富甲烷气体的重整工艺研究

发布时间：2018-04-13 01:28

本文选题：甲烷重整 + 工艺条件　；参考：《安徽理工大学》2015年硕士论文

【摘要】：针对目前我国较为突出的环境问题,大量使用煤炭和石油作为能量来源并不符合国情发展。因此清洁的甲烷能源被人们所关注,尤其甲烷二氧化碳重整在制备合成气方面表现出良好的环境效益和经济效益,但催化剂积炭问题使得此技术无法实现大规模工业化,众多科研工作者从提升催化剂的抗积炭性能研究方向入手,但目前仍处于实验研究阶段。本实验则考虑到甲烷部分氧化重整和甲烷水蒸气重整的优势有助于改善甲烷二氧化碳重整反应性能,因此将甲烷二氧化碳重整、甲烷二氧化碳临氧重整和甲烷三重整作为研究的体系。实验中使用统一的Ni/MgAl2O4催化剂,甲烷重整工艺的模拟通过FSM-3060催化剂评价装置和气相色谱SP-6890联用的方式实现,在此装置中完成反应温度、原料气配比、空速对甲烷重整体系反应性能的影响的考察,根据转化率和选择性结果,总结实验规律并分析原因,并将各甲烷重整体系的实验结果作进一步的对比分析,从中找出甲烷重整的有利条件和不利因素。主要结论如下： (1)通过对甲烷二氧化碳重整工艺条件的研究发现：甲烷和二氧化碳转化率随着反应温度的升高而升高,一氧化碳与氢气选择性则降低。随着催化剂使用时间的延长,温度越高各性能指标下降速率越快,说明高温不利于甲烷二氧化碳重整反应；随着CH4/CO2配比的提高,甲烷转化率和一氧化碳选择性降低,二氧化碳转化率和氢气选择性升高；随着空速的提高,甲烷、二氧化碳转化率和氢气、一氧化碳选择性下降,说明空速对属于慢反应的甲烷二氧化碳重整反应影响较为明显。甲烷二氧化碳重整所制备的合成气中H2/CO体积比基本小于1,只有当CH4/CO2配比较高时,H2/CO体积比才出现大于1的情况。 (2)通过对甲烷二氧化碳临氧重整工艺条件的研究发现：甲烷、二氧化碳转化率随着反应温度的增加逐渐增加,尤其是低温条件下反应物转化率相比甲烷二氧化碳重整有明显的改善,说明氧气的加入有利于反应物转化率的提升。但高温条件下,反应物转化率和一氧化碳选择性随反应的进行依然下降较快,体系的稳定性依然较差。随着C02/02配比的提高,甲烷转化率和H2/CO体积比逐渐下降,二氧化碳转化率则逐渐提高,氢气和一氧化碳选择性出现增长；随着空速的增加,甲烷和二氧化碳转化率快速下降,产物选择性则出现增长。 (3)通过对甲烷三重整工艺条件的研究发现：随着反应温度的提高,反应物转化率相应增加,一氧化碳选择性和H2/CO体积比则降低。当温度为1073K,催化剂使用12h后,反应物转化率依然下降,但下降的幅度明显弱于其他两种体系,当温度较低时,体系稳定性和高效性也要优于另外两种体系,说明水蒸气形成消碳作用在一定程度上缓解了催化剂积炭效应,同时保留了反应物高转化率的特性。甲烷和二氧化碳转化率以及H2/CO体积比都随着O2/H2O配比的增加而增加,一氧化碳选择性则降低。空速的提高降低了反应物转化率,但是提高了产物选择性。
[Abstract]:In view of the outstanding environmental problems in China , the use of coal and petroleum as the source of energy is not in accord with the development of the national conditions . Therefore , the clean methane energy source is concerned , especially the methane - carbon dioxide reforming shows good environmental benefits and economic benefits in the preparation of synthesis gas , but the problem of catalyst carbon deposition makes the technology impossible to realize large - scale industrialization , and a large number of scientific research workers are starting from the research direction of the anti - carbon performance of the promotion catalyst , but are still in the experimental research stage .

In this experiment , the advantages of methane partial oxidation reforming and methane steam reforming are considered to improve the performance of methane carbon dioxide reforming reaction .

( 1 ) The conversion rate of methane and carbon dioxide is increased with the increase of the reaction temperature , and the selectivity of carbon monoxide and hydrogen is decreased .

With the increase of CH4 / CO2 ratio , methane conversion rate and carbon monoxide selectivity decrease , carbon dioxide conversion rate and hydrogen selectivity increase ;
With the increase of space velocity , the conversion of methane , carbon dioxide and hydrogen and carbon monoxide selectivity decrease , it is indicated that the effect of airspeed on methane carbon dioxide reforming reaction with slow reaction is more obvious . The H2 / CO volume ratio in the synthesis gas produced by methane carbon dioxide reforming is less than 1 , and only when CH4 / CO2 ratio is high , the H2 / CO volume ratio appears more than 1 .

( 2 ) The conversion of methane and carbon dioxide is increased with the increase of the reaction temperature , especially at low temperature . The conversion rate of the reactants and the selectivity of carbon monoxide are still decreased with the reaction , and the stability of the system is still poor .

With the increase of the ratio of CO2 / 02 , the conversion of methane and the ratio of H2 / CO volume gradually decreased , the conversion rate of carbon dioxide increased gradually , and the selectivity of hydrogen and carbon monoxide increased ;
With the increase of space velocity , the conversion rate of methane and carbon dioxide decreased rapidly , and the selectivity of products increased .

( 3 ) With the increase of reaction temperature , the conversion rate of the reactants increased correspondingly , the selectivity of carbon monoxide and the ratio of H2 / CO volume decreased . When the temperature was 1073K , the conversion rate of the reactants decreased , but the decrease was obviously weaker than that of the other two systems . When the temperature was lower , the stability and the efficiency of the system were better than that of the other two systems .

the conversion rate of methane and carbon dioxide and the H2 / CO volume ratio increase with the increase of the ratio of O2 / H2O , the selectivity of carbon monoxide is reduced , and the conversion rate of the reactants is reduced , but the selectivity of the product is improved .

【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE665.3

【参考文献】