不同煤种下循环流化床灰渣特性的试验研究

在一台 0 .5MW的循环流化床燃烧炉上对 4种不同煤种分别进行燃烧试验 ,对燃烧产生的灰渣的分析结果表明了煤种特性如挥发分、灰分和含碳量等对循环流化床燃烧过程的灰渣形成及其排放特性有很大影响 ,并获得了煤中挥发分、灰分及含碳量对底渣粒径及其含碳量、飞灰粒径及其含碳量、飞灰份额及燃烧效率等影响特性 ,对循环流化床锅炉的设计和运行有一定的指导意义。     

混烧石油焦油页岩循环流化床灰渣特性的试验研究

在1 MW流化床(CFB)燃烧试验台试烧5种不同掺烧比例的石油焦和油页岩混合燃料.对燃烧产生的灰渣特性进行了分析研究.分析结果表明,石油焦和油页岩混合燃料试烧后形成的底渣和飞灰粒度与常规煤种相比趋于偏细;而且,随着混合燃料中油页岩掺烧比例的升高,对灰渣份额、燃烧效率、飞灰比电阻值、飞灰磨损特性等都有明显的影响.在钙硫比...     

医疗垃圾焚烧炉回转窑转速与灰渣二恶英排放的关系

通过某回转窑-流化床医疗垃圾焚烧炉的燃烧实验,采集了不同回转窑转速条件下的飞灰和底渣样品,测定了其中的二恶英含量,并研究了回转窑转速与灰渣二恶英排放的关联特性.研究发现,随回转窑转速增加,灰渣的二恶英毒性排放总量增加;当转速为0.82 r/min时,飞灰中二恶英总量和毒性当量排放分别为41.05 ng/g和7.58 ng(I-TEQ)/g;流化床底渣样品中的二恶英含量比飞灰小很多.研究还发现,随着焚烧炉尾部烟气中NO<,x>和H<,2>O含量的增加,飞灰中二恶英总量呈现减少的趋势;随着烟气中O<,2>浓度的增加,飞灰中二恶英总量也随之增加,因此,通过关联性较好的常规气体成分(污染物)浓度的检测,可以在一定程度上预测燃烧_T况的好坏及飞灰中二恶英排放的程度.     

桉树类生物质燃烧飞灰可燃物含量分析方法研究

通过灰成分分析、热重-差示扫描量热-傅里叶红外光谱分析联用(TG-DSC-FTIR)试验,对桉树类生物质锅炉燃烧后飞灰可燃物含量的分析方法进行了研究.结果表明:桉树类生物质燃烧后飞灰中含有多种金属化合物,在空气高温加热过程中会同时发生缓慢氧化反应、碳酸盐分解反应、碱金属氯化物的蒸发过程,影响其中可燃物含量的准确测量;灰中可燃物燃烧温度约在350~550℃范围内,采用低浓度硫酸酸洗对灰样进行预处理,可排除碳酸盐分解反应、碱金属及氯元素的蒸发过程对可燃物含量测量的干扰,且以10K/min及以下的低升温速率加热时灰样中化合物不会发生缓慢氧化反应,使灰中可燃物含量测量结果较为准确.     

循环流化床锅炉飞灰综合利用初探

该文通过分析循环流化床锅炉灰渣活性，提出了再煅烧工艺来提高循环流化床飞灰的活性，使得循环流化床飞灰直接生产高标号水泥成为可能。     

CFB高钙脱硫灰渣制备硫铝酸盐水泥熟料试验研究

针对循环流化床锅炉(CFB)产生的高钙脱硫灰渣制备硫铝酸盐水泥熟料开展试验研究。试验选取某电厂CFB脱硫飞灰和底渣,分别配制硫铝酸盐水泥生料,在实验室高温炉中进行煅烧,探究煅烧温度、碱度系数C_m对熟料抗压强度和f-CaO含量的影响。试验结果表明,由CFB飞灰制备的熟料在碱度系数C_m=1、1350℃时性能较好,抗压强度可达49.5 MPa;由CFB底渣制备的熟料在碱度系数C_m=0.98、1350℃时性能较好,抗压强度可达44.4 MPa。试验通过XRD、水化放热分析的方法,验证了烧制所得熟料具有早强、快硬的特点。高钙脱硫灰渣可以用来制备硫铝酸盐水泥,通过合理控制工艺参数可有效提高熟料质量。     

生物质灰在低温受热面上的沉积点腐蚀机理分析

针对纯烧生物质锅炉,位于高温烟气区的低温介质管道短时间内发生腐蚀泄露问题,通过腐蚀产物和20G管壁的SEM和XRD检测,确认其原因是氯化物造成的点腐蚀。氯元素造成的点腐蚀随着金属温度的升高而加快,介质温度低于400℃的钢管由于点腐蚀也可以在短时间内泄露。抑制受热面上的灰的沉积,将有效改善氯化物造成的点腐蚀。     

循环流化床灰渣利用研究进展

在分析循环流化床灰渣特性的基础上,综述了国内外循环流化床灰渣的综合利用最新进展。一般由于成渣含炭量低,且具备一定的水硬活性,可以直接用作制造水泥或建筑材料的原料;而飞灰含碳量高,以及水硬活性不理想,继而开发了飞灰造粒回燃、飞灰直接返送和水化后返送脱硫,用作水泥的原料和土壤改良剂等。     

循环流化床锅炉灰渣综合利用

本文概述了循环流化床锅炉灰渣中的冷渣与分离灰综合利用的情况，讨论了影响灰渣活性的诸多因素。如何提高占灰渣总排量相当部分的飞灰的活性。除了提高煅烧温度外，还要保证适量的ＣａＯ，因为缺ＣａＯ的灰渣本身没有水硬胶凝性能，只有火山灰活性，我们让灰渣中存在适量的ＣａＯ后，在高温下ＣａＯ才能与灰渣中的ＳｉＯ２，Ａｌ２Ｏ３，Ｆｅ２Ｏ３等化合生成水硬性矿物成分，直接用于高标号水泥的生产     

国内外燃煤电厂二恶英排放及控制

原煤中二恶英含量极低,主要为煤燃烧过程中产生.对国内外燃煤电厂排放烟气和灰渣中二恶英排放情况进行调研,结果显示,火电行业二恶英大气和灰渣(飞灰、底灰、炉渣、烟尘和脱硫废物)排放状况相差较大,其大气排放质量浓度范围为0.365～1 400 pgI-TEQ/m~3,大气排放因子为0.002 04～6.2μgI-TEQ/t煤,灰渣中PCDD/Fs质量分数为0.02～52.6 ngI-TEQ/kg灰.通过火电企业大气和灰渣排放量,以及耗煤量,可得到大多数国家或地区燃煤电厂大气PCDD/Fs排放量为0～95 g I-TEQ/a范围,灰渣PCDD/Fs排放量也能达到相当的程度,燃煤电厂排放二恶英应引起关注.通过分析燃煤电厂PCDD/Fs生成条件,提出控制二恶英生成的策略.本研究对我国履行斯德哥尔摩公约(POPs公约),制定燃煤电厂二恶英排放标准和提高控制能力提供基础.     

Drought,ethanol, and livestock

The 2012 drought in the U.S. Midwest resulted in volatile crop prices. With field crops constituting a major input in livestock production, livestock producers sought a waiver to Renewable Fuel Standard biofuel mandates. They believed such a waiver would mitigate crop-price volatility; given crops are major inputs in biofuel production. The U.S. Environmental Protection Agency (EPA) denied the waiver under the belief that the waiver would have minimal if any impact on mitigating price volatility. Employing a VECM, the objective is to investigate if it was prudent for the EPA to reject the waiver. Results generally support EPA's conclusion that the waiver relaxing the biofuel mandate would have minimal impact.     

Providing all global energy with wind,water, and solar power,Part I: Technologies,energy resources,quantities and areas of infrastructure,and materials

Climate change, pollution, and energy insecurity are among the greatest problems of our time. Addressing them requires major changes in our energy infrastructure. Here, we analyze the feasibility of providing worldwide energy for all purposes (electric power, transportation, heating/cooling, etc.) from wind, water, and sunlight (WWS). In Part I, we discuss WWS energy system characteristics, current and future energy demand, availability of WWS resources, numbers of WWS devices, and area and material requirements. In Part II, we address variability, economics, and policy of WWS energy. We estimate that ∼3,800,000 5 MW wind turbines, ∼49,000 300 MW concentrated solar plants, ∼40,000 300 MW solar PV power plants, ∼1.7 billion 3 kW rooftop PV systems, ∼5350 100 MW geothermal power plants, ∼270 new 1300 MW hydroelectric power plants, ∼720,000 0.75 MW wave devices, and ∼490,000 1 MW tidal turbines can power a 2030 WWS world that uses electricity and electrolytic hydrogen for all purposes. Such a WWS infrastructure reduces world power demand by 30% and requires only ∼0.41% and ∼0.59% more of the world's land for footprint and spacing, respectively. We suggest producing all new energy with WWS by 2030 and replacing the pre-existing energy by 2050. Barriers to the plan are primarily social and political, not technological or economic. The energy cost in a WWS world should be similar to that today.     

Providing all global energy with wind,water, and solar power,Part II: Reliability,system and transmission costs,and policies

This is Part II of two papers evaluating the feasibility of providing all energy for all purposes (electric power, transportation, and heating/cooling), everywhere in the world, from wind, water, and the sun (WWS). In Part I, we described the prominent renewable energy plans that have been proposed and discussed the characteristics of WWS energy systems, the global demand for and availability of WWS energy, quantities and areas required for WWS infrastructure, and supplies of critical materials. Here, we discuss methods of addressing the variability of WWS energy to ensure that power supply reliably matches demand (including interconnecting geographically dispersed resources, using hydroelectricity, using demand-response management, storing electric power on site, over-sizing peak generation capacity and producing hydrogen with the excess, storing electric power in vehicle batteries, and forecasting weather to project energy supplies), the economics of WWS generation and transmission, the economics of WWS use in transportation, and policy measures needed to enhance the viability of a WWS system. We find that the cost of energy in a 100% WWS will be similar to the cost today. We conclude that barriers to a 100% conversion to WWS power worldwide are primarily social and political, not technological or even economic.     

Wood preparation, storage, and drying

The research cooperation in this activity has shown a fundamentally different attitude between the participating scientists in the scientific line of procedure considered.

One group proceeds pragmatically. The group has the opinion that drying progress in big chip stacks is determined by so many intercorrelated factors that it is practically impossible to work out mathematical models of the drying progress. Therefore, the group conducts full scale field trials.

Contrary to this attitude a more scientific line of procedure is maintained by other scientists. This line of procedure tries to establish the natural laws which determine drying of comminuted wood fuels. This is done by mathematical modelling and controlled laboratory experiments.

Both types of experiment are described in this paper.     

Energy,industry and politics: Energy,vested interests,and long-term economic growth and development

The article seeks to explicate a link between energy and long-term economic growth and development. While in many ways intuitive, attempts at sketching theoretical frameworks explicating this link have been few and simplistic, typically limited to technology and economics. This article emphasizes the importance of politics as well, fostering a symbiosis between the dominant industries of a historical epoch and the energy system that enabled them to flourish. The framework combines Joseph Schumpeter and Mancur Olson, emphasizing 1) the importance of structural economic change for long-term growth and development and 2) vested interests. The framework yields one theoretical proposition: In order to rise, states must prevent vested interests from blocking structural change. States that are unable to do this will get locked into yesterday's technologies, industries and energy systems, effectively consigning themselves to stagnation and decline. A brief empirical section provides historical data from 6 historical epochs (including present-day renewables) over a period of 250 years to demonstrate the usefulness of the approach. While no exhaustive test, the data suggests that countries that have prevented vested interests from blocking change have been far more successful in fostering a symbiosis between energy and industry than those countries that have not.