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.     

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。     

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％.     

循环流化床锅炉掺烧生物质前景研究

我国是世界上生物质资源较为丰富的国家,同时又是循环流化床锅炉装机数量与装机总容量最多的国家。循环流化床锅炉掺烧生物质对于整个社会的节能减排、提高农民收入有着重要意义。循环流化床锅炉掺烧生物质在技术上完全可行,不仅锅炉不需作大的改动,而且掺烧有助于提高锅炉效率。在目前没有有力政策支持的情况下,如果将生物质掺烧与CDM项目联系起来,有利于推动此项工作的顺利开展。     

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.     

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。     

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.     

生物质与煤混燃过程中碱金属对汞氧化影响的热力学研究

针对生物质中Cl和碱金属含量高的特点,研究生物质与煤混燃过程中Hg的氧化机制。使用化学热力学软件Chemical Equilibrium with Applications(CEA)建立C/H/O/N/S/Cl/K/Na模型,分析碱金属元素K、Na与非金属元素Cl和S的反应,发现1100K以下Cl仍然主要以HCl形式存在,SO2的含量逐渐减少,碱金属主要以碱金属硫酸盐(A2SO4)的形式存在,这对Hg的氧化反应变得更为有利,同时随着生物质的添加,这种趋势更为明显。同时使用动力学软件Chemkin4.1构建了Hg/C/H/O/N/S/Cl/K/Na的化学和气相平衡模型,进一步研究了生物质与煤混燃过程中对Hg氧化的影响。计算结果表明,生物质与煤之比越高,对Hg的氧化越有利,生物质中高含量的Cl是促进Hg氧化最主要的因素,而K、Na的存在对Hg的氧化有进一步的促进作用,这进一步证实了热力学计算结果。     

玉米秸秆与煤掺烧对循环流化床锅炉性能的影响

在75t/h工业循环流化床锅炉上进行了玉米秸秆与煤的掺烧试验,测试了掺烧比例为0%、10%、15%、20%、25%等5种工况下的锅炉运行性能。结果表明,当掺烧比不大于25%时,锅炉能够安全、稳定地运行,掺烧比对床存量、物料循环量的影响不大,没有出现床层超温和炉膛结渣现象;秸秆的掺入一方面使入炉灰量有所减少,另一方面提高了煤的燃尽程度,使机械不完全燃烧热损失有所降低;随着掺烧比的增大,锅炉排渣量随之减小,锅炉热效率随之升高。     

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).