Effect of demineralization on hydrogen transfer of coal with tritiated gaseous hydrogen

Roles of mineral matters and oxygen functional groups of coal on hydrogen transfer reaction with gaseous hydrogen were investigated by using a tritium tracer technique in a fixed-bed reactor system. Mineral matters in coal were removed by HCl or HCl/HF treatments. Alkali metals and a part of pyrite were removed by HCl treatment. SiO2 and Al2O3 were removed only by HCl/HF treatment. A large part of pyrite was removed by HCl/HF treatment but about 20% of them still remained even after the treatment. It was observed that the efficiency of hydrogen transfer of coal decreased to some extent when cations and mineral matters were removed by HCl treatment. Further decrease in hydrogen transfer was observed after HCl/HF treatment. These results suggested that iron species from pyrite may catalyze the hydrogen transfer reaction with H2 gas. Mineral matters assist the Htransfer to the carbon network of coal but does not promote hydrogen transfer to hydroxy groups. D 2004 Elsevier B.V. All rights reserved.