【作者】 刘建国；

【导师】 姜秀民；

【作者基本信息】 上海交通大学 ， 热能工程， 2009， 博士

【摘要】 含油污泥是石油开采和加工过程中的“伴生品”,是一种危险废弃物,产生在石油生产的各个环节(原油的开采、运输、原油的精加工)。在我国每年有近百万吨的油污泥产量,而到目前为止还没有成熟完善的油污泥处理方法。由于工业生产所带来的环境问题越来越受到社会的关注,对油污泥进行无害化处理已是一个迫在眉睫的问题,科学、有效地解决含油污泥处理难题对石油行业的可持续发展具有重要意义。焚烧工艺被世界各国认为是污泥处理中的最佳实用技术之一,它以处理速度快,减量化程度高,能源再利用等突出特点而著称。针对目前国内油污泥的处理现状和污泥处理的发展趋势,文本提出了油污泥流化床焚烧处理方法,油污泥经过焚烧处理后,污泥中的有机质被高温分解并燃烧,同时残渣体积小,热能可以利用。油污泥在流化床内燃烧是一个崭新的课题,关于油污泥在流化床内燃烧的研究鲜见报道。其中油污泥在流化床内的燃烧特性及机理是实现油污泥流化床焚烧处理和稳定运行的关键,本文针对此关键问题较为系统地展开了实验、理论和应用研究工作。油污泥的理化特性是油污泥流化床焚烧的基础,本文第二章对油污泥的化学成分、热化学特性、升温过程中的挥发分析出及组分等进行了实验研究,在实验中采用了多种实验方法,主要包括:利用萃取方法分析了油污泥的有机组分;应用色谱质谱联用仪(GC/MS)确定了有机组分的化学成分;利用热重分析分析了油污泥在程序升温过程中的热解、燃烧特性;利用带有火焰离子检测器的油气评价系统分析了程序升温过程中的烃类物质的挥发释放特性;应用固定床反应器研究了一定升温速率下热解挥发分组分随温度的析出规律。从油污泥的特性分析入手,基于其工业分析、元素分析、成分分析及热重分析等基础数据,根据不同升温速率下热解的烃析出曲线采用等转化率法求解了热解过程中烃析出活化能随反应程度的变化规律,并讨论了其变化机理。在油污泥流化床处理系统中,石英砂作为惰性床料其在床内的破碎和磨损规律对流化床的稳定运行有重要影响。本文第三章在热态实验台上进行了石英砂破碎、磨损规律的实验研究。在破碎实验中考虑了颗粒尺寸(2.5~6mm)和床温(650~950℃)对破碎的影响。研究结果发现破碎随着床温的升高和颗粒尺寸的增大而加剧,对于较小颗粒在床温较低的情况下,破碎主要发生在颗粒表面,破碎的主要动力是温度梯度引起的在颗粒表面产生的压应力,其特征为产生大量的细小颗粒,而平均粒径不发生明显变化。对于较大颗粒在床温较高的情况下,颗粒会由于颗粒中心处的拉应力超过颗粒的抗拉极限而发生热破碎,其特征是母颗粒会分裂成几个大小相当的子颗粒,使平均粒径明显减小。采用正交实验的设计方法在热态实验台上进行了石英砂床料的磨损实验,通过对不同运行参数(颗粒平均直径、床温、流化数、床料高度)对石英砂床料磨损影响的级差分析,得到不同运行参数对石英砂床料磨损影响程度的主次关系依次是流化数、平均粒径、床温、料层高度。基于灰色预测理论推导了GM(1, 5)灰色模型,预测了石英砂在流化床内的磨损,实验结果验证了GM(1, 5)模型的准确性,其平均预测误差仅为0.508%。本文第四章在小型热态流化床上进行了单颗粒油污泥球的热解和燃烧实验以及油污泥的连续燃烧实验。实验中考虑了油污泥球径的变化对热解过程中挥发分组分和热解时间的影响;分析了燃烧过程中油污泥球径、床温、流化风速和水分含量对燃尽时间、烟气组分和浓度的影响。在单颗粒油污泥球燃烧实验结果的基础上,研究了油污泥连续燃烧过程中表观流化风速和床温对燃烧的影响,分析了炉膛高度方向上的烟气成分的变化规律;最后讨论了油污泥在流化床内燃烧的成灰特性,并在小型实验台上进行了油污泥灰的扬析实验,得到了扬析速率常数Ki*与相关因素的实验关联式。结合油污泥流化焚烧工艺专利,在深入研究分析油污泥流化床燃烧特点的基础上,在本文的第五章确定了油污泥洁净焚烧装置的结构设计参数,优化设计了一套完整的洁净焚烧装置。在本文第6章对所设计的20t/h油污泥循环流化床燃烧锅炉进行了系统的性能测试。研究了油污泥-水煤浆混烧的燃烧特性、气体污染物排放特性、灰渣特性。通过分析沿床高的温度分布总结了油污泥-水煤浆混烧比对燃烧的影响,分析表明,采用水煤浆作为伴烧燃料可以非常灵活地调节密相区的运行温度。应用油污泥-水煤浆流化燃烧综合数学模型,对油污泥-水煤浆流化床炉内床高方向上的温度分布及烟气组分分布进行了数值模拟,通过对模型模拟结果和实测结果的比较,表明该模型可以描述油污泥-水煤浆流化燃烧过程的主要特征。更多还原

【Abstract】 Oil sludge is a kind of hazardous petroleum waste, and accumulates from all kinds of craft processes in petroleum production including exploitation, transporting and refining processes. In China, more than 1000 000 tones of oil sludge are generated annually. However, there is not a method or craft can efficiently treat this kind of oil sludge by now. Environment issues in industries production have attracted more and more attention; the treatment and disposal of petroleum oily sludge represent major challenges for petroleum industries.Incineration technology is thought as one of the most practicable technology in the field of sludge treatment in the world. Aiming at existing state of treatment technology in China and development trend of treatment technology of sludge, fluidized bed (FB) incineration technology of treating oily sludge are proposed with its obvious advantages such as fast disposal speed, decreasing components efficiently and recycle energy as well. Incineration of oil sludge in FB a now subject, not much has been reported on the combustion mechanism of oily sludge in a fluidized bed. This research considered the application of incineration principles to petroleum oily sludge using a new technique. The fundamental fuel properties and its combustion process and mechanism in a fluidized bed are concerned.Physicochemical characteristics are basis for the oil sludge combustion in a FB, the petroleum oily sludge taken from the bottom of crude oil storage tanks was investigated by a series of experiment to gain organic group compositions, the chemical components, the thermal properties including pyrolysis and combustion and evolution of volatile and hydrocarbon release. For these proposes, various approaches including solvent extraction, GC/MS, thermogravimetric analysis (TGA), electrically heated fixed bed quartz reactor coupled with Vario Plus emission monitoring system, and oil-gas evaluation workstation (OGE-II) equipped with a flame ionization detector (FID) were used. The CHs (hydrocarbons) data from the OGE-II were used for kinetic analysis by Vyazovkin model-free iso-conversion approach to obtain activation energy (Eα) dependency on conversion (α) in the pyrolysis of oil sludge. The mechanism of the dependency of the activation energy on the degree of conversion was also discussed.Fragmentation and attrition of bed materials are very important for stable operation of the oil sludge incinerator. In the chapter 3, the fragmentation and attrition of bed materials in a hot FB were investigated. In the fragmentation experiment, the influences of a variety of factors such as the bed temperature (650-950oC), the size of particles (2.5-6mm) on the fragmentation of quartzite particles are studied. The research results show that the extent of fragmentation increases with increasing bed temperature and particle size. For the small particles at low bed temperature, the research shows that, it is compressive stresses within the outer region of particles cause the particle to fracture, with the characteristics that many small fragments peeled from the surface of the particles and the average particle size after fragmentation change very little. However, for the large particle at high bed temperature, it is tense stresses within the center of particle causing the particle to fracture, the particle is divided into several equivalent size particles, as a consequence, and a more intense size reduction after fragmentation is gained. In the attrition experiment, the influence of operating parameters such as bed temperature, mean diameter of bed particles, fluidizing number and height of bed materials on attrition process is investigated. The influential extent of operating parameters on attrition is sequenced by mean of the range analysis. The result is shown as follow: fluidizing number>mean diameter of particles >bed temperature> height of bed materials. Based on the grey theory, a grey forecasting model GM (1, 5) is developed to predict the attrition of the quartzite particles in a hot FB. The result demonstrates that the forecasted values are in good agreement with the experimental data with the average residual error lower than 0.508%.In the chapter 4, the combustion experiment of the oil sludge was carried out in a laboratory scale thermal fluidized bed. Firstly the pyrolysis and combustion properties of oil sludge ball in the hot FB are investigated. In pyrolysis experiment, the influence of oil sludge ball diameter on volatiles release time and contents of volatiles are considered; in the combustion experiment, the influences of bed temperature, ball diameter, superficial fluidization velocity and moisture content on combustion are studied. Secondly, under the stable combustion state of oil sludge in the fluidized bed, the influences of bed temperature and superficial fluidization velocity on combustion process are studied; the gas compositions along the bed height are analyzed. Finally, ash formation and its properties in the combustion process in the hot FB are discussed. The elutriation experiment was conducted in order to determine the elutriation rate constant of oil sludge ash in the fluidized bed.Based on the patent of oil sludge incineration in a FB and combustion mechanism oily sludge in a FB, a craft process and technical characteristics of an incineration treatment system of oily sludge are described in chapter 5, the design parameters and structure of a 20t/h circulating fluidized bed (CFB) boiler are introduced.In the chapter 6, the field test of the combustion of the oil sludge was carried out in the 20t/h CFB boiler treating oil sludge. Co-firing of oil sludge with coal-water slurry (CWS) was investigated in the new incineration system to study combustion characteristics, gaseous pollutant emissions and ash characteristics. The combustion along the furnace height was also investigated in order to understand the influences of feeding rate of oil sludge on temperature distribution along the furnace height. The study results show CWS as an auxiliary fuel can flexibly control the dense bed temperatures by adjusting its feeding rate. A one-dimention comprehensive mathematical CFB model for describing the co-firing process of oil sludge with CWS in a CFB is tested against the experimental data from the 20t/h FB boiler. The model results for the axial temperatures and gas concentrations along the furnace height are compared to experimental measurement. The general agreement is reached between the calculated and measured parameters.更多还原