A new kinetic model for the NO-carbon reaction

The kinetics of the NO-carbon reaction was studied by thermogravimetric ana lysis (TGA). The reactivity as a function of carbon conversion was systemat ically investigated through characterization of the pore structure and carb on active site evolution during reaction. Total surface area measured by CO , adsorption at 273 K gives a relatively constant normalized reactivity ove r a wide range of carbon conversions. The carbon active surface area (ASA) and unoccupied active surface area (UASA) were estimated from low-temperatu re NO chemisorption capacities. Large amounts of stable C-O complexes are f ound to form during the reaction. Results show that ASA or UASA measured in this way do not represent the reactive surface area under gasification con ditions. A new kinetic model is introduced by taking into account the contr ibutions from different carbon-oxygen surface complexes during reaction, ba sed on the recently proposed unified kinetic scheme of Yang and coworkers. (C) 1999 Elsevier Science Ltd. All rights reserved.