钾对生物质超临界水气化过程典型中间产物转化影响研究

Biomass gasification in supercritical water (SCW) is one of the trends in converting biomass energy into hydrogen energy. This approach has advantages of high efficiency, less secondary pollution, low energy consumption and so on. Because of the high complexity of biomass gasification in SCW, it is difficult to achieve the large-scale industrial applications at present. Potassium is the active element with a high content in inorganic compositions. Studies on the effects of potassium existing in biomass on typical intermediates gasification conversion are conductive to fully understanding the biomass gasification mechanism in SCW. By combining experiment with theory, studies will be carried on systematically. First of all, the experimental study on real biomass gasification in SCW will help to ascertain the main species of potassium and their relationship with the process conditions, which will also provide the corresponding basis for follow-up study. Then the influence extent and law of potassium on the typical intermediates will be explored. And based on the chemical kinetic theory, the macro kinetic model will be established. Finally, using Gaussian03 which is the classical quantum chemistry calculation software, the micro mechanism of the gasification conversion will be analyzed. The realization of this project can provide some preliminary theoretical foundation and key data for the industrial applications of this technology.

在超临界水中，将生物质能转化为清洁的氢能是当前发展趋势之一。该制氢方法具有效率高、二次污染少、能耗低等优点，然而由于生物质超临界水气化工艺的高度复杂性，目前无法实现大规模工业集成应用。钾是生物质中含量较高的活性无机成分，研究生物质中钾对生物质超临界水气化过程典型中间产物转化的影响有利于认识生物质超临界水气化转化过程及机理。本项目拟研究生物质超临界水气化转化过程中钾的存在规律，确定钾的主要存在形式及其与反应过程条件的关系，并以此为基础，获得钾对典型中间产物超临界水气化转化的影响程度和规律，建立钾对典型中间产物气化转化过程影响的宏观动力学模型。同时采用量子化学理论，对典型中间产物气化转化过程及钾作用的重要路径进行微观动力学及微观反应机理分析。本项目的实现可为该技术的工业应用提供理论基础和关键数据。

钾是生物质中含量较高的活性无机成分，研究钾对生物质超临界水气化过程典型中间产物转化的影响有利于认识生物质超临界水气化转化过程及机理。本项目选择了乙醛、乙醇、水气变换过程为研究对象，实验及理论研究了钾等碱金属成分对其超临界水转化过程及产物的影响。在理论研究中，采用集总动力学和量子化学计算耦合的方式，对其影响的宏观和微观过程进行了分析。通过开展以上研究工作，构建了适合水气变换反应的实验体系；获得了钾、钠等碱金属对水气变换反应的影响程度及规律；揭示了钾对乙醛超临界水气化转化过程及产物的影响程度及规律；初步认识了钾对乙醇超临界水气化产物的影响程度。本项目的开展为超临界水气化技术的研究和应用提供了基础数据和理论指导。