生物质循环流化床燃烧灰中元素分布和迁移特性研究

EXPERIMENTAL STUDY ON ELEMENT DISTRIBUTION AND TRANSFER CHARACTERISTICS OF BIOMASS COMBUSTION IN CIRCULATING FLUIDIZED BED

以小麦秸秆、棉秆、玉米秸秆和皇竹草为研究对象,在0.15MW t循环流化床试验装置上进行生物质循环流化床燃烧试验,利用电感耦合等离子体发射光谱仪(ICP-OES)和离子色谱仪对试验前后床料、飞灰和循环灰元素进行检测分析,研究生物质灰中特有的碱金属、碱土金属元素以及S、Cl等元素的迁移分布特性。结果表明:生物质中的K元素主要分布在飞灰中,循环灰中的K含量高于床料中;飞灰中K、S和Na等元素主要为水溶性,小麦秸秆和皇竹草试验的床料和循环灰中水溶性K、S和Na元素含量较高;飞灰中Cl-、SO2-4含量较高,相比于其他两种生物质燃料,皇竹草和小麦秸秆循环灰中Cl-、SO2-4含量较高。

Taking corn stalk, teristics of biomass were inves wheat straw, cotton stalk and king grass as research subjects, the combustion charac-tigated in a 0.15MWt circulating fluidized bed combustor. In order to study the ele-ment distribution and transfer characteristics of alkali metal, alkali earth metal, sulfur and chlorine in the fuel, in-ductively coupled plasma-optical emission spectroscopy （ICP-OES） and ion chromatograph were used to measure the amount of all the element compounds in bed materials, bottom ash, circulating materials and fly ash. The re-sults show that there is high content of K in fly ash, and the circulating materials contain more K than bed materi-als. The K, S and Na in fly ash are mainly water soluble, and also these four water soluble elements are found to be highly contained in bed materials and circulating ash of wheat straw and king grass. The Cl^-, SO4^2- are mainly in fly ash, and compared with corn stalk and cotton stalk, there is higher content of Cl^-, SO4^2- in the circulating mate- rials of wheat straw and king grass.