松木粉气流床气化特性实验研究

Experimental investigation of gasification characteristics of pine powder in an entrained flow gasification reactor

在气流床气化实验装置上进行了松木粉气化特性的研究。考察了温度、氧当量比、水蒸气配比对气体产物的成分、气化特性和固体产物的微观形态及成分的影响,结果表明,随着温度的升高,CO与H2浓度显著升高,CO2与CH4浓度明显下降,碳转化率、产气率、产气热值有所提高;氧当量比从0.2上升至0.5时,CO与H2浓度降低超过10%,CO2浓度则上升100%以上,碳转化率提高至92.9%,产气率有所上升,而产气热值则降低超过20%;水蒸气配比从0增大至0.58时,H2/CO体积比由0.63提高为1.40,碳转化率、产气率和产气热值均呈现先增大后减小趋势。由SEM照片可以看出,固体残渣主要由类球状或块状结构与纤维团聚结构两部分组成。温度升高使残渣颗粒由呈现不规则形状逐渐向球形转化,氧当量比的增大使残渣中类球状颗粒表面孔洞与裂缝明显增多直至破碎。

The pine powder gasification was conducted in a bench-scale entrained flow reactor. The influences of temperature,oxygen equivalence ratio and steam/biomass ratio on the composition of the gaseous products, carbon conversion, gas yield, LHV, morphology and composition of solid products were studied. The results show that when the reaction temperature increases gradually, the concentrations of CO and H2 rise dramatically and the concentrations of CO2 and CH4 significantly decrease. The carbon conversion, gas yield, and LHV also improve slightly. With a rise of oxygen equivalence ratio from 0. 2 to 0. 5, the concentrations of CO and H2 decrease by over 10%, the concentration of CO2 increases by 100%, and the carbon conversion reaches to 92. 9%. Simultaneously, the gas yield also increases slightly, while the LHV exhibits opposite trends. When the steam/biomass ratio increases from 0 to 0. 58, the H2/CO volume ratio grows gradually from 0. 63 to 1. 40. At the same time, the carbon conversion, gas yield and LHV first increase slowly then decrease rapidly. The analysis by scanning electron microscopy shows that the solid residue of gasification mainly consists of particles and fiber reunion. With increasing reaction temperature, the shape of particles in the solid residue changes gradually from irregular to spherical, while the higher oxygen equivalence ratio makes the number of pores and slits on particles increase rapidly and leads to the breaking of the particles.