Abstract:
The gasification characteristics of petroleum coke, fine slag and Shenfu coal char were comparatively studied using a high temperature stage microscope (HTSM) system. Petroleum coke mixed with Shenfu slag was prepared for comparison. A thermogravimetric analyzer was used to test the gasification reactivities of the different samples. It was found that the gasification reactivity of fine slag was better than that of petroleum coke and slightly worse than that of Shenfu coal char at 1200 ℃. The addition of Shenfu slag accelerated the reaction rate of petroleum coke, suggesting that the ash contained in the fine slag enhanced the gasification reaction. The images of the micro structure of petroleum coke and fine slag samples obtained by a scanning-electron microscope showed a dense surface of petroleum coke with few pores being observed. The structure of the fine slag particles was relatively loose with micron-sized pores observed. The results of specific surface area and pore structure analyses showed that compared with petroleum coke, the pore structure of fine slag developed after the gasification process. More pores of 2—10 nm in size were found in the fine slag sample. The irregular pore structure of fine slag provided more active surface for the gasification reaction with an accelerated reaction rate. According to the results obtained from micro-Raman analysis, fine slag has a lower tendency in graphitization, and thus a better gasification reactivity than petroleum coke.