Regenerative Process for Desulfurization of High Temperature Combustion and Fuel Gases. Progress Report No. 14, October 1-December 31, 1979

摘要

The characteristics of Portland Type III cement (PC III) as a potential sorbent for use in a regenerative process for desulfurization of coal in fluidized-bed combustion were examined. The sulfation rates for PC III + 5% amorphous SiO sub 2 at temperatures between 860 and 1100 exp 0 C and at 1 atm were studied thermogravimetrically, using a simulated combustion gas mixture containing 0.25% SO sub 2 . The sulfation rates were found to be independent of temperature between 950 and 1050 exp 0 C. The isothermal regeneration with a mixture consisting of 5% CO, 15% CO sub 2 and the balance N sub 2 , in this 100 exp 0 C temperature interval approached an equilibrium value of over 90% within thirty minutes. Sulfation/regeneration efficiency did not decrease with cycling and was unaffected by additives introduced to increase the porosity and/or conversion of free CaO in PC III to silicates which are known to be more regenerative than CaSO sub 4 . Pressurized TGA experiments within the optimum sulfation temperature range were conducted at 5 and 10 atm to establish the viability of this sorbent for pressurized fluidized-bed combustion use. Within the experimental accuracy, no pressure dependence of sulfation rate was observed. Our experiments indicate that the attrition resistance of PC III is significantly better than natural limestones. (ERA citation 05:035908)