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Utilization of AFBC waste by-product as a FGD sorbent for circulating dry scrubbing

Book ·
OSTI ID:287988
; ;  [1]; ; ;  [2]
  1. Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research
  2. Tennessee Valley Authority, Chattanooga, TN (United States)

The Tennessee Valley Authority (TVA) is currently interested in finding applications for the spent bed sorbent by-product generated at their 160 MW AFBC facility. Calcium utilization in this by-product is relatively low, having an available alkalinity from 20 to 40 wt%, as Ca(OH){sub 2}, thus, creating a potential disposal problem. It is possible that this byproduct material could be used as a supplemental sorbent in the Gas Suspension Absorption (GSA) reactor located at the TVA`s Center for Emissions Research in Paducah, Kentucky. GSA technology is a semi-dry, lime based, FGD process that utilizes a circulating bed arrangement for contacting sorbent with SO{sub 2}-laden flue gas under coolside conditions. A pilot-scale fluid bed reactor was modified to simulate a generic circulating dry scrubber (CDS) process similar to the GSA technology.The purpose of this program was to investigate the feasibility of using AFBC waste in conjunction with hydrated lime as a sorbent for the CDS process. An AFBC by-product from the 160 MW plant was pulverized to liberate CaO and slaked along with a fresh lime feedstock. CDS sulfur capture was evaluated with and without chloride addition to the sorbent slurry. Control tests using lime-only feeds were also conducted. In general, the sulfur capture reactivity of the sorbent which included slaked lime/AFBC material was found to be equivalent to or greater than that containing only fresh lime. With a nominal Ca/S ratio of 1.3 (1.0 with fresh lime, 0.3 slaked by-product), the reactor sulfur capture varied between 65 and 90% depending on the specific test conditions. An effective fuel chloride of 0.2 wt% was found to enhance the sulfur capture by as much as 8 to 12%.

OSTI ID:
287988
Report Number(s):
CONF-950522--; ISBN 0-7918-1305-3
Country of Publication:
United States
Language:
English