Chemical Characteristics of Coal in the Yili Basin and Its Corrosion Mechanism on Gasifiers

Abstract

The reaction environment within a gasifier is highly complex, and understanding this process is critical for elucidating the corrosion mechanisms of the gasifier. To investigate the corrosion induced by feed coal on gasifier, coal and slag samples were collected from major coal mines and two typical coal chemical enterprises (hereinafter referred to as “Enterprise A and B”) in the Yili Basin. These samples were analyzed by element analyzer, X-ray fluorescence, and fluorine chlorine tester. The results show that coals from the Yili Basin are characterized by low to medium ash and low sulfur content. Compared with the average value of coal in China, the concentration coefficients of alkali and alkaline earth metals in coal from the Yili Basin are higher, which is consistent with the characteristics of high alkali coal in Xinjiang. Analysis reveals that the corrosion types attributable to coal quality on the gasifier include high-temperature oxidation corrosion, physical erosion and abrasion, hydrogen sulfide corrosion, acidic electrochemical corrosion, and halogenated oxidation corrosion. The more severe corrosion observed in Enterprise A compared to Enterprise B can be attributed to that corrosion processes are intrinsically more aggressive in Enterprise A due to difference of feed coal. This work elucidates the corrosion mechanisms induced by feed coal on gasifier, providing a theoretical basis for their stable operation, and is of great value to the safe and efficient production in the field of coal chemical industry.