城市生活垃圾焚烧过程中硫和氯的行为研究

【作者】 吕国强；

【导师】 王华；

【作者基本信息】 昆明理工大学 ， 冶金物理化学， 2004， 硕士

【摘要】 城市生活垃圾（MSW）引起的环境问题已受到全世界的普遍关注，对其有效合理处理是保护环境领域里的一个重要环节。未经处理或处理不当的城市生活垃圾会侵占耕地、污染水源、破坏自然景观，甚至危及到人们生命财产安全。目前城市生活垃圾处理主要有填埋、堆肥和焚烧三种较成熟的方法。焚烧法处理垃圾能彻底杀菌灭毒，并可回收其中的热能，是实现减量化最快捷有效的方法，逐渐成为国内外处理垃圾的主要方式。燃烧工况的合理组织和二次污染的控制是焚烧法处理垃圾的关键所在。由于城市生活垃圾成分复杂和不当的焚烧处理，焚烧过程常常伴随严重的二次污染。焚烧垃圾产生的二次污染包括焚烧过程产生的飞灰、以Dioxins为代表的有毒有机物、重金属、HCl、SOx、NOx、HF、CO等有害气体和固体灰渣污染物。其中一些如HCl、重金属污染物以及Dioxins有机污染物等，毒性大，形态复杂，对人身安全和环境造成了极大危害，因此对其形成机理和控制机理进行深入的探索和研究十分必要。 本文针对城市生活垃圾焚烧过程中硫和氯的行为及其影响因素进行了研究和讨论，主要的研究结果如下： 1．实验样品1组分为：厨余垃圾50.29％，纸张14.17％，橡胶塑料0.61％，纤维1.16％，金属0.92％，玻璃0.8％，杂草及其它32.05％，其中S^y0.54％。 （1）焚烧温度对垃圾中硫的行为具有明显影响，SO₂的转化率随温度的升高而增大，600℃时SO₂转化率为60.32％左右，1000℃时为83％；SO₂的析出浓度在焚烧开始后第5分钟左右达到最大值，实验的前10分钟为SO₂的集中排放时间；第25分钟后几乎再无SO₂析出。 （2）垃圾中加入CaCO₃一起焚烧可以显著降低SO₂的排放量，从而减少垃圾焚烧带来的二次污染；石灰石最佳的固硫温度范围为700℃～900℃，固硫率最高可达88％。 （3）煤与垃圾混烧可以提高焚烧炉的热稳定性；煤与垃圾混烧烟气中SO₂的浓度因掺烧比的增大而升高；掺烧比一定时焚烧温度越高SO₂排放浓度就会越高。昆明理工大学硕十学位论文2004.3 2.我们增加了垃圾中塑料橡胶含t来研究垃圾焚烧过程中抓的行为，样品2的EDS分析结果为:’C，67.09%，O，22.03%，S’0.29%，Cl’4.18%，其它6.41%。 （1）当温度从600，C升高到1000℃时，HCI的转化率n。。，从80%单调缓慢增加到89%:在600℃到700℃这一段增加的趋势相对明显。 （2）空气供给t会对HCI的转化率产生影响;焚烧温度为600℃时，空气量由Q二l增加到a二1.5，HCI的转化率从74%迅速增加到89%，。>1.5后HCI的转化率开始平缓递减，a二3时HCI的转化喇为84%。 （3）垃圾中加入CaCO，一起焚烧能有效的将Cl固化在灰渣中，从而减少了垃圾焚烧形成的二次污染;固抓率随Ca/（S+0.5CI）比的增大而增加，结果表明，当Ca/（S+0.5CI）=2.5时的固抓率为82.23%，此时的Ca/（S十O，SCI）比就墓本满足理想的固氛效果，当CaCO，的添加t进一步增加时，CaCO:的利用率降低;综合CaCO3的利用率和固抓效果我们认为CaCO，添加量以Ca/（S十0.5CI）=2.5时最适合. （4）焚烧温度对石灰石燃烧固抓具有显著影响，温度越高不利于固抓反应的进行;Ca/（S+0.SCI）=2.5时，温度从600℃升高到1000，C，固抓率由80.97%逐渐下降到1 1.24%，下降的趋势十分明显。更多还原

【Abstract】 The environment problem brought by Municipal Solid Waste(MSW) has attracted generally attention all over the world, so the effective and sound treatment was an important part in the field of environment protection. The non-disposal or improper disposal of MSW caused serious problems, such as trenching on infield, contaminateding water source, disfeaturing nature scenery, even endangering people’ s life and properties. At present, there were three main mature methods in the disposal MSW: landfill, compost and incineration. The incineration was a quick and effective method, through which could kill germina completely, recovery energy and reduce the volume of MSW obviously. The method was becoming a main approach of disposal MSW in domestic and abroad. The effective controlling of combustion conditions and secondary pollution was the key to MSW incineration. There was serious secondary pollution during incineration. The secondary pollution including fly ash, heavy metals, HC1, SOx, NOx, HF, CO, bottom ash, dioxins and others poisonous organic pollutant. Some pollutants with deadly toxicity and complex form, such as HC1, heavy metals and dioxins were very harmful to peopel health and environment. It is very nessary to research formation and control mechanism of these harmful pollutants during the MSW incineration.In this thesis, the behaviors of sulfur and chlorin and their influence factorswere discussed. The major reseach results are as fellows:1. The component of experiment sample: 50.29% kitchen waste, 14.17% waste paper, 0.61% rubber and plastic, 1.16% fiber, 0.92% metal, 0.8% glass, 32.05% grass and others. There are 0. 54% S in the sample.(1) The behaviors of sulfur in MSW were influenced obviously by incineration temperature) the conversion ratio of S02 increased with the temperature, the ratio aroud 60. 32 % in 600癈and 83% in 1000 C; The max concetration of S02 got at 5 minute, most S02 emission within the 10 minutes; After 25 minutes there were almost not SO2 emission(2) The S02 emission quantity were decreased obviously by dashing CaCO3 with MSWduring incineration , consequently the secondary pollution declined; The best sulfur fixation temperature of CaC03 were 700 C~900 C, the max of sulfur fixation ratio was 88% .(3) The co-combustion of municipal solid waste (MSW) and coal could ensure stable combustion; The concetration of SO2 increased with the co-combustion ratio; The concetration of S02 increased with the temperature.2. We increased the ratio of plastic and rubber in waste to study the chlorin behavior during incineration, the sample EDS: Cy67. 09%, Oy22. 03%, SyO. 29%, Cly4. 18%, and others 6. 41%.(1) The conversion ratio of HC1 ( Hcl) humdrum and slow increase from 80% (600 C ) to 89% (1000 C) with the temperature get high; The trendline was steep correspondingly from 600C~700C.(2) The air volume influenced on the conversion ratio of HC1 ( HCl) ; In 600 C, HCl increased rapidly from 74%( a =1) to 89% ( a =1. 5), but HCl decreased slowly when a >1.5, HCl was 84% when a =3. (3) The chlorin was solidfied obviously in the slag when dashing CaCO3, with MSW during incineration, the chlorin fixation ratio increased with Ca/(S+0. 5C1) added; When Ca/(S+0. 5C1) =2. 5, the chlorin fixation was 82. 23%, this ratio of Ca/(S+0. 5C1) can settle for perfect purpose of chlorin fixation; When CaCO?supplied continued, the ues factor of CaC03 decreased; Ca/(S+0. 5Cl)=2. 5 better than others based on the chlorin ratio and the ues of factor of CaCO3.(4)The chlorin fixation of CaC03 was inflenced by temperature, the reaction of chlorin fixation was disadvantagous with the temperature; hen Ca/(S+0. 5C1) =2. 5, the chlorin fixation decreased from 80. 97% to 11. 24% with the temperature increased from 600 C to 1000 C.更多还原