Kinetics of steam and CO₂ gasification with high ash fusion temperature coal char under elevated pressure

ABSTRACT

A high ash fusion temperature (AFT) coal char was gasified with steam and CO₂ under elevated pressure in a modified pressurized thermogravimetric analyzer. The ambient pressure varied from 0.5 MPa to 3 MPa. It was found that activation energy E_a (char-CO₂ reaction) was from 214.19 kJ/mol to 240.35 kJ/mol, and activation energy E_a (char-steam reaction) was from 170.02 kJ/mol to 174.02 kJ/mol by using shrinking core model. The factor of partial pressure influence (n) was 0.44 and 0.54 for CO₂ and steam gasification, respectively. The results proved that the high AFT coal (LJ coal) has poor gasification reactivity by comparing with other research and provided complete kinetic data for developing the entrained flow gasification technology using high AFT coal.

KEYWORDS:

• Gasification
• high AFT coal
• kinetic
• pressure
• shrinking core model