木质素在生物质炭尿素肥料中的应用研究

发布时间：2018-05-20 20:17

  本文选题：木质素 + 粘结剂　； 参考：《东北农业大学》2015年硕士论文

【摘要】：我国是农业生产大国,每年大量的农作物秸秆等得不到有效处理,加剧环境污染。秸秆的性质更适合资源化利用—还田处理。生物质炭能够改善土壤的性质,能够长期储存,作为长效的土壤改良剂具有良好前景。目前热解技术生产的生物质炭多为粉末状,给运输、储藏和施用等带来不便。成型对生物质炭的利用尤为必要,本文以木质素为粘结剂,分别制备了柱状生物质炭基尿素和生物质炭包膜尿素,研究其工艺条件,并对得到的生物质炭肥料进行了力学、缓释性质的测定,具体工作如下:(1)对木质素进行工业分析、元素分析及热力学性质的测定,并对经过不同溶剂改性后的木质素进行表征分析、红外光谱分析及差热分析,发现经过不同溶剂处理后的木质素分子结构发生改变;同时研究了木质素含量、加热温度和尿素含量对不同溶剂条件下的溶液体系黏度的影响,发现溶剂不同,各因素对溶液体系黏度的影响也不同。(2)用热压成型的方式制备了柱状生物质炭基尿素,选择质量比1:1的生物质炭和尿素配比进行研究,讨论粘结剂的含量、成型温度、成型压强等因素对生物质炭基尿素力学与缓释性能的影响,结果表明粘结剂的加入能够防止生物质炭基尿素表面爆裂,且能增强力学与缓释性能;生物质炭基尿素力学及缓释性能随着木质素添加量及成型压力增加呈增强趋势,随着成型温度增加呈现先增强后减弱趋势,成型温度为70℃时性能最优;同时生物质炭基尿素周围土壤脲酶活性随木质素含量增加而降低,制备的生物质炭基尿素对土壤脲酶活性有抑制作用。(3)选择了乙醇和木醋液两种溶剂对木质素改性,制备两种木质素粘结剂,并运用圆盘造粒机对尿素用生物质炭进行包膜,对得到的两种生物质炭包膜尿素进行了成粒性能、力学及缓释性能测试,结果表明:以木质素-木醋液粘结剂制备的包膜尿素的造粒率比以木质素-乙醇为粘结剂的包膜尿素高12~24%,包膜率高34~42%,且粒径分布的均匀性较好,力学与缓释性能也较好。(4)利用改性粘结剂制备生物质炭包膜尿素,研究发现以木质素-木醋液粘结剂制备生物质炭包膜尿素随着烘干温度的提高,成粒率和包膜率略有升高,生物质炭包膜尿素含氮量降低,力学及缓释性能随着烘干温度升高呈现先升高后降低趋势,65℃时性能较好;随着粘结剂含量增加,生物质炭包膜尿素成粒率及包膜率也增加,含氮量相应的降低,其力学性能与缓释性能也随之降低;随着固液比的升高,其包膜率逐渐降低,而其成粒率呈现先升高后降低的趋势,含氮量随着固液比的降低而降低,抗压力及缓释性能呈现先升高后降低的趋势。
[Abstract]:China is a large agricultural production country, a large number of crop stalks can not be effectively treated every year, aggravating environmental pollution. The nature of straw is more suitable for resource utilization-return treatment. Biomass carbon can improve the properties of soil and can be stored for a long time. At present, biomass carbon produced by pyrolysis technology is mostly powdered, which brings inconvenience to transportation, storage and application. It is particularly necessary to utilize biomass carbon by briquetting. In this paper, columnar carbon-based urea and coated urea were prepared with lignin as binder, and the process conditions were studied. For the determination of slow-release properties, the specific work is as follows: (1) Industrial analysis, elemental analysis and thermodynamic determination of lignin, characterization and analysis of lignin modified by different solvents, infrared spectrum analysis and differential thermal analysis. The effects of lignin content, heating temperature and urea content on the viscosity of solution system under different solvent conditions were studied. The effects of various factors on the viscosity of the solution system were also different.) the columnar biomass carbon-based urea was prepared by hot pressing. The ratio of biomass carbon to urea at 1:1 mass ratio was studied. The content of binder and molding temperature were discussed. The effect of molding pressure on the mechanical and sustained release properties of carbon-based urea was investigated. The results showed that the addition of binder could prevent the surface of carbon-based urea from bursting and enhance the mechanical and slow-release properties. With the increase of lignin content and molding pressure, the mechanical properties and slow-release properties of carbon-based urea increased, and then weakened with the increase of molding temperature, and the best performance was obtained at 70 鈩，

本文编号：1916076