Ash Fusion Characteristics and Transformation Behaviors during Bamboo Combustion in Comparison with Straw and Poplar

• Published in: Energy & fuels Vol. 32; no. 4; pp. 5244 - 5251
• Main Authors: Zhu, Youjian, Hu, Junhao, Yang, Wei, Zhang, Wennan, Zeng, Kuo, Yang, Haiping, Du, Shenglei, Chen, Hanping
• Format: Journal Article
• Language: English
• Published: American Chemical Society 19.04.2018
• ISSN: 0887-0624; 1520-5029; 1520-5029
• DOI: 10.1021/acs.energyfuels.8b00371

In this work, the bamboo ash fusion and sintering characteristics were studied to evaluate its potential application in combustion for the production of heat and power. Poplar and wheat straw were used in the experimental test as the reference fuels for comparison. Standard ash fusion tests and ash sintering tests were carried out at elevated temperatures. The results indicate that bamboo has a low ash melting temperature of 862 °C, much lower than that of poplar. In spite of the high K content in bamboo ash, no severe melting and sintering was observed under the temperature lower than 1000 °C. The ashes after the tests were analyzed using SEM/EDX, XRF, and XRD techniques to illustrate the ash transformation behavior. Standard ash fusion tests indicated that the melting temperatures of bamboo, wheat straw, and poplar ashes are 862 °C, 770 °C, and 1088 °C, respectively. No severe sintering can be observed for poplar due to the large existence of refractory compounds. Ash sintering occurred when the temperature is higher than 800 °C, for wheat straw, due to the formation of the low melting temperature K-rich silicate. Additionally, bamboo ash has a relatively high P content compared to that of wheat straw, which facilitates the formation of high melting temperature compounds of K–Ca/Mg phosphates. Moreover, the ash content in bamboo is low. As a conclusion, bamboo is a good quality biofuel which can be fired in biomass combustion plants without severe sintering at a temperature lower than 1000 °C.