Deactivation mechanism of coal char gasification reactivity induced by cow manure biomass volatile–coal char interactions

Abstract

Cow manure is a special biological waste with potential for energy utilization and heat recovery. Various aspects of biomass utilization process is affected by volatile–char interaction. In order to reveal the changes of chemical structure and reactivity of coal char induced by cow manure biomass volatile–coal char interactions, five types of volatile–char contact modes were designed to obtain coal chars through fixed bed reactor. Fourier infrared transform spectroscopy (FT–IR), X-ray photoelectron spectroscopy (XPS), temperature programmed oxidation (TPO), and laser Raman spectroscopy (Raman) were used to analyze the change of char chemical structure. The results indicate that the type and content of O-containing functional groups have important influence on char reactivity, and the aromatic C–O is particularly obvious. Volatile–char interactions lead to the decrease of the gasification reactivity which is attribute to the decreased aromatic C–O, C = O and increased graphite carbon structures in coal char. By the deconvolution of the TPO curves, it found that the volatile–char interaction inhibits the cracking of alkyl aryl ethers structures. This work is helpful to understand the mechanism of volatile–char interaction on the structure evolution of coal char.