The U.S. Department of Energy (DOE) issued Public Service Company of Colorado (PSCO) a cost sharing contract to evaluate carbon-based sorbents for mercury control on a 600 acfm laboratory-scale particulate control module (PCM). The PCM can be configured as simulate an electrostatic precipitator, a pulse-jet fabric filter, or a reverse-gas fabric filter and is installed on an operating coal-fired power plant. Three different dry carbon-based sorbents were tested this quarter to determine their mercury removal capability in the different configurations. The project is currently in the seventh quarter of an eight-quarter Phase I project. Testing in all configurations is nearly complete. Original plans included the use of an on-line mercury analyzer to collect test data. However, due to very low baseline mercury concentration, on-line measurement did not provide accurate data. The project used a modified MESA method grab sample technique to determine inlet and outlet mercury concentrations. A major concern during sorbent evaluations was the natural ability of the flyash at the test site to remove mercury. This often made determination of sorbent only mercury removal difficult. The PCM was configured as a reverse-gas baghouse and brought online with "clean" flue gas on March 10* at an A/C of 2.0 ft/min. The dustcake forms the filtering media in a reverse gas baghouse. In the absence of flyash, the bags were precoated with a commercially available alumina silicate material to form an inert dustcake. Some baseline tests were completed with clean gas for comparison to clean gas pulse jet tests. The PCM was reconfigured as a TOXECON unit in April 1997 with testing completed in May 1997. TOXECON, an EPIU patented technology, is a pulse-jet baghouse operating at a high A/C ratio downstream of a primary particulate colIector with sorbent injection upstream of the baghouse for air toxics removal. Mercury removals of O to 97o/0 were obtained depending on test conditions.