Distribution and fate of environmentally sensitive elements (arsenic, mercury, stibium and selenium) in coal-fired power plants at Huainan, Anhui, China

Abstract

The present study has investigated the distribution of arsenic (As), mercury (Hg), stibium (Sb) and selenium (Se) in feed coal and its combustion by-products in two pulverized coal-fired power plants at Huainan city, Anhui province, China, both of which burned the bituminous coals. Experimental analysis of simultaneously sampled coal, bottom ash, fly ash and FGD products showed that the concentrations of As, Hg, Sb and Se in coal were in the ranges of typical Chinese power plants reported by others publications. Mercury was found to be the most volatile, whereas Sb was the least volatile. The overall material balances of As, Hg, Sb and Se were established based on the operation parameters of their respective boiler. The average removal efficiencies of As, Hg, Sb and Se by the ESP unit were 83%, 16%, 100%, and 72%, respectively, whereas those by the FGD process were 61%, 80%, 0% and 55%, respectively. The stack emission proportions of As, Hg and Se were 6%, 17% and 13%, respectively. And the total annual emissions of As, Hg and Se from two coal-fired power plants were estimated at 0.46t, 0.04t and 2.27t, respectively.