基于TG-FTIR研究海藻与稻壳共热解协同耦合机理

TG-FTIR analysis of seaweed / rice husk blends during co-pyrolysis

为了研究大型海藻与木质类生物质的混合热解机理,基于热重-红外联用(TG-FTIR)技术,对条浒苔、稻壳及条浒苔+稻壳混合物(质量比为1∶1)进行热解试验.通过样品的微观结构分析可知,条浒苔主要成分为硫酸多糖、蛋白质等.通过热解热重试验研究可知,在样品的主要挥发分析出阶段,海藻表现为放热反应,其与稻壳共热解时也为放热,说明混合热解实现了能量的耦合;混合后热失重速率试验值相对理论叠加值有所提高,说明混合热解使各组分之间产生协同反应.通过在线红外光谱分析热解过程中的气体产物,可知条浒苔和稻壳在混合热解速率最大时羰基C=O和S=O析出峰增强,并产生伸缩振动的醚键C—O—C的特征峰.最后采用Coats-Redfern积分法对热解过程进行动力学分析,发现混合后反应的活化能降低,使得热解更易进行.

To investigate the pyrolysis mechanism of the mixture, the algae mixed with 1 ： 1 husk was investigated by TG-FTIR analysis. The results indicate that the Enteromorpha clathrate is mainly composed of sulfated polysaccharides and protein by micro-structure analysis. The main pyrolysis of the EN is a special exothermic process by the differential scanning calorimetry analysis. The pyrolysis of mixture is also exothermal process, which illustrates that the co-pyrolysis can activate the reaction to achieve energy coupling. The comparison of DTG and calculated curves of the mixture indicates that in the stage of main volatile gases emitting, the pyrolysis rate is increased after mixture. The results show that the mixture feature is not a simple superposition of different component but existing synergy effects. The FFIR analysis of volatile gases during pyrolysis illuminates that due to the co-pyrolysis of EN and HU, the intensities of C=O and S=O precipitation peaks are enhanced. According to the kinetic analysis by Coats-Redfern method, it is indicated that activation energy is decreased, and the pyrolysisbecomes easier after the mixture.