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1.
生物质等离子体气化研究   总被引:13,自引:0,他引:13  
在热等离子体提供的高温、高能量反应环境中,进行生物质的快速热解气化研究。生物质的等离子体热解气化产物由固体残渣和气体组成,无焦油存在。气体产物中主要以化学合成气(H2和CO为主。增加水蒸气流量,H2和CO含量之和均在96%以上,且V(H2)/V(CO)比率为0.90~1.15,气体产率达到2.0L/g,碳的气相转化率很高。  相似文献   

2.
TG-MS联用研究生物质的热解特性   总被引:1,自引:0,他引:1  
采用TG-MG技术研究稻秆、稻壳和玉米芯的热解特性。采用活化热解区与消极热解区法、热解特性指数法分析了3种生物质的热解特性,质谱分析重点关注热解过程中不凝性气体和焦油产物的形成。结果表明:(1)含木质素较低的秸秆类生物质在消极区的热解不活跃;在同升温速率下,3种生物质的热解难易程度为:玉米秆玉米芯稻秆;(2)含氧气体量大大高于烃类和H2,H2O是所有试样中的主要产物;在相同实验条件下,稻秆热解生成H2O最多,而生成焦油量最少;而玉米秆和玉米芯生成少量H2O和大量焦油;对于不可凝性气体产物,CO和CO2是主要的气体产物,而H2和CH4只占小部分;(3)焦油的主要产物为苯、甲苯和苯酚,除苯在550℃后还有析出外,其余芳香烃产物的析出范围均为300℃~550℃。  相似文献   

3.
高温移动床废轮胎与生物质直接热解制气性能研究   总被引:1,自引:0,他引:1  
对以不同比例组成的废轮胎与生物质均匀混合物在移动床内高温直接热解的制气性能进行了研究,考察了温度和废轮胎含量对产物产率、气体组分以及热值等影响。结果表明,温度对直接热解气产率和热值影响较大,温度越高,气体产率越大而热值越小;混合物中废轮胎含量增大,热解气中碳氢气体含量增多而含氧气体减少,气体产率逐渐减小而热值增大。温度升高,合成气(H2+CO)含量和H2/CO比值均增大;废轮胎含量增大,合成气(H2+CO)含量和H2/CO比值先增大后减小。当热解温度为1 000℃,废轮胎含量为35%时,热解产物中(H2+CO)含量最高为61%,且H2/CO的比值达到最大值为1.53,有利于作为工业合成气原料。同一温度下,混合物直接热解气热值远远高于生物质单独热解,说明废轮胎的掺入有助于优化热解气组成,提升燃气品质。  相似文献   

4.
以水蒸气为流化气在鼓泡流化床中进行木屑的热解特性研究,考察一些主要参数[如热解温度、生物质颗粒粒径、水蒸气/生物质(S/B)]对产气率和目标气体(H2,CO)产率的影响.试验结果表明,提高热解温度和降低生物质颗粒粒径有利于气体的产生;在热解过程中加入水蒸气,能提高气体产率,但是水蒸气的引入量有一个最佳值.本试验中产气率和H2,CO的产率都随着S/B的增加先上升后降低,适宜的S/B为2~2.5.  相似文献   

5.
连续式超临界水中煤/CMC催化气化制氢   总被引:6,自引:0,他引:6  
在向水煤浆中添加CMC(羧甲基纤维素钠),成功实现水煤浆高压均匀输送基础上,对超临界水中煤/CMC催化气化制氢性能进行了进一步研究。结果表明:在压力20~25MPa、停留时间15~30s、NaOH添加量0.1%、反应器外壁温650℃条件下,超临界水中煤/CMC催化气化制氢气体产物中H2摩尔含量远比常规气化高,主要气体产物是H2、CO2和CH4。增加物料中CMC的含量、升高压力均有利于提高气体产物中心的产量,延长停留时间虽有利于物料气化但不利于氢气的制取。  相似文献   

6.
城市生活垃圾气化产气特性实验研究   总被引:1,自引:0,他引:1  
在氮气、空气和富氧三种气氛条件下对城市生活垃圾气化过程进行实验研究,考察了温度、升温速率及反应气氛对城市生活垃圾气化的影响。总结出了城市生活垃圾气化过程中产生的CO,H2,CH4,CO2四种主要气体产物的体积分数在250~950℃的变化规律。氮气气氛下,在250~500℃的低温区段,CO气体的体积分数随升温速率的升高而降低;在500~950℃的高温区段,CO气体的体积分数随升温速率的升高而增加。H2在500℃之后才开始产生,其体积分数在500~950℃随升温速率的升高而增加。CO,H2,CH4三种气体在各个温度点处的体积分数都随气氛中氧气体积分数的增加而降低,而CO2气体在各个温度点处的体积分数则随气氛中氧气体积分数的增加而升高。  相似文献   

7.
利用惰性溶剂除去生物质中的可溶抽提物得到相应的抽提残渣,采用FT-IR对抽提残渣和生物质原样进行结构表征,并利用管式炉反应器以10℃/min的升温速率对抽提残渣和生物质原样进行热裂解实验,以了解它们的热裂解产物分布及热解规律。结果表明,抽提物的去除不会改变生物质的基本结构,对其热失重行为的影响也很小。热裂解三相产物中气体产物产率最大,达50%,其主要成分为H2,CO,CO2,CH4以及小分子烃类。与生物质原样相比,抽提残渣中的H2产率上升,而CO产率下降。液相产物中主要是酚类、烷烃类、四氢呋喃类、酮类、酸类、酯类、多环芳香类化合物和少量脱水单糖。其中酚类物质含量最多,超过55%。而且在抽提残渣的焦油产物中,酚类的总量和种类均比生物质原样多,其他类物质产率与生物质原样相比则有所减少。  相似文献   

8.
《可再生能源》2013,(10):92-97
针对生物质微波热解生物油产率低且含水量高,气体产物较为复杂的特点,通过实验对热解参数、堆积程度、传热介质3个方面进行考察研究。实验结果表明,在热解温度为600℃,预热温度为160℃,填充程度为100%的条件下得生物油最大产率为51.12%,生物炭产率为26.56%,合成气产率为22.32%;生物油以酚类化合物和呋喃类化合物为主,合成气以CO,H2,CH4,CO2,C2~C4小分子气体为主。  相似文献   

9.
宋翔 《节能》2013,32(2)
利用色谱分析技术对油泥-煤混合燃料热解产物的析出规律进行研究。研究表明油泥-煤混合燃料热解主要产物为H2、N2、CO2、CO、CH4、C2H6、C2H4、C3H8和C3H6。无机气体产量在热解温度900℃达到最大值,烃类气体产量在热解温度650℃达到最大值。热解产物产量在煤占混煤比例为40%时达到最大值。  相似文献   

10.
生物质合成气的化学当量比调整   总被引:2,自引:1,他引:1  
王铁军  常杰 《太阳能学报》2005,26(4):533-537
针对生物质气化气中硫化物少、V(H2/CO)低和V(CO2)高的特点,采用气化炉内铁系高温变换催化剂和气化炉外钛促进的钴钼耐硫催化剂进行水煤气变换调整H2/CO比,添加部分沼气重整过量CO2,对生物质合成气化学当量比调整进行了实验研究。结果表明:气化炉内铁系催化剂调整效果不明显;在高温低硫的生物质气化气中,钛促进的钴钼耐硫催化剂具有较高的变换活性,CO转化率达到80%以上,合成气H2/CO比在1-8范围内可调;在V(CH4,CO2)=1、常压、750℃和镍基催化剂作用下沼气重整过量CO2,制备出宽V(H2/CO)、V(CO2)和V(CH4)均低于5%(摩尔百分比)的合成气;通过水煤气变换过程结合沼气重整过程,可依据目的产物合成的要求,制备合适化学当量比、高碳转化率的生物质合成气。  相似文献   

11.
在小型流化床(50mm、高1600mm)实验装置上对沛城煤矿天然焦-蒸汽气化反应进行实验研究,考察蒸汽中掺入氧气,共同作为气化介质对气化反应产气量、碳转化率、煤气热值和煤气组分等因素的影响,同时与ASPENPLUS软件对其气化过程的模拟结果进行了对比。实验中,天然焦试样量0.2kg/h,蒸汽量1.05kg/h,气化温度900℃,实验结果表明:气化介质中氧量明显影响天然焦蒸汽气化特性。随着氧含量的增加,初始阶段(0~0.2L/min)煤气产量提高了1.76倍,碳转化率提高了1.94倍,两者均显著增加;随着氧量的进一步增加(0.2~1.0L/min),其增加幅度趋缓,产气量增加1.16倍,碳转化率增加1.34倍。煤气中有效气体(H2+CO+CH4)的体积分数和煤气热值均持续减少,有效气体份额从76.9%下降到54.3%,煤气热值从9.01MJ/m3减少到6.34MJ/m3,而CO2体积分数增加明显,从23.1%增加到37.3%。Aspen模拟结果与实验结果基本一致,具有实际指导意义。  相似文献   

12.
介绍了一种基于CO_2接受体气化法的生物质无氧气化制氢系统。采用热力学平衡模型,研究了以玉米秸这一典型生物质为原料时系统压力、温度、[H_2O]/[C]比、[Ca]/[C]比对制氢过程的影响规律。获得典型工况下,系统制氢效率对这几个参数的相对线性敏感性系数。结果表明,H_2浓度在一定范围内随压力升高而明显增大,同时H_2产量会有少量降低,过高的温度会明显降低H_2产量及浓度。综合考虑,合适的气化压力在1.3~2.5MPa之间,不同压力具有不同适合制氢的最高温度。[H_2O]/[C]比的提高可以促进H_2生成,但大于1.5之后,H_2浓度明显下降,合适的[H_2O]/[C]比在1.5~2.0之间。[Ca]/[C]比的增加有利于H_2产量及浓度的提高。线性敏感性系数的计算表明,计算工况下[H_2O]/[C]比对制氢效率的影响非常大,压力和温度的影响也比较显著,[Ca]/[C]比的影响为零。  相似文献   

13.
In this work, the relation between hydrogen-rich syngas production and the gasification parameters such as equivalence ratio (ER), gasification temperature and biomass moisture content were studied. Stoichiometric equilibrium model that developed during this study was used to investigate the optimum hydrogen output generated from woody biomass in a fixed bed downdraft gasifier by considering the thermodynamic equilibrium limit. The mathematical model, based on thermodynamic equilibrium is necessary to understand complicated gasification process that will contribute to obtain maximum attainable hydrogen production. The effects of different oxidizing agents on the hydrogen concentration in the product gas as well as the effect of various air-biomass, oxygen-biomass and steam-biomass ratios were investigated. For validation, the results obtained from the mathematical model were compared with the experimental data obtained from the gasifier that uses air as gasification medium. The validated mathematical model was used to represent the gasifier that uses both oxygen and air-steam mixture as the gasification medium and the theoretical results were obtained for both cases. The theoretical results clearly show that the gasification process specially ones that use the air-steam mixture as the gasification medium can be used for hydrogen production.  相似文献   

14.
林良生  赵长遂 《热能动力工程》2012,27(3):355-360,395,396
运用Aspen Plus软件平台对天然焦-H2O气化反应进行了热力学模拟计算,研究了反应碳份额、水蒸气流量、反应温度、压力和反应气氛对天然焦气化反应煤气成份、热值的影响。结果表明,RYIELD模块在整个模拟系统中能很好地描述天然焦"热解"过程;水蒸气流量1.16 kg/h是天然焦完全气化的临界点;增大温度和压力能有效促进气化和改善煤气的品质,但并非越大越好,综合考虑下,实际运行的温度和压力宜分别在850~1 000℃和0.1~6.0 MPa范围内选定;不同的反应气氛下,天然焦气化反应特性有很大差异,在水蒸气气氛下能获得更好的煤气品质。  相似文献   

15.
A novel system of hydrogen production by biomass gasification in supercritical water using concentrated solar energy has been constructed, installed and tested at the State Key Laboratory of Multiphase Flow in Power Engineering (SKLMF). The “proof of concept” tests for solar-thermal gasification of biomass in supercritical water (SCW) were successfully carried out. Biomass model compounds (glucose) and real biomass (corn meal, wheat stalk) were gasified continuously with the novel system to produce hydrogen-rich gas. The effect of direct normal solar irradiation (DNI) and catalyst on gasification of biomass was also investigated. The results showed that the maximal gasification efficiency (the mass of product gas/the mass of feedstock) in excess of 110% were reached, hydrogen fraction in the gas product also approached to 50%. The experimental results confirmed the feasibility of the system and the advantage of the process, which supports future work to address the technical issues and develop the technology of solar-thermal hydrogen production by gasification of biomass in supercritical water.  相似文献   

16.
In this article, an equilibrium model based on Gibbs free energy minimisation is presented for steam gasification of biomass in process simulator ASPEN PLUS. Carbon is assumed as fully converted into product gases and no tar content is assumed to be present in gaseous product. The objective is to arrive at the optimum process conditions of gasification. An analysis on the sensitivity of producer gas composition, lower heating value, combustible gas yield, and first and second law efficiencies on gasification process variables including reactor temperature, pressure and steam to biomass mass ratio is also envisaged. Simulations are performed with wood as the biomass material, based on real gas behaviour for product gases and gasifying medium. The predicted results of the model are compared with another Gibbs free energy model formulated using simulated annealing minimisation algorithm. The present ASPEN PLUS model is validated with published experimental results on steam gasification on a fluidised bed gasifier.  相似文献   

17.
Partial oxidative gasification in supercritical water is a new technology for hydrogen production from biomass. Firstly in this paper, supercritical water partial oxidative gasification process was analyzed from the perspective of theory and chemical equilibrium gaseous product was calculated using the thermodynamic model. Secondly, the influence of oxidant equivalent ratio on partial oxidative gasification of model compounds (glucose, lignin) and real biomass (corn cob) in supercritical water was investigated in a fluidized bed system. Experimental results show that oxidant can improve the gasification efficiency, and an appropriate addition of oxidant can improve the yield of hydrogen in certain reaction condition. When ER equaled 0.4, the gasification efficiency of lignin was 3.1 times of that without oxidant. When ER equaled 0.1, the yield of hydrogen from lignin increased by 25.8% compared with that without oxidant. Thirdly, the effects of operation parameters including temperature, pressure, concentration, and flow rate of feedstock on the gasification were investigated. The optimal operation parameters for supercritical water partial oxidative gasification were obtained.  相似文献   

18.
An analysis of high temperature gas cleaning systems for cleaning the product gas of biomass gasification for fueling solid oxide fuel cells (SOFCs) is presented. Influence of biomass derived contaminants on SOFCs is briefly presented and the removal of potential contaminants such as tar, particulates, H2S and HCl, alkali compounds from biosyngas is reviewed. It appears that the gasification product gas can be cleaned to meet the requirements of SOFCs based on Ni/GDC anodes at high temperatures (typically in the range of 1023–1223 K) by using currently known gas cleaning methods. Although information from literature, results from chemical equilibrium studies and preliminary experiments were sufficient to put forward a conceptual design for a high temperature gas cleaning system, detailed experimental investigations are still required. This is needed to obtain detailed information on contaminant tolerance of SOFCs, and to arrive at detailed designs of gas cleaning units that are economically viable for biomass gasifier-SOFC systems.  相似文献   

19.
于海龙  刘建忠 《动力工程》2007,27(5):820-824
对石油焦水煤浆(PCCWS)在多喷嘴新型水煤浆气化炉内的气化过程进行了数值计算,考察了气化炉内的温度分布、各种气化产物浓度分布规律.结果表明:同浓度的石油焦水煤浆气化与普通水煤浆气化相比,气化炉内平均温度略有上升,碳转化率提高,气化炉出口粗煤气中有效气(CO H2)含量提高7.91%,CO2和H2O浓度大幅下降,水分解率大大提高;石油焦水煤浆气化可以节约氧气约6%,气化效果明显优于普通水煤浆.  相似文献   

20.
Simulation of gasification of high‐ash Indian coal in an updraft moving bed gasification system is presented in this paper. A steady one‐dimensional numerical model, which takes into account of drying, devolatilization, combustion and gasification processes, is used to solve the mass and energy balances in the gasification system. The results from the model have been validated against the experimental data available in literature for various types of coals. The predicted product gas composition, its calorific value and the exit temperature are in agreement with the reported results. The validated model is used to study the effect of input parameters such as oxygen content in air stream, steam flow rates and the pressure of the gasification system. Results indicate that the value of oxygen mole fraction around 0.42 in the oxidizer stream can provide optimum performance in oxygen‐based gasification systems. There is a range of steam‐to‐coal ratio that is dependent on the oxygen content in oxidizer stream. For air‐based systems, this value is around 0.4 and for oxygen‐based systems it is 1.5. The gasification performance improves with operating pressure significantly. An operating pressure of around 8 bar and higher, based on the application, can be used for achieving the required performance with high‐ash coals. The model is useful for predicting the performance of high‐ash Indian coals in a moving bed gasification system under different operating parameters. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

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