添加剂对煤气化过程中石灰石固硫行为的影响

EFFECT OF ADDITIVE ON SULFUR CAPTURE BY LIMESTONE DURING COAL GASIFICATION

为了研究添加剂在石灰石固硫过程中的作用，选择了一系列添加剂对含不同氧化镁的二种石灰石进行改性，采用ＸＲＤ、ＸＰＳ及ＤＴＡＴＧ技术，研究了石灰石改性前后及煤气化过程中固硫反应前后钙基固硫剂的结构、表面组成及热性能，并与固硫特性相关联。实验得出：无机氯化物及一系列钠盐对石灰石的固硫能力具有不同程度的影响，其中氯化钠的促进作用最明显，其添加量有一最佳值；氯化镁及氢氧化钠具有负作用。添加剂通过影响石灰石的热分解性能及其气化残物的表面组成而起作用，对石灰石的结构影响较小。

In order to promote the sulfur capture capacity by calciumbased sorbents during coal gasification, a series of tests were carried out with limestones soaked by a series of saline solution The function of additives on limestone was determined by Xray diffraction (XRD), Xray photoelectron (XPS) and thermal analysis (DTATG) techniques The experimental results showed that the orders of promotion are NaCl>KCl>CaCl2>MgCl2 and NaCl>Na2CO3>NaNO3>NaOH and 5% (w) NaCl solution has the best promotive effect on limestone Magnesium oxide contained in limestone can play important roles by affecting decomposition temperature of limestone The additive on limestone with high magnesium oxide content is less effective The promotive roles of additive is caused by improving limestone thermal decomposition characteristics and forming macromolecule compounds restrained the decomposition of CaS and CaSO4