Comparison of various gasification furnaces

No one pays attention to me! Why? :'(

The gray fusion gasification technology was developed by the Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences, and it is said to have been applied in the 300,000-ton methanol production project using coke oven gas at the Shanxi Fertilizer Plant (for the gas generation stage in the carbon supplementation process).

A domestically produced fluidized bed furnace, which differs from other fluidized bed gasification furnaces in that: typical fluidized bed gasification furnaces need to maintain a high carbon-to-ash ratio in the bed material, as well as ensure even mixing of carbon in order to preserve stable conditions free from slag formation. Therefore, the carbon content of the ash discharged from the furnace bottom is relatively high (15%-20%). To address these issues, an ash discharging method based on ash agglomeration (also known as ash compaction or ash cohesion) has been proposed. The specific method involves creating localized high-temperature areas in the fluidized bed layer, causing the ash particles to soften (above ST) without melting (below FT), thereby gaining a certain degree of viscosity. These particles then collide with each other and stick together to form ash balls with a low carbon content. When these ash balls grow to a size such that they can no longer be held up by the upward airflow, they separate from the coal powder and fall into the ash hopper at the bottom of the furnace, from where they are removed from the furnace. This reduces the carbon content in the ash (which can reach 5%-10%), thereby improving the carbon utilization efficiency in the gasification process. It seems that temperature control and industrial agglomeration are the challenges, but fluidized beds have low requirements regarding the moisture content of the feed material; therefore, they could be considered in areas where lignite resources are abundant.

Gray pyrolysis belongs to the fluidized bed gasification technology, and its advantage lies in the gasification of lignite； The current mainstream gasification technology is the fluidized bed, such as Texaco, Shell, HT-L, GSP, multi-nozzle, and two-stage furnaces

Personally, I think pressurized gasification and water-coal slurry are more mature at present

The ash fusion gasification technology is primarily used for gasifying lignite, and its gasification efficiency is not sufficient to meet the requirements for large-scale applications. The current mainstream coal gasification technologies, such as fluidized bed gasification and dry coal powder gasification, each come in several different variants; it is possible to examine their advantages and disadvantages and choose the one that suits one’s specific type of coal

This ash agglomeration needs to be updated; in fact, industrial plants don’t experience ash agglomeration, especially when gasifying lignite – ash agglomeration is nothing but a gimmick. They keep the gray aggregates around just to maintain a facade.

It is estimated that for dry coal powder gasification, space furnaces will remain more economical and practical in the future.

Reply to 1# Robert-lee: Indeed, there is no agglomeration in gray melt polymerization, but it was still operated for a certain period of time. I have some experience that I’d like to share with everyone! ! ! ! !

I think pressurized gasification is relatively cost-effective, but in some cases low-pressure or atmospheric-pressure gasification is better, such as when using lump coal. As for whether to use a fixed-bed or a fluidized-bed system, it still depends on the type of coal; I’m not sure if that’s correct?