Let’s discuss what requirements Shell’s gasifiers have for the raw coal
Thread Content
Let’s discuss what requirements Shell’s gasifiers have for the raw coal
The coal needs to be ground and dried, and limestone must be added as a preliminary step for desulfurization. High requirements are placed on coal grinding; the particle size is in the range of several dozen micrometers, which is even smaller than the particles of flour. Limestone is added to remove sulfur from the components of gas produced during the gasification reaction, thereby forming calcium sulfite. The coal grinding process takes place under hot air and slight negative pressure; the hot air is supplied by a hot air furnace, while the circulation fan provides the necessary power. If there are any shortcomings, I would appreciate some guidance from experts······
The parameters of raw coal include: ash content, moisture, volatile matter, calorific value, sulfur content, grindability index, and ash fusion point. Both the grindability index and moisture affect the grinding process, that is, the process of turning coal into powder. Ash content and ash fusion point influence slag discharge, while the calorific value and sulfur content have an impact on the manufacturing processes. The parameters for pulverized coal are: no more than 10% of particles larger than 90 microns, and at least 90% of particles larger than 5 microns; in other words, a particle size range of 5 to 90 microns is optimal
Ash content and ash fusion point are quite important, as they determine whether slag can form on the water wall of the gasification furnace and what the gasification temperature will be
Thank you for your guidance. What are the specific values required for each indicator? Are there any friends who use imported coal?
To improve the economic efficiency of operation and the stability of performance of the device, the raw coal can be selected based on the following criteria: ① Water content < 8%； ②Fixed carbon > 50% ； ③Ash content <30% ； ④(SiO2+Al2O3)/(Fe2O3+CaO+MgO) < 6.5; otherwise, more limestone needs to be added ； ⑤The SiO2/Al2O3 ratio is controlled at 1.8–2.3.
To improve the economic efficiency of operation and the stability of performance of the device, the raw coal can be selected based on the following criteria: ① Water content < 8%； ②Fixed carbon > 50% ； ③Ash content <30% ； ④(SiO2+Al2O3)/(Fe2O3+CaO+MgO) < 6.5; otherwise, more limestone needs to be added ； ⑤The SiO2/Al2O3 ratio is controlled at 1.8–2.3.
To improve the economic efficiency of operation and the stability of performance of the device, the raw coal can be selected based on the following criteria: ① Water content < 8%； ②Fixed carbon > 50% ； ③Ash content <30% ； ④(SiO2+Al2O3)/(Fe2O3+CaO+MgO) < 6.5; otherwise, more limestone needs to be added ； ⑤The SiO2/Al2O3 ratio is controlled at 1.8–2.3.