REMOVAL OF MERCURY FROM COAL-DERIVED SYNTHESIS GAS

Barton, Tom

Western Research Institute

关键词: Coal Gasification;    Removal;    Combustion;    Activated Carbon;    Absorption;   

DOI  :  10.2172/882283
RP-ID  :  none
RP-ID  :  FC26-98FT40322
RP-ID  :  882283

美国|英语

来源: UNT Digital Library

【 摘 要 】

The reduction of mercury emission from fossil fuel applications is an increasing priority for the US power industry due to regulatory pressure. While mercury removal during combustion is well studied, mercury removal in gasification is less so. The increasing application of coal gasification in future plant designs supplies the incentive for more study of mercury removal gasification processes. In gasification where the mercury is expected to be elemental, activated carbon injection has been the most effective method of mercury removal. Absorption of elemental mercury at high temperature has not been shown to be effective. The carbon is best injected downstream where the temperature has moderated and an independent collector can be established. Experiments have been conducted at 400 F to compare mercury absorption on activated carbon as received and ''super'' activated carbon. The ''super'' activated carbon was prepared by soaking the carbon in 6M nitric acid followed by neutralization and washing. Each absorption experiment has been run for 16 hours of exposure time to the gasifier product stream. The carbon samples were tested for mercury absorption by ICP hydride generation. The two carbon samples which had been washed in nitric acid then exposed to the gasifier slipstream showed higher concentrations of mercury even at this elevated absorption temperature when compared to the as received activated carbon.