Development and Pilot Plant Evaluation of Silica- Enhanced Lime Sorbents for Dry Flue Gas Desulfurization
Year: 1988
Type: article
Abstract: EPA’s efforts to develop low cost, retrofitable flue gas cleaning technology include the development of highly reactive sorbents. Recent work addressing lime enhancement and testing at the bench-scale followed by evaluation of the more promising sorbents in a pilot plant are discussed here. The conversion of Ca(OH)2 with SO2 increased several-fold compared with Ca(OH)2 alone when Ca(OH)2 was slurrled with fly ash first and later exposed to SO2 in a laboratory packed bed reactor. Ca(OH)2 enhancement increased with the increased fly ash amount. Dlatomaceous earths were very effective reactivity promoters of lime-based sorbents. Differential scanning calorimetry of the promoted sorbents revealed the formation of a new phase (calcium silicate hydrates) after hydration, which may be the basis for the observed Improved SO2 capture. Fly ash/lime and diatomaceous earth/lime sorbents were tested in a 100 m3/h pilot facility incorporating a gas humidifier, a sorbent duct injection system, and a baghouse. The inlet SO2 concentration range was 1000-2500 ppm. With once-through dry sorbent injection into the humidified flue gas [approach to saturation 10–20°C (18–36°F) in the baghouse], the total SO2 removal ranged from 50 to 90 percent for a stoichiometric ratio of 1 to 2. Recycling the collected solids resulted in a total lime utilization exceeding 80–90 percent. Increased lime utilization was also investigated by the use of additives.
Source: JAPCA
Authors: Wojciech Jozewicz, Claus Jorgensen, John C.S. Chang, Charles B. Sedman, Theodore G. Brna
Institution: Environmental Protection Agency
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
Funder: University of Texas at Austin
OpenAlex ID: W2086176079