摘要随着化石能源的日益枯竭，以及使用化石能源产生的环境问题日益严重，迫切需 要寻求一种清洁能源来减少环境的污染。生物质能属于清洁能源，有助于我国的环境 建设和 CO2 减排，生物质焦作为一种可再生能源具有很好的发展前景。83549

文中采用差热分析仪对不同生物质焦、煤粉及其混合物进行气化反应实验，并对其动力学进行分析，考察不同 CO2 流量、气化终温、不同煤粉混合比例等对生物质 焦混煤 CO2 气化反应过程中的碳转化率、气化反应速率等气化特性的影响。并利用 扫描电子显微镜对生物质焦和煤粉的表面形貌进行分析。研究结果表明：

（1）生物质焦的孔隙非常发达，其气化特性比煤粉好，而木质焦的气化性又比 竹焦好。在相同的条件下，木质焦完成气化反应的时间最短，反应速率最快。接下来 分别是竹焦、烟煤和无烟煤。

（2）随着 CO2 浓度的增加，木质焦和竹焦的转化率逐渐增大，达到相同转化率 所需要的时间不断减少。当 CO2 流量大于 100ml/min 后，随着流量的增加明显改善 CO2 反应特性。

（3）随着气化温度的提高，木质焦与无烟煤的转化率均增加，直至最大值。无 烟煤在 900、1000、1100 和 1200℃下的转化率分别达到 0。11、0。20、0。54 和 1。00。而 木质焦在 900℃下的转化率为 0。42，1000℃下的转化率几乎已经达到最大值。

（4）随着混合物中烟煤或者无烟煤掺混比例的增加，气化反应完全结束的温度 越来越高，最快气化速率值有所降低，同时曲线也越来越趋近于单一煤粉气化的曲线。 由此可见，烟煤或者无烟煤的存在能够提高气化反应温度，并降低气化速率。随着反 应的进行，反应速率随着转化率的增大而增大，但当转化率达到 0。9 后，反应速率值 急剧降低。

（5）采用 Coats-Redfern 法对木质焦掺混烟煤气化反应动力学进行分析，得到木 质焦和烟煤的活化能分别为 76。18kJ·mol 和 154。84kJ·mol。共气化过程中的活化能均 比木质焦和烟煤单独气化时的活化能小，说明生物质焦混煤更容易气化。

毕业论文关键词：热重分析；生物质焦；煤；气化；特性

Abstract With the increasing depletion of fossil energy and the increasingly serious environmental problems caused by the use of fossil fuels, it is urgent to seek a kind of clean energy to reduce environmental pollution。 Biomass energy belongs to clean energy, which is helpful to the environmental construction of our country and the CO2 emission reduction。 Biomass char is a kind of renewable energy and has a good development prospect。

In this paper the differential thermal analyzer is used to do some gasification reaction experiments with different biomass chars, coals and co-gasification of their mixtures and and their dynamics are analyzed。 The effects of different reaction conditions (different CO2 flow rates,final temperature of gasification and different mixing proportions of pulverized coal) on the characteristics of CO2 gasification (the carbon conversion and gasification reaction rate) in the process of CO2 gasification of biomass char were investigated。 Meanwhile,the surface morphology of biomass char and coals were analyzed by scanning electron microscope (SEM)。 Results of the research are shown as follow:

(1)The gasification characteristics of biomass char with high porosity are better than that of coals, and the gasification of woody char is better than that of bamboo char。Under the same conditions, the woody char completes gasification reaction in the shortest time and its reaction rate is the fastest。 The next is bamboo char, bituminous coal and anthracite, respectively。

(2)With the increase of CO2 concentration, conversion rate of woody char and bamboo char increases gradually and time required to achieve the same conversion decreases continuously。 When the flow rate of CO2 is more than 100ml/min, the CO2 reaction characteristics are improved obviously with the increase of the flow rate。