H2S REMOVAL FROM COAL-GAS AT ELEVATED-TEMPERATURE AND PRESSURE IN FLUIDIZED-BED WITH ZINC TITANATE SORBENTS .1. CYCLIC TESTS

Simplified integrated gasification combined cycle (IGCC) processes are considered to be among the most efficient and environmentally accepta ble technologies for power generation from coal. In such processes the coal is gasified at pressure and the coal gas is cleaned and combuste d in a gas turbine; Coal gas cleanup at elevated pressure and temperat ure in the IGCC proCesses offers advantages in higher power generation efficiency and simpler plant configuration. Regenerable mixed metal o xide sorbents are the prime candidates for removal of hydrogen sulfide (the main pollutant) from the hot coal gas in the simplified IGCC pro cesses. In this paper, the results of cyclic sulfidation/regeneration tests conducted with two zinc titanate sorbents are presented and disc ussed. These tests were carried out at high pressure and temperature ( 20 bar, 550-650 degrees C) in a bench-scale fluidized-bed reactor. The results indicate that the reactivity of both sorbents towards H2S gra dually decline in cyclic sulfidation/regeneration tests.