Due to its adverse impact on health, as well as its global distribution, long atmospheric lifetime and propensity for deposition in the aquatic environment and in living tissue, the US Environmental Protection Agency (US EPA) has classified mercury and its compounds as a severe air quality threat. Such widespread presence of mercury in the environment originates from both natural and anthropogenic sources. Global anthropogenic emission of mercury is evaluated at 2000 Mg year−1. According to the National Centre for Emissions Management (Pol. KOBiZE) report for 2014, Polish annual mercury emissions amount to approximately 10 Mg. Over 90% of mercury emissions in Poland originate from combustion of coal.The purpose of this paper was to understand mercury behaviour during sub-bituminous coal and lignite combustion for flue gas purification in terms of reduction of emissions by active methods. The average mercury content in Polish sub-bituminous coal and lignite was 103.7 and 443.5 μg kg−1. The concentration of mercury in flue gases emitted into the atmosphere was 5.3 μg m−3 for sub-bituminous coal and 17.5 μg m−3 for lignite. The study analysed six low-cost sorbents with the average achieved efficiency of mercury removal from 30.6 to 92.9% for sub-bituminous coal and 22.8 to 80.3% for lignite combustion. Also, the effect of coke dust grain size was examined for mercury sorptive properties. The fine fraction of coke dust (CD) adsorbed within 243–277 μg Hg kg−1, while the largest fraction at only 95 μg Hg kg−1. The CD fraction < 0.063 mm removed almost 92% of mercury during coal combustion, so the concentration of mercury in flue gas decreased from 5.3 to 0.4 μg Hg m−3. The same fraction of CD had removed 93% of mercury from lignite flue gas by reducing the concentration of mercury in the flow from 17.6 to 1.2 μg Hg m−3. The publication also presents the impact of photochemical oxidation of mercury on the effectiveness of Hg vapour removal during combustion of lignite. After physical oxidation of Hg in the flue gas, its effectiveness has increased twofold.
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机译：由于其对健康的不利影响及其全球分布，较长的大气寿命以及在水生环境和生物组织中的沉积倾向，美国环境保护署（US EPA）已将汞及其化合物归类为严重空气。质量威胁。汞在环境中的这种广泛存在源自自然和人为来源。全球人为汞排放量估计为2000 Mg年 -1 。根据国家排放管理中心（Pol。KOBiZE）2014年的报告，波兰的年度汞排放量约为10毫克。波兰超过90％的汞排放源于煤的燃烧。本文目的是通过主动方法减少排放，了解亚烟煤和褐煤燃烧烟道气净化过程中的汞行为。波兰次烟煤和褐煤中的平均汞含量为103.7和443.5μgkg -1 。亚烟煤排放到大气中的烟气中汞浓度为5.3μgm -3 ，褐煤为17.5μgm -3 。该研究分析了六种低成本吸附剂，亚烟煤的平均除汞效率为30.6％至92.9％，褐煤燃烧的平均除汞效率为22.8％至80.3％。此外，检查了焦炭粉尘粒度对汞吸附性能的影响。焦炭尘（CD）的细小部分吸附在243–277μgHg kg -1 之内，而最大部分仅为95μgHg kg -1 。 CD分数<0.063 mm在燃煤过程中去除了将近92％的汞，因此烟气中的汞浓度从5.3降至0.4μgHg m -3 。通过将流中的汞浓度从17.6降低到1.2μgHg m -3 ，相同比例的CD从褐煤烟道气中去除了93％的汞。该出版物还提出了汞的光化学氧化对褐煤燃烧过程中汞蒸气去除效率的影响。烟气中的汞物理氧化后，其有效性提高了两倍。
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