【作者】 刘志超；

【导师】 廖艳芬；

【作者基本信息】 华南理工大学 ， 工程热物理， 2015， 硕士

【摘要】 伴随着污泥处置的“减量化、无害化、资源化和稳定化”原则,如何高效无害化处理工业污泥成了国内重点关注的课题。本文通过生命周期评价的方法,并结合掺烧实验机理研究,对经济性评价、能耗评价、环境评价进行系统的全方位的分析,为发电企业经济环保地处置工业污泥提供路线方案的理论依据。使用生命周期费用(LCC)对直接干化-掺烧、间接干化-掺烧、直接干化-填埋、间接干化-填埋、不干化-掺烧等23种方案进行评价和分析,发现:在其他干化条件相同情况下,存在一个初始含水率W(约60%),当含水率高于W,间接干化-掺烧的LCC现值低于直接干化-掺烧,低于W,则反之。在论文的理论方法和经济数值情况下,并且最终干化含水率在20~35%区间内,直接掺烧65%及以下含水率的污泥比干化-掺烧LCC值都低。干化-填埋方案仅为干化-掺烧方案的成本的一半。通过掺烧的热重分析和烟气排放分析,研究不同工况下燃烧及排放特性。实验结果发现:印尼烟煤单样燃烧DTG曲线只存在一个波峰,平均燃烧速率相对较高,造纸污泥DTG存在两个明显的波峰,分别为挥发分和固定碳的燃烧。印尼烟煤和造纸污泥掺烧的热重DG和DTG曲线呈现一定的线性叠加性,但混合物着火点提前,燃尽温度升高,燃烧时间更长,随着掺烧比例的增加,各指数均降低,说明混合燃料更加适合在循环流化床锅炉燃烧。印尼烟煤随着燃烧温度升高,NOX排放总量随着温度先升后降,900℃最高。印尼烟煤挥发分中有机硫大于固定碳的有机硫,随着温度升高,SO2的排放速度和排量提高。在1100℃的燃烧下,印尼烟煤与造纸污泥的NO排放曲线呈现一个波峰,NO排放随掺烧比增大而减少,SO2呈现两个波峰,SO2排量不随掺烧比的变化而变化,添加剂Ca O对NO排放特性无影响,对SO2的排放特性有明显的抑制效果,随着Ca O掺入量的增加,抑制的幅度逐渐减少。由于掺烧前后S、N排放与污泥煤粉本身S、N含量高低有直接关系,对于造纸污泥而言,掺烧后N、S排放并不增加脱离脱硝的压力。使用LCA方法构建直接干化-掺烧和间接干化-掺烧系统边界,获得能耗及排放清单,干化-掺烧运行阶段的能耗和排放最大,主要来源于运行所需的电耗和煤耗,而电耗和煤耗取决于干化水分量的大小。在资源耗竭分析中,煤炭消耗是资源消耗的主体,经过加权后的资源消耗,煤炭的消耗依然为主体部分。环境影响潜值中,直接干化-掺烧和间接干化-掺烧的生命周期环境加权后的影响潜值分别为8.357PET2010和4.98PET2010,光化学臭氧(PO)的地区性影响和固废(SW)的局地性影响最大。更多还原

【Abstract】 With the principle of “reduction, harmlessness, recycling and stabilization” was come up with, the problem that disposing industrial wastewater efficiently and harmlessly was an important project. This thesis analyzed industrial sludge drying-co-combustion cost, energy consumption and environmental impact by using life cycle assessment and co-combustion(paper sludge and Indonesian bituminous coal) experiments, in order that provided theoretical guidance for power generation enterprises to disposing industrial wastewater environmentally and economically.This paper adopted twenty-three kinds of schemes, consisted of direct-drying-co-co-mbustion, indirect-drying-co-combustion, direct-drying-landfill, indirect-drying-landfill and non-drying-co-combustion. Through analysis of life cycle cost(LCC), following conclusions were formed: When the initial moisture content exceeds W(60%) and other drying conditions were the same, LCC was ranked below: indirect-drying-co-combustion< direct-drying-co-combustion. When the initial moisture of sludge below 65%, LCC of non-drying-co-combustion was the lowest than other drying-co-combustion schemes. LCC of drying-landfill was about a half of drying-co-combustion.This paper studied co-combustion characteristics of sludge and coal in diverse burning temperature and different maxing ratios. Thermogravimetric experiment indicated following discoveries: DTG of Indonesian bituminous coal existed one wave crest and the average burning rate is relatively high; While DTG of paper sludge existed two apparent wave crests, each wave crest came from volatiles burning and fixed carbon burning, respectively; From the co-combustion rule of DG and DTG, it is drawn a conclusion that the blend possesses relative linear superposition, but the kindling point is in advance, the burnout temperature increases, combustion time is longer, all combustibility parameters decrease. Blend of paper sludge and Indonesian bituminous coal is more suitable for CFB burning. Flue gas analysis experiment showed that Indonesian bituminous coal tended to generated NO/NOX more easily under medium temperature at approximately 900℃, the amount of organic sulfur in volatile is greater than that in solid particle, higher burning temperature is appropriate for generating more SO2; Under the co-combustion temperature of 1100℃, NO/NOX emission curve existed one wave crest, SO2 emission curve existed two wave crests; As the proportion of sludge in blend increased, NO/NOX emission decreased, but SO2 emission and generation speed increased; Ca O could lower down SO2 emission, but could not restrain NO/NOX emission; With the mixing amount of Ca O linear increasing, the inhibitory effect weakened. Co-combustion confirmed that the emission of N and S would not mak a difference on desulfurization and denitration.The entire life of industrial sludge drying and co-combustion with coal was evaluated to identify and quantify the energy requirements and environmental impact loading in this paper. The life-cycle assessment(LCA) consisted of wet sludge transportation stage, the drying-co-combustion operation stage and equipment reconstruction stage. Analytical results revealed that the drying-co-combustion operation stage consumed the most primary energy and discharged the most pollutants; Energy consumption come from coal and electric power, which depend on the amount of drying moisture. Coal is the main body of resource consumption, and the weighted resource consumption is still coal. The total environmental impact potential of two drying-co-combustion schemes were 8.357 PET2010 and 4.98 PET2010(person equivalents, targeted, in 2010), and the effect of photochemical ozone formation(PO) and solid waste(SW) were the most serious among all calculated category impacts.更多还原