Study of the kinetic behaviour of biomass and coal during oxyfuel co-combustion

In this study, the thermogravimetric analysis(TGA) method has been used to evaluate the kinetic behavior of biomass, coal and its blends during oxyfuel co-combustion. The thermogravimetric results have been evaluated by the Coats–Redfern method and validated by Criado's method. TG and DTG curves indicate that as the oxygen concentration increases the ignition and burn out temperatures approach a lower temperature region. The combustion characteristic index shows that biomass to coal blends of 28% and 40% respectively can achieve enhanced combustion up to 60% oxygen enrichment. In the devolatilization region, the activation energies for coal and blends reduce while in the char oxidation region, they increase with rise in oxygen concentration. Biomass, however, indicates slightly different combustion characteristic of being degraded in a single step and its activation energies increase with rise in oxygen concentration. It is demonstrated in this work that oxygen enrichment has more positive combustion effect on coal than biomass. At 20% oxygen enrichment, 28% and 40% blends indicate activation energy of 132.8 and 125.5 kJ·mol~(-1) respectively which are lower than coal at 148.1 kJ·mol~(-1) but higher than biomass at 81.5 kJ·mol~(-1) demonstrating synergistic effect of fuel blending. Also, at char combustion step, an increase in activation energy for 28% blend is found to be 0.36 kJ·mol~(-1) per rise in oxygen concentration which is higher than in 40% blend at 0.28 kJ·mol~(-1).     

天然气与煤粉混烧技术在工业锅炉上的应用

介绍了在链条炉的基础上,以煤粉、天然气的悬浮燃烧方式配合火床燃烧的节能改造技术,对一台20t/h快装链条炉改造后,锅炉启动时升温速度提高,负荷调节的响应时间缩短,锅炉灰渣含碳量由原来的20％降低到5％以下,机械不完全燃烧损失大为降低.过量空气系数由改造前的2.5 ～3降低至1.2 ～1.3,大幅减少了锅炉排烟量,降低了锅炉排烟热损失.锅炉热效率由改造前的62％提高至改造后的77％ ～ 80％.     

生物质混煤燃烧过程中的腐蚀作用及其影响因素探析

生物质中较高的碱金属及氯元素含量,使其在与煤混燃过程中引起了过热器管壁的严重腐蚀.综合分析了生物质混煤燃烧过程中的腐蚀作用类型,考查了腐蚀的各种影响因素,并对炉内温度、燃料成分、炉内气氛、金属材质等因素进行了探讨.     

半焦与垃圾衍生燃料混烧的排放特性

在非均匀布风流化床中进行了半焦与垃圾衍生燃料（RDF）的混合燃烧实验，研究了不同半焦混烧率对烟气组分的影响以及二者混烧的可行性与经济性．实验结果表明，随着半焦混烧率的增加，H2O（气态）、CO、HCl、NO及C3H6含量均呈下降趋势，而CO2、SO2含量则呈增加趋势．同时发现，在燃烧过程中增加C1元素含量，可以促进NO的生成．     

Energy generation from biomass and waste in the Netherlands: A brief overview and perspective

For a number of years, the interest in energy generation on the basis of biomass and waste has been increasing. A brief overview is given of biomass waste availability in the Netherlands. In recent years several new projects related to energy generation from biomass and waste are initiated in the Netherlands. The results and status of some major projects are outlined in this paper. In the short term only biomass waste (available at low and even negative prices) can play an important role. Establishment of a carbon tax will increase the feasibility of energy crops for energy generation.     

棉秆炭与生物质焦油混合成型及燃烧特性研究

为研究棉秆炭与生物质焦油混合成型及燃烧特性,以成型压力、成型温度和焦油添加量为试验因素,采用正交试验方法,开展成型条件对抗压强度、跌落强度、松弛密度及吸潮率影响规律的试验研究,并采用差热热重同步分析仪,分析棉秆炭、焦油混合试样燃烧特性。试验结果表明：最优成型工艺参数为成型压力8 kN、成型温度20 ℃、焦油添加量6%。棉秆炭与焦油混合试样的综合燃烧特性指数（28.86~24.21）×10^-8 K^-3·min^-2随焦油添加量（0%~6%）的增加而逐渐减小,说明在棉秆炭中加入适量焦油制备成型炭可获得良好的成型及燃烧性能。     

Biogas and biomass technology: Energy generation from biomass and waste in the Netherlands

Within the European Community, the interest in energy generation from biomass and waste is increasing. A brief overview is given of several thermal conversion technologies, of biomass production and waste availability in the Netherlands. Based on this, the possibilities for energy generation from biomass and waste in the Netherlands are evaluated.     

低温烘焙下城市生活垃圾与烟煤的混燃特性

为了探讨垃圾与煤的混燃特性,选取城市生活垃圾(MSW)和烟煤(BC)为研究对象,通过热重分析法研究烘焙温度、掺混比例、升温速率对样品燃烧特性的影响,并采用Kissinger-Akahira-Sunose(KAS)法计算样品的活化能。结果表明:MSW经220℃,260℃和300℃低温烘焙后,热值都有所提升,随着烘焙温度上升,其质量产率和能量产率逐渐降低,挥发分析出与燃烧区间逐渐减小,固定碳燃烧区间逐渐增大;MSW-260与BC掺混能有效改善烟煤的燃烧特性,提高混合样的燃烧速率;升温速率上升会产生热滞后现象,MSW-260与BC混合燃烧各反应阶段向高温侧移动,且升温速率越快偏移越明显。综合动力学分析以及燃烧特性参数分析来看,在保证资源高利用率和良好的燃烧状况条件下,MSW-260与BC混燃质量比可以选用5∶5。     

300 MW燃煤锅炉污泥掺烧现场试验关键技术研究与工程应用

针对某电厂300 MW掺烧生活污泥的1号锅炉开展了锅炉燃烧特性理论研究、现场掺烧试验,评估了不同掺烧比例对锅炉燃烧特性、污染物排放的影响。结果表明:掺烧40%含水率的生活污泥,掺烧比例在10%以下时,理论燃烧温度降低了7 K,污泥掺烧对于煤的元素成分影响不大,对飞灰浓度影响不大,不会造成省煤器等受热面的磨损加剧,烟囱出口处NO_(x )、SO₂和粉尘排放浓度都能满足超低排放要求,脱硫石膏、脱硫废水、脱硫浆液、飞灰和炉渣中重金属排放浓度满足相关环保标准的排放要求。     

麦草木素与煤混烧灰熔融特性

为合理利用造纸工业酸法制浆的副产品麦草木素，结合工程实际需要，对木素与煤混烧灰的熔融特性进行了研究.将质量分数为0～95％的麦草木素与煤混烧制成混烧灰，通过测定混烧灰的熔点，观察到随着木素质量分数的增大，混烧灰的熔点出现下降、上升再下降的趋势.结合灰成分分析，利用K₂O-Al₂O₃-SiO₂和CaO-Al₂O₃-SiO₂ 2个三元系统相图，验证了混烧灰熔融特性曲线的变化趋势与相图中矿物形成温度的变化趋势相一致，从而得出灰成分变化是造成混烧灰熔融特性变化的根本原因，同时也发现了生物质与煤混烧可以改变生物质类燃料低熔点的性质，在燃烧利用上较单纯燃烧生物质更具优越性.