Is this type of coal suitable for two-stage dry pulverized coal gasification technology?

For this coal, wet gasification technology should be the preferred method; its slurry-forming properties will be excellent. It has a high volatil content and a low ash melting point. Dry gasification is also a viable option, though the processing process is somewhat more complicated! Please ask Teacher Ren to help you answer; I’ll take the chance to learn too!

Based on the coal quality analysis data, this type of coal is a typical bituminous coal with a relatively low degree of coalification, similar to Shenmu coal or Huating coal in Gansu. It is an excellent coal for gasification, and it is also well-suited for coal slurry gasification. The two-stage furnace gasification process proposed by the original poster should be fine; further discussions and exchanges can be carried out with Xi’an Thermal Power Institute.

Where does this such good coal come from? For low-ash and low-sulfur bituminous coal, dry coal powder gasification is certainly possible; slurry coal gasification can also be used.

It is indeed good coal; using it for dry gasification is a bit of a waste. Can dry distillation be carried out first if the volatile content is high?

Low sulfur content is not suitable for using sulfur-resistant shift reactions to produce syngas. Low ash content and low ash melting point are not suitable for fluidized bed gasification with water-cooled furnace designs, including two-stage furnace types. High volatile content is not suitable for dry gasification processes

The water wall in dry gasification utilizes the principle of slag resistance against slag; for coals with low ash content, fly ash recirculation is usually employed to address this issue. For coals with low ash fusion points, dry gasification can reduce the operating temperature. For coal types with a relatively high ash melting point, more oxygen is generally supplied to facilitate the reaction of C+O=CO ； For coal types with a lower ash melting point, more water vapor can be introduced and a certain amount of oxygen can be reduced, resulting in the reaction C+H2O=CO+H2. It can be seen that the second reaction can produce more useful gas while consuming less oxygen, thereby reducing the specific oxygen consumption and specific coal consumption of low-melting-point ash coal. This is also why finer coals (higher-quality coal types) have better gasification parameters. A high volatile content is not very suitable for dry gasification – where does this theory come from? It can be said that the carbon conversion rate will be higher.

Teacher Ren is right. One more negative point: If water walls that use slag to resist slag are employed, low-ash coal could theoretically be processed using fly ash recycling, but this inevitably leads to increased consumption, reduced capacity, and greater operational difficulties. The operating experience of the currently in-service SCGP units shows that using coal with a low ash fusion point does not yield any benefits at lower temperatures; instead, it leads to difficulties in controlling the slag layer and damage to the water wall. It is understood that at least 3 out of the 5 companies have experienced this situation. A high volatile content is not very suitable for dry gasification, as it implies high explosivity; therefore, the particle size needs to be relaxed and the amount of inert gas must be controlled more strictly during powder production. Relaxing the particle size control partially offset the benefits of high conversion rates. Since it works well with the wet method, why go to the extra trouble of using the dry method? This should be given full consideration when selecting the gasification process. I’m not quite sure.

Both coal-water slurry gasification and dry coal powder gasification are feasible. At least 3 out of the 5 units currently in operation have experienced damage to their slag pins, which is likely due to poor control of the oxygen and steam levels, resulting in excessively high gasification temperatures. I think we can wait until the Shenhua coal-to-oil project is operational before seeing if this issue still exists. Bituminous coal with a high volatile content is prone to spontaneous combustion, which is easy to understand; it is necessary to control the oxygen concentration in the coal dust environment. One advantage of using dry coal powder gasification instead of water-coal slurry gasification is low oxygen consumption, low coal consumption, good economic efficiency, and reduced water usage. I think Shenhua’s coal-to-oil project may have given more importance to this aspect when choosing SHELL for gasification. This post was last edited by ren_yq on 2007-12-11 14:42]

It is particularly suitable for GE’s water-coal slurry gasification technology; those interested can contact GE’s business team: lol

Next, it is discussed that if it is only a renovation of the existing plant, with just one gasification furnace installed, dry coal powder is considered, and a two-stage system is used. If building a new plant, what do people think – is it better to use a multi-material slurry or Texaco, considering overall technology and investment costs?

Fixed carbon 54.00% – it’s not bituminous coal, right?

If it’s not bituminous coal, then what kind of coal is it? Can it be determined from the fixed carbon as well?

The poster is from Shilin, right?:lol :lol