Sewage sludge gasification in supercritical water with fluidized bed reactor: Reaction and product characteristics

Sewage sludge supercritical water gasification in fluidized bed reactor was studied in this work. Effect of temperature on the distribution of products and gas compositions were researched. In order to improve the gasification process more effectively, the effect of temperature on reaction process development and gas products generation was also studied. A variety of analytical methods were used to study the detailed characteristics of products generated at different reaction conditions. The variation of product yield distribution and products properties showed that organic matter in sewage sludge was completely dissolved and hydrolyzed at 480 °C. Multiple reactions happened in these dissolved and hydrolyzed products and then gas products were formed when temperature increased from 480 to 540 °C further. At the same time, dehydrogenation and polymerization also took place in the solution and hydrolyzed products, and it could be explained by the Diels-Alder reaction mechanism well.