Proceedings of the Second International Energy 2030 Conference,
November 4-5, 2008, Abu Dhabi, U.A.E.

Pyrolysis and Steam Gasification of Waste Paper

I. Ahmed
University of Maryland, USA

A. K. Gupta
University of Maryland, USA

Abstract
Main characteristics of gaseous yield from steam gasification have been investigated experimentally. Results of steam gasification have been compared to that of pyrolysis. The temperature range investigated were 600 ^oC to 1000 ^oC in steps of 100 ^oC. Results have also been obtained under pyrolysis conditions at same temperatures. For steam gasification experiments, steam flow rate was kept constant at 8.0 gr./min. Evolution of syngas flow rate with time, hydrogen flow rate, energy yield and apparent thermal efficiency have been investigated. Residuals from both processes were quantified and compared as well. Material destruction, hydrogen yield and energy yield is better with gasification as compared to pyrolysis under identical thermal conditions. This advantage of the gasification process is attributed mainly to char gasification process. Char gasification is found to be more sensitive to the reactor temperature than pyrolysis. Pyrolysis can start at low temperatures of 400 ^oC; however char gasification starts at about 700 ^oC. A partial overlap between gasification and pyrolysis exists and is also examined here. This partial overlap increases with increase in temperature. As an example, at reactor temperature of 800 ^oC this overlap represents around 27% of the char gasification process and almost 95% at reactor temperature of 1000 ^oC.