A technical assessment of a particle hybrid collector in a pilot plant

We developed a hybrid collector (ESP + FF) to improve particulate matter removal from flue gases from coal power plants and then tested it in a pilot plant that processes up to 15,000 m(3)/h of real flue gas. The tests were designed to achieve economic and operating optimization of the hybrid collector. The removal efficiency in relation to the PM10 and PX12.5 and trace metals emissions, according to the legal limits in the European Union and the United States of America, was specifically considered. The efficiencies obtained were very high: PM10 removal efficiency of more than 99.95% and PM2.5 removal efficiency of between 96 and 98%, and a metal deposition greater than 99% depending on the metal, overcoming the limitations of ESPs with regard to achieving the particulate matter emission limits. However, a lower efficiency was obtained for the capture of mercury in the vapor phase (only 30%). We discovered a relationship between the rate of pressure loss and both the filtration velocity and the number of active fields in ESP. Likewise, we found a relation between these two parameters and the number of cleaning cycles. Within the study a database was created and considered as a basis for designing hybrid collectors and retrofitting existing ESPs. Based on to these results, we determined the criteria for a full-scale design of hybrid collectors, and we have proposed a basic retrofitting of an existing ESP to convert it into a hybrid collector, for both a 550 MWe and a 220 MWe pulverized coal power station. (c) 2006 Elsevier B.V. All rights reserved.