Ash chemistry issues and efficient combustion research progress in pure coal combustion of high-alkali coal
LI Linxuan
REN Qiangqiang
YANG Shaobo
ZHOU Li
Abstract：Coal constitutes a pivotal element of China's energy consumption structure.Xinjiang,which boasts consider-able coal deposits,is a crucial energy succession zone and strategic reserve area within China.The coal resources in Xinji-ang,particularly the Zhundong variety,typically exhibit elevated concentrations of alkali metals and alkaline earth metals(AAEMs),which are typical high-alkali coal well-suited for prolonged utilisation.The large-scale mining and utilisation of coal resources in Xinjiang has resulted in significant challenges,particularly in the form of slagging,staining and corro-sion of high-alkali coal during combustion.These issues have severely limited the large-scale and efficient utilisation of this coal resource.The objective of achieving 100%clean combustion of high-alkali coal represents a significant chal-lenge in the field of high-alkali coal utilisation.However,the primary obstacle lies in the resolution of the ash issue inher-ent to the clean combustion process.In this paper,about 4401 literatures in the field of high-alkali coal research in the past 20 years were obtained by using CiteSpace software.These literatures were subjected to literature clustering analysis,keyword highlighting analysis and time-series analysis.In addition,the peak interval of the heat of research in different periods was systematically analysed.It is highlighted that the future research in this field should prioritise the investiga-tions into the existence form and migration characteristics of AAEMs,the low-temperature eutectic formation mechanism,and the development of combustion-efficient utilisation regulation measures.Based on a representative high-alkali coal,a summary of the fundamental physicochemical properties was presented,with a particular focus on the impact of the al-kaline component of coal ash on the melting temperature of coal ash and the existence form of AAEMs.This study invest-igates the research progress of two core aspects,namely,AAEMs and low-temperature eutectics,with the objective of ex-ploring the migration characteristics of AAEMs and the generation mechanism of low-temperature eutectics.This is of great significance for the clean and efficient utilisation of coal with low carbon.Subsequently,the regulatory measures for the efficient utilisation of high-alkali coal combustion are categorised into three principal groups:the reduction of AAEMs content,the increase of acidic components,and the optimisation of reactor operation and structure.The principles and ef-fects of the utilisation measures on the mitigation of slagging and staining of high-alkali coals are then analysed,and the shortcomings of the corresponding methods are identified.Furthermore,it is proposed that the coal dust purification-com-bustion efficient utilisation technology may prove an effective means of solving the problem of efficient utilisation of high-alkali coal combustion.Ultimately,the dual-carbon context underscores the necessity for thermal power units to enhance their variable load regulation capabilities,thereby ensuring a stable power output.This paper puts forward suggestions and proposes avenues for future research in order to achieve the efficient utilisation of high-alkali coal combustion.It is essen-tial that these are combined with local diversified resource advantages and that an overall plan is formulated in order to ac-curately control the problems of slagging,staining and corrosion throughout the entire process.This will enable the clean,efficient and low-carbon utilisation of the resource to be achieved.
Keywords：high-alkali coalCiteSpaceslagging and foulingefficient combustion utilizationpurification-combustion
Publication Date：2024-10-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：29( 4088-4116 )