生物质与美煤合气化炉基础设计参数实验研究

发布时间：2018-06-01 06:59

本文选题：生物质 + 煤　；参考：《沈阳工程学院》2015年硕士论文

【摘要】：世界能源形势的日趋紧张,生态环境给人类带到的灾难越来越严重,积极合理开发利用无污染的绿色新能源是解决问题的重中之重。生物质能作为唯一的碳基绿色能源,正日益受到全世界的瞩目。洁净高效利用生物质能源,对于建立多元能源体系、维护生态系统平衡、保证社会经济的可持续发展有着重要的现实意义。生物质与煤混合气化技术,不仅减少了化石能源的消耗,同时合理地利用了生物质能源,符合国家可持续发展的战略要求。天津某公司根据天津市政府的规划,在循环经济区建设煤气化装置,同时要煤气化装置能够处理附近棉田出产的棉杆和木耳养殖业产生的废料碎木屑。为了对煤气化装置的设计提供基础设计参数支持,委托沈阳工程学院生物质利用沈阳市重点实验室分析棉杆/木屑与煤共气化/热解过程中的相互作用情况。结合国内外生物质与煤共热解气化的研究进展,本文以生物质(棉杆、木屑)和褐煤为研究对象,在不同工况条件下(热解气氛、升温速率、混合方式)深入研究生物质与煤共热解过程中相互作用。首先对生物质(棉杆、木屑)和煤进行单独热解实验,改变热解过程的气氛和升温速率,得出各热解过程的TG曲线。结果表明:在N2气氛下的热解过程,生物质和煤的主要热解温度区间差异较大,棉杆(250～350℃)、木屑(280～400℃)、煤(400～500℃);在气化气氛下的热解过程,棉杆在800℃以后发生二次气化反应,而木屑和煤均则没有发生二次反应;升温速率对于生物质和煤的单独热解过程影响不明显。然后进行生物质与煤混合热解的热重实验,改变热解过程的气氛、升温速率及混合方式,得出各工况下共热解过程的TG曲线。将生物质和煤单独热解过程的各温度点的实验数据按混合比例进行折算,得到共热解过程的理论值,用实验值减去理论值得出差值,绘制出差值曲线,通过观察对比差值曲线,得出共热解过程中相互作用的产生及改变。结果表明:N2气氛下,升温速率为60℃/min,采用均匀混合方式时,棉杆与煤共热解过程中的协同作用表现最强烈,在350℃达到峰值;木屑与煤共热解过程中,升温速率在20℃/min时,抑制作用表现最小,随着升温速率的增加,均在360℃时表现出强烈的抑制作用。气化气氛下,木屑与煤共热解过程,在360℃左右表现出微弱的协同作用,过程中相互作用整体表现不明显;棉杆与煤共热解过程,均在900℃时协同作用表现强烈,且均匀混合时达到最大。对上述各实验过程进行反应动力学分析,采用Coats-Redferm法得出各热解过程的活化能E值。结果表明:单独热解时,各工况条件下煤热解过程的E值均高于生物质,木屑热解过程中的E值均略高于棉杆;升温速率的增加,生物质与煤的共热解过程表现出活化能增加的趋势;混合方式对于共热解过程中的活化能没有显著影响,但混合热解过程中的活化能均低于生物质和煤的单独热解。最后深入探讨研究生物质与煤共热解过程中相互作用的产生机理,以及不同因素对于相互作用的影响。从碱金属、气氛、温度及升温速率这四个方面分析对相互作用的影响机理,主要体现在活化能、最大热解速率、催化反应、碳原子晶格结构及排列方式、颗粒结构等方面的变化,从而最终表现出不同的结果。本文结合实验数据,对生物质与煤混合气化过程中煤的气化速度和煤单独气化进行分析对比。首先根据各热解过程的TG曲线求出气化速度,然后分析各种情况下煤主热解温度区间内的气化速度,最后求出共气化过程煤的气化速度较煤单独气化时的速度变化相对量。棉杆与煤共气化过程中煤的气化速度较煤单独气化过程中煤的气化速度大约提高了 4.2%～9.1%;木屑与煤共气化过程,大约提高了 8.3%～10.6%。
[Abstract]:The energy situation in the world is becoming more and more tense. The ecological environment has brought more and more serious disasters to mankind. It is the most important problem to actively rationally develop and utilize the new green energy without pollution. As the only carbon based green energy, the biomass energy is becoming more and more attractive to the whole world. The meta energy system, maintaining the balance of the ecosystem and ensuring the sustainable development of the society and economy is of great practical significance. Biomass and coal gasification technology not only reduces the consumption of fossil energy, but also makes use of biomass energy rationally. It is in line with the strategic requirements of the national sustainable development. A company in Tianjin is based on the government of Tianjin. The plan is to build a coal gasification unit in the circular economy area, and at the same time, the coal gasification unit can handle the scraps of scrap wood produced by the cotton rod and the wooden ear breeding industry produced by the nearby cotton field. In order to provide the basic design parameters for the design of the coal gasification plant, the Shenyang Institute of Engineering bioquality is entrusted to the Key Laboratory of Shenyang to analyze the cotton rod / sawdust. In the process of CO gasification / pyrolysis of coal, combined with the research progress of CO thermal decomposition of biomass and coal at home and abroad, biomass (cotton rod, wood chip) and lignite are studied in this paper. The interaction between biomass and coal during CO pyrolysis under different conditions (pyrolysis atmosphere, heating rate, mixing mode) is studied. The pyrolysis experiments of biomass (cotton rod, wood chip) and coal were carried out to change the atmosphere and heating rate of the pyrolysis process, and the TG curves of the pyrolysis process were obtained. The results showed that the main pyrolysis temperature range of biomass and coal in N2 atmosphere was different, the cotton rod (250~350), wood chips (280~400 degrees C) and coal (400~500 degrees C); In the process of pyrolysis in the atmosphere of gasification, the cotton rod has two gasification reactions after 800 C, while the wood and coal have no two reactions. The heating rate has no obvious influence on the separate pyrolysis of biomass and coal. Then, the thermogravimetric experiment of biomass and coal pyrolysis is carried out to change the atmosphere, heating rate and mixing of the pyrolysis process. The TG curves of CO pyrolysis under various working conditions are obtained. The experimental data of each temperature point in the pyrolysis process of biomass and coal are converted to the theoretical value of the co pyrolysis process. The theoretical value of the co pyrolysis process is obtained. The theoretical value is reduced by the experimental value, and the travel value curve is drawn and the difference curve is passed through the observation and contrast, and the co pyrolysis process is obtained. The result shows that the heating rate is 60 /min under the atmosphere of N2, the synergistic effect of the co pyrolysis of the cotton rod and coal is the strongest and the peak value is reached at 350 C when the co pyrolysis of the coal is used in the process of CO pyrolysis. In the gasification atmosphere, the co pyrolysis process of wood chips and coal showed a weak synergistic effect at about 360 C, and the overall performance of the interaction was not obvious in the process of gasification. The co pyrolysis of cotton rod and coal was both strong at 900 C and reached the maximum at the time of uniform mixing. The reaction kinetics analysis was carried out in the experiment, and the activation energy E value of each pyrolysis process was obtained by Coats-Redferm method. The results showed that the E value of coal pyrolysis process was higher than that of biomass under the condition of separate pyrolysis. The E value in the pyrolysis of wood chips was slightly higher than that of the cotton rod; the rate of heating rate increased and the co pyrolysis of biomass and coal showed the process of pyrolysis. The activation energy is increasing, and the mixing method has no significant effect on the activation energy in the co pyrolysis process, but the activation energy in the mixed pyrolysis process is lower than the pyrolysis of biomass and coal. Finally, the mechanism of the interaction of biomass and coal in the process of CO pyrolysis and the influence of different factors on the interaction are discussed. From the four aspects of alkali metal, atmosphere, temperature and heating rate, the influence mechanism of the interaction is analyzed, which is mainly reflected in the changes of activation energy, maximum pyrolysis rate, catalytic reaction, lattice structure and arrangement of carbon atoms, particle structure and so on, and finally shows different results. The gasification rate of coal and coal gasification in the mixed gasification process are analyzed and compared. First, according to the TG curve of each pyrolysis process, the gasification speed is calculated. Then the gasification rate in the main pyrolysis temperature range is analyzed. Finally, the gasification rate of coal in the process of CO gasification is compared with that of the coal gasification. The gasification rate of coal in the process of CO gasification of rod and coal is about 4.2% ~ 9.1% higher than that of coal in the process of coal gasification alone. The process of CO gasification of wood and coal has increased by about 8.3% ~ 10.6%..
【学位授予单位】：沈阳工程学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK6;TK175

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