Abstract
Catalytic coal gasification technology shows prominent advantages in enhancing coal gasification reactivity and is restrained by the cost of catalyst. Two typical biomass ash additions, corn stalk ash (CSA, high K–Na and low Si) and poplar sawdust ash (PSA, high K–Ca and high Si), were employed to study the influence of biomass ash on pyrolysis process and char gasification reactivity of the typical anthracite. Microstructure characteristics of the char samples were examined by X-ray diffraction (XRD). Based on isothermal char-CO2 gasification experiments, the influence of biomass ash on reactivity of anthracite char was determined using thermogravimetric analyzer. Furthermore, structural parameters were correlated with different reactivity parameters to illustrate the crucial factor on the gasification reactivity varied with char reaction stages. The results indicate that both CSA and PSA additives hinder the growth of adjacent basic structural units in a vertical direction of the carbon structure, and then slow down the graphitization process of the anthracite during pyrolysis. The inhibition effect is more prominent with the increasing of biomass ash. In addition, the gasification reactivity of anthracite char is significantly promoted, which could be mainly attributed to the abundant active AAEM (especially K and Na) contents of biomass ash and a lower graphitization degree of mixed chars. Higher K and Na contents illustrate that the CSA has more remarkable promotion effect on char gasification reactivity than PSA, in accordance with the inhibition effect on the order degree of anthracite char. The stacking layer number could reasonably act as a rough indicator for evaluating the gasification reactivity of the char samples.
Highlights
Coal is the second largest resource in the word’s primary energy consumption (Zhang et al 2019), and many efforts have been made to meet the increasing demand for clean and efficient coal utilization
The results indicate that both CSA and PSA additives hinder the growth of adjacent basic structural units in a vertical direction of the carbon structure, and slow down the graphitization process of the anthracite during pyrolysis
The results demonstrated that the addition of both CSA and PSA could hinder the order degree of AC char, and the corresponding effect was more prominent with the increase of the proportion of biomass ash in mixed char sample
Summary
Coal is the second largest resource in the word’s primary energy consumption (Zhang et al 2019), and many efforts have been made to meet the increasing demand for clean and efficient coal utilization. Gasification is generally considered as the core technology for efficiently and cleanly utilizing carbonaceous materials (Xie et al 2019), and advanced large-scale coal gasification has achieved widespread industrial application. Low gasification reactivity of anthracite results in restricted utilization, indicating that longer reaction time and higher. Catalytic coal gasification technology and the co-gasification technology of coal and other carbonaceous materials have shown prominent effect on the gasification reaction rate of coal sample, which provides effective ways to promote the low gasification reactivity of anthracite (Kopyscinski et al 2014; Wu et al 2019). To achieve industrial application of co-gasification technology, it is necessary to make an in-depth understanding of the interaction mechanism between anthracite and additives
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Coal Science & Technology
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
