三种煤的部分气化生成多环芳烃的试验研究

EXPERIMENTAL STUDY ON POLYNUCLEAR AROMATIC HYDROCARBONS EMISSION FROM PARTIAL GASIFICATION OF THREE TYPES OF COALS

多环芳烃(PAHs)是煤气化过程中产生的一类有害有机物质，具有强烈的致癌性和致突变性，越来越受到人们的关注。文中在一台小型常压流化床气化炉上进行了以空气和水蒸气为气化剂的3种煤部分气化试验，采用高效液相色谱法(HPLC)对煤气化产物中被美国环保署(US EPA)指定的16种PAHs进行了测定，研究了煤部分气化过程中煤自身性质对多环芳烃生成和赋存规律的影响。试验结果表明：煤部分气化PAHs生成量高于原煤PAHs含量(徐州烟煤除外)；原煤固定碳和硫含量增加，煤部分气化PAHs生成量先增后降，挥发分含量增加，PAHs生成量却呈现出相反的变化规律；提高灰分含量或采用低发热量原煤，可以降低煤部分气化PAHs生成。

Polynuclear aromatic hydrocarbons (PAHs) are considered to be a group of compounds that pose potential health hazards since some PAHs are known as mutagens and carcinogens. PAHs released from coal gasification have received considerable attention. Three types of coals were gasified partially in a bench-scale atmospheric fluidized bed gasifier by using air and steam as gasifying medium. The 16 PAHs specified by US EPA in the products of coal partial gasification were analyzed by high performance liquid chromatography (HPLC). The aim of this work is to study the influences of the structure and composition of coal on the formation and fate of PAHs during coal partial gasification. The experimental results show that the total PAHs contents generated in coal partial gasification are higher than in raw coal (except Xuzhou bituminous coal). The total PAHs contents increase and then decrease with the rise of fixed carbon and sulfur of coal, but the increase of volatile matters leads to an opposite phenomena about the total PAHs contents. The quantities of PAHs reduce with the increase of ash content of coal or the drop of heating value of coal during coal partial gasification.