生物质型煤在固硫剂条件下的燃烧特性研究

本文研究了生物质型煤在不同Ca/S比和不同生物质加入量下的燃烧特性,并进行了动力学分析.结果表明,固硫型煤的TG,DTG曲线变化趋势相似,都出现两个明显的失重峰挥发分析出阶段和煤焦燃烧阶段.一般在310-320℃范围内挥发分析出达到最大,在520-530℃范围内,煤焦燃烧失重速率最大.由于固硫反应的增重和型煤燃烧的失重的相对变化,导致第二个失重峰变化比较平缓,且失重温度范围较宽.不同Ca/S比的样品试验结果相比,Ca/S=2样品的最大失重点温度要比Ca/S=1.5样品的最大失重点温度要低;同一Ca/S比下,随着生物质量的增加,相应失重峰的峰值增加,最终失重百分比增加.通过动力学分析,生物质型煤在固硫剂条件下的燃烧反应服从燃烧动力学的基本方程表征的规律,对于不同的温度阶段可用不同的一级反应来描述.     

Adsorption of CO on,and S poisoning of,a perfect Ni(111) single crystal and a Ni(111) crystal with small angle boundaries

A Ni(111) crystal with small angle boundaries was used to examine the adsorption of CO. The adsorption of CO on a perfect Ni(111) single crystal was used for reference. Auger spectra show that the boundary lines on the sample surface provide favorable sites for the adsorbed CO to dissociate at temperatures as low as 25°C. The post-dissociation carbon appears mostly in the form of a nickel carbide on the surface. After heating the crystal to 850°C, sulfur diffused to the surface and blocked the surface adsorption sites uniformly. The boundary-enhanced dissociation of absorbed CO is no longer observed after the diffusion of sulfur to the crystal surface. AES depth profiling of sulfur concentration at different positions on the crystal with respect to the boundary lines show no evidence that the boundary lines provide an enhanced path for sulfur diffusion.     

The determination of thermodynamics of oxygen complexes of anions of sulfur dioxide and fluoronitrobenzenes using atmospheric pressure ionization mass spectrometry

The thermodynamic properties of oxygen complexes of the negative ions of 1-fluoro-2,4-dinitrobenzene (FDNB), 1,5-difluoro-2,4-dinitrobenzene (DFDNB), and sulfur dioxide have been determined by measuring the temperature dependence of the pertinent ion ratios by using a mass spectrometer equipped with a⁶³Ni atmospheric pressure ionization source. The values of -H° and -S°are SO ₂ ^–(O₂), 101 ± 2.1 kJ mole¹ and 121 ± 3.8 J/K-mole; FDNB^–(O₂), 51.5 ±3.4 kJ mole^–1 ± 9.2 J/K-mole; and DFDNB^–(O₂), 65.7 ± 0.4 kJ mole^–2 and 110 ± 5.0 J/K-mole.