流化床式生物质快速热解设备监控系统的设计与开发

介绍了自主研发的喷动循环流化床式快速热解技术.通过对流化床式快速热解设备的温度、流量及压力监控方案的研究和设计,把计算机数据采集与控制技术应用于快速热解设备的工程实践中,实现了实时检测和半自动控制,使得热解反应效率提高,同时还增加了快速热解反应操作工艺的安全性.     

热解废水循环流化床焚烧工艺模拟研究

研究了煤热解分级利用多联产工艺产生的热解废水的循环流化床焚烧处理工艺。能量平衡计算结果表明,热解废水进入循环流化床燃烧炉,炉膛温度下降7.6℃。数值模拟了热解废水喷入流化床燃烧炉不同位置的4种工况,各工况炉膛出口温度均下降约16℃,2种计算方法虽有一定偏差,但误差在工程可控范围内。研究结果表明,热解废水送入循环流化床燃烧炉内焚烧的方案可行,能实现热解废水零排放。     

导向喷动流化床生物质快速热解技术

综述了生物质在导向喷动流化床反应器中快速热解的理论基础与过程特征,分别从反应机理、流体动力学特性与传热传质、二次裂解、气相和固相停留时间、操作相图、热解产物的收集与处理等方面进行阐述。比较了喷动流化床与其它流化床在快速热解上的异同,概述了导向喷动流化床生物质热解特性, 并提出了导向喷动流化床生物质快速热解技术的发展方向。     

油砂热解特性及工艺与装置研究开发现状与评述

油砂是一种储量巨大的非常规石油资源,油砂热解技术具有良好的工业化前景。本文概述了油砂热解的相关基础研究进展,包括油砂热解的3个阶段、气液固三相产物的性质及多种油砂热解动力学模型的总结。分析了常压干馏、惰性气体保护热解、加氢热解、减压热解及复合热解工艺,简述了不同工艺对产品收率和产品性质等方面的影响。回顾了油砂热解的装置,从固定床、旋转干馏炉、流化床干馏炉到Alberta Taciuk Process （ATP） 装置,重点介绍了具有不同载热方式和能量回收方式的旋转干馏炉和流化床干馏炉。从能源利用效率的角度分析对比了各种热解工艺和热解设备的优势与劣势,阐明了降低能耗提高能源效率是热解技术的主要问题,进而提出了旋转干馏炉和流化床干馏炉具有更好的工业前景。     

废轮胎热解技术研究

本文概述了国内外废轮胎热解技术研究的现状及发展趋势。国外废轮胎热解采用移动床、固定床、流化床、烧蚀床、悬浮炉和回转窑等反应器,有代表性的热解工艺包括真空移动床、两段移动床、流化床、连续烧蚀床和回转窑热解工艺等;通常热解炭被粉碎处理作为炭黑使用,热解油作为燃料油使用,废钢丝回收再利用。国内对废轮胎热解技术的研究大多局限于微型和小型试验台研究,产业化应用研究水平和国外相比较低,相对技术成熟的热解工艺还在进行研究试验中。开发经济性更佳、资源利用更彻底的热解工艺将是今后废轮胎热解技术研究的重点。     

煤在流化床反应器中的热解研究进展

流化床煤热解技术是一种操作简便、处理量大、适用范围广的煤转化手段。热解产品９气、液、固）可奶有价值的工业或原料。就流化床煤热解技术的研究作一介绍。     

50 MW循环流化床煤炭分级转化多联产技术开发

为了进一步推进煤炭热解分级转化多联产技术工业化应用,实现煤炭清洁高效资源化利用,通过试验研究和理论分析相结合的方法,利用1 MW流化床热解分级转化工业示范装置对煤炭热解分级转化产物的释放及其组分分布特性进行研究,分析了温度、煤种特性对挥发产物煤气产率、焦油产率、煤气组分、煤气热值等的影响,并对煤炭热解-燃烧双流化床协同耦合运行调控特性进行研究,最后以获得的1 MW流化床热解分级转化过程的相关产物转化特性参数及运行特性参数为基础,进行了50 MW循环流化床煤热解燃烧多联产工艺装置设计开发。结果表明,该装置煤气主要成分CH_4与H_2含量分别高达41.97%、28.32%,设计煤种条件下焦油产量3.16 t/h,煤气产量35 262 Nm~3/h,煤气热值达到26.7 MJ/Nm~3,焦油提取率达到90%以上,实现了较高的煤气热值与焦油回收率,为煤炭热解分级转化多联产技术工业化应用提供借鉴。     

流化床式生物质热解过程模拟研究进展

生物质能作为一种可再生的清洁能源,受到国内外研究者越来越多的关注。流化床式生物质热解转化技术是清洁高效转化利用生物质的新方法。本文在分析流化床式生物质热解过程的特征结构基础上,着重对各类热解流化床模拟进展进行了归纳总结。并提出了采用多尺度建模方法来提高生物质热解模拟的计算速度和精度,表明该类模型具有指导生物质热解过程优化与放大的应用潜力。     

废轮胎热解技术的现状及发展趋势

概述国内外废轮胎热解技术的研究现状及发展趋势,国外废轮胎热解采用移动床,固定床、流化床、烧蚀床、悬浮炉和回转窑等反应器,有代表性的热解工艺包括真空移动床,两段移动床、流化床、连续烧蚀床和回转窑热解工艺等;通常热解炭被粉碎处理作为炭黑使用,热解油作为燃料油使用,废钢丝网收再利用.国内对废轮胎热解技术的研究大多局限于微型和小型试验台研究,产业化应用研究水平相对于国外较低,尚末开发出技术成熟的中试规模以上的热解工艺.开发经济性更佳、资源利用更彻底的热解工艺将是今后废轮胎热解技术研究的重点.     

废塑料制取液体燃料试验研究

利用热解法将废塑料制成高品质液体燃料是资源回收和避免二次污染的重要途径。为此,设计了一套连续给料的鼓泡流化床反应器,对废塑料在鼓泡流化床中热解的关键工艺参数进行了试验研究。通过对试验数据的分析,得到了热解温度对液体产率的影响规律、气体产物的主要成分及其所占份额,并计算了废塑料热解过程的能量收支关系,为废塑料制取液体燃料的工业装置的设计、运行提供了理论及试验依据。     

聚合物系的挥发分脱除——起泡脱挥机理及模型

聚合物系的挥发分脱除(以下简称脱挥)是聚合物生产中的关键工艺之一。本文对国外有关聚合物系脱挥领域的文献作了综述,介绍了聚合物脱挥的基本概念,重点描述了起泡脱挥传质中气泡的成核、生长、破裂,气泡合并、凝聚的机理以及它们的表达式,并介绍了几种起泡脱挥的模型。     

Devolatilization characteristics of large particles of tyre rubber under combustion conditions

A systematic experimental study has been performed in order to investigate the effect of particle size and temperature on the devolatilization rate of large tyre rubber particles. Cylindrical tyre particles with diameters between 7.5 and 22 mm were devolatilised in a macro-TGA reactor, at temperatures between 490 and 840 °C in an inert atmosphere. The effect of particle size and surrounding temperature on the rate of devolatilization was observed to be significant, i.e. larger particle diameters and lower temperatures increased the devolatilization time. A detailed mathematical model for the devolatilization process including internal and external heat transfer, three parallel independent devolatilization reactions and reaction enthalpy effects has been developed and solved using an implicit finite difference method. Comparison of the model predictions with experimental data, reveals that the devolatilization process of large tyre rubber particles at temperatures above 490 °C can be considered to be controlled mainly by heat transfer and reaction kinetics. The model analysis further shows that exothermic devolatilization reaction enthalpy effects cannot be neglected in the prediction of the intra particle temperature rise. A sensitivity analysis of the model parameters, demonstrates that the specific heat capacity of the virgin fuel and the activation energies of the devolatilization reactions is the most important model parameters in the prediction of devolatilization times of large tyre rubber particles.     

Modelling and experimental investigation of devolatilizing wood in a fluidized bed combustor

A two-dimensional model is developed for the determination of devolatilization time and char yield of cylindrical wood particles in a bubbling fluidized bed combustor. By using the concept of shape factor, the model is extended to particles of cuboid shape. The model prediction of the devolatilization time agrees with the measured data (present and those reported in the literature) for cylindrical and cuboidal shaped particles within ±20% while the char yield is predicted within ±17%. Influence of some important parameters namely, thermal diffusivity, external heat transfer coefficient and shrinkage, on the devolatilization time and char yield are studied. Thermal diffusivity shows noticeable influence on devolatilization time. The external heat transfer coefficient shows little influence beyond a value of 300 W/(m² K). However particle shrinkage shows negligible effect on the devolatilization time but has a significant influence on the char yield.     

Characterization of the devolatilization rate of solid fuels in fluidized beds by time‐resolved pressure measurements

The characterization of volatile matter (VM) release from solid fuel particles during fluidized‐bed combustion/gasification is relevant to the assessment of the reactor performance, as devolatilization rate affects in‐bed axial fuel segregation and VM distribution across the reactor. An experimental technique for the characterization of the devolatilization rate of solid fuels in fluidized beds is proposed. It is based on the analysis of the time series of pressure measured in a bench‐scale fluidized‐bed reactor as VM is released from a batch of fuel particles. A remarkable feature of the technique is the possibility to follow fast devolatilization with excellent time‐resolution. A mathematical model of the experiment has been developed to determine the time‐resolved devolatilization rate, the devolatilization time and the volume‐based mean molecular weight of the emitted volatile compounds. Devolatilization kinetics has been characterized for different solid fuels over a broad range of particle sizes. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Devolatilization of large coal particles in fluidized beds

Analysis of devolatilization of predried large coal particles in fluidized beds requires consideration of both the chemical kinetics of coal decomposition and transport processes. Models available either assume the devolatilization particle to be isothermal (whereas it may be shown that, in general, large temperature gradients may exist within the particle) or require extensive numerical integration procedures. This Paper describes a model which permits formulation of analytical and easy-to-use equations for the estimation of the devolatilization history of a large predried coal particle in a fluidized bed. The model predictions are compared with experimental data collected for Mississippi lignite. A correlation is proposed for the estimation of the total devolatilization time. The analytical solutions presented may be used with ease in coupling the devolatilization process to the other phenomena, such as drying and/or combustion of volatiles and residual char, occuring during fluidized bed combustion of coal.     

双螺杆挤出机在高比例溶剂POE脱挥及挤压造粒中的应用

对双螺杆挤出机在聚烯烃弹性体（POE）制备过程中高比例溶剂脱挥及挤压造粒应用进行了介绍,并经过试验平台验证,探索出“可控分布脱挥技术”,通过脱挥过程中各个区段不同的工艺要求,设置不同的工艺温度和螺杆的组合排列,同时通过合理控制各个区段不同的真空要求;最终利用双螺杆挤出机将POE流体中的高比例溶剂（质量分数为75 %的溶剂）脱挥至50~200 ppm;同时,阐述了在脱挥过程中的技术关键点,这对大型双螺杆脱挥机组的设计起到了良好的技术支撑作用。     

Polymer Extrusion Devolatilization

Polymer devolatilization, including flash, surface renewal and stripping‐agent‐added techniques in screw extruders, is one of the most important polymer processing technologies. Its development requires an understanding of the relationships among some facts and subjects. Surface renewal devolatilization (SRDV) is a commonly used technique, which includes the two essential elements of film interface area and exposure time. A main feature of SRDV in various types of screw extruders is extrusion devolatilization, in which those elements vary with screw speed and throughput. An extrusion‐devolatilization model for SRDV model has been developed, which solves some important engineering problems encountered in devolatilization.     

聚合物高效脱挥技术进展

聚合物中挥发分含量的不同导致聚合物脱挥过程遵循不同的热质传递机理，基于脱挥过程关键机制开发高能效的聚合物脱挥技术与装备具有重要工程意义。本文分别简述了闪蒸脱挥、起泡脱挥以及扩散脱挥3种脱挥方式的传递机理、过程特征以及过程模型，在此基础上从脱挥工艺和装备两个方面综述了近年来聚合物脱挥过程强化的手段与方法，并系统介绍了栅缝降膜脱挥、超重力旋转强化脱挥、超临界流体辅助脱挥、超声空化强化脱挥等过程强化新技术及其应用现状，提出了未来聚合物脱挥理论与工程实践的研究方向：一方面仍需深入研究扩散脱挥与起泡脱挥的耦合作用机制，建立精准、普适的脱挥过程模型；另一方面指出立式降膜脱挥技术因其能效优势，有望成为未来大规模工业脱挥器的重要选择。     

Coal devolatilization in fluidized-bed combustors

Experimental data for devolatilization of coal in sizes and at operating conditions pertinent to fluidizedbed combustors are examined. The time for devolatilization is shown to be characteristic of a diffusion-limited situation. A model, in which the diffusion of the volatiles outwards through the char is the rate-controlling step, is shown to agree with the data.     

油页岩脱挥发分动力学的分布活化能模型解析

为了研究矿物质催化对油页岩脱挥发分行为的影响,文中利用热天平对桦甸油页岩脱挥发分行为进行了考察,采用分布活化能模型(DAEM)对其进行了动力学解析,结果发现,桦甸公河第4层和第5层油页岩脱挥发分过程中频率因子的对数lnA和活化能E之间的补偿效应发生了明显分段,活化能的变化趋势发生了改变。通过分析得出结论,矿物质催化作用改变了公河4层和公河5层油页岩脱挥发分过程中的络合物的性质,并使活化能有所降低,络合物性质的不同使补偿效应出现了明显分段,其中矿物质的催化作用对补偿效应影响较大。另外,活化能的变化趋势和补偿效应对判断催化反应具有一定的参考价值,补偿效应的折点是催化反应和非催化反应的分界点。