heating value (LHV) Cold gas efficiency (CGE) and Caron conversion efficiency (CCE) in the gasification process Also the optimal equivalence ratio (ER) was found to depend on the fuel species The LHV and CGE of the product gas increased with decreases in BR The addition of 25% and 75% sewage sludge in the blend had a positive effect in terms of improving the CCE when the ER was 0 25 Therefore sludge co-gasification with shiitake improves the CCE and may help promote the use of sludge as a gasification assistance resource The kinetic model was found to be more reliable for simulating the gasification process as compared with the Gibbs equilibrium model Compared with Gibbs equilibrium model the trend of the kinetic model result is coinciding with experimental data in this study

Date of Award	2020
Original language	English
Supervisor	Ta-Hui Lin (Supervisor)