Abstract

Finely dispersed calcium compounds have a quite large catalytic effect for char gasification in O_2, CO_2 and steam. In this work, a new effective utilization of Ca ion-exchanged brown coal as not only a sorbent for desulfurization but also catalyst for char gasification in a brown coal fluidized-bed reformer was investigated. CaO produced from Ca ion-exchanged coal was much more reactive toward H_2S than that from limestone. CaS involved in the Ca-exchanged char reacted with H_2S have a large catalytic effect for the char gasification in steam. It is concluded that ultra fine CaO particles in the char can play important roles not only in the desulfurization as a highly efficient sorbent but also in the gasification of coal char as a catalyst.