Black Liquor Gasification with Direct Causticization Using Titanates in a Pressurized Entrained-Flow Reactor. Part II: Carbon and Carbon Species Transitions

摘要

Experiments on black liquor conversion in the presence of sodium titanates were carried out in a pressurized entrained-flow reactor, at temperatures of 900, 950 and 1000℃, at pressures of 0.5 and 1 MPa and in atmospheres of pure nitrogen (N_2) or N_2 with 2% carbon dioxide (CO_2). Up to 80-90% conversion of the carbon in black liquor to gases was obtained within 5 s at these conditions. This is a very promising result for industrial scale gasiflers. Char carbon was gasified two to four times faster in N_2 with 2% CO_2 than in N_2 alone. Overall, carbon conversion increased with increasing temperature, but the gasification rate decreased with increasing temperature. CO was found to be the main carbon-containing gas formed.