Impact of Mercury Sorbents on Fly Ash Use for Cement Replacement

摘要

Sorbent injection with activated carbons for mercury control in coal-derived flue gas can compromise the sale of fly ash for use as cement replacement. EPRI and DOE are evaluating how various parameters for sorbent injection systems, such as sorbent type and injection rate, impact important fly ash cement replacement properties. This paper presents results from fly ash cement replacement testing conducted as part of several full-scale mercury sorbent injection test programs performed at four coal-fired power plants representing PRB and PRB/Texas lignite blended fired units and equipped with either an ESP or a fabric filter. Several sorbents, including novel sorbents projected to reduce the impact on fly ash cement replacement, have been tested longer-term (≥24 hours). The test results presented in this paper include fly ash test results for foam index, loss-on-ignition, and fineness; fresh concrete test results for air response, slump, and water to cement (WC) ratio; and cured concrete test results for compressive strength, freeze/thaw testing, and petrography analysis. The results show that there is potential for selling fly ash containing mercury sorbents for fly ash cement replacement.