摘要生物质作为一种可再生的能源成为人类未来能源的主要来源,但由于生物质具有 体积大,单位能量密度低等特点,故本论文致力于选取几种常见的生物质进行炭化, 探讨炭化时的原料种类、温度、升温速率对生物质焦的影响,并且同对制成的生物质 焦进行燃烧特性分析。81315
首先,选取了常见的几种生物质:稻壳、麦秸、木屑、竹子,将它们放到管式电 阻炉中,设定炭化温度分别为 300℃、400℃、500℃、600℃,升温速率为 5℃/min 和 10℃/min。其次,将制成的生物质焦在热重分析仪上做燃烧特性研究,画出各种生 物质焦的 TG、DTG、转化率曲线,并得出它们相应燃烧特性参数:燃尽温度、着火 点、最大燃烧速率、平均燃烧速率等。最后,选取几个具有代表性的生物质焦,在扫 描电镜下,观察其微观结构、测出所含元素的比例。
研究结果表明:从炭化质量收得率、炭化规律以及炭化成本角度可知,提高炭化 温度和升温速率,虽然质量收得率都有不同程度的下降,但由于其脱除的是挥发分的 质量。因此,炭化效果是提高的,确定 DKT-600-10、MJT-600-10、MT-500-10、ZT-600-10 这四种生物质焦炭化效果较佳,其质量收得率分别为 30。61%、25。73%、20。40%、 23。04%。生物质炭化升温速率对生物质焦的燃烧特性没有太大影响;炭化温度的升高 会降低稻壳焦和麦秆焦的燃尽温度,提高其着火点,而木焦和竹焦其燃尽温度和着火 点都会随着炭化温度的升高而升高。综合分析确定 DKT-500-5、MJT-500-5、MT-500-5、 ZT-500-5 这四种生物质焦的燃烧效果较好。通过对生物质焦进行 SEM 微观形貌和 EDS 能谱分析,确定稻壳焦、麦秸焦、木焦和竹焦的碳含量约分别为 73。69%、86。82%、 89。27%、93%。因此,认为木质类生物质更适合炭化。结合生物质的炭化效果和燃烧 特性以及炭化成本,确定 500℃炭化温度、5℃/min 升温速率的炭化工艺得到的四种 生物质焦 DKT-500-5、MJT-500-5、MT-500-5、ZT-500-5 的综合燃烧性能为最优。
毕业论文关键词:生物质;热解炭化;燃烧;生物质焦
Abstract The biomass as a renewable energy will become the main source of human energy future。 But because the biomass has large volume and unit of low energy density, so this paper is devoted to the selection of several common biomass of coking, and discusses the influence of biomass tar about the kinds of raw materials and carbonization temperature and heating rate, then with the biomass made of coke combustion characteristic analysis。
First ,Choose several common biomass: such as the rice husk, straw, wood, bamboo, and then place them into self-made tubular furnace, set carbonization temperature 300℃, 400℃ 500℃ and 600℃, the heating rate of 5℃/min and 10℃/min。 Second, Will be made from biomass tar combustion characteristic research on thermogravimetric analyzer, draw various kinds of biomass tar TG, DTG and conversion rate curve, and their corresponding
combustion characteristic parameters: the burning temperature, ignition, maximum combustion rate, average burning rate, etc。 Finally, Select a few representative bio char, under the scanning electron microscopy (SEM), the microstructure was observed and measured the ratio of the containing element。
The results showed that: From coking quality yield and carbonized regularity and cost perspective, found that increasing carbonization temperature and heating rate, although there are different levels of quality yield decline, But as a result of its removal is the quality of the volatile matter。 therefore, Carbonization effect is to improve, determine DKT
- 600-10, MJT - 600-10, MT - 500-10, ZT - 500-10 of these four types of biomass char effect is better, and the quality yield were 30。61%, 25。73%, 20。40% and 25。73% respectively。 Biomass carbonization heating rate will not much affect the combustion characteristic of biomass tar; Carbonization temperatures can reduce coke rice husk and straw burning temperature of the coke, improve the ignition, bamboo and wood tar and coke its burning temperature and ignition as carbonization temperature rises。 Comprehensive analysis to determine the DKT - 500-5, MJT - 500-5, MT - 500-5, ZT - 500-5 this four kinds of biomass of coke burning effect is better。 Through the biomass coke microstructure by SEM and EDS spectrum analysis, determine the focal, wheat straw, rice husk carbon content of coke, bamboo wooden coke and coke about 73。69%, 86。82%, 89。27% and 86。82% respectively。 Therefore, the thought of wooden biomass is more suitable for coking。 Combined with biomass carbonization effect and combustion